Epidemiology and Molecular Characterization of Zoonotic Gastrointestinal Protozoal Infection in Zoo Animals in China

Zoo animals, harboring zoonotic gastrointestinal protozoal diseases, pose potential hazards to the safety of visitors and animal keepers. This study involved the collection and examination of 400 fresh fecal samples from 68 animal species, obtained from five zoos. The aim of this study was to determine the occurrence, genetic characteristics, and zoonotic potential of common gastrointestinal protists. PCR or nested PCR analysis was conducted on these samples to detect four specific parasites: <i>Cryptosporidium</i> spp., <i>Giardia duodenalis</i>, <i>Enterocytozoon bieneusi</i>, and <i>Blastocystis</i> spp. The overall prevalence of <i>Cryptosporidium spp</i> was 0.5% (2/400), <i>G. duodenalis</i> was 6.0% (24/400), <i>Blastocystis</i> spp. was 24.5% (98/400), and <i>E. bieneusi</i> was 13.5% (54/400). <i>G. duodenalis</i>, <i>Blastocystis</i> spp., and <i>E. bieneusi</i> were detected in all of the zoos, exhibiting various zoonotic genotypes or subtypes. <i>G. duodenalis</i>-positive samples exhibited three assemblages (D, E, and B). <i>Blastocystis</i> spp. subtypes (ST1, ST2, ST3, ST4, ST5, ST8, ST10, ST13, and ST14) and one unknown subtype (ST) were identified. A total of 12 genotypes of <i>E. bieneusi</i> were identified, including SC02, BEB6, Type IV, pigEBITS 7, Peru8, PtEb IX, D, CD9, EbpC, SCBB1, CM4, and CM7. Moreover, significant differences in the positive rates among different zoos were observed (<i>p</i> < 0.01). The findings indicate that zoo animals in China are affected by a range of intestinal protozoa infections. Emphasizing molecular identification for specific parasite species or genotypes is crucial for a better understanding of the zoonotic risk. Preventing and controlling parasitic diseases in zoos is not only vital for zoo protection and management but also holds significant public health implications.