Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2003
Publication Date: 5/1/2003
Citation: Santin-Duran, M., Trout, J.M., Fayer, R. 2003. Molecular epidemiology of zoonotic pathogens in dairy cattle and wildlife in eastern United States. BARC Poster Day. p.21 Interpretive Summary:
Technical Abstract: Dairy cattle were examined for the presence of zoonotic pathogens including Giardia, Microsporidia, Cryptosporidium, Listeria, Salmonella and Escherichia coli during a survey in Eastern United States. Fecal specimens were obtained from a total of 413 dairy calves from 15 farms in Vermont, New York, Pennsylvania, Maryland, Virginia, North Carolina, and Florida. Approximately 20-30 calves per farm were examined. In addition, fecal specimens from wildlife, including 22 coyotes, 82 white-tailed deer and 25 beaver from Pennsylvania, Maryland, and Massachusetts, respectively were also examined for protozoan pathogens. After removal of fecal debris by sieving and density gradient centrifugation, specimens were examined by microscopy, polymerase chain reaction (PCR), and gene sequencing analysis for the presence of protozoan pathogens. In summary, PCR using genetic primers for microsporidia revealed 70 positive calves. When specific PCR primers for Enterocytozoon bieneusi, the most frequently found microsporidian in human infections, were used to further examine these 70 positive specimens, 13 calves from 6 farms in 5 states were found positive, the first finding of E. bieneusi in cattle in North America. To define the role of animals in the transmission of giardiasis to humans, genotypes of Giardia isolates from cattle, coyotes, white-tailed deer and beaver were examined by direct sequencing of the PCR amplified TPI, 16S and ß-giardin genes. Most sequences obtained from bovine isolates aligned with the proposed "Hoofed livestock" genotype. However, a small number of the bovine isolates had an identical genetic sequence to Assemblage A, a common human genotype of Giardia. Moreover, one of the 82 white-tailed deer was found positive for Giardia by microscopy and PCR. Sequencing the PCR product of the ß-giardin and TPI genes revealed that this Giardia deer isolate also belonged to Assemblage A. Three of 25 beaver and one of the 22 coyotes were found positive for Giardia. The three beaver isolates belonged to Assemblage B, ordinarily found in humans, and the coyote isolate belonged to Assemblage C, ordinarily found in dogs. These findings suggest that deer, beaver and cattle could be a potential sources of infectious Giardia cysts for humans and other animals.