Unexpectedly high diversity of parabasalids in captive snakes from China

Snakes are frequently kept as pets and are considered important reservoirs of pathogenic protists. Parabasalids, single-celled protists that parasitize a broad variety of hosts, are transmitted via the fecal-oral route. Some species pose zoonotic risks, endangering the health of both humans and animals. This study reports on the diversity and prevalence of parabasalids in six captive, non-native snake species from China. A total of 753 fecal samples were collected from non-native snakes across 26 provinces in China, including five open farms, 16 private breeders, and five pet shops. The nuclear ITS1-5.8S-ITS2 region was PCR amplified to investigate the infection rates of parabasalids and assess their kinships through phylogenetic analysis. The overall prevalence of parabasalids in the snake fecal samples was 13.28 % (100/753). While infection rates did not differ significantly among the snake species, significant differences were observed among the breeding environments. Snakes raised on farms had significantly higher infection rates (31.62 %, 43/136) compared to those from pet shops (13.24 %, 18/136) and private breeders (8.11 %, 39/481). In addition to Monocercomonas colubrorum, commonly found in reptiles, five other parabasalids were identified in snake fecal samples: Tritrichomonas musculus, Tritrichomonas muris, Trichomonas gallinae, Simplicimonas moskowitzi, and Trichomitus batrachorum. To our best knowledge, this is the first time these parabasalids have been detected in captive snakes from China. Our study revealed a diverse community of parabasalids in the intestines of snakes, including species typically parasitic in other animal groups such as mammals, birds, and amphibians. However, further investigations are required to determine whether these parabasalids have pathogenic effects on snakes or if they could be transmitted to other animals.