Submitted to: Parasitology Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2012
Publication Date: 9/12/2012
Publication URL: http://handle.nal.usda.gov/10113/56659
Citation: Fayer, R., Santin, M., Macarisin, D. 2012. Detection of concurrent infection of dairy cattle with Blastocystis, Cryptosporidium, Giardia, and Enterocytozoon by molecular and microscopic methods. Parasitology Research. 111(3):1349-1355. Interpretive Summary: Protozoan parasites in the genera Blastocystis, Cryptosporidium , Giardia, and Enterocytozoon cause abdominal distress, diarrhea, and dehydration. Blastocystis has been implicated as a cause of inflammatory bowel disorder. Encysted forms of each of these parasites are excreted in feces and can be waterborne, foodborne, or transmitted by direct contact from infected animals or humans. Each parasite has been identified by molecular methods in feces from many hosts including cattle and humans. The present study was conducted to determine if apparently healthy cattle with no signs of infection could be carriers and potential transmitters of any or all of these pathogens. In addition to DNA testing for the presence of all of these pathogens, a new microscopic test was employed to determine the presence of Blastocystis. Feces from 47 dairy cattle were examined; 9, 10, 24, and 17 specimens were found positive for Blastocystis, Cryptosporidium, Giardia, and Enterocytozoon, respectively, The new microscopic test was found to be as effective as DNA testing for the presence of Blastocystis. Overall, these findings indicate that apparently healthy, symptom-free cattle of all ages can be carriers (excretors) of one or multiple genera of these parasites so that without testing for their presence they can represent potential risk to public health. These finds will be usefull to other research scientists, and regulatory and public health agencies.
Technical Abstract: Of fecal specimens examined from 47 dairy cattle ranging in age from neonates to multiparous cows, 9, 10, 24, and 17 were positive for Blastocystis spp., Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi, respectively, as determined by PCR. Eight 3- to 5-month-old cattle were concurrently infected with 3 or 4 of these parasites. This is the first report to identify multiple concurrent infections with these four potentially zoonotic protist pathogens in cattle. None of the cattle exhibited signs of illness or effects of infection on growth and are regarded as healthy carriers. A commercially available immunofluorescence (IFA) microscopic test confirmed 6 of 7 available PCR-positive Blastocystis specimens and identified one IFA positive cow that was PCR negative.