Occurrence of Pseudomonas aeruginosain drinking water - DOI: 10.4025/actascibiolsci.v28i1.1053

Abstract

A total of 413 samples of drinking water, taken from principal and secondary water systems in the municipality of Bandeirantes, state of Paraná, southern Brazil, were analyzed through membrane filtration for P. aeruginosa and on Plate Count agar for heterotrophic bacteria. Total and fecal coliforms were determined by multiple dilution tube methods. Turbidity, pH, chlorine, fluoride, alkalinity, color, dissolved oxygen, hardness and organic matter were also measured. Of the 413 samples examined, 10.41% were contaminated by P. aeruginosa, including 23,53% of the water from secondary water system, 8,56% of the water from principal water system. No coliform was found in any of the samples. One sample counted above the maximum heterotrophic bacteria level permitted. P. aeruginosa isolated from the water samples were tested for chlorine sensitivity and survived up to three times the minimum chlorine concentration used. It is desirable that Pseudomonas enumeration be performed periodically, in addition to data routinely collected by most water supply systems