DETECTION OF SALMONELLA SPP IN ESTUARINE WATERS BY USING BOTH THE CONVENTIONAL CULTURE

The presence of Salmonella spp in estuarine waters was investigated al ong the Patras harbor where pipes containing urban sewage terminate. S almonellae detection was performed by a conventional culture and a DNA probe technique (Gene-Trak Salmonella assay - Gene Trak Systems, Fram ingham). The Gene Trak colorimetric Salmonella assay uses the ribosoma l hybridization format followed by a colorimetric detection system. Sa lmonellae were detected in 3 out of 102 water samples (2.9%) when the culture tehnique was used and in 7 out of 102 samples (6.8%) when the DNA probe technique was used. All DNA probe positive samples were conf irmed by culture of the pre-enrichment Gram-negative broth and biochem ical tests according to the manufacturers instructions. Culture positi ve samples were confirmed by serological tests in the National Salmone lla-Shigella Center (National Institute of Public Health). The data de monstrate that the colorimetric hybridization method and the conventio nal culture method are equivalent in their ability to detect Salmonell ae in estuarine waters (chi(2) = 0.33 < 2.43). Both methods have the d isadvantage of giving false negative results. However, the Gene Trak a ssay saves time by lessening the response time in the case of a contam ination problem.