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Flea-borne diseases are endemic in Texas, U.S.A., with an increasing incidence of flea-borne typhus and cat scratch disease. Knowledge of flea natural history could provide information to protect public health, yet many knowledge gaps remain outside of plague-endemic regions. Our objective was to characterize seasonal activity patterns of fleas on common mammalian wildlife species and test fleas and wildlife for Rickettsia and Bartonella pathogens. We performed one year of monthly trapping for rodents and medium-sized mammals in a national forest with high recreational use and urban encroachment in East Texas. From 90 mammal captures representing seven species, 101 fleas were collected representing Polygenis spp., Ctenocephalides felis, and Orchopeas species. Virginia opossums (Didelphis virginianus) hosted 99% of the collected fleas (100 fleas) and a single flea was on an eastern woodrat (Neotoma floridana). Flea infestation prevalence of opossums was 79% (23/29). Mean flea abundance was 4.39 fleas, with intensity peaking in spring. One cat flea removed from an opossum was positive for Bartonella henselae. Furthermore, we identified tissue or blood of four raccoons (Procyon lotor) and one golden mouse (Ochrotomys nuttalli) positive for Rickettsia amblyommatis. These findings provide an ecological basis for the maintenance of vectors and pathogens from sylvatic settings. [ABSTRACT FROM AUTHOR]

We developed a venipuncture technique of the ventral caudal vein in conscious Virginia opossums (Didelphis virginiana) in cage traps, enabling blood sampling without anesthesia. Blood samples were successfully collected from all 28 opossums in this study by this technique. Draw volume of <0.1 mL occurred in only four opossums (14%). [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Models can greatly reduce time and expense when designing housing systems for non-domesticated species like the opossum. Using housing design guidelines and animal production principles, three theoretical models of a semi-intensive housing facility for the widely hunted, neo-tropical opossum (Didelphis marsupialis insularis, Allen, 1902) were developed. The models were then critiqued to determine the most cost effective and efficient design features. Overall, it was found that the behaviour of the opossum was very important to the design of the housing system. Features of the neo-tropics, safety and affordability were important considerations, while accessibility and layout did not always agree. The designs presented in this paper can serve as a blueprint for the construction and trial of experimental housing systems for the neo-tropical opossum. [ABSTRACT FROM AUTHOR]

Summary The opossum (family Didelphidae) is a marsupial endemic to the Americas. Apart from the South American short-tailed opossum ( Monodelphis domestica ) and the Virginia opossum ( Didelphis virginiana ), there is considerable lack of knowledge about the health and diseases of most opossum species. Among these, the big-eared opossum ( Didelphis aurita ) is found in Argentina, Brazil and Paraguay. Natural and experimental studies have shown this species to be susceptible to infectious agents with zoonotic potential and the animals may play a role in transmission of such agents. However, neoplasia appears to be uncommon in this species. We describe the gross, microscopical and immunohistochemical features of a parotid salivary gland basal cell adenocarcinoma in a free-living big-eared opossum. This case represents the first report of salivary gland neoplasia in opossums. [ABSTRACT FROM AUTHOR]

This review focuses on the information that is available on the reproductive biology of Didelphis. From the findings of over 60 scientific documents - beginning as early as 1704- it was found that opossums possess some very exclusive reproductive adaptations, including: short gestation period, paired spermatozoa and a temporary pseudo-vaginal canal. These findings, however, were based on investigation on one or two species of the genus only. An overall picture of the reproductive biology and any adaptations or differences between the six species in the genus was therefore not possible. In conclusion, many gaps remain and novel theories on the topic have yet to be proposed on tropical and neo-tropical opossum species. Therefore, further study into the reproductive biology of South American and Caribbean species is highly recommended. This will allow for a clearer understanding of the reproductive biology of this marsupial, which can be a guide in the development of an intensive animal production system in the tropics. [ABSTRACT FROM AUTHOR]

Didelphostrongylus hayesi is an important and prevalent pulmonary nematode in the opossum ( Didelphis virginiana). An in-depth description of the pulmonary lesions caused by this nematode is lacking. The objective of this investigation was to make a detailed account of the gross, subgross, and microscopic changes that occur in the lungs of opossums naturally infected with D. hayesi. Forty-four opossums trapped in the state of Colima, Mexico, were euthanized by an overdose of barbiturates. Following a postmortem examination, the right lung was cut from the main bronchi and placed in a Petri dish containing a saline solution for the detection and identification of live parasites. The left lung was fixed and cut serially for subgross microscopic examination and sections of lung were cut and stained for histopathologic examination. The most remarkable gross change in parasitized lungs was a poorly collapsible pulmonary parenchyma and mild emphysema. The right lung tested positive for lungworms on gross examination in 20/44, and 11/44 (25%) of the left lungs showed tan nodules on the pleural surface. Microscopically, the bronchi of 20/44 animals harbored adult and larval stages of D. hayesi (left lung), the same 20 opossums from which nematodes were grossly evident at necropsy (right lung). Adults and larvae were present in bronchi, bronchioles, and alveoli mixed with desquamated cells and many eosinophils, and to a lesser extent neutrophils, alveolar macrophages, and giant cells. Bronchi and bronchioles exhibited goblet cell hyperplasia and metaplasia respectively, and infiltration of lymphoplasmacytic cells in the interstitium and lamina propria. The tan nodules consisted of focal alveolar endogenous lipidosis, which likely resulted from parasitic airway obstruction. The lungs of 3/20 parasitized opossums also showed alveolar bronchiolization (Lambertosis). The absence of Eucoleus aerophilus or bacterial pneumonia incriminates D. hayesi as the putative cause of pulmonary lesions in these opossums. [ABSTRACT FROM AUTHOR]

The genus Didelphis contains six species of marsupials that are found only in the Americas. Commonly referred to as opossums, Didelphis species have been widely studied over the years and possess a number of features that make them suitable for semi-intensive production. Rearing any species for production requires a solid knowledge on species biology and behaviour. The following paper is a review of the state of knowledge on Didelphis species and focuses on the natural history, animal behaviour, diet and digestion. It further highlights the gaps of information on this genus. In total over 140 years of documented literature on the species was examined and synthesized. It was found that much is known on the natural history of the genus, except for the neo-tropical species which are yet to be studied. Animal behaviour and digestion were both intensively studied in the 1900s, but focussed almost solely on captive Didelphis virginiana specimens, with limited research on its congeners. Although much work was completed over a wide span of years, there remain a number of areas still requiring investigation, particularly for the neo-tropical species of Didelphis that live in South America and the Caribbean. [ABSTRACT FROM AUTHOR]

Five sugar gliders ( Petaurus breviceps), ranging in age from 3 mo to 3.5 yr of age, and one opossum ( Didelphis virginianus), age 4.5 mo, presented for elective orchiectomy and scrotal ablation. The LigaSure™ device was safely used for orchiectomy and scrotal ablation in both species. Surgical time with the LigaSure was approximately 4 sec. No grooming of the incision site or self-mutilation was seen in the first 72 hr postoperatively. One sugar glider required postoperative wound care approximately 10 days postoperatively following incision-site grooming by a conspecific. The LigaSure provides a rapid, technologically simple and safe surgical technique for scrotal ablation and orchiectomy in the marsupial patient that minimizes surgical, anesthetic, and recovery times. [ABSTRACT FROM AUTHOR]

Copyright of Pesquisa Veterinaria Brasileira is the property of Colegio Brasileiro de Patologia Animal - CBPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a case study of a 2-yr-old, intact female Virginia opossum or Didelphis virginiana with a history of ulcerative dermatitis and weight loss. The opossum was diagnosed with mature lymphocytes and cutaneous lymphoma wherein the opossum was placed under anesthesia using isoflurane during the treatment of lesion. It examines the medical treatment for the recurrence of facial and axillary skin lesions due to the presence of mature lymphocytes in the axilla.

Abstract: This study was designed to investigate the morphology and distribution of argyrophil, argentaffins, and insulin-immunoreactive endocrine cells in the large intestine of the opossum Didelphis aurita. Fragments of the large intestine of 10 male specimens of the opossum D. aurita were collected, processed, and submitted for histochemistry, immunohistochemistry, and scanning electron microscopy. The tunics of the large intestine of D. aurita presented morphological characteristics that have already been described for eutherian mammals. The morphometric data showed that the inner circular layer of all portions and regions analyzed is thicker relative to the longitudinal layer, and these layers in the rectum are thicker compared to the cecum and ascending colon. The majority of mucus-secreting cells have acid and neutral mucins, suggesting that the production of mucus is mixed. The number of these cells increases in the region of the cecum toward the rectum. Important findings include the occurrence of argyrophil, argentaffins, and insulin-immunoreactive endocrine cells in all segments of the large intestine of the opossum (D. aurita). To the best of our knowledge, this is the first report about the presence of insulin-immunoreactive endocrine cells in the large intestine of the opossum (D. aurita). [Copyright &y& Elsevier]

Abstract: Internal parasitic infections are common in the Virginia opossum (Didelphis virginiana). More than 50 different species of nematodes have been identified from the genus Didelphis. Of them, 3 can cause significant illness to native opossums in Southern California, 2 gastrointestinal nematodes and 1 pulmonary nematode. This article provides an overview of the life cycles, methods for identification, pathologic findings, diagnostic tests, clinical signs, and options for treating these common nematode species. [Copyright &y& Elsevier]

Abstract: The aim of this study was to identify and quantify the argyrophil, argentaffin and insulin-immunoreactive cells (IIC) in the small intestine of the opossum Didelphis aurita. Seven adult male specimens of opossums were investigated. The animals were captured, and their blood insulin levels were determined. After euthanasia, fragments of the small intestine were processed for light microscopy and transmission electron microscopy, and submitted to histochemistry and immunohistochemistry for identification of argyrophil and argentaffin endocrine cells, and IIC. Argyrophil and argentaffin cells were identified in the intestinal villi and Liberkühn crypts, whereas IIC were present exclusively in the crypts. Ultrastructure of the IIC revealed cytoplasmic granules of different sizes and electron densities. The numbers of IIC per mm2 in the duodenum and jejunum were higher than in the ileum (p <0.05). The animals had low levels of blood insulin (2.8±0.78μIU/ml). There was no correlation between insulin levels and the number of IIC in the small intestine. The IIC presented secretory granules, elongated and variable morphology. It is believed that insulin secretion by the IIC may influence the proliferation of cells in the Liberkühn crypts, and local glucose homeostasis, primarily in animals with low serum insulin levels, such as the opossum. [Copyright &y& Elsevier]

The article presents case studies of four Virginia opossums (Didelphis virginiana) with severe clinical disease and inflammation associated with besnoitiosis. It says that symptoms include incoordination, circling, and sudden death. Besnoitia darlingi was confirmed in three of the four opossums through polymerase chain reaction (PCR) and sequencing.

The article discusses research which examines the chromosomal instability and growth inhibition of cultured marsupial (opossum) cells following DNA polymerase α inhibitor treatment. The study showed that dehydroaltenusin inhibits euthorian and metatherian DNA replication. Further, it revealed that dehyroaltenusin clearly suppressed the growth of metatherian cultured cells.

BLAT (BLAST-Like Alignment Tool) analyses of the opossum (Monodelphis domestica) and zebrafish (Danio rerio) genomes were undertaken using amino acid sequences of the acylglycerol acyltransferase (AGAT) superfamily. Evidence is reported for 8 opossum monoacylglycerol acyltransferase-like (MGAT) (E.C. 2.3.1.22) and diacylglycerol acyltransferase-like (DGAT) (E.C. 2.3.1.20) genes and proteins, including DGAT1, DGAT2, DGAT2L6 (DGAT2-like protein 6), AWAT1 (acyl CoA wax alcohol acyltransferase 1), AWAT2, MGAT1, MGAT2 and MGAT3. Three of these genes (AWAT1, AWAT2 and DGAT2L6) are closely localized on the opossum X chromosome. Evidence is also reported for six zebrafish MGAT- and DGAT-like genes, including two DGAT1-like genes, as well as DGAT2-, MGAT1-, MGAT2- and MGAT3-like genes and proteins. Predicted primary, secondary and transmembrane structures for the opossum and zebrafish MGAT-, AWAT- and DGAT-like subunits and the intron–exon boundaries for genes encoding these enzymes showed a high degree of similarity with other members of the AGAT superfamily, which play major roles in triacylglyceride (DGAT), diacylglyceride (MGAT) and wax ester (AWAT) biosynthesis. Alignments of predicted opossum, zebrafish and other vertebrate DGAT1, DGAT2, other DGAT2-like and MGAT-like amino acid sequences with known human and mouse enzymes demonstrated conservation of residues which are likely to play key roles in catalysis, lipid binding or in maintaining structure. Phylogeny studies of the human, mouse, opossum, zebrafish and pufferfish MGAT- and DGAT-like enzymes indicated that the common ancestors for these genes predated the appearance of bony fish during vertebrate evolution whereas the AWAT- and DGAT2L6-like genes may have appeared more recently prior to the appearance of marsupial and eutherian mammals. [Copyright &y& Elsevier]

Movements of Raccoons (Procyon lotor) ... = 479 km) and Opossums (Dideiphis virginiana) ... = 688 km) by means of transport trailers and a train from the USA and Quebec into Ontario were significantly greater than Raccoon movements (... = 15 km) from Ontario to New York State determined by mark-recapture. Human-assisted movements of wildlife could have significant impacts with respect to cross-border movements of diseases such as rabies. Proactive communication programs, especially at International border crossing areas, should be encouraged to decrease the occurrence of the unintentional movement of wildlife and associated diseases. [ABSTRACT FROM AUTHOR]