study of microbial contamination of the public swimming pools with escherichia coli and pseudomonas aeruginosa and their physical parameters in kermanshah, iran

Background and Objectives: Public swimming pools' waters are contaminated with a wide variety of pathogenic microorganisms and are a suitable environment for transmission of different diseases. The aim of this study was to investigate the microbial contamination of the public swimming pools' waters with Escherichia coli and Pseudomonas aeruginosa and to determine certain parameters such as residual chlorine, pH, temperature and turbidity in these pools' waters in Kermanshah. In this descriptive, cross-sectional study, 129 water samples were taken from all active pools in Kermanshah and their bacteriologic and physicochemical properties were investigated. Phosphatase alkaline (PHO-A) gene was used for molecular confirmation of E. coli isolates, and exotoxin A (ETA) gene in PCR was employed to confirm pathogenicity of P. aeruginosa isolates. Data were analyzed by chi-square and t-test. p<0.05 was considered to be level of significance. This study indicated that pH, turbidity, and residual chlorine were permissible in 72%, 22.5% and 85.3% of the samples. Of the total samples, 10.9% and 12.4% were contaminated with E. coli and P. aeruginosa, respectively. PCR results showed that 93.75% of P. aeruginosa isolates carried ETA gene and all isolates of E. coli carried PHO-A gene and were confirmed as E. coli. There was a significant, direct correlation between microbial contamination and level of free residual chlorine and temperature (p=0.001), but there was no statistically significant association between microbial contamination and level of turbidity and pH in the swimming pools' waters (p>0.05). Conclusion: The results of this study indicated that appropriate amount of residual chlorine caused reduction in microbial contamination in the public swimming pools' waters in Kermanshah.