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 <i>Coxiella burnetii</i>, <i>Cryptosporidium</i> species, <i>Enterocytozoon bieneusi</i>, and <i>Giardia duodenalis</i> 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 <i>C. burnetii</i>, <i>E. bieneusi</i>, and <i>G. duodenalis</i>, respectively. <i>Cryptosporidium</i> species were not detected in zoo animals. Sequence analysis of <i>C. burnetii</i> based on the <i>IS1111</i> gene revealed that one sequence obtained from a black goat (<i>Capra hircus</i>) exhibited 100 % homology with those reported from a rodent in the ROK. A zoonotic assemblage B (<i>n</i> = 1) of <i>G. duodenalis</i> was identified in Patagonian mara (<i>Dolichotis patagonum</i>). Of the 12 <i>E. bieneusi</i>-positive samples, eleven novel genotypes (KRZB1-4 and KRZS2-8) were identified in four Asian black bears (<i>Ursus thibetanus ussuricus</i>) and eight squirrel monkeys (<i>Saimiri sciureus</i>). 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 <i>C. burnetii</i>, <i>E. bieneusi</i>, and <i>G. duodenalis</i> 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.