To increase the typeability of Cryptosporidium slide genotyping and improve the industry’s response to Cryptosporidium detections and the management of events.
To assess the state of the art, and identify candidate PCR-based assays for genotyping, a systematic literature review was undertaken, followed by a laboratory-based approach to assay design, evaluation and validation. The newly developed PCR-based assay was challenged step-wise to assess how pre-amplification processes affected the outcome, beginning with DNA extracted from purified oocysts through to that extracted from material removed from Cryptosporidium-positive water monitoring slides. To assess any improvements that were achieved, the new assay was compared with the existing genotyping
method used at the Cryptosporidium Reference Unit.
This project achieved its principal aim of designing, evaluating and validating a PCR-based assay for genotyping Cryptosporidium oocysts. Typeability varied greatly by submitting laboratory (most likely influenced by water source), but from some laboratories was up to 60 %. The performance of the assay was influenced by unpredictable, unknown factors in water monitoring slides.