Detection and Differentiation of Cryptosporidium Oocysts in Water by PCR-RFLP
Consumption of contaminated water has been implicated as a major source of Cryptosporidium infection in various outbreak investigations and case control studies. Surveys conducted in various regions of the United States demonstrated the presence of Cryptosporidium oocysts in 67–100% of wastewaters, 24–100% of surface waters, and 17–26.8% of drinking waters (1, 2, 3, 4). The identity and human infective potential of these waterborne oocysts are not known, although it is likely that not all oocysts are from human-infecting Cryptosporidium species. Likewise, the source of the oocyst contamination is also not fully clear. Farm animals and human sewage discharge are generally considered to be the major sources of surface water contamination with C. parvum (5). Because Cryptosporidium infection is common in wildlife, it is conceivable that wildlife can also be a source for Cryptosporidium oocysts in waters (4). The presence of host-adapted Cryptosporidium spp. and genotypes makes it possible to develop molecular tools to assess the human infection potential and source of Cryptosporidium oocysts in water.
KeywordsCryptosporidium Oocyst Cryptosporidium Infection Polymerase Chain Reaction Inhibitor Cryptosporidium Species Polymerase Chain Reaction Tube
- 13.Kimbell, L. M., Miller, D. L., Chavez, W., and Altman, N. (1999) Molecular analysis of the 18S rRNA gene of Cryptosporidium serpentis in a wild-caught corn snake (Elaphe guttata guttata) and a five-species restriction fragment length polymorphism-based assay that can additionally discern C. parvum from C. wrairi. Appl. Environ. Microbiol. 65, 5345–5349.PubMedGoogle Scholar
- 19.Morgan, U. M., Deplazes, P., Forbes, D. A., Spano, F., Hertzberg, H., Sargent, K. D., Elliot, A., and Thompson, R. C. A. (1999) Sequence and PCR-RFLP analysis of the internal transcribed spacers of the rDNA repeat unit in isolates of Cryptosporidium from different hosts. Parasitology 118, 49–58.PubMedCrossRefGoogle Scholar
- 29.Di Giovanni, G. D., Hashemi, F. H., Shaw, N. J., Abrams, F. A., LeChevallier, M. W., and Abbaszadegan, M. (1999) Detection of infectious Cryptosporidium parvum oocysts in surface and filter backwash water samples by immunomagnetic separation and integrated cell culture-PCR. Appl. Environ. Microbiol. 65, 3427–3432.PubMedGoogle Scholar
- 36.Rochelle, P. A., Ferguson, D. M., Handojo, T. J., De Leon, R., Stewart, M. H., and Wolfe, R. L. (1997) An assay combining cell culture with reverse transcriptase PCR to detect and determine the infectivity of waterborne Cryptosporidium parvum. Appl. Environ. Microbiol. 63, 2029–2037.PubMedGoogle Scholar