Submitted to: International Society of Protistologists
Publication Type: Abstract only
Publication Acceptance Date: 5/18/2006
Publication Date: 6/20/2006
Citation: Feng, Y., Ortega, Y., He, G., Das, P., Zhang, X., Fayer, R., Gatei, W., Cama, V., Xiao, L. 2006. The wide geographic range of Cryptosporidium bovis and the deer-like genotype in bovines. International Society of Protistologists Workshop on Opportunistic Pathogens, June 20-24, 2006, Lisbon, Portugal. Interpretive Summary:
Technical Abstract: Recent studies in the United States reported that of preweaned dairy calves infected with Cryptosporidium ~85% were infected with zoonotic C. parvum whereas of postweaned calves infected with Cryptosporidium, only 1% were infected with C. parvum. Cryptosporidium bovis (syn. Cryptosporidium bovine genotype B) and the deer-like genotype were much more prevalent in postweaned and older calves. It is not clear whether the disproportionately high prevalence of C. parvum in preweaned calves is influenced by intensive animal production methods in the United States or if it is primarily a host age-related phenomenon. To determine whether the same infection pattern was present in other geographic areas Cryptosporidium specimens from pre- and post-weaned calves on two farms in China and India and farms in Georgia, USA were genotyped. The most frequently detected species in pre- and post-weaned calves in all three areas was C. bovis. In Georgia, the deer-like genotype was found frequently in pre- and post-weaned calves, one weaned calf had C. andersoni, two milking cows had C. bovis, and one milking cow had C. bovis and the deer-like genotype. A Cryptosporidium related to C. bovis was found in an adult yak in China. There were no differences in the small subunit rRNA gene sequences obtained from C. bovis or deer-like genotype among the three areas. One adult yak was infected with a Cryptosporidium similar to C. bovis, with only three nucleotide mutations; one of the nucleotide changes produced a new SspI restriction site. All the five Cryptosporidium spp. could be differentiated from each other by RFLP analysis with enzymes SspI and MboII. Thus, both C. bovis and the deer-like genotype are found in cattle in diverse geographic areas and may infect neonatal calves more often than previously suggested, and host adaptation of C. bovis might have occurred in yaks.