Detection of Cyclospora cayetanensis using a quantitative real-time PCR assay

Cyclospora cayetanensis, a coccidian parasite, with a fecal-oral life cycle, has become recognized worldwide as an emerging human pathogen. Clinical manifestations include prolonged gastroenteritis. While most cases of infection with C cayetanensis in the United States have been associated with foodborne transmission, waterborne transmission has also been implicated. We report on the development and application of a real-time, quantitative polymerase chain reaction assay for the detection of C. cayetanensis oocysts, which is the first reported use of this technique for this organism. Both a species-specific primer set and dual fluorescent-labeled C cayetanensis hybridization probe were designed using the inherent genetic uniqueness of the 18S ribosomal gene sequence of C. cayetanensis. The real-time polymerase chain reaction assay has been optimized to specifically detect the DNA from as few as 1 oocyst of C. cayetanensis per 5 mul reaction volume. Published by Elsevier Science B.V.