Genomic insights into anthropozoonotic tuberculosis in captive sun bears (Helarctos malayanus) and an Asiatic black bear (Ursus thibetanus) in Cambodia.

Contact between humans and wildlife presents a risk for both zoonotic and anthropozoonotic disease transmission. In this study we report the detection of human strains of Mycobacterium tuberculosis in sun bears and an Asiatic black bear in a wildlife rescue centre in Cambodia, confirming for the first time the susceptibility of these bear species to tuberculosis when in close contact with humans. After genotyping revealed two different strains of M. tuberculosis from cases occurring between 2009 and 2019, 100 isolates from 30 sun bear cases, a single Asiatic black bear case, and a human case were subjected to whole genome sequencing. We combined single nucleotide polymorphism analysis and exploration of mixed base calls with epidemiological data to indicate the evolution of each outbreak. Our results confirmed two concurrent yet separate tuberculosis outbreaks and established a likely transmission route in one outbreak where the human case acted as an intermediatory between bear cases. In both outbreaks, we observed high rates of transmission and progression to active disease, suggesting that sun bears are highly susceptible to tuberculosis if exposed under these conditions. Overall, our findings highlight the risk of bi-directional transmission of tuberculosis between humans and captive bears in high human tuberculosis burden regions, with implied considerations for veterinary and public health. We also demonstrate the use of standard genomic approaches to better understand disease outbreaks in captive wildlife settings and to inform control and prevention measures.

Epidemiology and pathological progression of erythematous lip lesions in captive sun bears (Helarctos malayanus).

This study investigates the occurrence of erythematous lip lesions in a captive sun bear population in Cambodia, including the progression of cheilitis to squamous cell carcinoma, and the presence of Ursid gammaherpesvirus 1. Visual assessment conducted in 2015 and 2016 recorded the prevalence and severity of lesions. Opportunistic sampling for disease testing was conducted on a subset of 39 sun bears, with histopathological examination of lip and tongue biopsies and PCR testing of oral swabs and tissue biopsies collected during health examinations. Lip lesions were similarly prevalent in 2015 (66.0%) and 2016 (68.3%). Degradation of lip lesion severity was seen between 2015 and 2016, and the odds of having lip lesions, having more severe lip lesions, and having lip lesion degradation over time, all increased with age. Cheilitis was found in all lip lesion biopsies, with histological confirmation of squamous cell carcinoma in 64.5% of cases. Single biopsies frequently showed progression from dysplasia to neoplasia. Eighteen of 31 sun bears (58.1%) had at least one sample positive for Ursid gammaherpesvirus 1. The virus was detected in sun bears with and without lip lesions, however due to case selection being strongly biased towards those showing lip lesions it was not possible to test for association between Ursid gammaherpesvirus 1 and lip squamous cell carcinoma. Given gammaherpesviruses can play a role in cancer development under certain conditions in other species, we believe further investigation into Ursid gammaherpesvirus 1 as one of a number of possible co-factors in the progression of lip lesions to squamous cell carcinoma is warranted. This study highlights the progressively neoplastic nature of this lip lesion syndrome in sun bears which has consequences for captive and re-release management. Similarly, the detection of Ursid gammaherpesvirus 1 should be considered in pre-release risk analyses, at least until data is available on the prevalence of the virus in wild sun bears.

KNEMIDOKOPTINID (EPIDERMOPTIDAE: KNEMIDOKOPTINAE) MITE INFESTATION IN WILD RED-CROWNED PARAKEETS (CYANORAMPHUS NOVAEZELANDIAE): CORRELATIONS BETWEEN MACROSCOPIC AND MICROSCOPIC FINDINGS.

During a study on health and disease in Red-crowned Parakeets (Cyanoramphus novaezelandiae) on Tiritiri Matangi Island and Little Barrier Island (Hauturu-o-Toi) in New Zealand between 2011 and 2013, an outbreak of feather loss prompted the collection of skin biopsies (n = 135) under anesthesia from the head of captured birds. A subset of samples (n = 7) was frozen to obtain whole specimens for identification of ectoparasites. Mites (range 1-11) were observed in 79/135 (58.5%) skin biopsies, whereas feather loss was only found in 47/142 (33.1%) birds captured during the sampling period. Compact orthokeratotic hyperkeratosis and acanthosis were found in association with mites. Procnemidocoptes janssensi (Acari: Epidermoptidae, Knemidokoptinae) was identified from whole mites obtained from skin biopsies. We describe the presence, pathology, and stages of infestation for knemidokoptinid mange in a wild parrot population in New Zealand. Given the clinical and pathologic changes observed and poor knowledge of the parasite's New Zealand host and geographic distribution, further work is recommended for this and sympatric parrots, to understand relationships between the host, parasite, environment, and expression of disease. Results from this study reinforce the value of including biopsy samples for the investigation of skin disease in wild birds, particularly to link etiologic agents with pathologic changes.

Identification of novel Babesia and Theileria genotypes in the endangered marsupials, the woylie (Bettongia penicillata ogilbyi) and boodie (Bettongia lesueur).

Piroplasms, which include the genera Theileria and Babesia, are blood-borne parasites transmitted mainly by tick vectors. Relatively little is known about their prevalence and clinical impact in Australian marsupials. In the present study the occurrence and molecular phylogeny of these parasites were studied in both wild and captive marsupials from Western Australia (WA) and Queensland (QLD). Blood samples were screened by microscopy and molecular methods, using PCR and DNA sequencing of the 18S ribosomal RNA gene (18S rDNA). Overall, 7.1% of the blood samples (8/113) were positive for piroplasm 18S rDNA. Theileria and Babesia rDNA was detected in 0.9% (1/113) and 6.2% (7/113) of the animals, respectively. The single Theileria positive was identified in one of three boodies (Bettongia lesueur) screened from a wildlife rehabilitation centre in WA, while all seven Babesia positives were detected in WA in wild captured woylies (Bettongia penicillata ogilbyi). Small intraerythrocytic inclusions were observed in blood films made from six of these individuals. This is the first report of a Babesia sp. in woylies, and Theileria sp. in boodies. Phylogenetic analysis indicated that the woylie-derived Babesia was genetically distinct and most closely related to Babesia occultans, the causative agent of a benign form of cattle babesiosis (genetic similarity 98.4%). The Theileria identified was most closely related to the marsupial-derived species Theileria penicillata from the woylie, Theileria brachyuri from the quokka (Setonix brachyurus), and Theileria sp. from the long-nosed potoroo (Potorous tridactylus).

Identification of novel trypanosome genotypes in native Australian marsupials.

In the present study, the occurrence and molecular phylogeny of trypanosome parasites were studied in both wild and captive marsupials from Western Australia and Queensland. Blood samples were screened by PCR at the 18S rDNA locus, and the glycosomal glyceraldehyde phosphate dehydrogenase gene. Overall, 5.3% of the blood samples were positive at the 18S rDNA locus. All positives belonged to wild-captured Western Australian individuals, where trypanosome-specific DNA was detected in 9.8% of the screened samples from wild marsupials, in common brushtail possums, and woylies. The detection rate of trypanosome DNA in these two host species was 12.5% and 20%, respectively. Phylogenetic analyses based on two loci, indicated that the possum-derived trypanosome isolates were genetically distinct, and most closely related to the Australian marsupial trypanosomes H25 from a kangaroo, and BRA2 from a bush rat. This is the first study to genetically characterise trypanosome isolates from possums. The analysis of the woylie-derived isolates demonstrated that this marsupial host can harbour multiple genotypes within the same geographical location and furthermore multiple genotypes within the same host, indicative of mixed infections. All the woylie-derived genotypes grouped with trypanosomes found in Australian marsupials, suggesting that they are more likely to belong to an endemic or Australasian trypanosome species. This is the first study to genetically characterise trypanosome isolates from possums (Trichosurus vulpecula). Although the clinical significance of these infections is currently unknown, the identification of these novel sequences may support future investigations on transmission, threats to endangered wildlife, and evolutionary history of the genus Trypanosoma.

Rapidly growing mass on the tricuspid valve in an elderly woman: a diagnostic dilemma.

BACKGROUND: Papillary fibroelastoma is a rare, benign cardiac valve tumour, which can mimic conditions such as atrial myxoma and infective endocarditis. CASE REPORT: An elderly lady presented with shortness of breath and chest pain and a mass on echocardiogram, which was confirmed on surgical excision to be a papillary fibroelastoma. DISCUSSION: There were aspects of this lady's case that caused confusion over the diagnosis and showed how rare conditions can cause diagnostic problems.