VINODKUMAR C.S., SRINIVASA H., BASAVARAJAPPA K.G., PUTTASWAMY C.T., VYSHAK A. AND SUNEETA KALASURAMATH
Abstract
The wide application of antimicrobial agents in clinical settings to treat infectious disease and improper sewage treatment is of great concern to public health as this can lead to the development and evolution of antibiotic resistant bacteria. This occurs as a result of the high selective pressure that antibiotics place on bacteria, resulting in the proliferation and subsequent dissemination of resistant bacteria in the community. We investigated the presence and survival of antibiotic resistant bacteria in untreated hospital wastewaters and their survival after post sewage treatment at three busy hospitals at Davangere, Karnataka. Physiochemical parameters showed high COD levels (552.8 to 714 mg/L), and BOD level observed ranged from 108.6 to 148.4 mg/L. The total heterotrophic bacterial counts, ranged from 2.8 * 105 to 7.3 *106CFU/mL, total coliform counts ranged from 0.9 * 103 to 2.4 * 103 MPN/100mL and faecal coliforms count ranged from 110 to 310. In untreated hospital wastewater high frequency of multidrug resistant bacteria like E.coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Acinetobacter baumannii, Citrobacter freundii, Proteus vulgaris, Staphylococcus aureus and Enterococcus faecium, Salmonella enteritidis and Enterococcus faecaliswere isolated. In treated hospital wastewater majority of the bacteria were re-isolated in lesser frequency indicating chlorine is less effective in removal of drug resistant bacteria. Bacteriophages were isolated against all the pathogens from the environment. When secondary treated hospital wastewater was challenged with the cocktail of bacteriophages, it resulted in 100 % removal of all the multidrug resistant bacteria from the hospital wastewater within 16 hours suggesting bacteriophages could be an alternative to chlorine in wastewater treatment plant and could easily be integrated into any sewage treatment technologies.