Effect of Sodium Hypochlorite on Biofilm-Producing Organisms Isolated from A Hospital Drinking Water

Objectives: Providing safe drinking water is essential for maintaining healthcare quality. The presence of biofilms in the water supply protects the organism from the antimicrobial effects of disinfectants leading to the formation of the MDR pathogen pool. Therefore, this study was taken up to determine the prevalence of biofilm formation in the bacteria isolated from the water system of a tertiary health care setup and study the effect of disinfectants on biofilms. Methods: Thirty-four drinking water samples were collected in sterile glass stopper bottles and transported to the lab. Standard bacteriological procedures identified isolates. Biofilm detection was carried out by the tissue culture plate (TCP) method. The effect of disinfectant (sodium hypochlorite) at various concentrations (0, 0.25, 0.5, 1, 2, and 4 %) on biofilm-producing organism were studied for 30 minutes and analyzed. Results: The culture positivity was 76.4% (26/34). Twenty samples showed monomicrobial growth, while only six samples showed polymicrobial growth of organisms. The most common organism isolated was Pseudomonas aeruginosa. Biofilm production was seen more in polymicrobial organisms, 91.66 % (11/12). A high level of resistance to chlorine compounds was seen in biofilm-producing microorganisms, especially those that produced robust biofilms. Conclusion: Resistance of biofilms against high levels of chlorine has implications for the delivery of safe drinking water. Drug resistance was seen in these organisms, which can be transmitted from drinking water sources to humans. Therefore, it is recommended that biofilm production should be evaluated in drinking water samples regularly..J Microbiol Infect Dis 2022; 12(4):17-24.