Molecular characterization of Cryptosporidium spp. in native calves in Nigeria.

Most studies on the distribution of Cryptosporidium species in cattle were done with dairy breeds in industrialized nations. In this study, 65 fecal samples from randomly selected 12-24-week-old diarrheic calves in four white Fulani herds in southwestern Nigeria were screened for Cryptosporidium spp. using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis of the small subunit rRNA gene. Thirty-four (52.3%) of the samples were positive for Cryptosporidium. RFLP analysis of PCR products showed that 18 (27.7%) and five (7.7%) of the positive samples had Cryptosporidium bovis and Cryptosporidium ryanae, respectively, and 11 (16.9%) had mixed infections of the two species. The absence of C. parvum suggests that the age group of calves studied is not likely to be source of zoonotic infection to humans.