Full Description

Determining the source of Cryptosporidium parvum contamination in source water is critical to preventing future waterborne outbreaks of cryptosporidiosis. Therefore, an important issue which must be addressed is whether oocysts in drinking water supplies are the result of human, agricultural, or feral contamination. Consequently, the water industry needs methods that can discriminate between different isolates of C. parvum. Molecular fingerprinting methods were evaluated to determine whether isolates can be characterized according to the animal host from which they were derived. In addition, the reproducibility and reliability of these fingerprinting methods were assessed. Also, a stragegy for applying these techniques to water samples as part of a monitoring program is presented. Over 200 fecal samples from various animal hosts and 25 water concentrates were characterized using the polymerase chain reaction (PCR) targeting three polymorphic markers: the B-tubulin gene, a thrombospondin related adhesive protein gene, and a gene encoding an oocyst wall protein. The results demonstrated that PCR-based fingerprinting methods can be used to differentiate between at least three types of isolates based on animal host. Optimization of methods and thorough evaluations and validation of genetic typing schemes is necessary, along with an understanding of the inherent errors and limitations of the techniques. Nevertheless, PCR-based molecular characterization methods provide the water industry with a powerful tool which will be useful in determining the sources of C. parvum contamination. Includes 16 references, tables, figure.

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Edition: Vol. - No. Published: 08/29/1999File Size: 1 file , 70 KB