DIFFERENTIATION OF CRYPTOSPORIDIUM-PARVUM, CRYPTOSPORIDIUM-MURIS, ANDCRYPTOSPORIDIUM-BAILEYI BY PCR-RFLP ANALYSIS OF THE 18S RIBOSOMAL-RNAGENE

We have developed a combined polymerase chain reaction (PCR)-restricti on fragment length polymorphism (RFLP) assay for the detection and dif ferentiation of Cryptosporidium parvum, Cryptosporidium muris, and Cry ptosporidium baileyi. The assay utilizes PCR to amplify an approximate ly 1750 basepair product of the Cryptosporidium 18S rRNA gene. Followi ng double digestion with restriction endonucleases DraI and VspI, this PCR product yields DNA fragments that can be resolved electrophoretic ally into RFLP profiles that are distinct fbr C. parvum, C. muris, and C. baileyi. Previous PCR-restriction analyses could not simultaneousl y differentiate all three species. Future application of this techniqu e could include predicting the disease-causing potential of oocyst-con taminated environmental specimens and helping to determine the source of oocyst contamination.