Identification of a novel Cryptosporidium genotype in pigs.

Over a 3-year period, a total of 646 fecal samples from pigs in 22 indoor and outdoor herds from Western Australia were screened for Cryptosporidium spp. by microscopy. Results revealed that 39 of 646 samples (6.03%) were positive for Cryptosporidium. Cryptosporidium was much more common in outdoor herds (17.2%) than in indoor herds (0.5%) and was more common in animals between the ages of 5 and 8 weeks (69.2%) than in younger animals (P < 0.0001). Molecular characterization of the positive samples at the 18S ribosomal DNA locus identified two distinct genotypes of Cryptosporidium: the previously identified pig genotype I and a novel pig genotype (pig genotype II), both of which warrant species status.