Characteristics of Cryptosporidium transmission in pre - weaned dairy cattle in 1 Henan , China 2 3 Running title : Cryptosporidium spp . in dairy cattle

24 25 To estimate the prevalence and public health significance of cryptosporidiosis in 26 pre-weaned calves in China, 801 fecal samples from eight farms in seven areas in 27 Henan Province were examined for Cryptosporidium oocysts. The overall infection 28 rate of Cryptosporidium was 21.5%, with the farm in Xinxiang having the highest 29 prevalence (40%). No significant difference in infection rates was observed between 30 seasons. Cryptosporidium spp. were characterized by PCR-restriction fragment length 31 polymorphism (RFLP) analysis of the small subunit (SSU) rRNA gene and DNA 32 sequencing of the 60 kDa glycoprotein (gp60) gene. The SSU rRNA-based PCR 33 identified four Cryptosporidium species, including C. parvum (54/172), C. bovis 34 (65/172), C. ryanae (19/172), C. andersoni (12/172), and the occurrence of infections 35 with mixed species (22/172). The earliest detection of C. bovis was in calves of one 36 week of age, showing that the prepatent period was shorter than the previously stated 37 10-12 days. Infections with C. parvum peaked in summer, whereas C. bovis 38 dominated in autumn and winter. There was no apparent difference in the age of cattle 39 infected with either C. parvum or C. bovis. Sequencing analysis of the gp60 gene 40 showed all 67 C. parvum samples belonged to subtype IIdA19G1. These findings 41 suggested that the transmission of Cryptosporidium spp. in pre-weaned calves in 42 Henan, China appeared to be different from other areas both at genotype and subtype 43 levels. Further molecular epidemiologic studies (including samples from both calves 44 and humans) are needed to elucidate the transmission dynamics and public 45 significance of C. parvum in cattle in China. 46 on N ovem er 5, 2017 by gest ht://jcm .sm .rg/ D ow nladed fom