Publication

Abstract : BACKGROUND: Coliforms and other bacterial indicators are known to be present in Community water samples causing faecal pollution of water. There is also a growing body of evidence demonstrating that the aquatic environmental microbes are drug resistant. OBJECTIVE: The objective of this study was to evaluate the microbial quality of the water from tap, well and pond in urban households of Kochi, Kerala state. MATERIALS AND METHODS: A total of 100 water samples (46 from well water, 45 from tap water and 9 from lakes and ponds) were analysed by the multiple fermentation tube method to determine the presumptive coliform count or the most probable number (MPN) of coliforms, and the isolates were identified using standard procedures, followed by susceptibility testing. RESULTS: Eighty samples were positive for growth (76 grew coliforms, four samples grew non-pathogens). A total of 105 coliform isolates were grown in culture. The MPN numbers were noted to be >100 for over 50% of all the samples (n = 56), thus making the water unsatisfactory for drinking purposes. The highest number of organism isolated was Klebsiella pneumonia (n = 55), followed by Enterobacter spp (n = 34) and Escherichia coli (n = 16). Well water had the highest proportion of all three of these organisms. Up to 26%–40% resistance was seen to amoxicillin–clavulanic acid and 5.4%–5.8% of resistance was noted to third-generation cephalosporins, while two isolates were extended-spectrum beta-lactamase-producing Enterobacteriaceae (CTX-M and TEM types). CONCLUSION: The city municipal water authorities need to adopt more aggressive treatment/disinfection practices to combat high coliform contamination. The bacteriological quality of well water at the source needs to be monitored. Meanwhile, continued adequate home purification is suggested for drinking water. The city water does not pose a threat of antibiotic resistance for now. Environmental sampling should be given equal priority as clinical sampling in the coming days.