An outbreak of toxoplasmosis in squirrel monkeys (Saimiri sciureus) in South Korea.

BACKGROUND: Toxoplasma gondii (T. gondii) is an intracellular protozoan parasite that can infect warm-blooded animals including humans. New World monkeys, such as squirrel monkeys, are more susceptible to T. gondii than Old World monkeys, often developing fatal disease. METHODS: In this study, seven of thirteen dead squirrel monkeys at Seoul Grand Park were tested to find the cause of sudden death. RESULTS: The main histopathological findings included interstitial pneumonia, necrotizing hepatitis, and splenitis. Periodic acid-Schiff staining of liver, spleen, and lung revealed cyst structures consistent with bradyzoites. Amplification of the B1 gene was detected in the liver or spleen of all monkeys. Additionally, a restriction fragment length polymorphism assay and phylogenetic analysis of the GRA6 amplicon revealed a consistent clustering with the type II strain of T. gondii. CONCLUSIONS: This study is the first report of T. gondii infection of squirrel monkeys in Korea, and the first report of type II T. gondii based on GRA6 analysis in Korea.

Antimicrobial resistance of commensal Escherichia coli and Enterococcus faecalis isolated from clinically healthy captive wild animals in Seoul zoo.

Despite the importance of antimicrobial resistance, only a few studies on the antimicrobial susceptibility on wild animals have been conducted owing to their population, accessibility, and characteristics. The objective of this study was to investigate the prevalence and characteristics of antimicrobial resistance pattern in Escherichia coli and Enterococcus faecalis isolated from the feces of captive wild animals in a zoo. A total of 61 captive wild animals were included in this study. E. coli was isolated from 58 of the 61 animals and E. faecalis was isolated from 29 animals. Among the isolated E. coli strains, ampicillin exhibited the highest resistance rate (27/29, 93.1%). Of these, 18 strains (18/29, 62%) showed multidrug resistance. The multilocus sequence typing (MLST) test showed that only ST155 was detected twice, while the other 16 strains showed different ST types. Among the E. faecalis strains, two were susceptible to all tested antimicrobials, whereas the remaining 27 strains showed resistance to one or more antimicrobials. Nine strains (9/27, 31%) showed multidrug resistance. Among the E. faecalis strains, resistance to quinupristin/dalfopristin was the highest at 96.3% (26/27), while the MLST of the nine MDR strains showed no predominant ST. Genetic association with human isolates or livestock products was observed in the isolated ST types. This indicates that antibiotic resistance in the zoo is responsible for the use of antibiotics and the partial horizontal transmission between humans and animals through feeding or contact.

Prevalence of asymptomatic infections of Chlamydia psittaci in psittacine birds in Korea.

Avian chlamydiosis is an acute or chronic bacterial disease of birds. Chlamydia psittaci is the primary agent of the disease. It is also an important zoonotic pathogen. Chlamydia avium and Chlamydia gallinacea have also been recognized as potential causative agents of the disease. Clinical signs of this disease can vary in severity. Asymptomatic infections of Chlamydia have commonly been reported in various birds worldwide. In this study, we investigated the distribution of Chlamydia species in healthy psittacine birds in Korea. A total of 263 samples (pharyngeal/cloacal swabs and faeces) were collected from psittacine birds of 26 species in five zoos, five parrot farms and seven parrot cafes between 2020 and 2021. Ages of these birds had a wide range (1 month to 30 years). During sample collection, no bird showed any clinical signs indicating diseases such as chlamydiosis. Samples were tested for the presence of Chlamydia spp. using real-time PCR assays. Chlamydia spp. were detected in 168 (63.9%) samples and C. psittaci was detected in 96 (36.5%) samples. However, C. avium and C. gallinacea were not detected. There were no significant differences in the prevalence of asymptomatic infections in birds among three types of housing environments. Regarding ompA genotypes, 87 C. psittaci-positive samples had genotype A based on sequence analysis (n = 28) and genotype-specific real-time PCR (n = 59). Other positive samples were untyped (n = 9). Overall findings showed high prevalence of asymptomatic infections of C. psittaci in psittacine birds in Korea, posing a significant hazard to public health.

Epidemiological and Molecular Approaches for a Fatal Feline Panleukopenia Virus Infection of Captive Siberian Tigers (Panthera tigris altaica) in the Republic of Korea.

Feline panleukopenia virus (FPV), a member of the species Protoparvovirus carnivoran1, is one of the most fatal pathogens of domestic and wild carnivores. The virus endemically infects domestic carnivores worldwide and its cross-species transmission threatens endangered wild carnivores, including Siberian tigers. In this study, a fatal FPV infection in endangered Siberian tigers was investigated to trace the origin of the virus and elucidate the reason behind FPV's infection of the vaccinated tigers. Our genetic characterization and phylogenetic analysis revealed that the virus detected in the infected tigers, designated as the KTPV-2305 strain, was closely related to FPV strains circulating in Korean cats, suggesting that it might have been transmitted from stray cats wandering around the zoo. Compared with the prototype FPV reference strains, the KTPV-2305 strain carried three distinct amino acid (aa) mutations in the VP2 protein sequence (I101T, I232V, and L562V) in this study. These three mutations are commonly found in most global FPV strains, including Korean strains, indicating that these mutations are common evolutionary characteristics of currently circulating global FPVs. The reason why the vaccinated tigers were infected with FPV was most likely the insufficient protective immunity of the affected tigress or vaccine failure triggered by the interference of maternal-derived antibodies in the affected tiger cubs. These findings suggest that improved vaccination guidelines are urgently needed to save the lives of wild carnivores from this fatal virus.

Whole-genome sequencing revealed different demographic histories among the Korean endemic hill pigeon (Columba rupestris), rock pigeon (Columba livia var. domestica) and oriental turtle dove (Streptopelia orientalis).

BACKGROUND: The family Columbidae is known as the pigeon family and contains approximately 351 species and 50 genera. Compared to the wealth of biological and genomic information on these Columba livia var. domesteca, information on Columba rupestris and Streptopelia orientalis has been rather limited. The C. rupestris population size is decreasing in Korea. OBJECTIVES: Whole-genome sequencing and identification of population characterization of each species based genome variation on 9 Korean pigeon and dove samples, namely, six hill pigeon (C. rupestris), one rock pigeon (C. livia var. domestica) and two oriental turtle dove (S. orientalis) samples. RESULTS: The whole genome of 9 genotypes were sequenced and mapped to the C. livia reference genome. Sequence alignment showed over 96% identity in C. rupestris and 94% identity in S. orientalis to the reference genome (GenBank assembly accession: GCA_001887795.1). Sequence variations, including single nucleotide polymorphisms (SNPs), insertions and deletions (InDels), and structural variations, revealed that intergenus (Columba vs. Streptopelia) variations were approximately four times higher than intragenus variations (C. livia vs. C. rupestris). Of the two Columba species, C. livia var. domestica is closer to S. orientalis than C. rupestris. Pairwise sequentially Markovian coalescent (PSMC) demographic history analysis revealed that the three species underwent a common population bottleneck between 105 and 120 Kya; since then, the effective population sizes of the rock pigeon and oriental turtle dove have increased. CONCLUSION: The effective population size of the hill pigeon, an Endangered Species of Grade II in Korea, has increased slowly from the second severe bottleneck that occurred approximately 0.5-1.4 × 104 years ago. Our results showed no relationship between copy number variation in the Norrie disease protein (NDP) regulatory regions and plumage color patterns. We report the first comparative analysis of three pigeon genomes.

Ovarian adenocarcinoma with metastases in a white rhinoceros.

A 36-y-old white rhinoceros (Ceratotherium simum) was presented with respiratory distress, sanguineous vaginal exudate, and anorexia. The clinical signs progressed over 40 d, and the rhinoceros died. Autopsy revealed significant ascites; a unilateral, 12.5-cm diameter, polypoid mass in the left ovary; a white, firm transmural mass in the right uterine horn; a white, friable mass in the lung; and white-to-tan, friable small nodules in the diaphragm. Histologic examination revealed similar neoplastic cells in the masses in all 4 locations, composed predominantly of epithelial cells proliferating in a tubulopapillary pattern with significant nuclear atypia and numerous atypical mitotic figures (18-42 per 2.37 mm2). Immunohistochemistry for CK7 (cytokeratin 7) and CK20 (cytokeratin 20) suggest that the ovarian, pulmonary, and diaphragmatic lesions were of ovarian origin and that the ovary was the primary tumor site.

Skin lesions associated with Demodex sp. in a llama (Lama glama). [corrected]

A 2.5-yr-old female llama (Lama glama) [corrected] with skin lesions was presented to the Animal Health Center in Seoul Grand Park Zoo, Korea. Mites of the genus Demodex in the absence of other mites or fungi were identified from the lesions by skin scrapings. The bodies were elongated, tapered, and 200-280 1m in length; four pairs of stumpy legs were present at the front of the body, and the striated opisthosoma constituted about half of the body length. Histologic examination of the skin biopsy showed typical folliculitis, hyperkeratinization of epidermis, and infiltration of inflammatory cells, consisting mainly of eosinophils and monocytes, in dermis. Although mites were undetected in the dilated hair follicles, the histologic features are consistent with descriptions of infestation by Demodex spp. This is believed to be the first case of skin lesions associated with Demodex sp. in L. glama. [corrected] Incidental findings were previously described in a different species of llamas (Lama glama) without any recognized symptoms. Treatment with amitraz (0.025%) eliminated the mites and resolved the clinical signs.

Traumatic pericarditis caused by a bamboo twig in captive waterbuck (Kobus ellipsiprymnus).

A 19-year-old captive male waterbuck (Kobus ellipsiprymnus) exhibited traumatic pericarditis at necropsy. The animal weighed 182 kg at necropsy and revealed no remarkable findings in external observation. Severe pericardial adhesions with fibrosis, hepato-diaphragmatic adhesions, straw-colored ascites and hepatosplenomegaly were observed upon examining the internal organs. Perforations made by a 12-cm-long sharp-ended bamboo twig were detected in the reticulum, diaphragm, pericardium, lung and liver. Trueperella pyogenes was identified in pericardial fluid. To our knowledge, this is the first documented case of traumatic reticulopericarditis caused by a sharp-ended bamboo twig in a captive waterbuck.