The limit of detection of the BioFire (R) FilmArray (R) gastrointestinal panel for the foodborne parasite Cyclospora cayetanensis

Cyclosporiasis is a foodborne diarrheal illness caused by the parasite Cyclospora cayetanensis. The BioFire & REG; FilmArray & REG; gastrointestinal (FilmArray GI) panel is a common method for diagnosing cyclosporiasis from clinical stool samples. The currently published limit of detection (LOD) of this panel is in genome equivalents; however, it is unclear how this relates to the number of C. cayetanensis oocysts in a clinical sample. In this study, we developed a technique to determine the LOD in terms of oocysts, using a cell sorter to sort 1 to 50 C. cayetanensis oocyst(s) previously purified from three human stool sources. We found the FilmArray GI panel detected samples with & GE;20 C. cayetanensis oocysts in 100% of replicates, with varying detection among samples with 1, 5, or 10 C. cayetanensis oocysts. This method provides a parasitologically relevant LOD that should enable comparison among C. cayetanensis detection techniques, including the FilmArray GI panel.Published by Elsevier Inc.

Automated summary

This study developed a new technique to determine the limit of detection (LOD) of C. cayetanensis oocysts using a cell sorter. The FilmArray GI panel detected samples with ≥20 oocysts in 100% of replicates, but showed varying detection for samples with 1, 5, or 10 oocysts. This method provides a parasitologically relevant LOD for comparing C. cayetanensis detection techniques.