关键词: 微小隐孢子虫, 聚合酶链反应

Abstract: AIM: To develop a sensitive and specific procedure based on the polymerase chain reaction (PCR) for detection and identification of Cryptosporidium parvum in fecal samples from infected humans and animals. METHOD: DNA extracted directly from fecal samples with C. parvum oocysts from humans and guinea pigs was served as the source of template for the PCR. A pair of oligonucleotide primers was synthesized and used to prime the amplification of a 452 bp target fragment specific for C. parvum. The PCR products were analyzed by electrophoresis in agarose gels stained with ethidium bromide. RESULTS: The target fragment was present in DNA extracts of fecal samples from humans and guinea pigs infected with C. parvum, but not in DNA from any other parasite, Candida albicans, E. coli, normal humans or guinea pigs tested. The level of detection by this method is shown to be about 100 times more sensitive than the currently used laboratory methods for diagnosis of cryptosporidiosis. CONCLUSION: The PCR assay developed is a relatively simple, highly sensitive and specific method for detection of C. parvum and could serve as a valuable tool for clinical diagnosis and epidemiological survey.