PCR en tiempo real para el estudio de la calidad microbiana en aguas de baño.

PARAJE MG, CODONY F, ARADOS B, FITIPALDI M Y MORATÓ J.

Congreso; XIII Congreso Argentino de Microbiología; 2008

XIII Congreso Argentino de Microbiología

The use of microbial cultures is the current strategy for monitoring of fecal pollution in coastal waters. However, in future, more sensitive, specific and rapid molecular quantitative techniques will probably make this a more direct and shorter procedure. This paper aims to assess whether, as it occurs in inland waters, the detection of Bacteroides spp. by real-time polymerase chain reaction (Q-PCR) in seawater can also be a useful tool to monitor fecal pollution and quality of bathing water.  A prospective study was performed on the metropolitan beaches of Catalonia to quantify the levels of Bacteroides spp. by Q-PCR, which contrasted with others obtained by culture: Escherichia coli and enterococci. Our results allow critical values to be established that can be useful in determining alert and alarm levels: samples with Bacteroides spp. levels lower than 4 logs/100 ml can to be considered with excellent quality; levels between 4 and 7 logs/100 ml have about an 80% probability of being of sufficient quality, and for this reason, the culture confirmation is necessary and samples with Bacteroides spp. levels higher than 7 logs/100 ml should be considered as polluted and with insufficient quality. These results indicated the feasibility of Q-PCR for Bacteroides detection as a fast alternative to culture for fecal pollution monitoring in sea water.