Antibiotic resistant bacteria in urban hospital wastewater : a preliminary report

Water, one of the most available natural bacterial habitat, can act as a major reservoir of antibiotic resistant bacteria (ARB). The role of waste water in the development and dissemination of antibiotic resistance is a major concern nowadays. Among the different types of urban waste water, hospital effluent is a primary source of antibiotic residues and antibiotic resistant pathogenic bacteria released from patient excreta. Thus hospital waste water can serve as a hotspot for generation of new resistant population both through vertical and horizontal gene transfer. Lack of proper management of hospital effluent can lead to dissemination of new ARB and associated antibiotic resistance genes to the environmental water sources. Here we have assessed the prevalence of antibiotic resistance among bacterial isolates, mainly fecal coliforms, from a hospital wastewater of Kolkata. Majority of the isolates were resistant to more than one antibiotic. Of them five isolates were found to be resistant to ciprofloxacin, ofloxacin, tetracycline, cefepime, cefotaxime and amoxicillin. Four of them were found to be plasmid bearing. Our study established the presence of plasmid bearing MDR strains in hospital effluent which may facilitate horizontal gene transfer. As traditional waste water treatment plants are not designed for the removal of ARB. So ARBs are entering the aquatic environment which is a major point of concern and needs constant monitoring.