Evaluation of survival patterns and cellular injury of Pseudomonas aeruginosa in different bottled waters stored under various conditions

Pseudomonas aeraginosa cells were inoculated into different waters and samp led after different periods of starvation in order to evaluate the influenc es of storage under daylight or dark conditions, the presence or absence of the autochthonous flora, the chemical composition of the water and the sto rage temperature, on survival. Survival was investigated by plate counts on selective and nonselective agar media. Light, low temperature (4C) and pre sence of the autochthonous flora negatively influenced the survival of P. a eruginosa during starvation in water. Higher survival rates were observed i n waters with high mineral content. During starvation, cells developed sens itivity to the selective medium demonstrating that research is needed in th e development of new media, or improvement in the existing ones, for the en umeration of P. aeruginosa in water. Current selective media/methodologies for detecting P. aeruginosa in mineral waters may seriously underestimate t he levels of or presence of this organism which might represent, in some ca ses, a hazard to the public health.