Detection of Indicator Bacteria and Pathogens in Water by Polym Erase Chain Reaction (PCR) and Gene Probe Methods

Abstract

Sensitive methods for detecting coliform bacteria, and pathogenic bacteria (Salmonella and Shiqella) in environmental waters that do not require culturing of bacteria were developed by using the polymerase chain reaction (PCR) and gene probes. Cells were collected by filtration and DNA was released by freeze-thaw cycling. PCR amplification of region of lacZ gene was used as a target for detection of total coliform bacteria. A region of the lamB gene was the target for detection of Escherichia coli, Salmonella and Shigella. A region of the uid gene was used for detection of E. coli and Shigella. Biotin was incorporated during PCR amplification and the biotinylated DNA was detected by using membrane-bound poly-T-tailed capture probes. As little as 1 fg of total DNA and as few as 1 cell per 100 ml were detectable by the PCR-gene probe method.