Identification of zoonotic pathogens in zoo animals in the Republic of Korea

Zoo animals may harbor various zoonotic pathogens and may pose a potential risk to humans through close contact. Nevertheless, epidemiological data on zoonotic diseases are scarce. Here, we conducted an epidemiological investigation and genetic characterization of Coxiella burnetii, Cryptosporidium species, Enterocytozoon bieneusi, and Giardia duodenalis in zoo animals in the Republic of Korea (ROK) and evaluated their zoonotic potential. A total of 261 fecal samples were collected from 27 animal species at one zoo between July 2022 and December 2023. Out of the four pathogens tested, one (0.4 %), twelve (4.5 %), and one (0.4 %) animals were found positive for C. burnetii, E. bieneusi, and G. duodenalis, respectively. Cryptosporidium species were not detected in zoo animals. Sequence analysis of C. burnetii based on the IS1111 gene revealed that one sequence obtained from a black goat (Capra hircus) exhibited 100 % homology with those reported from a rodent in the ROK. A zoonotic assemblage B (n = 1) of G. duodenalis was identified in Patagonian mara (Dolichotis patagonum). Of the 12 E. bieneusi-positive samples, eleven novel genotypes (KRZB1-4 and KRZS2-8) were identified in four Asian black bears (Ursus thibetanus ussuricus) and eight squirrel monkeys (Saimiri sciureus). Phylogenetically, ten novel genotypes belonged to group 1 with zoonotic potential, and one novel genotype, KRZB4, was assigned to group 10. This study showed that C. burnetii, E. bieneusi, and G. duodenalis infections were identified in zoo animals in the ROK. Our findings highlight the need for ongoing monitoring and effective strategies to prevent and control these zoonotic pathogens.