Submitted to: Parasitology Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 27, 2003
Publication Date: May 9, 2003
Citation: Fayer, R., Santin, M., Trout, J.M. 2003. First detection of microsporidia in dairy calves in North America. Parasitology Research. 90:383-386.
Interpretive Summary: Fecal specimens were collected from 413 dairy calves on farms in Vermont, New York, Pennsylvania, Maryland, Virginia, North Carolina, and Florida to determine if cattle might be a source of an emerging pathogen in humans. Enterocytozoon bieneusi, the most frequently found microsporidian in human infections, was found in 13 calves from 6 farms in 5 states. We recently reported the presence of this organism in fur-bearing animals in wetlands adjacent to farms, including a high percentage of infection in raccoons that frequent farms while scavenging for food and could serve as a source of infection for cattle. The present study is the first to report E. bieneusi in cattle in North America.
Fecal specimens were obtained from a total of 413 dairy calves from farms in Vermont, New York, Pennsylvania, Maryland, Virginia, North Carolina, and Florida. After removal of fecal debris by sieving and density gradient centrifugation, specimens were examined by fluorescence microscopy, polymerase chain reaction (PCR), and gene sequencing for the presence of microsporidia. Microscopic examination revealed no spores. PCR using generic primers for microsporidia revealed 70 positive calves. PCR was then conducted using specific primers for Enterocytozoon bieneusi. PCR primers for E. bieneusi, the most frequently found microsporidian in human infections, revealed 13 positive calves from 6 farms in 5 states. Gene sequencing of the 13 E. bieneusi-positive specimens confirmed PCR results and indicated 96.8- 99.8% homology with E. bieneusi sequences in GenBank. This is the first report of E. bieneusi in cattle in North America.