Infections with the zoonotic pathogen Yersinia (Y.) pseudotuberculosis are commonly causing clinical diseases and acute deaths in various mammal and bird species in zoos. These findings prompted us to conduct a targeted study that included animals of 18 German and 1 Swiss zoo that had been affected by the pathogen previously. This study provides a comprehensive overview of susceptible zoo animal species, clinical signs, therapies, antimicrobial resistance, pathogen monitoring, and prophylactic measures. In addition, fecal samples from species with documented infections and organ samples from deceased mammals and birds from two of the participating zoos, the urban zoo Wilhelma and the rural Opel Zoo, were examined for Y. pseudotuberculosis using both direct plating and enrichment. The overall prevalence of Y. pseudotuberculosis was 3.1% at the Opel Zoo and 1.3% at the Wilhelma. Fecal samples yielded positive results in 1.4% of the tested samples from the Opel Zoo but none from the Wilhelma. Among carcasses, 16.7% and 1.7% tested positive at the Opel Zoo and the Wilhelma, respectively (p = 0.006). Y. pseudotuberculosis was significantly more frequently isolated during the cold season (p = 0.002). Affected animals often died suddenly, displaying no or only non-specific clinical signs, but postmortem examinations revealed septicemia with multiple bacterial organ abscesses. Rodents, ruminants, primates, and Piciformes were the most commonly affected orders. Considering the zoonotic potential of Y. pseudotuberculosis, this research underscores the importance of investigations in zoos in accordance with the targets of the One Health approach.

Background: Mycobacteria of the Mycobacterium avium complex (MAC) pose a significant risk to zoological collections. Mycobacterium avium subspecies paratuberculosis (MAP) is a member of MAC and the causative agent of Johne’s disease. Despite many reports in animals kept in zoological gardens, systemic surveillance has rarely been reported. Methods: In this study, archived serum samples collected from animal species at the Wilhelma Zoological and Botanical Gardens in Stuttgart, Germany, were screened for the presence of antibodies against MAC and MAP. In addition, molecular investigations were performed on necropsy, fecal, and environmental samples. Results: In total, 30/381 serum samples of various mammalian species were positive for MAC antibodies in ELISA, while one sample of a reticulated giraffe (Giraffa camelopardalis reticulata) was positive in MAP-specific ELISA. Samples from many species were positive in pan-Mycobacterium real-time PCR (40/43 fecal samples, 27/43 environmental samples, and 31/90 necropsy samples). Surprisingly, no sample was positive in the MAP-specific molecular assays. However, two environmental samples from primate enclosures were positive in Mycobacterium avium subspecies hominissuis (MAH)-specific real-time PCR. Conclusions: The results reveal serological indications of MAC infections in the zoological collection. However, the presence of a MAP-contaminated environment by a high-shedding individual animal or MAP-infected population is unlikely.

Circular replicase-encoding single-stranded (CRESS) DNA viruses and other circular DNA agents are increasingly found in various samples and animals. A specific class of these agents—termed bovine meat and milk factors (BMMF)—has been supposed to act as a factor in indirect carcinogenesis in humans. Initial observations attributed the BMMF to European cattle breeds and foodstuffs produced thereof. In the present study, blood and fecal samples from African and Asian cattle were examined. BMMF molecules and genomoviruses were detected in all bovids under study. The majority (79%) of the 29 circular elements could be assigned to BMMF groups 1 and 2, whereas CRESS viruses of the family Genomoviridae accounted for the smaller part (21%). Two genomoviruses belong to the genus Gemykibivirus and one to the genus Gemykrogvirus. The remaining three might be considered as novel species within the genus Gemycircularvirus. The majority of all isolated molecules originated from fecal samples, whereas only three derived from blood. The results from this study expand our knowledge on the diversity and presence of circular DNA in different ruminants that serve for food production in many countries over the world.