USE OF PCR FOR THE EARLY DETECTION OF PATHOGENIC BACTERIA AND CYANOBACTERIA IN WATER SAMPLES FROM DIFFERENT URBAN WATER SOURCES (PORTO, PORTUGAL)

Faecal contamination and eutrophication of aquatic ecosystems cause serious problems of public health. The monitoring of microbiological contaminants in recreational water is important in order to avoid human health hazards. Nevertheless, due to the absence of specific legislation and to the difficulty and price of some techniques, fountains, urban lakes and non-designated beaches are not monitored. The PCR technique is very precise and gives fast results compared to the standard methods, being important the implementation of this method in water quality analysis. In this study, some bacterial species associated to faecal contamination were detected mainly in samples collected in the Douro River as well as fountains and lakes of the city. Cyanobacteria were detected in samples of the sea, lakes and in a fluvial beach. PCR techniques should be used as early warning techniques in sites where monitoring is not compulsory but may pose human health risk.