Submitted to: International Society of Protistologists
Publication Type: Abstract Only
Publication Acceptance Date: 7/26/2007
Publication Date: 8/5/2007
Citation: Fayer, R., Santin, M., Trout, J.M. 2007. A 2 year longitudinal study of Cryptosporidium species and genotypes in dairy cattle. International Society of Protistologists. August 5-9, 2007, Providence, Rhode Island. p. 29.
Technical Abstract: In this, the first long term longitudinal study of cryptosporidiosis in cattle, 30 pure-bred Holstein female cattle on a dairy farm in Maryland were examined consecutively at weekly, biweekly, or monthly intervals from 1 week to 24 months of age for the presence of Cryptosporidium oocysts. Feces were sieved and subjected to CsCl2 density gradient centrifugation to concentrate oocysts. The presence of oocysts was determined by both immunofluorescence microscopy and PCR/gene sequence analysis of the 18S rRNA gene. Prevalence was higher by PCR than by IFA. All 30 calves shed Cryptosporidium oocysts at some time during the study. Of 990 fecal specimens collected, 172 (17%) contained oocysts. Differences in prevalence were found based on the age of the animals. A higher prevalence was detected in pre-weaned calves (less than 8 weeks of age) (38.3 %) than post-weaned calves (3-12 months of age) (18.2%) or heifers (12-24 months of age) (2.2%). The species/genotypes of Cryptosporidium that were identified included C. parvum, C. bovis, C. andersoni and Cryptosporidium deer-like genotype. The prevalence of each of these species and this genotype was age related: C. parvum was the most prevalent species in pre-weaned calves whereas C. bovis and Cryptosporidium deer-like genotype were more prevalent in post-weaned calves and heifers. Cryptosporidium parvum, the zoonotic species, was detected in all thirty pre-weaned calves, confirming previous cross-sectional studies from dairy farms.