Compared with dairy and beef cattle, few data are available on the occurrence and distribution of Cryptosporidium species in yaks, which live in a very different habitat. In this study, 327 fecal specimens were collected from yaks in 4 counties in Qinghai Province of China and screened for Cryptosporidium by nested PCR analysis of the 18S rRNA gene. A total of 98 (30.0%) specimens were positive for Cryptosporidium. The occurrence of Cryptosporidium varied significantly among age groups; infection rates were 49.3% in weaned calves, 31.7% in yearlings, and 17.4% in adults. PCR products of all Cryptosporidium-positive specimens were successfully sequenced, with 56 specimens (57.1%) having C. bovis, 33 (33.7%) having C. ryanae, 2 (2.0%) having C. andersoni, 1 (1.0%) having C. ubiquitum, 1 (1.0%) having C. xiaoi, 2 (2.0%) having a novel genotype, and 3 (3.1%) having mixed infections of C. bovis and C. ryanae. There were some age-related differences in the distribution of Cryptosporidium species in post-weaned yaks examined. To our knowledge, this is the first report of C. andersoni, C. ubiquitum, C. xiaoi and a novel Cryptosporidium genotype in yaks.
Keywords: 18S rRNA gene; Cryptosporidium; Genotype; Nested PCR; Qinghai; Yaks.
Published by Elsevier B.V.