Prevalence and diversity of Cryptosporidium spp. in bamboo rats (Rhizomys sinensis) in South Central China

Cryptosporidium is one of the most prevalent zoonotic parasites and is responsible for the high burden of diarrheal disease across the globe. Rodents are globally overpopulated and are reservoirs for a variety of zoonotic pathogens. Bamboo rats are a common species of rodent that are bred for meat and wool in China. However, the genetic characterization of Cryptosporidium in bamboo rats in China is limited. The aim of this study was to determine the occurrence and genetic characterization of Cryptosporidium in bamboo rats from South Central China. From February2017to February 2018, 435 fecal samples were collected from bamboo rats in 13 farms located in 12 cities in South Central China. All fecal specimens were examined for Cryptosporidium by PCR, and through sequencing the partial small subunit of ribosomal DNA (SSU rRNA). C. parvum-positive samples were further subtyped through analysis of the 60-kDa glycoprotein (gp60) gene sequence. Meanwhile, all the new Cryptosporidium genotypes samples were selected for further sequence characterization at the 70-kDa heat shock protein (HSP70) gene and oocyst wall protein (COWP) gene as well as gp60 gene. Infection rates of 2.1% (9/435) were recorded for Cryptosporidium. Sequence analysis confirmed the presence of two Cryptosporidium species including C. parvum (n = 2), C. occultus (n = 1) and two new Cryptosporidium genotypes termed Cryptosporidium bamboo rat genotype I (n = 5) and Cryptosporidium bamboo rat genotype II (n = 1). Two subtypes of C. parvum were identified including IIdA15G1 and IIpA19 (one each).The discovery of zoonotic Cryptosporidium species/genotypes in bamboo rats suggests they have significant zoonotic potential and pose a threat to human health. The novel sequences discovered provide new insight into genotypic variations in Cryptosporidium in bamboo rats.