Molecular detection and genetic characterization of Cryptosporidium in kindergarten children in Southern Xinjiang, China.

Cryptosporidium is a common cause of diarrhea in children globally. However, there is limited information on the prevalence and genetic characteristics of Cryptosporidium in children in Xinjiang, China. This study aimed to assess the genetic characteristics and epidemiological status of Cryptosporidium in kindergarten children in Southern Xinjiang, China. A total of 609 fecal samples were collected from kindergartners aged 2-6 years from 11 counties in Southern Xinjiang, China. We used nested PCR amplification of the partial SSU rDNA gene to screen samples for Cryptosporidium spp. Isolates containing Cryptosporidium parvum and C. hominis were further subtyped for a gene encoding a 60-kDa glycoprotein (gp60). We used MEGA7 to construct a phylogenetic tree to study the genetic relationship between the gp60 subtypes of these two species via the Maximum Likelihood method based on the Tamura-Nei model. Only 1.3% (8/609) of asymptomatic children were confirmed to be infected with Cryptosporidium, with a 2.0% (6/299) infection rate in boys and 0.6% (2/310) infection rate in girls. Three Cryptosporidium species were identified including C. felis (37.5%; 3/8), C. hominis (37.5%; 3/8), and C. parvum (25.0%; 2/8). Three C. hominis subtypes (IbA9G3, IdA14, and IfA12G1) and two C. parvum subtypes (IIdA14G1 and IIdA15G1) were also found. This study is the first to identify the presence of Cryptosporidium in kindergarten children in Southern Xinjiang, China. The presence of zoonotic C. parvum subtypes IIdA14G1 and IIdA15G1 indicates the possible cross-species transmission of Cryptosporidium between children and animals.