Physicochemical and microbial pollution of a reservoir in South India and role of bacteriophage treatment to curtail drug-resistant bacterial pollution in water

This study aimed to assess the physicochemical and microbiological pollution of water samples collected from Bellandur Lake, Bengaluru, South India, and to study the potential of bacteriophage treatment to curtail drug-resistant bacterial pathogens. The water samples were collected from the lake during four time periods in 2018-19. The physic-ochemical, heavy metal, and bacteriological analyzes were studied by standard protocol. The antibiotic sensitivity profiles of the major isolates from the water samples were assessed by disk diffusion assay, and two isolates that showed resistance to the highest percentage of the tested antibiotics were characterized by 16S rRNA gene sequencing. The lake water samples were treated with the isolated bacteriophages with controls, and the reduction of viable bacterial count in the treated water samples was estimated. This study revealed that the physicochemical, heavy metal and microbiological qualities of water samples were exceeded the permissible limits set by the standard authorities (p <= 0.05). When tested against 44 antibiotics, most of the isolates were found to be multidrug-resistant in which IS1 and IS2 showed resistance to the highest percentage of antibiotics, which were confirmed to be Pseudomonas aeruginosa strain DSCEbt-Bellandur01 and Pseudomonas sp. strain DSCEbt-Bellandur022, respectively. When the lake water samples were treated with the isolated bacteriophages, the study showed a 99.99 % reduction in the viable bacterial count (CFUL/ml) when compared to untreated water samples (p <= 0.05). Thus, the present study suggests that bacteriophage-based therapy is one of the promising approaches to treat various water bodies to reduce microbial pollution, and the approach can be used to curtail the emergence of multi-drug resistant pathogens in the water samples. (C) 2021 The Authors. Published by Elsevier B.V.

Automated summary

The study revealed that the physicochemical, heavy metal, and microbiological qualities of water samples from Bellandur Lake exceeded the permissible limits set by standard authorities. Most isolates were found to be multidrug-resistant against 44 antibiotics. Two isolates showing the highest resistance were identified through 16S rRNA gene sequencing. Treatment with isolated bacteriophages resulted in a 99.99% reduction in viable bacterial count in the lake water samples.