A comprehensive study on microbial contamination and physicochemical properties assessment of swimming pools

Abstract

Background

The present study aims to improve safety and quality assurance of swimming pools located in Sharkia governorate, Egypt. A total of 144 water samples were collected from eight pools. The water quality of the tested pools was assessed according to national swimming pool quality standards in terms of physiochemical and microbial characterization. Microbial contamination was assessed by the detection and enumeration of standard indicator organisms. 16S rDNA sequencing and phylogenetic analysis were utilized for further identification of most resistant bacterial isolate. Antimicrobial susceptibility to various natural potentially antimicrobial agents; including aqueous, alcoholic plant extracts and essential oils was conducted. Both MIC and MBC for tested natural antimicrobial agents were determined. Finally, field application of the most effective antimicrobial agents was carried out to highlight the cons and pros of their usage in field, in order to possess a broader scope of both theoretical and practical aspects of this study.

Results

In terms of physical analysis; 82.9% of tested samples were nonconformed to temperature standard, while 100% were conformed to color and odor. Regarding chemical analysis; 54.3% and 53.3% of samples were nonconformed to alkalinity and combined chlorine, respectively. Assessment of microbial contamination indicated the prevalence of Pseudomonas aeruginosa as a main contaminator of tested pool water (57.1%) followed by total coliforms which ranked second among detected microorganisms (52.4%). Upon performing antimicrobial susceptibility testing of plant extracts and essential oils, cinnamon hot water extract and essential oil showed narrowest MIC ranges. Upon testing various combinations between different tested antimicrobial agents, combination of cinnamon hot water extract and clove essential oil was identified as a promising synergetic combination against resistant isolates. In field application of the most effective antimicrobial compounds resulted in that compatibility markedly decreased for physical standards and slightly for chemical standards. However, microbial pollution was totally eliminated after treatment, which was considered and discussed within the context of the study.

Conclusion

This study targeted full assessment of pools water in Egypt, one of the most prominent findings of this study is prevalence of P. aeruginosa as the main resistant microorganism responsible for microbial pollution of pool water. Cinnamon hot water extract and clove essential oil were identified as the most effective natural antimicrobial agents used in the study. Field application of these antimicrobial agents was a significant step confirming the validity and credibility of current results highlighting the pros and cons of practical application of the suggested pool decontaminators.