Background Cryptosporidium is an apicomplexan zoonotic pathogen primary causing diarrhea in vertebrate hosts notably bovines and humans. Here, we characterized Cryptosporidium isolates by using the GP60 gene fragment of C. parvum to observe the dynamics of cryptosporidiosis transmission in dairy calves from two distant biogeographical regions of Chile (Metropolitan and Los Rios Regions). We collected 72 fecal samples from diarrheic calves screening the parasite carried out microscopy of an acid-fast staining smear and molecular characterization employing PCR to directly detect the Sanger GP60 C. parvum subtype and simultaneously in one selected sample the NGS profile of the GP60 same gene fragment to determine same and/or others Cryptosporidium subtypes
Results The IIaA15G2R1 subtype was present in the 100% of the bovine fecal samples studied from Los Rios Region. Along with this same subtype, another two were observed in the Metropolitan Region, IIaA17G2R1 and IIaA17G4R1. The NGS analysis of a single selected GP60 PCR amplicon of one selected sample of our study showed similarly the Sanger sequencing determined subtype, the IIaA17G4R1 in 90% of readable sequences observed. By using this approach another multiple low frequency IIa subtypes of C. parvum were observed confirming that in an infected host multiple subtypes of the parasite can be present.
Conclusions Cryptosporidiosis in these dairy farms calves in Chile is produced by C. parvum limited number of subtypes, being IIaA15G2R1 the most frequent. The IIa subtype family is considered prevalent in calves in South America. Subtypes IIaA17G2R1 and IIaA17G4R1 had been worldwide distribution. As all C. parvum subtypes observed in calves in Chile were isolated from diarrheic animals, so, it can be possible to relate its presence with the pathogenic role in the bovine host and with a potential digestive disease risk for humans.