Development and Application of an Interactive Neuropathology iBook as a Complementary Learning Tool for Veterinary Medicine Students.

Neuropathology is a challenging subject for most medical students. Delivering a gamified learning tool on this topic may motivate students and increase knowledge in the discipline. We report the development of such a tool in iBook format for the systemic pathology course delivered at Ross University School of Veterinary Medicine. Composed of 10 chapters (cases), this Neuropathology iBook (NP-iB) reviews basic clinical manifestations, neuropathology, and pathogenesis of common non-neoplastic conditions that cause brain disease in domestic animals. The goal of each chapter is to reach a diagnosis by interactively answering specific questions after reviewing relevant medical history, clinical pathology, and autopsy findings. Our hypothesis: the NP-iB improves students' ability to recognize these diseases, reflected in higher test scores. Using a post-test only control group design, data were gathered from all students enrolled in the course in two different semesters, fall 2017 and spring 2018 (n = 300). NP-iB users (n = 51, 17%) and usage time were identified by answers to multiple-choice questions embedded in the course assessments. Ninety percent of users had a positive perception although no statistically significant differences were found in median test scores between users and non-users. Statistically significant test score differences were found across how much time students used the NP-iB (p = .005); the lowest test score median values were found for neuropathology questions not related to the NP-iB, in students who used it for more than 3 hours. Unexpectedly, a low number of students preferred this digital learning tool, and its use did not improve their learning outcomes.

The prevalence of ultrasonographic abnormalities and histopathologic lesions is high in testes of yearling tropical hair rams.

Ultrasonography is commonly used to examine testes as part of a breeding soundness examination in sheep, especially, in cases of infertility or when gross testicular abnormalities are present. A descriptive, prospective, prevalence study was conducted to characterize the ultrasonographic, histopathologic, and spermatozoal morphology abnormalities present in a group of yearling tropic hair rams on the island of St. Kitts. Hyperechoic and shadowing abnormalities increased over a 6 month study period. Hyperechoic abnormalities were present in one or both testes in 89% (25/28) of yearling rams and 71% (40/56) of testes at castration. Shadowing abnormalities were present in one or both testes in 46% (13/28) of rams and 34% (19/56) of testes at castration. Shadowing was present more with moderate and severe hyperechoic abnormalities, with few testes in the mild category having any shadowing. As hyperechoic and shadowing abnormalities increased in severity, so did the severity of microscopic lesions including increased interstitial cellularity/fibrosis, interstitial mineralization, seminiferous tubules mineralization (hyperechoic only), and chronic lymphoplasmacytic orchitis. There were no spermatozoal morphologic abnormalities other than an increase in distal cytoplasmic droplets. The study findings detail a pathologic event in this group of yearling rams that has an unknown etiology. Potential causes may include scrotal insulation, trauma, infectious causes, immunity alterations, nutritional imbalances, and ingestion of a toxin. Further studies are required to elucidate the causative agent.

Multispecies Epidemiologic Surveillance Study after an Outbreak of Yersiniosis at an African Green Monkey Research Facility.

After an outbreak of Yersinia enterocolitica at a NHP research facility, we performed a multispecies investigation of the prevalence of Yersinia spp. in various mammals that resided or foraged on the grounds of the facility, to better understand the epizootiology of yersiniosis. Blood samples and fecal and rectal swabs were obtained from 105 captive African green monkeys (AGM), 12 feral cats, 2 dogs, 20 mice, 12 rats, and 3 mongooses. Total DNA extracted from swab suspensions served as template for the detection of Y. enterocolitica DNA by real-time PCR. Neither Y. enterocolitica organisms nor their DNA were detected from any of these samples. However, Western blotting revealed the presence of Yersinia antibodies in plasma. The AGM samples revealed a seroprevalence of 91% for Yersinia spp. and of 61% for Y. enterocolitica specifically. The AGM that were housed in cages where at least one fatality occurred during the outbreak (clinical group) had similar seroprevalence to that of AGM housed in unaffected cages (nonclinical group). However, the nonclinical group was older than the clinical group. In addition, 25%, 100%, 33%, 10%, and 10% of the sampled local cats, dogs, mongooses, rats, and mice, respectively, were seropositive. The high seroprevalence after this outbreak suggests that Y. enterocolitica was transmitted effectively through the captive AGM population and that age was an important risk factor for disease. Knowledge regarding local environmental sources of Y. enterocolitica and the possible role of wildlife in the maintenance of yersiniosis is necessary to prevent and manage this disease.

Nocardia cyriacigeorgica as the causative agent of mandibular osteomyelitis (lumpy jaw) in a cat.

An unusual case of osteomyelitis caused by Nocardia cyriacigeorgica infection and resulting in mandibular osteomyelitis and cellulitis (lumpy jaw) is described in a young cat. A 1-cm hard nodular mass was an incidental finding in the right mandible of a 14-month-old cat during routine physical examination. The lesion was fast growing, reaching up to 6 cm in its largest dimension over a 5-week period. A core biopsy of the affected mandible revealed foci of osteolysis, woven bone formation, and a few large clusters of filamentous bacteria surrounded by fine eosinophilic amorphous material bordered by neutrophils, plasma cells, macrophages, and occasional multinucleated giant cells. Pure cultures of acid-fast variable, Gram-positive filamentous bacteria were recovered on blood and chocolate agar plates at 48-hr postinoculation. On amplification and sequencing of the 16S ribosomal RNA and 65-kDa heat shock protein genes, the microorganisms were identified as N. cyriacigeorgica, within the actinomycetes.

An outbreak of Yersinia enterocolitica in a captive colony of African green monkeys (Chlorocebus aethiops sabaeus) in the Caribbean.

Yersinia enterocolitica is a zoonotic gram-negative pathogen that causes mesenteric lymphadenitis, terminal ileitis, acute gastroenteritis, and septicemia in domestic animals and primates. In 2012, 46 captive African green monkeys (Chlorocebus aethiops sabaeus) died during an outbreak of acutely fatal enteric disease over a period of 1 mo on the island of St Kitts. The affected monkeys presented with a history of mucohemorrhagic diarrhea, marked dehydration, and depression. Fifteen bacterial isolates were recovered from the spleen, liver, and lungs of affected monkeys. All isolates were identified as Y. enterocolitica by biochemical analysis and sequence comparison of the 16S rRNA gene. Phenotypic and genotypic analysis of the recovered isolates revealed homogeneity among the recovered bacteria, and all isolates gave a random amplified polymorphic DNA pattern resembling that given by genotype D under serotypes O:7,8. This outbreak represents the first isolation and characterization of Y. enterocolitica as the causative agent of fatal enteric disease in primates in the Caribbean.

Edwardsiella ictaluri as the causative agent of mortality in cultured Nile tilapia.

Edwardsiella ictaluri was consistently isolated from the spleens, livers, and head kidneys of diseased Nile tilapia Oreochromis niloticus from a farm experiencing mortality events in several culture ponds. We describe the first published outbreak of E. ictaluri-induced edwardsiellosis in Nile tilapia. Pure cultures of the isolated bacteria were characterized both biochemically and molecularly. Biochemical analysis was performed using the API-20E and RapID One systems, and antimicrobial susceptibility was determined by the broth microdilution method. Molecular analysis involved sequencing of the 16S rRNA gene, species-specific real-time polymerase chain reaction (PCR), and PCR-mediated genomic fingerprinting (rep-PCR). Pairwise sequence analysis of the 16S rRNA gene identified the case isolates to be a 100% match to E. ictaluri cultured from channel catfish in the southeastern United States. However, rep-PCR analysis identified the case isolates to be genetically different from representative strains isolated from disease outbreaks in cultured channel catfish in Mississippi. Infectivity challenges (intraperitoneal injection and immersion) demonstrated that a representative E. ictaluri strain isolated from tilapia was pathogenic to naive tilapia, reproducing clinical signs and mortality, thereby establishing Koch's postulates.

Molecular and immunohistochemical diagnosis of Francisella noatunensis subsp. orientalis from formalin-fixed, paraffin-embedded tissues.

Members of the genus Francisella (viz., F. noatunensis subsp. orientalis [Fno] and F. noatunensis subsp. noatunensis) have been described as causative agents of chronic granulomatous and pyogranulomatous lesions in wild and cultured fish species. In the present study, 68 archived formalin-fixed, paraffin-embedded (FFPE) tissues from several fish species, collected at different geographical locations from 2000 to 2011, were analyzed using a real-time polymerase chain reaction assay for the detection of the Fno intracellular growth loci C (iglC) gene and by immunohistochemistry for the demonstration of Fno antigens. The results revealed a high correlation between these 2 diagnostic techniques validating their use for the diagnosis of Fno infection in archived FFPE tissues and confirming the presence of Fno in fish species from the Cari y years of the present century.