89 results on '"Keel MK"'
Search Results
2. Detection of Chronic Wasting Disease prions in fetal tissues of free-ranging white-tailed deer
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Nalls, AV, primary, McNulty, EE, additional, Mayfield, A, additional, Crum, JM, additional, Keel, MK, additional, Hoover, EA, additional, Ruder, MG, additional, and Mathiason, CK, additional
- Published
- 2021
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3. Trichomonad Disease in Wild Turkeys (Meleagris gallopavo): Pathology and Molecular Characterization of Histomonas, Tetratrichomonas, Tritrichomonas, and Simplicimonas spp.
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Adcock KG, Weyna AAW, Yabsley MJ, Bäck RE, Garrett KB, Niedringhaus KD, Kunkel MR, Fenton HMA, Keel MK, Bahnson CS, Elsmo E, and Nemeth NM
- Abstract
The Wild Turkey (Meleagris gallopavo) is a geographically widespread, popular game bird and conservation icon in North America. Following successful reestablishment in parts of the US and Canada, regional declines have fueled population health concerns; therefore, understanding mortality causes and spatiotemporal patterns of disease is important to uncover potential ongoing and future health risks. Histomonosis, caused by the trichomonad Histomonas meleagridis, is a well-established and potentially fatal disease in Wild Turkeys; however, its prevalence and potential population health impacts remain poorly understood. Moreover, molecular tools recently have allowed for the detection of additional trichomonads that similarly can cause fatal disease in Wild Turkeys. We describe and compare disease due to H. meleagridis with that of Tetratrichomonas gallinarum, Tritrichomonas sp., and Simplicimonas sp. in Wild Turkeys in the southeastern US. Among 857 Wild Turkeys evaluated postmortem from 2002 to 2023, 34 (4.0%) were diagnosed with trichomonad disease, often assumed to be histomonosis prior to molecular testing. However, among 25 debilitating to fatal trichomonad disease cases for which etiologies were confirmed by PCR from 2015 to 2023, H. meleagridis was detected in 16/25 (64.0%), T. gallinarum in 6/25 (24.0%), Tritrichomonas sp. in 2/25 (8.0%) and Simplicimonas sp. in 1/25 (4.0%). These turkeys had similar clinical manifestations, and although lesion patterns varied to some extent, liver and/or intestinal tract was most commonly affected. Coinfections were common among all turkeys with trichomonad disease from 2015 to 2023 (21/25, 84.0%) and included viruses (lymphoproliferative disease virus, avian poxvirus), bacteria (Streptococcus gallolyticus, Listeria monocytogenes, Escherichia coli), and other protozoa (Sarcocystis sp., Haemoproteus sp.). Our results highlight the importance of molecular diagnostic testing in determining etiologies of trichomonad disease in Wild Turkeys. Further evaluation of the epidemiology and pathogenesis of trichomonad disease and its varied etiologies in Wild Turkeys and other birds is warranted to better understand risk factors and potential health impacts., (© Wildlife Disease Association 2024.)
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- 2024
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4. Artificial intelligence-based quantification of lymphocytes in feline small intestinal biopsies.
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Wulcan JM, Giaretta PR, Fingerhood S, de Brot S, Crouch EEV, Wolf T, Isabel Casanova M, Ruivo PR, Bolfa P, Streitenberger N, Bertram CA, Donovan TA, Keel MK, Moore PF, and Keller SM
- Abstract
Feline chronic enteropathy is a poorly defined condition of older cats that encompasses chronic enteritis to low-grade intestinal lymphoma. The histological evaluation of lymphocyte numbers and distribution in small intestinal biopsies is crucial for classification and grading. However, conventional histological methods for lymphocyte quantification have low interobserver agreement, resulting in low diagnostic reliability. This study aimed to develop and validate an artificial intelligence (AI) model to detect intraepithelial and lamina propria lymphocytes in hematoxylin and eosin-stained small intestinal biopsies from cats. The median sensitivity, positive predictive value, and F1 score of the AI model compared with the majority opinion of 11 veterinary anatomic pathologists, were 100% (interquartile range [IQR] 67%-100%), 57% (IQR 38%-83%), and 67% (IQR 43%-80%) for intraepithelial lymphocytes, and 89% (IQR 71%-100%), 67% (IQR 50%-82%), and 70% (IQR 43%-80%) for lamina propria lymphocytes, respectively. Errors included false negatives in whole-slide images with faded stain and false positives in misidentifying enterocyte nuclei. Semiquantitative grading at the whole-slide level showed low interobserver agreement among pathologists, underscoring the need for a reproducible quantitative approach. While semiquantitative grade and AI-derived lymphocyte counts correlated positively, the AI-derived lymphocyte counts overlapped between different grades. Our AI model, when supervised by a pathologist, offers a reproducible, objective, and quantitative assessment of feline intestinal lymphocytes at the whole-slide level, and has the potential to enhance diagnostic accuracy and consistency for feline chronic enteropathy., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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- 2024
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5. Demographic Risk Factors Vary in the Invasion Front of Chronic Wasting Disease in West Virginia, USA.
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Dugovich BS, Barton EP, Crum JM, Keel MK, Stallknecht DE, and Ruder MG
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- Animals, West Virginia epidemiology, Risk Factors, Male, Female, Prevalence, Deer, Wasting Disease, Chronic epidemiology
- Abstract
After detecting chronic wasting disease (CWD) in white-tailed deer (Odocoileus virginianus) in Hampshire County, West Virginia, USA, in 2005, we investigated the change of CWD apparent prevalence and potential factors influencing infection risk during the invasion front. Over eight sampling years (2006-2012 and 2017) during a 12-yr period within a 101-km2-area monitoring zone, we sampled and tested a total of 853 deer for CWD by ELISA and immunohistochemistry. Bayesian logistic regression of risk factors included collection year, age class, sex, and adjusted body weight (weight after accounting for sex, age, kidney fat index, and number of fetuses). In the whole-herd model (n=634), collection year, age, and adjusted body weight were associated with increased odds of CWD, whereas an age-weight interaction had a negative relationship. We found that males drove the positive associations with age and adjusted body weight, whereas females were responsible for the negative interaction effect. These findings suggest potential behavioral and physiological mechanisms related to sex that may influence CWD exposure. Older males exhibited higher CWD prevalence, aligning with previous studies. Notably, the novel finding of adjusted body weight as a risk factor in males warrants further investigation, and this study highlights the need for future research on social behavior and its role in CWD transmission within white-tailed deer populations., (© Wildlife Disease Association 2024.)
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- 2024
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6. Validation of a Field-Portable, Handheld Real-Time PCR System for Detecting Pseudogymnoascus destructans, the Causative Agent of White-Nose Syndrome in Bats.
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Greening SS, Haman K, Drazenovich T, Chacon-Heszele M, Scafini M, Turner G, Huckabee J, Leonhardt J, vanWestrienen J, Perelman M, Thompson P, and Keel MK
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- Animals, Real-Time Polymerase Chain Reaction veterinary, Nose microbiology, Syndrome, Chiroptera microbiology, Ascomycota genetics
- Abstract
White-nose syndrome (WNS), caused by the fungus Pseudogymnoascus destructans, has decimated bat populations across North America. Despite ongoing management programs, WNS continues to expand into new populations, including in US states previously thought to be free from the pathogen and disease. This expansion highlights a growing need for surveillance tools that can be used to enhance existing monitoring programs and support the early detection of P. destructans in new areas. We evaluated the feasibility of using a handheld, field-portable, real-time (quantitative) PCR (qPCR) thermocycler known as the Biomeme two3 and the associated field-based nucleic acid extraction kit and assay reagents for the detection of P. destructans in little brown bats (Myotis lucifugus). Results from the field-based protocol using the Biomeme platform were compared with those from a commonly used laboratory-based qPCR protocol. When using dilutions of known conidia concentrations, the lowest detectable concentration with the laboratory-based approach was 108.8 conidia/mL, compared with 1,087.5 conidia/mL (10 times higher, i.e., one fewer 10× dilution) using the field-based approach. Further comparisons using field samples suggest a high level of concordance between the two protocols, with positive and negative agreements of 98.2% and 100% respectively. The cycle threshold values were marginally higher for most samples using the field-based protocol. These results are an important step in establishing and validating a rapid, field-assessable detection platform for P. destructans, which is urgently needed to improve the surveillance and monitoring capacity for WNS and support on-the-ground management and response efforts., (© Wildlife Disease Association 2024.)
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- 2024
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7. California sea lion ( Zalophus californianus ) lymph-node explant reveals involvement and possible transcriptional regulation of SLAM and nectin-4 during phocine distemper virus infection.
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Gonzales-Viera O, Goldstein T, Duignan P, Eiamcharoen P, and Keel MK
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- Dogs, Animals, Distemper Virus, Phocine physiology, Nectins, Receptors, Cell Surface, Sea Lions, Distemper, Seals, Earless, Dog Diseases
- Abstract
Phocine distemper virus (PDV) is a significant cause of mortality for phocid seals; however, the susceptibility of otariids to this virus is poorly understood. The authors used a lymph-node explant culture system from California sea lions ( Zalophus californianus , CSL) to investigate: (1) the role of signaling lymphocyte activation molecule (SLAM) and nectin-4 in PDV infection and their cellular expression patterns, (2) if PDV induces transcriptional regulation of cell-entry receptors, and (3) the involvement of apoptosis in PDV infection. PDV replicated in the lymph-node explants with peak replication 3 days post-infection (dpi), but the replication was not sustained 4 to 5 dpi. The PDV+ cells co-localized SLAM and nectin-4. These cells expressed IBA1, indicating a histiocytic lineage. Comparison of receptor expression between infected and mock-infected lymph nodes suggested transcriptional downregulation of both receptors during the initial stage of infection and upregulation during the late stage of infection, but the values lack of statistical significance. Cleaved caspase-3+ cells were slightly increased in the infected lymph nodes compared with the mock-infected lymph node from 1 to 4 dpi, but without statistical significance, and a few apoptotic cells co-expressed PDV. The results suggest that lymph-node explants might be an important model to study PDV pathogenesis. CSLs have the potential to be infected with PDV, as they express both cell-entry receptors in histiocytes. The lack of statistical significance in the PDV replication, transcriptional regulation of viral receptors, and changes in apoptosis suggest that although CSL might be infected by PDV, they might be less susceptible than phocid species., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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- 2024
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8. Respiratory Distress Caused by Neoplastic Upper Respiratory Tract Obstructions in 2 Pet Rats (Rattus norvegicus domestica).
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Figueroa R, Sadar MJ, Frank C, McCarthy MA, Keel MK, and Guzman DS
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- Rats, Animals, Anti-Inflammatory Agents, Airway Obstruction veterinary, Airway Obstruction etiology, Respiratory Distress Syndrome complications, Respiratory Distress Syndrome veterinary, Rodent Diseases
- Abstract
Respiratory disease is one of the primary reasons for pet owners to seek veterinary attention for their rats. While chronic respiratory disease complex is most often responsible for respiratory signs in pet rats and is well characterized, upper respiratory obstructive disease has been rarely reported in the literature. This report describes 2 pet fancy rats (Rattus norvegicus domestica) presenting with a several day history of progressive respiratory signs that were minimally responsive to supportive therapies, including antibiotics, nonsteroidal anti-inflammatories, and fluid and oxygen support. Survey radiographs were performed under sedation in both cases. In the first case, no cause for the clinical signs could be identified, in part due to suboptimal radiographic positioning, although severe aerophagia was noted. In the second case, cervical tracheal luminal narrowing and increased soft tissue opacity along the walls of the trachea were identified. Both rats declined while under sedation, resulting in cardiopulmonary arrest in the first case and humane euthanasia in the second. On necropsy, the first case had a oropharyngeal squamous cell carcinoma originating from the Zymbal's gland, which was obstructing the larynx. The second case had an intra-luminal tracheal mass obstructing the airway. This was mostly likely B-cell lymphoma or a plasma cell tumor, although definitive diagnosis was unable to be obtained. For future such cases empiric management of respiratory disease in rats with antimicrobials, anti-inflammatories, and supportive care is often appropriate based on the high prevalence of infectious agents, however, other noninfectious causes should be considered, such as neoplastic processes leading to upper airway obstructive disease and diagnostic imaging may be indicated., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2024
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9. N-dihydrogalactochitosan reduces mortality in a lethal mouse model of SARS-CoV-2.
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Weiss CM, Liu H, Ball EE, Hoover AR, Wong TS, Wong CF, Lam S, Hode T, Keel MK, Levenson RM, Chen WR, and Coffey LL
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- Mice, Animals, Acetylglucosamine, Virus Replication, SARS-CoV-2, COVID-19
- Abstract
The rapid emergence and global dissemination of SARS-CoV-2 that causes COVID-19 continues to cause an unprecedented global health burden resulting in nearly 7 million deaths. While multiple vaccine countermeasures have been approved for emergency use, additional treatments are still needed due to sluggish vaccine rollout, vaccine hesitancy, and inefficient vaccine-mediated protection. Immunoadjuvant compounds delivered intranasally can guide non-specific innate immune responses during the critical early stages of viral replication, reducing morbidity and mortality. N-dihydrogalactochitosan (GC) is a novel mucoadhesive immunostimulatory polymer of β-0-4-linked N-acetylglucosamine that is solubilized by the conjugation of galactose glycans with current applications as a cancer immunotherapeutic. We tested GC as a potential countermeasure for COVID-19. GC was well-tolerated and did not produce histopathologic lesions in the mouse lung. GC administered intranasally before and after SARS-CoV-2 exposure diminished morbidity and mortality in humanized ACE2 receptor expressing mice by up to 75% and reduced infectious virus levels in the upper airway. Fluorescent labeling of GC shows that it is confined to the lumen or superficial mucosa of the nasal cavity, without involvement of adjacent or deeper tissues. Our findings demonstrate a new application for soluble immunoadjuvants such as GC for preventing disease associated with SARS-CoV-2 and may be particularly attractive to persons who are needle-averse., Competing Interests: TH, CFW, SSKL declare a conflict of interest as employees with minority ownership stakes of Immunophotonics, Inc., the manufacturer of the proprietary immune stimulant GC. RML declares a conflict of interest as an advisor with minority ownership stake in Immunophotonics. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)
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- 2023
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10. Severe Acute Respiratory Syndrome Coronavirus 2 Vasculopathy in a Syrian Golden Hamster Model.
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Ball EE, Weiss CM, Liu H, Jackson K, Keel MK, Miller CJ, Van Rompay KKA, Coffey LL, and Pesavento PA
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- Cricetinae, Animals, Humans, Mesocricetus, SARS-CoV-2, Lung pathology, Disease Models, Animal, COVID-19 pathology, Vascular Diseases pathology
- Abstract
Clinical evidence of vascular dysfunction and hypercoagulability as well as pulmonary vascular damage and microthrombosis are frequently reported in severe cases of human coronavirus disease 2019 (COVID-19). Syrian golden hamsters recapitulate histopathologic pulmonary vascular lesions reported in patients with COVID-19. Herein, special staining techniques and transmission electron microscopy further define vascular pathologies in a Syrian golden hamster model of human COVID-19. The results show that regions of active pulmonary inflammation in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are characterized by ultrastructural evidence of endothelial damage with platelet marginalization and both perivascular and subendothelial macrophage infiltration. SARS-CoV-2 antigen/RNA was not detectable within affected blood vessels. Taken together, these findings suggest that the prominent microscopic vascular lesions in SARS-CoV-2-inoculated hamsters likely occur due to endothelial damage followed by platelet and macrophage infiltration., (Copyright © 2023 American Society for Investigative Pathology. All rights reserved.)
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- 2023
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11. Characterization of Pseudogymnoascus destructans conidial adherence to extracellular matrix: Association with fungal secreted proteases and identification of candidate extracellular matrix binding proteins.
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Eiamcharoen P, Gelli A, Byrne BA, and Keel MK
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- Animals, Spores, Fungal, Peptide Hydrolases, Extracellular Matrix Proteins, Laminin, Extracellular Matrix, Endopeptidases, Virulence Factors, Fibronectins, Chiroptera microbiology
- Abstract
Pseudogymnoascus destructans is the etiological agent of white-nose syndrome (WNS), a fungal skin infection of hibernating bats. Pathophysiology of the disease involves disruption of bat metabolism and hibernation patterns, which subsequently causes premature emergence and mortality. However, information on the mechanism(s) and virulence factors of P. destructans infection is minimally known. Typically, fungal adherence to host cells and extracellular matrix (ECM) is the critical first step of the infection. It allows pathogenic fungi to establish colonization and provides an entry for invasion in host tissues. In this study, we characterized P. destructans conidial adherence to laminin and fibronectin. We found that P. destructans conidia adhered to laminin and fibronectin in a dose-dependent, time-dependent and saturable manner. We also observed changes in the gene expression of secreted proteases, in response to ECM exposure. However, the interaction between fungal conidia and ECM was not specific, nor was it facilitated by enzymatic activity of secreted proteases. We therefore further investigated other P. destructans proteins that recognized ECM and found glyceraldehyde-3-phosphate dehydrogenase and elongation factor 1-alpha among the candidate proteins. Our results demonstrate that P. destructans may use conidial surface proteins to recognize laminin and fibronectin and facilitate conidial adhesion to ECM. In addition, other non-specific interactions may contribute to the conidial adherence to ECM. However, the ECM binding protein candidates identified in this study highlight additional potential fungal virulence factors worth investigating in the P. destructans mechanism of infection in future studies., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kevin Keel reports financial support was provided by The American Association of Zoo VeterinariansWild Animal Health Fund. Piyaporn Eiamcharoen reports financial support was provided by The Anandamahidol Foundation Scholarship under the royal patronage of His Majesty the King of Thailand., (Copyright © 2022. Published by Elsevier Ltd.)
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- 2023
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12. Lung and lymph node explants to study the interaction between host cells and canine distemper virus.
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Gonzales-Viera O, Woolard KD, and Keel MK
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- Animals, Dogs, Lung, Lymph Nodes, Distemper Virus, Canine, Distemper, Dog Diseases
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Canine distemper virus (CDV, family Paramyxoviridae) is a widely known fatal disease in unvaccinated dogs and wild carnivores. The virus enters via the respiratory tract and rapidly spreads to the lymphoid organs. To investigate viral entry into these tissues, a dog tissue explant model was developed for lung and lymph nodes. Canine lung explants were cultured with CDV for three days. During this time CDV antigens were visible on alveolar cells, which were CD163-positive and SLAM-positive (signaling lymphocytic activation molecule), demonstrating that they were macrophages. The lymph node explants were maintained for five days. During this time the viral replication increased progressively by each day post infection and syncytia were observed by day three, post exposure. The microscopic distribution of CDV-positive cells in the lymph nodes, including the syncytia, and co-expression of CD163 and SLAM, demonstrated that they were macrophages. These findings suggest that alveolar macrophages are the first cells in the lung to become infected during CDV infection, and lymph node explants showed similar replication rates and virus-cell interactions as seen in experimental live animals. This demonstrates the utility of canine respiratory and lymphoid explant model to evaluate cell entry and viral replication of CDV and other morbilliviruses in dogs or other susceptible carnivores., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest for the completion of the manuscript., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
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- 2023
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13. Plant pathogens provide clues to the potential origin of bat white-nose syndrome Pseudogymnoascus destructans .
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Meteyer CU, Dutheil JY, Keel MK, Boyles JG, and Stukenbrock EH
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- Animals, Nose microbiology, Ascomycota genetics, Chiroptera microbiology, Hibernation
- Abstract
White-nose syndrome has killed millions of bats, yet both the origins and infection strategy of the causative fungus, Pseudogymnoascus destructans , remain elusive. We provide evidence for a novel hypothesis that P. destructans emerged from plant-associated fungi and retained invasion strategies affiliated with fungal pathogens of plants. We demonstrate that P. destructans invades bat skin in successive biotrophic and necrotrophic stages (hemibiotrophic infection), a mechanism previously only described in plant fungal pathogens. Further, the convergence of hyphae at hair follicles suggests nutrient tropism. Tropism, biotrophy, and necrotrophy are often associated with structures termed appressoria in plant fungal pathogens; the penetrating hyphae produced by P. destructans resemble appressoria. Finally, we conducted a phylogenomic analysis of a taxonomically diverse collection of fungi. Despite gaps in genetic sampling of prehistoric and contemporary fungal species, we estimate an 88% probability the ancestral state of the clade containing P. destructans was a plant-associated fungus.
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- 2022
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14. Distribution of canine distemper virus and nectin-4 in raccoon ( Procyon lotor ) skin.
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Garcia PAT, Cartoceti A, Affolter VK, Jackson K, Keel MK, Agnew D, Cooley T, Melotti J, Fitzgerald SD, and Pesavento PA
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- Animals, Animals, Wild, Dogs, Nectins, Raccoons, Distemper, Distemper Virus, Canine, Dog Diseases
- Abstract
Raccoons ( Procyon lotor ) are abundant in urban/wildland interfaces and are key sources of canine distemper virus (CDV) outbreaks in domestic, zoo, and free-ranging wildlife species. CDV is pantropic, which provides multiple potential routes of transmission (urine, respiratory secretions, feces), but the specific role of skin as a target of infection, as a diagnostic sample, or as a potential source of environmental persistence and transmission is unknown. We have characterized the distribution of CDV and its known receptor, nectin-4, in skin samples of 36 raccoons. Even with skin samples that were grossly and histologically normal, immunohistochemistry of skin was useful in the diagnosis of CDV infection, which was found in both epithelium and endothelium. Nectin-4 was codistributed with cellular targets of viral infection. Skin secretions, shed keratinocytes, and hair of CDV infected raccoons are all potential environmental fomites.
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- 2022
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15. Zika virus persistence in the male macaque reproductive tract.
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Ball EE, Pesavento PA, Van Rompay KKA, Keel MK, Singapuri A, Gomez-Vazquez JP, Dudley DM, O'Connor DH, Breitbach ME, Maness NJ, Schouest B, Panganiban A, and Coffey LL
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- Animals, Genitalia, Male, Humans, Macaca, Male, RNA, Semen, Zika Virus genetics, Zika Virus Infection
- Abstract
Zika virus (ZIKV) is unique among mosquito-borne flaviviruses in that it is also vertically and sexually transmitted by humans. The male reproductive tract is thought to be a ZIKV reservoir; however, the reported magnitude and duration of viral persistence in male genital tissues vary widely in humans and non-human primate models. ZIKV tissue and cellular tropism and potential effects on male fertility also remain unclear. The objective of this study was to resolve these questions by analyzing archived genital tissues from 51 ZIKV-inoculated male macaques and correlating data on plasma viral kinetics, tissue tropism, and ZIKV-induced pathological changes in the reproductive tract. We hypothesized that ZIKV would persist in the male macaque genital tract for longer than there was detectable viremia, where it would localize to germ and epithelial cells and associate with lesions. We detected ZIKV RNA and infectious virus in testis, epididymis, seminal vesicle, and prostate gland. In contrast to prepubertal males, sexually mature macaques were significantly more likely to harbor persistent ZIKV RNA or infectious virus somewhere in the genital tract, with detection as late as 60 days post-inoculation. ZIKV RNA localized primarily to testicular stem cells/sperm precursors and epithelial cells, including Sertoli cells, epididymal duct epithelium, and glandular epithelia of the seminal vesicle and prostate gland. ZIKV infection was associated with microscopic evidence of inflammation in the epididymis and prostate gland of sexually mature males, pathologies that were absent in uninfected controls, which could have significant effects on male fertility. The findings from this study increase our understanding of persistent ZIKV infection which can inform risk of sexual transmission during assisted reproductive therapies as well as potential impacts on male fertility., Competing Interests: The authors have declared that no competing interests exist.
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- 2022
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16. Distinctive Gross Presentation in Free-Ranging White-Tailed Deer (Odocoileus virginianus) with Rabies.
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Weyna AAW, Ruder MG, Dalton MF, Bahnson C, Keel MK, Fenton H, Ballard JR, and Nemeth NM
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- Animals, Animals, Wild, Brain pathology, Female, Humans, Male, Deer, Rabies epidemiology, Rabies veterinary
- Abstract
The white-tailed deer (Odocoileus virginianus) is a popular game species in North America and often lives in close proximity to humans and domestic animals. Deer with neurologic signs are of high interest to the general public and wildlife managers because of disease and safety concerns. Our aim was to describe diagnostic findings from free-ranging white-tailed deer diagnosed with rabies from across the eastern US from 2000 to 2021, with emphasis on gross lesions in the skin and soft tissue overlying the skull. We reviewed diagnostic reports of white-tailed deer cases submitted to the Southeastern Cooperative Wildlife Disease Study for those diagnosed with rabies from 2000 to 2021. Rabies virus infection was confirmed by immunohistochemistry or fluorescent antibody test of brain, or both. Nine adult deer from five states were diagnosed with rabies, including seven (78%) females and two (22%) males. Three (33%) deer were found dead, and six (67%) were humanely dispatched for abnormal behavior. Six deer heads were examined grossly and had lesions, including forehead or periorbital alopecia, cutaneous erythema, abrasions and ulcers, and subcutaneous edema. Histologic examination was performed for eight of nine cases, all of which had intraneuronal eosinophilic inclusion (Negri) bodies in cerebrum, cerebellum, or both. Most (6/8; 75%) had perivascular lymphoplasmacytic encephalitis. Rabies should be considered a differential diagnosis in deer with this pattern of head lesions, suggestive of head rubbing or head pressing., (© Wildlife Disease Association 2022.)
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- 2022
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17. Listeriosis with viral coinfections in 8 gray foxes, 8 wild turkeys, and 2 young cervids in the southeastern United States.
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Weyna AAW, Niedringhaus KD, Kunkel MR, Fenton HMA, Keel MK, Webb AH, Bahnson C, Radisic R, Munk B, Sánchez S, and Nemeth NM
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- Animals, Animals, Wild, DNA, Viral, Dogs, Foxes, Necrosis veterinary, Southeastern United States epidemiology, Turkeys genetics, United States, Coinfection veterinary, Deer, Distemper, Distemper Virus, Canine, Dog Diseases, Listeriosis epidemiology, Listeriosis veterinary
- Abstract
Listeria monocytogenes is a bacterium that can cause disease in many species, including humans, livestock, and wildlife. Increased interactions via shared habitats may promote pathogen transmission among these groups. Our objectives were to evaluate the Southeastern Cooperative Wildlife Disease Study diagnostic data to characterize and compare L. monocytogenes -induced lesions and comorbidities in gray foxes and wild turkeys, and to describe cases of listeriosis in 2 cervids. From 1991-2020, 8 gray foxes, 8 wild turkeys, a neonatal elk, and a white-tailed deer fawn from several eastern states in the United States were diagnosed with listeriosis. All 8 foxes had hepatitis and/or hepatic necrosis with intralesional gram-positive bacilli, and concurrent canine distemper virus (CDV) infection; 2 of the foxes had been vaccinated recently for CDV. L. monocytogenes was cultured from the liver (6 of 8) or lung (2 of 8) of foxes. Lesions in wild turkeys included hepatocellular necrosis (3 of 8), heterophilic hepatitis (1 of 8), heterophilic granulomas (1 of 8), intrasinusoidal gram-positive bacilli without hepatic lesions (1 of 8), granulomatous dermatitis (1 of 8), and/or granulomatous myocarditis (2 of 8). Lymphoproliferative disease viral DNA was detected in 5 of 6 turkeys tested; reticuloendotheliosis viral DNA was detected in 2 of 3 turkeys tested. Both cervids had systemic listeriosis, with L. monocytogenes isolated from liver. Immunohistochemistry for Listeria spp. on select cases revealed immunolabeling in affected organs. Listeriosis was thus established as a cause of morbidity and mortality in 3 wildlife species, which often suffered from concurrent infections and likely immunosuppression.
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- 2022
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18. Prevalence and genetic characterization of a Babesia microti-like species in the North American river otter (Lontra canadensis).
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Garrett K, Halseth A, Ruder MG, Beasley J, Shock B, Birkenheuer AJ, Gabriel M, Fiorello C, Haire MM, Olfenbuttel C, Keel MK, and Yabsley MJ
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- Animals, Dogs, Foxes, Male, Prevalence, RNA, Ribosomal, 18S genetics, Raccoons parasitology, Babesia genetics, Babesia microti genetics, Babesiosis parasitology, Dog Diseases parasitology, Otters parasitology
- Abstract
A 4.5-month-old, male, North American river otter (Lontra canadensis) from Athens-Clarke County, Georgia, USA being temporarily housed at a rehabilitation facility, presented with a three-day history of lethargy, anorexia, and severe anemia. Antemortem blood smears revealed intraerythrocytic piroplasms. Supportive care and antiparasitic treatments were initiated, but the animal died three days following presentation. Gross necropsy revealed yellow discoloration of all adipose tissue throughout the carcass and a mildly enlarged, diffusely yellow to pale orange liver. Microscopically, moderate, centrilobular hepatocellular degeneration and necrosis were observed, consistent with hypoxia secondary to apparent hemolytic anemia. Piroplasms were frequently observed in red blood cells in histologic sections. The nearly full-length 18S rRNA gene sequence (1588 bp) was identical to a previously described piroplasm from North American river otters from North Carolina. Phylogenetically, based on the 18S rRNA gene sequence, the otter Babesia sp. was in a sister group with a clade that included several strains of Babesia microti-like species including Babesia sp. from badgers (Meles meles), Babesia vulpes, and Babesia sp. from raccoons (Procyon lotor). To better understand the distribution and genetic variability of this Babesia species, otters from four states in the eastern U.S. and California were tested. Overall, 30 of 57 (53%) otters were positive for Babesia sp. None of four otters from California were positive, but prevalences in eastern states were generally high, 5/9 (55%) in Georgia, 7/14 (50%) in South Carolina, 10/17 (59%) in North Carolina, and 8/13 (62%) in Pennsylvania). Partial 18S rRNA gene sequences from all populations were identical to the clinical case sequence. No Babesia sensu stricto infections were detected. There were six unique COI sequences (937 bp) detected in 18 positive otters. The most common lineage (A) was detected in 12 of 18 (67%) samples from Georgia, North Carolina, South Carolina, and Pennsylvania. Lineage B was found in two otters and the remaining lineage types were found in single otters. These six lineages were 99-99.8% similar to each other and were < 88% similar to related parasites such as B. vulpes, B. microti-like species of raccoons, B. microti, and B. rodhaini. Phylogenetically, the Babesia sp. of otters grouped together in a well-supported clade separate from a sister group including B. vulpes from fox (Vulpes vulpes) and domestic dogs. In conclusion, this report demonstrates that this piroplasm is a potential pathogen of North American river otters and the parasite is widespread in otter populations in the eastern United States., (Copyright © 2022 Elsevier B.V. All rights reserved.)
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- 2022
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19. Detection of Chronic Wasting Disease Prions in Fetal Tissues of Free-Ranging White-Tailed Deer.
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Nalls AV, McNulty EE, Mayfield A, Crum JM, Keel MK, Hoover EA, Ruder MG, and Mathiason CK
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- Animals, Female, Fetal Diseases diagnosis, Infectious Disease Transmission, Vertical, Male, Pregnancy, Pregnancy Complications, Infectious veterinary, Wasting Disease, Chronic diagnosis, Wasting Disease, Chronic embryology, West Virginia, Deer embryology, Fetal Diseases veterinary, Fetus chemistry, Prions isolation & purification, Wasting Disease, Chronic transmission
- Abstract
The transmission of chronic wasting disease (CWD) has largely been attributed to contact with infectious prions shed in excretions (saliva, urine, feces, blood) by direct animal-to-animal exposure or indirect contact with the environment. Less-well studied has been the role that mother-to-offspring transmission may play in the facile transmission of CWD, and whether mother-to-offspring transmission before birth may contribute to the extensive spread of CWD. We thereby focused on a population of free-ranging white-tailed deer from West Virginia, USA, in which CWD has been detected. Fetal tissues, ranging from 113 to 158 days of gestation, were harvested from the uteri of CWD+ dams in the asymptomatic phase of infection. Using serial protein misfolding amplification (sPMCA), we detected evidence of prion seeds in 7 of 14 fetuses (50%) from 7 of 9 pregnancies (78%), with the earliest detection at 113 gestational days. This is the first report of CWD detection in free ranging white-tailed deer fetal tissues. Further investigation within cervid populations across North America will help define the role and impact of mother-to-offspring vertical transmission of CWD.
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- 2021
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20. Chlamydia buteonis in birds of prey presented to California wildlife rehabilitation facilities.
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Seibert BA, Keel MK, Kelly TR, Nilsen RA, Ciembor P, Pesti D, Gregory CR, Ritchie BW, and Hawkins MG
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- Animals, Animals, Wild, Antibodies, Bacterial blood, Bird Diseases immunology, Bird Diseases microbiology, California epidemiology, Chlamydia classification, Chlamydia genetics, Chlamydia immunology, Chlamydia Infections immunology, Chlamydia Infections microbiology, Cloaca microbiology, DNA, Bacterial chemistry, DNA, Bacterial genetics, DNA, Bacterial metabolism, Immunoglobulin M blood, Immunoglobulins blood, Phylogeny, Prevalence, Rehabilitation Centers, Risk Factors, Sequence Analysis, DNA, Bird Diseases epidemiology, Chlamydia isolation & purification, Chlamydia Infections epidemiology, Raptors microbiology
- Abstract
Chlamydial infections, caused by a group of obligate, intracellular, gram-negative bacteria, have health implications for animals and humans. Due to their highly infectious nature and zoonotic potential, staff at wildlife rehabilitation centers should be educated on the clinical manifestations, prevalence, and risk factors associated with Chlamydia spp. infections in raptors. The objectives of this study were to document the prevalence of chlamydial DNA shedding and anti-chlamydial antibodies in raptors admitted to five wildlife rehabilitation centers in California over a one-year period. Chlamydial prevalence was estimated in raptors for each center and potential risk factors associated with infection were evaluated, including location, species, season, and age class. Plasma samples and conjunctiva/choana/cloaca swabs were collected for serology and qPCR from a subset of 263 birds of prey, representing 18 species. Serologic assays identified both anti-C. buteonis IgM and anti-chlamydial IgY antibodies. Chlamydial DNA and anti-chlamydial antibodies were detected in 4.18% (11/263) and 3.14% (6/191) of patients, respectively. Chamydial DNA was identified in raptors from the families Accipitridae and Strigidae while anti-C.buteonis IgM was identified in birds identified in Accipitridae, Falconidae, Strigidae, and Cathartidae. Two of the chlamydial DNA positive birds (one Swainson's hawk (Buteo swainsoni) and one red-tailed hawk (Buteo jamaicensis)) were necropsied, and tissues were collected for culture. Sequencing of the cultured elementary bodies revealed a chlamydial DNA sequence with 99.97% average nucleotide identity to the recently described Chlamydia buteonis. Spatial clusters of seropositive raptors and raptors positive for chlamydial DNA were detected in northern California. Infections were most prevalent during the winter season. Furthermore, while the proportion of raptors testing positive for chlamydial DNA was similar across age classes, seroprevalence was highest in adults. This study questions the current knowledge on C. buteonis host range and highlights the importance of further studies to evaluate the diversity and epidemiology of Chlamydia spp. infecting raptor populations., Competing Interests: Dr. Branson Ritchie is the Director of the Infectious Disease Laboratory, College of Veterinary Medicine, Univ. of GA, Athens, GA and contributed in-kind support by providing the EBA serology, qPCR testing and whole genome sequencing for this project.
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- 2021
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21. TEMPORAL AND SPATIAL PATTERNS IN CANINE DISTEMPER VIRUS CASES IN WILDLIFE DIAGNOSED AT THE SOUTHEASTERN COOPERATIVE WILDLIFE DISEASE STUDY, 1975-2019.
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Taylor K, Wilson JJ, Park AW, Nemeth NM, Yabsley MJ, Fenton H, Keel MK, and Gottdenker NL
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- Animals, Animals, Wild, Dogs, Foxes, Raccoons, Coyotes, Distemper epidemiology, Distemper Virus, Canine, Dog Diseases
- Abstract
Canine distemper is a high-impact disease of many mammal species and has caused substantial carnivore population declines. Analysis was conducted on passive surveillance data of canine distemper (CDV)-positive wild mammal cases submitted to the Southeastern Cooperative Wildlife Disease Study, Athens, Georgia, US, between January 1975 and December 2019. Overall, 964 cases from 17 states were CDV positive, including 646 raccoons (Procyon lotor), 254 gray foxes (Urocyon cinereoargenteus), 33 striped skunks (Mephitis mephitis), 18 coyotes (Canis latrans), four red foxes (Vulpes vulpes), three gray wolves (Canis lupus), three American black bears (Ursus americanus), two American mink (Mustela vison), and one long-tailed weasel (Mustela frenata). Raccoon and gray fox case data from the state of Georgia (n=441) were selected for further analysis. Autoregressive integrated moving average models were developed predicting raccoon and gray fox case numbers. The best-performing model for gray foxes used numbers of gray fox CDV cases from the previous 2 mo and of raccoon cases in the present month to predict the numbers of gray fox cases in the present month. The best-performing model for raccoon prediction used numbers of raccoon CDV cases from the previous month and of gray fox cases in the present month and previous 2 mo to predict numbers of raccoon cases in the present month. Temporal trends existed in CDV cases for both species, with cases more likely to occur during the breeding season. Spatial clustering of cases was more likely to occur in areas of medium to high human population density; fewer cases occurred in both the most densely populated and sparsely populated areas. This pattern was most prominent for raccoons, which may correspond to high transmission rates in suburban areas, where raccoon population densities are probably highest, possibly because of a combination of suitable habitat and supplemental resources., (© Wildlife Disease Association 2021.)
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- 2021
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22. Evaluation of Atherosclerotic Lesions and Risk Factors of Atherosclerosis in Raptors in Northern California.
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Lujan-Vega C, Keel MK, Barker CM, and Hawkins MG
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- Animals, Birds, Female, Male, Prevalence, Risk Factors, Atherosclerosis epidemiology, Atherosclerosis veterinary, Raptors
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Atherosclerosis is a chronic inflammatory disease that has been reported to affect the cardiovascular system of many avian species. However, atherosclerosis in raptor species has not been fully evaluated. The aim of this study was to histologically characterize central and peripheral atherosclerotic lesions in raptors that were submitted to a pathology service in Northern California from 1986 to 2013. We also evaluated risk factors, including age, gender, origin, and avian family. Atherosclerotic lesions were categorized as minimal, mild, moderate, or severe, based on the severity of the lesions and their distribution within the arterial wall. Among the central arteries, lesions were determined to be of greater severity in the aorta than in the pulmonary artery. More than 50% of the peripheral arteries were affected, including 53.1% (17/32) myocardial, 52% (13/25) coronary, 62.9% (22/35) arteries in the kidney, 52.2% (12/23) gonadal and 51.7% (15/29) splenic arteries; however, hepatic and pulmonary arteries were uncommonly affected. Atherosclerosis was diagnosed in 17 raptor species representing 4 families: Accipitridae, Cathartidae, Falconidae, and Strigidae. The overall prevalence (95% CI) of atherosclerosis in raptors was 2.3% (36/1574; range, 1.63%-3.19%) with the Falconidae having the highest prevalence at 7.4% (9/122; range 3.64%-13.93%) and with 0% detected in the Tytonidae and Pandionidae families. A multiple logistic regression model that jointly accounted for differences in risk by family, age, and gender found that the risk in Accipitridae was significantly less than that of Falconidae, that adult raptors were at greater risk of atherosclerotic lesions than juveniles were, and that females were more frequently affected than males were.
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- 2021
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23. Demodectic mange in threatened southern sea otters (Enhydra lutris nereis).
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Javeed N, Foley J, Oliver-Guimera A, Affolter VK, Keel MK, Reed A, Pesapane R, Duignan PJ, Murray M, Tinker MT, and Miller MA
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- Animals, California, Risk Factors, Mite Infestations epidemiology, Mite Infestations veterinary, Otters
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Background: Southern sea otters (Enhydra lutris nereis) rely on intact pelage for thermoregulation, and thus clinically significant demodicosis and associated alopecia can cause morbidity and death., Hypothesis/objectives: This study aimed to describe lesions associated with follicular Demodex sp. infestation, estimate the prevalence and intensity of infestation, describe mite distribution across key anatomical regions, and assess mite presence or absence in relation to lesions and host risk factors., Animals: Twenty necropsied, wild southern sea otters that stranded along the central California coast from 2005 to 2018., Methods and Materials: Grossly normal and abnormal integument from the head, perineum, genitals, mamillary papillae and limbs was assessed microscopically for mites and mite-associated pathological findings., Results: Intrafollicular mites were observed in the integument of 55% of otters and 20% had clinical demodicosis. Demodicosis was considered to be contributory to death or euthanasia in two cases. Although Demodex sp. mites often were observed microscopically in grossly normal skin, the presence of multiple densely-packed intrafollicular mites generally was associated with pigmentary incontinence, ectatic follicles, lymphoplasmacytic perifolliculitis, and neutrophilic and lymphoplasmacytic, dermal inflammation. Other findings included epidermal hyperplasia, orthokeratotic hyperkeratosis of epidermis and follicular epithelium, concurrent pyoderma and cell necrosis. Perioral integument, especially of the chin, had the highest prevalence of mites and the highest mite density, suggesting facial contact as a means of mite transmission., Conclusions and Clinical Importance: Our research confirmed demodectic mange as a contributor to morbidity and mortality in sea otters, with important implications for clinical care, rehabilitation and conservation., (© 2021 ESVD and ACVD.)
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- 2021
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24. Granulomatous Inflammation of the Muzzle in White-Tailed Deer ( Odocoileus virginianus ) and Mule Deer ( Odocoileus hemionus ) Associated With Mannheimia granulomatis .
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Keel MK, Keeler S, Brown J, Fenton H, Munk B, Gerhold R, Gottdenker N, Ruder M, Elsmo E, and Nemeth N
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- Animals, Cattle, Equidae, Inflammation veterinary, RNA, Ribosomal, 16S, United States, Deer, Mannheimia isolation & purification, Mannheimia pathogenicity
- Abstract
Since 2002, reports of deer with swollen muzzles from throughout the United States have resulted in significant interest by wildlife biologists and wildlife enthusiasts. The condition was identified in 25 white-tailed deer ( Odocoileus virginianus ) and 2 mule deer ( O. hemionus ). Microscopic lesions consisted of severe, granulomatous or pyogranulomatous inflammation of the muzzle, nasal planum, and upper lip, as well as similar but less severe inflammation of the hard palate. Lymphadenitis of regional lymph nodes was common and granulomatous pneumonia was present in one individual. Splendore-Hoeppli material was typical in the center of inflammatory foci. Other than the single instance of pneumonia, systemic disease was not evident. Various bacterial species were isolated in culture, most of which were not morphologically consistent with the colonies of small, gram-negative bacteria observed in the center of the granulomas. Amplification and sequencing of the bacterial 16S rRNA gene from tissues of affected deer resulted in the identification of Mannheimia granulomatis . Laser capture microdissection was used to confirm that the colonies in the inflammatory foci were M. granulomatis . The cases described here are reminiscent of a bovine disease in Brazil and Argentina, locally called lechiguana. Although the inflammation of lechiguana is mostly truncal, the microscopic lesions are very similar and are also attributed to M. granulomatis . It is unclear if this is an emerging infectious disease of deer, or if it is a sporadic, uncommon condition that has only recently been recognized.
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- 2020
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25. Evaluation of transanal minimally invasive surgery for submucosal rectal resection in cadaveric canine specimens.
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Mayhew PD, Balsa IM, Guerzon CN, Gibson EA, Keel MK, Brun MV, and Lillo Araya FJ
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- Animals, Cadaver, Endoscopic Mucosal Resection instrumentation, Endoscopic Mucosal Resection methods, Female, Laparoscopy veterinary, Male, Rectal Neoplasms surgery, Transanal Endoscopic Surgery instrumentation, Transanal Endoscopic Surgery methods, Dog Diseases surgery, Dogs surgery, Endoscopic Mucosal Resection veterinary, Rectal Neoplasms veterinary, Rectum surgery, Transanal Endoscopic Surgery veterinary
- Abstract
Objective: To evaluate the feasibility of transanal minimally invasive surgery (TAMIS) for submucosal rectal resection in large breed dogs., Study Design: Cadaveric study., Sample Population: Canine cadavers (n = 6) weighing between 37.5 and 60 kg., Methods: Dogs were positioned in sternal recumbency. After rectal cleansing, a transanal access platform was placed in the rectum, and a pneumorectum was established. An area of ventral rectal wall approximately 2 × 2 cm was resected in a submucosal plane by using laparoscopic instruments and submitted for histopathological evaluation. The rectal wall defect was closed with a single-layer continuous suture pattern with barbed suture. Postoperatively, the rectum was removed en bloc and evaluated for suture or surgical penetration of the serosal surface., Results: Submucosal rectal resection was successfully completed by using TAMIS in all dogs. The median length of resected specimens after fixation was 24.5 mm (range 9.8-26.5). In two of six dogs, suture was macroscopically visible on the serosal surface, but no dogs had evidence of iatrogenic full-thickness surgical penetration of the rectum. The median distance from the aborad extent of the suture closure line to the anocutaneous junction was 35 mm (range, 35-105)., Conclusion: Submucosal resection of the canine rectal wall was feasible in large breed dogs by using TAMIS. No evidence of full-thickness penetration of the rectal wall was seen in these cadaveric specimens., Clinical Significance: Transanal minimally invasive surgery may provide an alternative minimally invasive approach for resection for benign adenomatous rectal polyps in large breed dogs that might otherwise require a rectal pull-through., (© 2020 The American College of Veterinary Surgeons.)
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- 2020
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26. Facial distortion due to chronic inflammation of unknown cause in a cat.
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Johnson LR, Vidal SA, Brust KD, Keel MK, and Steffey MA
- Abstract
Case Summary: An 8-year-old neutered male indoor cat was presented for evaluation of a year-long history of swelling over the bridge of the nose that extended from the subcutaneous tissue of the right upper eyelid to the dorsum of the skull. Intermittent regression of the mass lesion was reported with antibiotic or corticosteroid therapy; however, progressive swelling, malaise and hiding behavior persisted. CT revealed an aggressive osteolytic mass lesion in the right and left nasal cavities and extending into the frontal sinuses. Rhinoscopy using a 2.8 mm rigid telescope revealed somewhat normal-appearing turbinates rostrally and ventrally on the left side, with turbinate destruction on the right. After obtaining a biopsy from the right side of the nasal cavity, thick material filling the entire nasal cavity was visible caudally and was extracted endoscopically from a rostral approach. Surgical biopsy of the dorsal nasal bridge resulted in protrusion of inspissated material from the incision site. Rhinoscopic exploration revealed that the material extended into both frontal sinuses. Following extensive debridement and medical therapy, marked resolution of facial asymmetry was achieved., Relevance and Novel Information: Facial distortion is often considered suggestive of a neoplastic process; however, it can also be seen with fungal and mycobacterial infections, and, in this case, an inflammatory condition of unknown etiology. In this cat, aggressive intervention and debridement of necrotic debris resulted in substantial bony remodeling of the skull and return to normal activity levels., Competing Interests: Conflict of interest: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2020.)
- Published
- 2020
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27. A Baylisascaris Outbreak in Fox Squirrels ( Sciurus niger ) and Subsequent Detection of Francisella tularensis in Kansas, USA.
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Vincent EC, Ruder MG, Yabsley MJ, Hesting VS, Keel MK, Brown JD, and Nemeth NM
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- Animals, Ascaridida Infections epidemiology, Ascaridida Infections parasitology, Kansas epidemiology, Rodent Diseases epidemiology, Rodent Diseases parasitology, Tularemia epidemiology, Tularemia microbiology, Ascaridida Infections veterinary, Ascaridoidea isolation & purification, Disease Outbreaks veterinary, Francisella tularensis, Sciuridae parasitology, Tularemia veterinary
- Abstract
Thorough epidemiologic investigations of wildlife mortality events are often challenging, in part because of the dynamic variables involved. In May 2011, six fox squirrels ( Sciurus niger ) in Clinton State Park, Kansas, US were euthanized after exhibiting clinical signs of neurologic disease. Postmortem examination of two squirrels revealed that these individuals died of Baylisascaris larva migrans, which resulted in meningoencephalitis and variable pneumonia and myocarditis. Fecal flotation of raccoon ( Procyon lotor ) feces collected in the area revealed Baylisascaris sp. ova, presumably Baylisascaris procyonis , in one of nine samples. Additional fox squirrel carcasses were submitted for diagnostic evaluation from eastern Kansas for 1 yr following the Baylisascaris sp. outbreak. This monitoring unexpectedly resulted in the detection of Francisella tularensis , the zoonotic pathogen that causes tularemia, in two fox squirrels. The increased attention to fox squirrel mortalities prompted by the outbreak of Baylisascaris sp. larva migrans revealed cases of tularemia that may not have been otherwise detected. Although F. tularensis is endemic in Kansas, the current distribution and prevalence of B. procyonis in raccoons and other hosts in Kansas are poorly understood. This yearlong mortality investigation illustrated the importance of wildlife health monitoring as a means of assessing public health risks, especially during unusual wildlife mortality events.
- Published
- 2020
28. Author Correction: Cancer in wildlife: patterns of emergence.
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Pesavento PA, Agnew D, Keel MK, and Woolard KD
- Abstract
In the originally published article, the aetiology of the single case of B cell lymphoma found in the Mountain gorilla was incorrectly referred to as Gibbon lymphocryptovirus 1 in Table 1. The correct aetiology is Gbb lymphocryptovirus 1. This has now been corrected in both the html and PDF versions of the article.
- Published
- 2019
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29. Cancer in wildlife: patterns of emergence.
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Pesavento PA, Agnew D, Keel MK, and Woolard KD
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- Animals, Communicable Diseases, Emerging epidemiology, Communicable Diseases, Emerging pathology, Ecosystem, Neoplasms epidemiology, Neoplasms pathology, Animals, Wild, Communicable Diseases, Emerging veterinary, Neoplasms veterinary
- Abstract
Cancer is ubiquitous in wildlife, affecting animals from bivalves to pachyderms and cetaceans. Reports of increasing frequency demonstrate that neoplasia is associated with substantial mortality in wildlife species. Anthropogenic activities and global weather changes are shaping new geographical limitations for many species, and alterations in living niches are associated with visible examples of genetic bottlenecks, toxin exposures, oncogenic pathogens, stress and immunosuppression, which can all contribute to cancers in wild species. Nations that devote resources to monitoring the health of wildlife often do so for human-centric reasons, including for the prediction of the potential for zoonotic disease, shared contaminants, chemicals and medications, and for observing the effect of exposure from crowding and loss of habitat. Given the increasing human footprint on land and in the sea, wildlife conservation should also become a more important motivating factor. Greater attention to the patterns of the emergence of wildlife cancer is imperative because growing numbers of species are existing at the interface between humans and the environment, making wildlife sentinels for both animal and human health. Therefore, monitoring wildlife cancers could offer interesting and novel insights into potentially unique non-age-related mechanisms of carcinogenesis across species.
- Published
- 2018
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30. What is your diagnosis? Conjunctival smear in a dog.
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Gonzales-Viera O, Casey K, and Keel MK
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- 2018
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31. Whole-Slide Imaging: The Future Is Here.
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Aeffner F, Blanchard TW, Keel MK, and Williams BH
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- Animals, Diagnostic Imaging veterinary, Image Processing, Computer-Assisted, Pathology, Veterinary
- Published
- 2018
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32. Congenital Ocular Abnormalities in Free-Ranging White-Tailed Deer.
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Clarke LL, Niedringhaus KD, Carmichael KP, Keel MK, and Fenton H
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- Animals, Cataract pathology, Eye pathology, Eye Abnormalities pathology, Female, Male, Cataract veterinary, Deer abnormalities, Eye Abnormalities veterinary
- Abstract
Congenital ocular abnormalities in cervids have been previously reported as individual cases from various regions of the United States and include microphthalmia, anophthalmia, congenital cataracts, dermoids, and colobomata. A common underlying cause for these abnormalities, such as nutritional deficiencies, environmental toxin exposures, or genetic mutations, has not been established. This retrospective study summarized and compared cases of suspected congenital ocular abnormalities in free-ranging white-tailed deer ( Odocoileus virginianus) submitted to the Southeastern Cooperative Wildlife Disease Study (SCWDS) in Athens, Georgia, to the preexisting literature. Of 3645 accessions of white-tailed deer submitted to SCWDS, 15 qualifying case records were found. An additional 15 cases were reported previously in the literature. Conditions described in SCWDS cases included microphthalmia (8/15), congenital cataracts (3/15), anophthalmia (2/15), colobomata (1/15), anterior segment dysgenesis (1/15), ectopic lacrimal gland tissue (1/15), and congenital blindness with corneal opacity (1/15). Most (11/15; 73%) of the SCWDS cases were male fawns with an average age of 4 months at presentation, consistent with previously described cases. Most animals had bilateral abnormalities with few extraocular congenital abnormalities, also consistent with existing reports. Cases were variably tested for various infectious agents at the time of submission; 2 cases were seropositive for bluetongue virus. Spatiotemporal clustering of cases was not evident. This study provided a concise and systematic summary of known existing cases of congenital ocular defects in fawns but did not identify a cause.
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- 2018
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33. Rare Osteochondroma Associated with Natural Mortality of a Wild White-Tailed Deer ( Odocoileus virginianus).
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Kalb MM, Miller DL, Keel MK, and Bowman JL
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- Animals, Animals, Wild, Bone Neoplasms pathology, Deer, Fatal Outcome, Female, Osteochondroma pathology, Bone Neoplasms veterinary, Osteochondroma veterinary
- Abstract
Within a 6-mo period, a radio-collared, white-tailed deer ( Odocoileus virginianus) doe from Delaware, US, developed a fatal head mass consistent with osteochondroma. We suspected a retroviral etiology, but test results were negative. Population implications were not suspected, but this case is concerning as these tumors are not thought to cause mortality.
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- 2018
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34. Comparison of intraosseous pentobarbital administration and thoracic compression for euthanasia of anesthetized sparrows (Passer domesticus) and starlings (Sturnus vulgaris).
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Paul-Murphy JR, Engilis A Jr, Pascoe PJ, Williams DC, Gustavsen KA, Drazenovich TL, Keel MK, Polley TM, and Engilis IE
- Subjects
- Anesthesia veterinary, Animals, Animals, Wild, Electroencephalography veterinary, Pressure, Starlings, Thorax, Euthanasia, Animal methods, Hypnotics and Sedatives administration & dosage, Pentobarbital administration & dosage, Sparrows
- Abstract
OBJECTIVE To compare intraosseous pentobarbital treatment (IPT) and thoracic compression (TC) on time to circulatory arrest and an isoelectric electroencephalogram (EEG) in anesthetized passerine birds. ANIMALS 30 wild-caught adult birds (17 house sparrows [Passer domesticus] and 13 European starlings [Sturnus vulgaris]). PROCEDURES Birds were assigned to receive IPT or TC (n = 6/species/group). Birds were anesthetized, and carotid arterial pulses were monitored by Doppler methodology. Five subdermal braided-wire electrodes were used for EEG. Anesthetic depth was adjusted until a continuous EEG pattern was maintained, then euthanasia was performed. Times from initiation of euthanasia to cessation of carotid pulse and irreversible isoelectric EEG (indicators of death) were measured. Data (medians and first to third quartiles) were summarized and compared between groups within species. Necropsies were performed for all birds included in experiments and for another 6 birds euthanized under anesthesia by TC (4 sparrows and 1 starling) or IPT (1 sparrow). RESULTS Median time to isoelectric EEG did not differ significantly between treatment groups for sparrows (19.0 and 6.0 seconds for TC and IPT, respectively) or starlings (88.5 and 77.5 seconds for TC and IPT, respectively). Median times to cessation of pulse were significantly shorter for TC than for IPT in sparrows (0.0 vs 18.5 seconds) and starlings (9.5 vs 151.0 seconds). On necropsy, most (14/17) birds that underwent TC had grossly visible coelomic, pericardial, or perihepatic hemorrhage. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that TC might be an efficient euthanasia method for small birds. Digital pressure directly over the heart during TC obstructed venous return, causing rapid circulatory arrest, with rupture of the atria or vena cava in several birds. The authors propose that cardiac compression is a more accurate description than TC for this procedure.
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- 2017
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35. Differential Disease Susceptibilities in Experimentally Reptarenavirus-Infected Boa Constrictors and Ball Pythons.
- Author
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Stenglein MD, Sanchez-Migallon Guzman D, Garcia VE, Layton ML, Hoon-Hanks LL, Boback SM, Keel MK, Drazenovich T, Hawkins MG, and DeRisi JL
- Subjects
- Animal Structures pathology, Animal Structures virology, Animals, Arenaviridae Infections immunology, Arenaviridae Infections pathology, Inflammation pathology, Arenaviridae growth & development, Arenaviridae immunology, Arenaviridae Infections veterinary, Boidae virology, Disease Susceptibility
- Abstract
Inclusion body disease (IBD) is an infectious disease originally described in captive snakes. It has traditionally been diagnosed by the presence of large eosinophilic cytoplasmic inclusions and is associated with neurological, gastrointestinal, and lymphoproliferative disorders. Previously, we identified and established a culture system for a novel lineage of arenaviruses isolated from boa constrictors diagnosed with IBD. Although ample circumstantial evidence suggested that these viruses, now known as reptarenaviruses, cause IBD, there has been no formal demonstration of disease causality since their discovery. We therefore conducted a long-term challenge experiment to test the hypothesis that reptarenaviruses cause IBD. We infected boa constrictors and ball pythons by cardiac injection of purified virus. We monitored the progression of viral growth in tissues, blood, and environmental samples. Infection produced dramatically different disease outcomes in snakes of the two species. Ball pythons infected with Golden Gate virus (GoGV) and with another reptarenavirus displayed severe neurological signs within 2 months, and viral replication was detected only in central nervous system tissues. In contrast, GoGV-infected boa constrictors remained free of clinical signs for 2 years, despite high viral loads and the accumulation of large intracellular inclusions in multiple tissues, including the brain. Inflammation was associated with infection in ball pythons but not in boa constrictors. Thus, reptarenavirus infection produces inclusions and inclusion body disease, although inclusions per se are neither necessarily associated with nor required for disease. Although the natural distribution of reptarenaviruses has yet to be described, the different outcomes of infection may reflect differences in geographical origin. IMPORTANCE New DNA sequencing technologies have made it easier than ever to identify the sequences of microorganisms in diseased tissues, i.e., to identify organisms that appear to cause disease, but to be certain that a candidate pathogen actually causes disease, it is necessary to provide additional evidence of causality. We have done this to demonstrate that reptarenaviruses cause inclusion body disease (IBD), a serious transmissible disease of snakes. We infected boa constrictors and ball pythons with purified reptarenavirus. Ball pythons fell ill within 2 months of infection and displayed signs of neurological disease typical of IBD. In contrast, boa constrictors remained healthy over 2 years, despite high levels of virus throughout their bodies. This difference matches previous reports that pythons are more susceptible to IBD than boas and could reflect the possibility that boas are natural hosts of these viruses in the wild., (Copyright © 2017 Stenglein et al.)
- Published
- 2017
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36. Evolution and Cryo-electron Microscopy Capsid Structure of a North American Bat Adenovirus and Its Relationship to Other Mastadenoviruses.
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Hackenbrack N, Rogers MB, Ashley RE, Keel MK, Kubiski SV, Bryan JA, Ghedin E, Holmes EC, Hafenstein SL, and Allison AB
- Subjects
- Animals, Chiroptera, Dogs, Gene Order, Genome, Viral, Host Specificity, Mass Spectrometry, Mastadenovirus classification, Open Reading Frames, Phylogeny, RNA, Viral, Sequence Homology, Virion, Adenoviridae Infections transmission, Adenoviridae Infections virology, Biological Evolution, Capsid metabolism, Capsid ultrastructure, Cryoelectron Microscopy, Mastadenovirus physiology, Mastadenovirus ultrastructure
- Abstract
Since the first description of adenoviruses in bats in 2006, a number of micro- and megabat species in Europe, Africa, and Asia have been shown to carry a wide diversity of adenoviruses. Here, we report on the evolutionary, biological, and structural characterization of a novel bat adenovirus (BtAdV) recovered from a Rafinesque's big-eared bat (Corynorhinus rafinesquii) in Kentucky, USA, which is the first adenovirus isolated from North American bats. This virus (BtAdV 250-A) exhibits a close phylogenetic relationship with Canine mastadenovirus A (CAdV A), as previously observed with other BtAdVs. To further investigate the relationships between BtAdVs and CAdVs, we conducted mass spectrometric analysis and single-particle cryo-electron microscopy reconstructions of the BtAdV 250-A capsid and also analyzed the in vitro host ranges of both viruses. Our results demonstrate that BtAdV 250-A represents a new mastadenovirus species that, in contrast to CAdV, has a unique capsid morphology that contains more prominent extensions of protein IX and can replicate efficiently in a phylogenetically diverse range of species. These findings, in addition to the recognition that both the genetic diversity of BtAdVs and the number of different bat species from disparate geographic regions infected with BtAdVs appears to be extensive, tentatively suggest that bats may have served as a potential reservoir for the cross-species transfer of adenoviruses to other hosts, as theorized for CAdV., Importance: Although many adenoviruses are host specific and likely codiverged with their hosts over millions of years, other adenoviruses appear to have emerged through successful cross-species transmission events on more recent time scales. The wide geographic distribution and genetic diversity of adenoviruses in bats and their close phylogenetic relationship to Canine mastadenovirus A (CAdV A) has raised important questions about how CAdV A, and possibly other mammalian adenoviruses, may have emerged. Although most adenoviruses tend to cause limited disease in their natural hosts, CAdV A is unusual in that it may cause high morbidity and sometimes fatal infections in immunocompetent hosts and is thus an important pathogen of carnivores. Here, we performed a comparative evolutionary and structural study of representative bat and canine adenoviruses to better understand the relationship between these two viral groups., (Copyright © 2017 American Society for Microbiology.)
- Published
- 2017
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37. Choroidal Vasculopathy and Retinal Detachment in a Bald Eagle ( Haliaeetus leucocephalus ) With Lead Toxicosis.
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Eid R, Guzman DS, Keller KA, Wiggans KT, Murphy CJ, LaDouceur EE, Keel MK, and Reilly CM
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- Animals, Bird Diseases pathology, Choroid Diseases etiology, Lead Poisoning complications, Lead Poisoning pathology, Male, Retinal Detachment etiology, Retinal Detachment pathology, Bird Diseases etiology, Choroid Diseases veterinary, Eagles, Lead toxicity, Lead Poisoning veterinary, Retinal Detachment veterinary
- Abstract
A subadult male bald eagle ( Haliaeetus leucocephalus ) was presented for severe depression and weakness. Physical examination findings included depressed mentation, dehydration, sternal recumbency, poor body condition, and bilateral, whole-head, horizontal nystagmus. A heavy-metal panel was performed, and blood lead levels were 6.1 ppm. Treatment for lead poisoning was initiated, including subcutaneous fluids and parenteral calcium-disodium ethylenediaminetetraacetic acid, ceftiofur, and meloxicam. Ophthalmic examination findings included absent menace response, absent dazzle reflex, slow and incomplete direct pupillary light reflex, mild anterior uveitis, incipient cataracts, multifocal retinal tears, and retinal separation in both eyes. Because of poor prognosis for vision and release to the wild, the eagle was euthanatized. No lesions were observed on gross postmortem examination. Histologically, extensive myocardial necrosis and multisystemic arteriolar vasculopathy were identified. The eyes were examined after tissue processing, and the vasculopathy extended into the choriocapillaris and was associated with a secondary, bilateral, exudative, retinal detachment. This is the first report in avian species characterizing the histopathologic ocular lesions of lead poisoning.
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- 2016
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38. Description of the prevalence, histologic characteristics, concomitant abnormalities, and outcomes of mammary gland tumors in companion rats (Rattus norvegicus): 100 cases (1990-2015).
- Author
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Vergneau-Grosset C, Keel MK, Goldsmith D, Kass PH, Paul-Murphy J, and Hawkins MG
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- Adenoma pathology, Adenoma veterinary, Animals, Carcinoma pathology, Carcinoma therapy, Female, Fibroadenoma pathology, Fibroadenoma therapy, Male, Mammary Neoplasms, Animal therapy, Pets, Pituitary Neoplasms pathology, Pituitary Neoplasms secondary, Rats, Retrospective Studies, Rodent Diseases therapy, Treatment Outcome, Carcinoma veterinary, Fibroadenoma veterinary, Mammary Neoplasms, Animal pathology, Rodent Diseases pathology
- Abstract
OBJECTIVE To describe the prevalence, histologic characteristics, concomitant abnormalities, and outcomes for various types of mammary gland tumors in companion rats (Rattus norvegicus). DESIGN Retrospective case series. ANIMALS 100 client-owned rats. PROCEDURES Medical records of companion rats that had an SC mass and were examined at a veterinary teaching hospital between 1990 and 2015 were reviewed. Information regarding the signalment, age at mass detection, reproductive sterilization status, histologic diagnosis of the SC mass, location of the initial and all subsequent SC masses, treatments administered, and clinical outcomes was extracted from each record and summarized. RESULTS 105 SC masses were initially detected in 100 rats. The most prevalent SC mass identified was mammary gland fibroadenoma (56/105 [53%]), followed by mammary gland carcinoma (13/105 [12%]). Overall, 26 of 105 (25%) masses were malignant. Sexually intact males were more likely to have nonmammary SC tumors than sexually intact females. In rats receiving no adjunctive treatment after excision of a mammary gland fibroadenoma (n = 16), a second fibroadenoma was detected 1 to 8 months after initial excision, at a median of 4.5 months after surgery. A concomitant pituitary gland tumor was identified in most rats with mammary gland fibroadenoma (21/28 [75%]) and other types of mammary gland tumors (10/17 [59%]). Fourteen of 35 (40%) rats with mammary gland fibroadenoma had concomitant reproductive tract abnormalities. CONCLUSION AND CLINICAL RELEVANCE Results suggested that, like other species, companion rats with SC masses should undergo a thorough diagnostic workup that includes histologic examination of the excised mass.
- Published
- 2016
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39. Mycobacterial panniculitis caused by Mycobacterium thermoresistibile in a cat.
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Vishkautsan P, Reagan KL, Keel MK, and Sykes JE
- Abstract
Case Summary: A domestic shorthair cat was evaluated for chronic, bilateral, ulcerative dermatitis affecting the inguinal region and lateral aspects of both pelvic limbs. Histopathologic examination of skin biopsies collected throughout the course of disease revealed chronic pyogranulomatous ulcerative dermatitis. Aerobic bacterial skin cultures yielded growth of a methicillin-resistant Staphylococcus aureus and Corynebacterium amycolatum . Upon referral the clinical findings were suggestive of a non-tuberculous Mycobacterium species infection. Previously obtained skin cultures failed to yield growth of mycobacterial organisms. A deep skin biopsy was collected and submitted for mycobacterial culture. At 5 weeks of incubation Mycobacterium thermoresistibile was isolated. In previous reports, M thermoresistibile has been isolated after 2-4 days of incubation, suggesting that this strain may have been a slower growing variant, or other factors (such as prior antimicrobial therapy) inhibited rapid growth of this isolate. The cat was hospitalized for intravenous antibiotic therapy, surgical debridement of wounds, vacuum-assisted wound closure therapy and reconstruction procedures. The wounds were ultimately primarily closed and the cat was discharged to the owner after 50 days of hospitalization. Seven months after hospitalization, the ulcerative skin lesions had healed., Relevance and Novel Information: To our knowledge, only two cases of M thermoresistibile panniculitis have been reported in cats. In the only detailed report of feline M thermoresistibile panniculitis, treatment was not attempted. The second case only reported detection of M thermoresistibile by PCR without a clinical description of the case. In our case report, severe chronic skin infection with M thermoresistibile was addressed using prolonged specific antibiotic therapy, surgical debridement and reconstructions, and treatment of secondary bacterial infections., Competing Interests: Conflict of interest: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2016
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40. Lesions of Copper Toxicosis in Captive Marine Invertebrates With Comparisons to Normal Histology.
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LaDouceur EE, Wynne J, Garner MM, Nyaoke A, and Keel MK
- Subjects
- Animals, Aquatic Organisms drug effects, California, Ecosystem, Female, Invertebrates anatomy & histology, Male, Copper poisoning, Invertebrates drug effects
- Abstract
Despite increasing concern for coral reef ecosystem health within the last decade, there is scant literature concerning the histopathology of diseases affecting the major constituents of coral reef ecosystems, particularly marine invertebrates. This study describes histologic findings in 6 species of marine invertebrates (California sea hare [Aplysia californica], purple sea urchin [Strongylocentrotus purpuratus], sunburst anemone [Anthopleura sola], knobby star [Pisaster giganteus], bat star [Asterina miniata], and brittle star [Ophiopteris papillosa]) with spontaneous copper toxicosis, 4 purple sea urchins with experimentally induced copper toxicosis, and 1 unexposed control of each species listed. The primary lesions in the California sea hare with copper toxicosis were branchial and nephridial necrosis. Affected echinoderms shared several histologic lesions, including epidermal necrosis and ulceration and increased numbers of coelomocytes within the water-vascular system. The sunburst anemone with copper toxicosis had necrosis of both epidermis and gastrodermis, as well as expulsion of zooxanthellae from the gastrodermis. In addition to the lesions attributed to copper toxicosis, our results describe normal microscopic features of these animals that may be useful for histopathologic assessment of marine invertebrates., (© The Author(s) 2015.)
- Published
- 2016
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41. Potent Inhibition of Pseudogymnoascus destructans, the Causative Agent of White-Nose Syndrome in Bats, by Cold-Pressed, Terpeneless, Valencia Orange Oil.
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Boire N, Zhang S, Khuvis J, Lee R, Rivers J, Crandall P, Keel MK, and Parrish N
- Subjects
- Animals, Antifungal Agents chemistry, Antifungal Agents therapeutic use, Environment, Geography, Mycoses drug therapy, Plant Oils chemistry, Plant Oils therapeutic use, Antifungal Agents pharmacology, Ascomycota drug effects, Ascomycota physiology, Chiroptera microbiology, Mycoses veterinary, Plant Oils pharmacology, Pressure
- Abstract
The causative agent of White-nose Syndrome (WNS), Pseudogymnoascus destructans, has been shown to be fatal to several species of bats in North America. To date, no compounds or chemical control measures have been developed which eliminates the growth of the fungus in the environment or in affected animals. In the current study, we evaluated the activity of cold-pressed, terpeneless orange oil (CPT) against multiple isolates of P. destructans in vitro. For all assays, a modified Kirby-Bauer disk diffusion assay was used. Standardized spore suspensions were prepared, adjusted to a specific optical density, and used to plate fungal lawns. Plates were incubated at either 15°C or 4°C for up to 6 months and checked at regular intervals for growth. Once controls had grown, zones of inhibition were measured (mm) on test plates and compared to those obtained using current antifungal drugs. All P. destructans isolates were completely inhibited by 100% CPT (10 μL) at 1 month of incubation regardless of temperature (4°C and 15°C). Complete inhibition persisted up to 6 months following a single exposure at this concentration. Of the standard antifungals, only amphotericin B demonstrated any activity, resulting in zone diameters ranging from 58 mm to 74 mm. CPT, at the highest concentration tested (100%), had no significant effect against a variety of other environmental organisms including various filamentous fungi, bacteria and aerobic actinomycetes. Given that CPT is relatively non-toxic, the possibility exists that the all-natural, mixture could be used as an environmental pre-treatment to eradicate P. destructans from bat habitats. Additional studies are needed to assess any undesirable effects of CPT on bat behavior and health and overall impacts on other members of the interconnected ecosystem(s).
- Published
- 2016
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42. Cyclic avian mass mortality in the northeastern United States is associated with a novel orthomyxovirus.
- Author
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Allison AB, Ballard JR, Tesh RB, Brown JD, Ruder MG, Keel MK, Munk BA, Mickley RM, Gibbs SE, Travassos da Rosa AP, Ellis JC, Ip HS, Shearn-Bochsler VI, Rogers MB, Ghedin E, Holmes EC, Parrish CR, and Dwyer C
- Subjects
- Animals, Anseriformes, Bird Diseases pathology, Bird Diseases virology, Cluster Analysis, Female, Male, Models, Molecular, Molecular Sequence Data, New England epidemiology, Orthomyxoviridae classification, Orthomyxoviridae genetics, Orthomyxoviridae Infections pathology, Orthomyxoviridae Infections virology, Phylogeny, Protein Conformation, RNA, Viral genetics, Sequence Analysis, DNA, Viral Proteins chemistry, Viral Proteins genetics, Bird Diseases epidemiology, Bird Diseases mortality, Disease Outbreaks, Orthomyxoviridae isolation & purification, Orthomyxoviridae Infections epidemiology, Orthomyxoviridae Infections mortality
- Abstract
Unlabelled: Since 1998, cyclic mortality events in common eiders (Somateria mollissima), numbering in the hundreds to thousands of dead birds, have been documented along the coast of Cape Cod, MA, USA. Although longitudinal disease investigations have uncovered potential contributing factors responsible for these outbreaks, detecting a primary etiological agent has proven enigmatic. Here, we identify a novel orthomyxovirus, tentatively named Wellfleet Bay virus (WFBV), as a potential causative agent of these outbreaks. Genomic analysis of WFBV revealed that it is most closely related to members of the Quaranjavirus genus within the family Orthomyxoviridae. Similar to other members of the genus, WFBV contains an alphabaculovirus gp64-like glycoprotein that was demonstrated to have fusion activity; this also tentatively suggests that ticks (and/or insects) may vector the virus in nature. However, in addition to the six RNA segments encoding the prototypical structural proteins identified in other quaranjaviruses, a previously unknown RNA segment (segment 7) encoding a novel protein designated VP7 was discovered in WFBV. Although WFBV shows low to moderate levels of sequence similarity to Quaranfil virus and Johnston Atoll virus, the original members of the Quaranjavirus genus, additional antigenic and genetic analyses demonstrated that it is closely related to the recently identified Cygnet River virus (CyRV) from South Australia, suggesting that WFBV and CyRV may be geographic variants of the same virus. Although the identification of WFBV in part may resolve the enigma of these mass mortality events, the details of the ecology and epidemiology of the virus remain to be determined., Importance: The emergence or reemergence of viral pathogens resulting in large-scale outbreaks of disease in humans and/or animals is one of the most important challenges facing biomedicine. For example, understanding how orthomyxoviruses such as novel influenza A virus reassortants and/or mutants emerge to cause epidemic or pandemic disease is at the forefront of current global health concerns. Here, we describe the emergence of a novel orthomyxovirus, Wellfleet Bay virus (WFBV), which has been associated with cyclic large-scale bird die-offs in the northeastern United States. This initial characterization study provides a foundation for further research into the evolution, epidemiology, and ecology of newly emerging orthomyxoviruses, such as WFBV, and their potential impacts on animal and/or human health., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)
- Published
- 2015
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43. Antleroma in a free-ranging white-tailed deer (Odocoileus virginianus).
- Author
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Munk BA, Garrison E, Clemons B, and Keel MK
- Subjects
- Animals, Antlers pathology, Bone and Bones pathology, Deer, Male, Neoplasms pathology, Neoplasms veterinary
- Abstract
A 2-year-old male free-ranging white-tailed deer (Odocoileus virginianus) was diagnosed with bilateral expansile tumors of antler origin. The deer was found dead by a landowner in High Springs, Florida. Two roughly spherical, multilobular, broad-based, bony, velvet-covered masses originated from each antler pedicle. These masses replaced or displaced many of the bones and soft tissues of the skull and extended through the left cribriform plate and the right petrous temporal bone, compressing portions of the brain. Microscopically, the masses closely resembled normal-growing antler, containing all the elements thereof but with areas of necrosis and hemorrhage suggestive of ischemi or trauma. Tumorlike outgrowths termed antleromas have been described in free-ranging and captive cervids and typically are associated with disruptions in the seasonal rise and fall of circulating testosterone necessary for normal antler growth, casting, and regeneration., (© The Author(s) 2014.)
- Published
- 2015
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44. A preliminary report on the contact-independent antagonism of Pseudogymnoascus destructans by Rhodococcus rhodochrous strain DAP96253.
- Author
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Cornelison CT, Keel MK, Gabriel KT, Barlament CK, Tucker TA, Pierce GE, and Crow SA
- Subjects
- Animals, Mycelium metabolism, Spores, Fungal metabolism, Ascomycota metabolism, Chiroptera microbiology, Mycoses microbiology, Rhodococcus metabolism
- Abstract
Background: The recently-identified causative agent of White-Nose Syndrome (WNS), Pseudogymnoascus destructans, has been responsible for the mortality of an estimated 5.5 million North American bats since its emergence in 2006. A primary focus of the National Response Plan, established by multiple state, federal and tribal agencies in 2011, was the identification of biological control options for WNS. In an effort to identify potential biological control options for WNS, multiply induced cells of Rhodococcus rhodochrous strain DAP96253 was screened for anti-P. destructans activity., Results: Conidia and mycelial plugs of P. destructans were exposed to induced R. rhodochrous in a closed air-space at 15°C, 7°C and 4°C and were evaluated for contact-independent inhibition of conidia germination and mycelial extension with positive results. Additionally, in situ application methods for induced R. rhodochrous, such as fixed-cell catalyst and fermentation cell-paste in non-growth conditions, were screened with positive results. R. rhodochrous was assayed for ex vivo activity via exposure to bat tissue explants inoculated with P. destructans conidia. Induced R. rhodochrous completely inhibited growth from conidia at 15°C and had a strong fungistatic effect at 4°C. Induced R. rhodochrous inhibited P. destructans growth from conidia when cultured in a shared air-space with bat tissue explants inoculated with P. destructans conidia., Conclusion: The identification of inducible biological agents with contact-independent anti- P. destructans activity is a major milestone in the development of viable biological control options for in situ application and provides the first example of contact-independent antagonism of this devastating wildlife pathogen.
- Published
- 2014
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45. Demodectic mange, dermatophilosis, and other parasitic and bacterial dermatologic diseases in free-ranging white-tailed deer (Odocoileus virginianus) in the United States from 1975 to 2012.
- Author
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Nemeth NM, Ruder MG, Gerhold RW, Brown JD, Munk BA, Oesterle PT, Kubiski SV, and Keel MK
- Subjects
- Actinomycetales Infections epidemiology, Actinomycetales Infections pathology, Age Factors, Alopecia veterinary, Animals, Erythema veterinary, History, 20th Century, History, 21st Century, Incidence, Mite Infestations epidemiology, Mite Infestations pathology, Southeastern United States epidemiology, Actinomycetales Infections veterinary, Deer microbiology, Deer parasitology, Mite Infestations veterinary
- Abstract
The white-tailed deer (Odocoileus virginianus) is a common and widespread North American game species. To evaluate the incidence, clinical manifestations, demography, and pathology of bacterial and parasitic dermatologic diseases in white-tailed deer in the southeastern United States, we retrospectively evaluated white-tailed deer cases submitted to the Southeastern Cooperative Wildlife Disease Study from 1975 to 2012. Among 2569 deer examined, bacterial or parasitic dermatologic disease was diagnosed in 88 (3.4%) individuals, with Demodex spp (n = 37; 42.0%) and Dermatophilus congolensis (n = 19; 21.6%) as the most common causes. Demodicosis was significantly more common in deer older than 2 years and was most often detected in the fall; no statistically significant sex predilection was identified. Affected animals had patchy to generalized alopecia, often distributed over the head, neck, limbs, and trunk; microscopic lesions included epidermal crusts and cutaneous nodules with mild perifollicular, lymphoplasmacytic inflammation. Dermatophilosis was most common in males younger than 1 year that were often found dead. Crusting, erythema, and alopecia occurred on the face, ears, and distal extremities. Less commonly, infectious dermatologic diseases were associated with other bacteria (n = 13; 14.8%), fungi (n = 5; 5.7%), ectoparasites (chiggers, lice, mites, and ticks; n = 11; 12.5%), and larval nematodes (n = 7; 8.0%). Population-level effects of these diseases in white-tailed deer are likely minimal; however, due to their dramatic presentation, demodicosis, dermatophilosis, and other infectious skin diseases can be of concern to hunters and, in some cases, may have zoonotic potential.
- Published
- 2014
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46. Persistence of Mycobacterium avium subspecies paratuberculosis in endangered Florida Key deer and Key deer habitat.
- Author
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Murray HL, Yabsley MJ, Keel MK, Manning EJ, Wilmers TJ, and Corn JL
- Subjects
- Animals, Female, Florida epidemiology, Paratuberculosis epidemiology, Time Factors, Deer microbiology, Endangered Species, Mycobacterium avium subsp. paratuberculosis, Paratuberculosis microbiology
- Abstract
Mycobacterium avium subsp. paratuberculosis (MAP) was first reported in the endangered Key deer (Odocoileus virginianus clavium) in 1996 on Big Pine Key, Florida, USA. By 2008, eight additional MAP-positive Key deer had been identified on Big Pine Key and the nearby Newfound Harbor Keys. This study was conducted to determine if MAP was still present in Key deer and whether natural or man-made freshwater sources were contaminated with MAP. Between November 2009 and September 2012, MAP was isolated from 36/369 (10%) fecal samples collected from the ground throughout the Key deer range on Big Pine Key and the Newfound Harbor Keys, but all 36 positive samples were from Little Palm Island (36/142 [25%]). Only 1/729 (0.1%) environmental samples was positive; this was from the garden fountain on Little Palm Island (1/81 [1%]). In addition, MAP was detected in 3/43 (7%) necropsied Key deer, all from Little Palm Island (3/3 [100%]). Of these three Key deer, pooled samples from the ileum, cecum, and ileocecal lymph node from two were MAP-culture positive and feces from one of these were culture-positive. The third deer was only PCR-positive. Evidence of MAP was only detected on Little Palm Island during this sampling period and environmental contamination was limited.
- Published
- 2014
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47. Hemotropic mycoplasmas in little brown bats (Myotis lucifugus).
- Author
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Mascarelli PE, Keel MK, Yabsley M, Last LA, Breitschwerdt EB, and Maggi RG
- Subjects
- Animals, Appalachian Region epidemiology, Base Sequence, DNA, Bacterial chemistry, DNA, Bacterial genetics, DNA, Ribosomal chemistry, DNA, Ribosomal genetics, Disease Reservoirs, Molecular Sequence Data, Mycoplasma classification, Mycoplasma genetics, Mycoplasma Infections epidemiology, Mycoplasma Infections microbiology, Mycoplasma Infections mortality, Nose pathology, Phylogeny, Polymerase Chain Reaction veterinary, Prevalence, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA veterinary, Spleen pathology, Ascomycota isolation & purification, Chiroptera microbiology, Mycoplasma isolation & purification, Mycoplasma Infections veterinary
- Abstract
Background: Hemotropic mycoplasmas are epicellular erythrocytic bacteria that can cause infectious anemia in some mammalian species. Worldwide, hemotropic mycoplasmas are emerging or re-emerging zoonotic pathogens potentially causing serious and significant health problems in wildlife. The objective of this study was to determine the molecular prevalence of hemotropic Mycoplasma species in little brown bats (Myotis lucifugus) with and without Pseudogymnoascus (Geomyces) destrucans, the causative agent of white nose syndrome (WNS) that causes significant mortality events in bats., Methods: In order to establish the prevalence of hemotropic Mycoplasma species in a population of 68 little brown bats (Myotis lucifugus) with (n = 53) and without (n = 15) white-nose syndrome (WNS), PCR was performed targeting the 16S rRNA gene., Results: The overall prevalence of hemotropic Mycoplasmas in bats was 47%, with similar (p = 0.5725) prevalence between bats with WNS (49%) and without WNS (40%). 16S rDNA sequence analysis (~1,200 bp) supports the presence of a novel hemotropic Mycoplasma species with 91.75% sequence homology with Mycoplasma haemomuris. No differences were found in gene sequences generated from WNS and non-WNS animals., Conclusions: Gene sequences generated from WNS and non-WNS animals suggest that little brown bats could serve as a natural reservoir for this potentially novel Mycoplasma species. Currently, there is minimal information about the prevalence, host-specificity, or the route of transmission of hemotropic Mycoplasma spp. among bats. Finally, the potential role of hemotropic Mycoplasma spp. as co-factors in the development of disease manifestations in bats, including WNS in Myotis lucifugus, remains to be elucidated.
- Published
- 2014
- Full Text
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48. Mediastinal teratoma in a free-ranging American black bear (Ursus americanus).
- Author
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Munk BA, Turner JC, and Keel MK
- Subjects
- Animals, Female, Mediastinal Neoplasms pathology, Teratoma pathology, Mediastinal Neoplasms veterinary, Teratoma veterinary, Ursidae
- Abstract
A 2.75-yr-old female American black bear (Ursus americanus) was found emaciated and unable to rise. It was euthanized due to the perceived poor prognosis. An approximately 18 x 8 x 10-cm, multiloculated, well-demarcated mass that extended from the bifurcation of the trachea, laterally displacing the lung lobes and caudally displacing the heart. The mass contained fibrous connective tissue, cartilage, bone, nervous tissue, smooth muscle, and a variety of epithelial structures. A mediastinal teratoma was diagnosed based on the microscopic features of the neoplasm.
- Published
- 2013
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49. Infestation of two brown-headed cowbirds (Molothrus ater) with the hunchback mite (Harpirhynchus quasimodo).
- Author
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Magenwirth J, Nemeth NM, Yabsley MJ, Munk BA, Keel MK, and Brown JD
- Subjects
- Animals, Arkansas, Female, Male, Mites anatomy & histology, Mites classification, Tennessee, Bird Diseases parasitology, Bird Diseases pathology, Mite Infestations parasitology, Mite Infestations pathology, Mites physiology, Songbirds
- Abstract
A recently described North American mite, Harpirhynchus quasimodo (Acariformes: Harpirhynchidae), was identified in a wild brown-headed cowbird (Molothrus ater) from Tennessee and another from Arkansas, U. S. A., during 2010 and 2011, respectively. Consistent with a single previous report of H. quasimodo infestation, both cowbirds had multiple skin masses composed of epidermal cysts filled with harpirhynchid mites, keratin, and cellular debris. Although very little is currently known about this avian mite, these three reports suggest that H. quasimodo infestation is a rare source of overt disease in free-ranging brown-headed cowbirds from the southeastern United States; however, further research and surveillance efforts are needed.
- Published
- 2013
- Full Text
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50. First report of clinical disease associated with canine distemper virus infection in a wild black bear (Ursus americana).
- Author
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Cottrell WO, Keel MK, Brooks JW, Mead DG, and Phillips JE
- Subjects
- Animals, Animals, Wild, Distemper pathology, Encephalitis, Viral pathology, Encephalitis, Viral virology, Female, Phylogeny, Distemper virology, Distemper Virus, Canine isolation & purification, Encephalitis, Viral veterinary, Ursidae
- Abstract
An approximately 1-yr-old black bear was discovered on the porch of a rural residence in southwestern Pennsylvania on October 26, 2011, where it remained during the day in spite of efforts to frighten it away. The bear exhibited periods of somnolence and sporadic tremors and seizures. It was euthanized by gunshot that evening. Immediately after euthanasia it was observed to have footpads that exuded fluid when compressed. It was submitted for necropsy the next day where roughened footpads were noted. Histologic examination of the brain demonstrated nonsuppurative encephalitis with eosinophilic intranuclear and intracytoplasmic inclusion bodies in neurons. The footpads were thickened and hyperkeratotic. Canine distemper virus (CDV) was detected by immunohistochemistry (IHC) in the brain and footpads, and by reverse transcription polymerase chain reaction (RT-PCR) from the brain tissue. Phylogenetic analysis indicated that the CDV cDNA from the bear had 98.2% nucleotide identity to the Rockborn-Candur vaccine and a canine isolate from 2004 in Missouri, USA, and 97.3% nucleotide identity to a raccoon CDV isolated in 2011 from Tennessee, USA. This represents a first report of CDV as a cause of encephalitis or footpad hyperkeratosis in a wild black bear.
- Published
- 2013
- Full Text
- View/download PDF
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