Development of a loop-mediated isothermal amplification (LAMP) assay for the detection of Cyclospora cayetanensis

Many surveillance studies worldwide have reported the presence of Cyclospora cayetanensis oocysts, or DNA, on a variety of fruits and vegetables using either microscopy or PCR-based methods respectively. However, the true prevalence of C. cayetanensis on foods is still largely unknown due to a lack of efficient, accessible, and standardized detection methods. The present study describes, for the first time, a LAMP assay for the detection of C. cayetanensis DNA, which was found to be rapid, sensitive and specific. Using DNA extracted from a C. cayetanensis-positive stool specimen, LAMP products stained with SYBR Green I fluoresced down to at least a 1:10⁷ dilution. Colorimetric, pH-based visualization of the LAMP reaction with phenol red was found to be considerably less sensitive than with SYBR Green I. While further work is required, the LAMP assay described here may be useful in surveillance studies and outbreak investigations involving food and environmental samples, as well as in screening clinical specimens.