Molecular Detection of Cryptosporidium spp. in Coypu ( Myocastor coypus ) in China: Genetic Diversity and Zoonotic Potential

INTRODUCTION: Cryptosporidium is a globally important enteric pathogen commonly reported in rodents. The coypu (Myocastor coypus) is a large rodent adapted to semi-aquatic environments and is increasingly farmed as a fur-bearing animal. METHODS: To assess the occurrence and zoonotic potential of Cryptosporidium in farmed coypus across China, a total of 308 faecal samples were collected from seven cities and screened via PCR targeting the small subunit (SSU) rRNA gene. Positive samples were further analysed with nested PCR targeting the 60-kDa glycoprotein (gp60) gene. RESULTS: The overall infection rate was 8.8% (27/308), with city-level prevalence ranging from 0% (0/22) to 19.4% (19/98). Four distinct Cryptosporidium species/genotypes were identified: C. ubiquitum (n = 15), C. myocastoris (n = 5), C. parvum (n = 1), and the Cryptosporidium deer mouse genotype IV (n = 6). Further subtyping classified the C. parvum isolate as IIaA18G1R1 (n = 1) and revealed a novel C. ubiquitum subtype family, designated XIIk (n = 13). Phylogenetically, XIIk clustered with the zoonotic XIIa group. CONCLUSIONS: These results reveal the genetic diversity of Cryptosporidium in farmed coypus and highlight the need for further investigation of its zoonotic potential.