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. Systems using chlorine gas also have the disadvantage of producing toxic disinfection by-products. To meet wastewater discharge standards, most wastewater treatment systems using chlorine gas must use a dechlorinating technology to remove residual chlorine prior to discharge, increasing the cost of treatment. Chlorine used in the sewage treatment plant could render or promote bacteria to become resistant to antibiotics. We investigated the presence and survival of antibiotic resistant bacteria in untreated hospital wastewaters and their survival after post sewage treatment. 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, Enterococcus faecium, Salmonella enteritidis and Enterococcus faecalis were 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.