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An adult dog was presented for chronic cough and a recent development of ulcerated, erythematous nares with nasal discharge. Cytology of enlarged peripheral lymph nodes revealed many intracellular and extracellular organisms. These round or rarely oval organisms measured approximately 5‐9 µm in diameter and frequently contained several globular structures, ranging from deeply basophilic to magenta. A thin, clear halo was present. Smaller 1‐2 µm, magenta forms were also observed. Fungal culture yielded small, wet, raised, irregularly shaped, white to pale tan colonies. Microbiologic staining of cultured material revealed features suggestive of algae. Histopathology of the lymph nodes revealed marked granulomatous inflammation with intralesional algal organisms suggestive of Prototheca. Electron microscopic findings were also consistent with protothecosis. Polymerase chain reaction, followed by direct DNA sequencing, identified the organism as Prototheca wickerhamii. A brief literature review discussing protothecosis in veterinary medicine is included. [ABSTRACT FROM AUTHOR]

Fusarium spp. are saprobic moulds that are responsible for severe opportunistic infections in humans and animals. However, we need epidemiological tools to reliably trace the circulation of such fungal strains within medical or veterinary facilities, to recognize environmental contaminations that might lead to infection and to improve our understanding of factors responsible for the onset of outbreaks. In this study, we used molecular genotyping to investigate clustered cases of Fusarium solani species complex (FSSC) infection that occurred in eight Sphyrnidae sharks under managed care at a public aquarium. Genetic relationships between fungal strains were determined by multi-locus sequence typing (MLST) analysis based on DNA sequencing at five loci, followed by comparison with sequences of 50 epidemiologically unrelated FSSC strains. Our genotyping approach revealed that F. keratoplasticum and F. solani haplotype 9x were most commonly isolated. In one case, the infection proved to be with another Hypocrealian rare opportunistic pathogen Metarhizium robertsii. Twice, sharks proved to be infected with FSSC strains with the same MLST sequence type, supporting the hypothesis the hypothesis that common environmental populations of fungi existed for these sharks and would suggest the longtime persistence of the two clonal strains within the environment, perhaps in holding pools and life support systems of the aquarium. This study highlights how molecular tools like MLST can be used to investigate outbreaks of microbiological disease. This work reinforces the need for regular controls of water quality to reduce microbiological contamination dueto waterborne microorganisms. [ABSTRACT FROM AUTHOR]

The Prussian blue reaction (PB) detects ferric iron in histological sections but the nuclear fast red (NFR) counterstain does not selectively stain the surrounding tissue and cellular features very well. The PB/NFR stain has the advantage of detecting iron located in tissue sections, but a significant disadvantage of having poorly differentiated tissue components, as compared to a routine hematoxylin and eosin (H&E). We developed a combination of Gomori’s Prussian blue/H&E staining method (PB/H&E), and modified the technique for best performance and clarity, then assessed the ability of this new combination stain to differentiate histological features of the tissue and identify iron. Serial sections from seven formalin fixed paraffin-embedded liver samples previously diagnosed with the presence of ferric iron were subjected to our routine H&E, routine PB/NFR and three trials of the new Prussian blue/H&E combination (PB/H&E). The technique that best differentiated the histological components of tissues containing iron was further tested on liver sections from a variety of species to verify consistency i.e. equivalence in staining intensity, concentration, brightness between sections of the same sample and quality i.e. coloration, vividness, recognizable differentiation of tissue components, improved staining. [ABSTRACT FROM AUTHOR]

In the last 30 years, several large-scale marine mammal mortality events have occurred, often in close association with highly polluted regions, leading to suspicions that contaminant-induced immunosuppression contributed to these epizootics. Some of these recent events also identified morbillivirus as a cause of or contributor to death. The role of contaminant exposures regarding morbillivirus mortality is still unclear. The results of this study aimed to address the potential for a mixture of polychlorinated biphenyls (PCBs), specifically Aroclor 1260, to alter harbor seal T-lymphocyte proliferation and to assess if exposure resulted in increased likelihood of phocine distemper virus (PDV USA 2006) to infect susceptible seals in an in vitro system. Exposure of peripheral blood mononuclear cells to Aroclor 1260 did not significantly alter lymphocyte proliferation (1, 5, 10, and 20 ppm). However, using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), lymphocytes exposed to 20 ppm Aroclor 1260 exhibited a significant decrease in PDV replication at day 7 and a significant increase at day 11 compared with unexposed control cells. Similar and significant differences were apparent on exposure to Aroclor 1260 in monocytes and supernatant. The results here indicate that in harbor seals, Aroclor 1260 exposure results in a decrease in virus early during infection and an increase during late infection. The consequences of this contaminant-induced infection pattern in a highly susceptible host could result in a greater potential for systemic infection with greater viral load, which could explain the correlative findings seen in wild populations exposed to a range of persistent contaminants that suffer from morbillivirus epizootics. [ABSTRACT FROM AUTHOR]

Differentiating salient histopathologic changes from normal anatomic features or tissue artifacts can be decidedly challenging, especially for the novice fish pathologist. As a consequence, findings of questionable accuracy may be reported inadvertently, and the potential negative impacts of publishing inaccurate histopathologic interpretations are not always fully appreciated. The objectives of this article are to illustrate a number of specific morphologic findings in commonly examined fish tissues (e.g., gills, liver, kidney, and gonads) that are frequently either misdiagnosed or underdiagnosed, and to address related issues involving the interpretation of histopathologic data. To enhance the utility of this article as a guide, photomicrographs of normal and abnormal specimens are presented. General recommendations for generating and publishing results from histopathology studies are additionally provided. It is hoped that the furnished information will be a useful resource for manuscript generation, by helping authors, reviewers, and readers to critically assess fish histopathologic data. [ABSTRACT FROM PUBLISHER]

Brucellosis has emerged as a disease of concern in marine mammals in the last 2 decades. Molecular detection techniques have the potential to address limitations of other methods for detecting infection with Brucella in these species. Presented herein is a real-time polymerase chain reaction (PCR) method targeting the Brucella genus–specific bcsp31 gene. The method also includes a target to a conserved region of the eukaryotic mitochondrial 16S ribosomal RNA gene to assess suitability of extracted DNA and a plasmid-based internal control to detect failure of PCR due to inhibition. This method was optimized and validated to detect Brucella spp. in multiple sample matrices, including fresh or frozen tissue, blood, and feces. The analytical limit of detection was low, with 95% amplification at 24 fg, or an estimated 7 bacterial genomic copies. When Brucella spp. were experimentally added to tissue or fecal homogenates, the assay detected an estimated 1–5 bacteria/µl. An experiment simulating tissue autolysis showed relative persistence of bacterial DNA compared to host mitochondrial DNA. When used to screen 1,658 field-collected marine mammal tissues in comparison to microbial culture, diagnostic sensitivity and specificity were 70.4% and 98.3%, respectively. In addition to amplification in fresh and frozen tissues, Brucella spp. were detected in feces and formalin-fixed, paraffin-embedded tissues from culture-positive animals. Results indicate the utility of this real-time PCR for the detection of Brucella spp. in marine species, which may have applications in surveillance or epidemiologic investigations. [ABSTRACT FROM PUBLISHER]

Fledgling cliff swallows were cared for at a rehabilitation facility when clinical signs of ocular disease, characterized by conjunctivitis, epiphora, and hyperaemia of palpebrae and nictitans, were recognized. Treatment consisted of topical and oral antibiotic therapy and one topical steroid administration. However, one cliff swallow died and three were killed due to poor therapeutic response. Conjunctival swabs were obtained ante-mortem from the three cliff swallows and were submitted for mycoplasma culture and molecular diagnostics. Heads of the three birds were fixed in 10% neutral buffered formalin and submitted for histopathologic examination of oculonasal tissues. Mycoplasma cultures and molecular evaluation of isolates identified Mycoplasma sturni, but not Mycoplasma gallisepticum, from each specimen. Histopathologic examination revealed lymphoplasmacytic conjunctivitis, rhinitis and infraorbital sinusitis with follicular lymphoid hyperplasia, epithelial hyperplasia, and protozoal stages compatible with Cryptosporidium spp. arranged in and along the apical surfaces of epithelial cells. Identification of concurrent M sturni and Cryptosporidium spp. infections in these cliff swallows demonstrates an alternative infectious condition that can produce gross and microscopic lesions comparable with those commonly observed in M gallisepticum infections of house finches and other passerine species. Conjunctivitis associated with M. sturni and Cryptosporidium spp. in cliff swallows may represent an emerging disease risk to a naïve, high-density and colonial species such as colony-nesting cliff swallows. [ABSTRACT FROM AUTHOR]

The article presents a study which determines Myxobolus albi in the cartilage of captive lumpfish or Cyclopterus lumpus from two public aquaria. It identifies Myxozoan cysts in the sclera, vertebrae, and branchial arch of eleven affected fishes. It notes that the identification of the myxozoan cysts is based on the spore morphology along with sequence comparison of 18S ribosomal DNA and polymerase chain reaction.

The ethical and logistical challenges inherent in experimental infections of wild-caught animals present a key limitation to the study of wildlife diseases. Here we characterize a potentially useful domestic model for a wildlife disease that has been of particular interest in recent decades; that is, infection of North American house finches (Carpodacus mexicanus) with Mycoplasma gallisepticum, more commonly known as a worldwide poultry pathogen. Seven domestic canaries (Serinus canaria domestica) were infected experimentally with M. gallisepticum alongside two wild-caught house finches (C. mexicanus) and the resulting clinical disease, pathogen load, serology and pathology were compared. Although rates of morbidity were higher in domestic canaries in response to M. gallisepticum infection, no significant differences were detected between the two species in the four measures of infection and disease studied. Our results support previous field and experimental studies that have documented universal susceptibility to M. gallisepticum infection in the avian family Fringillidae, which includes domestic canaries. Our results also indicate that domestic canaries may serve as a potentially useful model system for the experimental study of M. gallisepticum infection in songbirds. [ABSTRACT FROM AUTHOR]