Laila Rashed

Citation:

Helmy, M. M. F., L. A. Rashed, and M. F. el-Garhy, "Molecular characterization of Cryptosporidium parvum isolates obtained from humans.", Journal of the Egyptian Society of Parasitology, vol. 34, issue 2, pp. 447-58, 2004 Aug.

Abstract:

Fifty stool specimens collected from severe diarrheic patients attending Misr University Hospital, were examined microscopically for protozoan parasites mainly, Cryptosporidium parvum. Stool examination revealed 22 cases with C. parvum, 8 with E. histolytica, 14 with G. intestinalis and six were parasite-free. The results were compared with the established nested PCR assay to detect DNA directly from stool specimens. After the extraction of DNA from stool, a 402-bp fragment of C. parvum DNA was amplified with two 26-mer outer primers. The amplified products, 194-bp DNA fragment, were used for a second run. This study indicated that the used primers are specific for DNA of C. parvum. The PCR detected a total of 28 positives; six of these cases were negative by AF stool examination, which eventually confirmed to be positive by several successive examinations of the stool and/or duodenal aspiration. Microscopy exhibited 78.5% sensitivity and 100% specificity compared to 100% specificity and sensitivity with PCR. Consequently, PCR is more sensitive and easier to interpret but required more hands-on time to perform and is more expensive than microscopy. However, PCR batch analysis reduces the cost considerably.

Notes:

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