Investigation and detection of multiple antibiotic-resistant pathogenic bacteria in municipal wastewater of Dhaka city.

Background: Water pollution in densely populated urban areas, mainly from municipal wastewater, poses a significant threat. Pathogenic bacteria, such as Vibrio spp. and fecal coliform, endanger public health and the environment. Additionally, antibiotic-resistant bacteria in wastewater complicate treatment and heighten public health concerns. Methods: The study sampled municipal wastewater from ten Dhaka neighborhoods, selecting treatment plants, sewage outlets, and various collection points using meticulous techniques for representative samples. Bacteriological and biochemical analyses were conducted using standardized methods. Antimicrobial susceptibility testing (AST) was performed with the disk diffusion method against 13 widely used antibiotics. Results: All sampled areas exhibited positive results for Vibrio spp., fecal coliform, E. coli, and Salmonella spp. Varying bacterial concentrations were observed, with the highest concentration of TVC, total vibrio spp., and total fecal coliform, total E. coli count, and total Salmonella spp. were found in Uttara (1.9 × 10⁴ CFU/ml), Bangshal (1.8 × 10² CFU/ml), and Lalbag (2.1 × 10³ CFU/ml), Mirpur (3.70 × 10² CFU/ml), and Lalbag (6 × 10² CFU/ml) respectively. AST results revealed significant resistance among all bacterial species to various antibiotics. Specifically, Vibrio spp. showed 100% resistance to cefuroxime, fecal coliform exhibited 90% resistance to cephradine, E. coli demonstrated 60% resistance to cephradine, and Salmonella spp. displayed 90% resistance to ampicillin. Conclusion: The study highlights the existence of multiple antibiotic-resistant bacteria in Dhaka's wastewater. Addressing antibiotic resistance is essential to manage the risks of multiple antibiotic-resistant infections and maintain antibiotic effectiveness. These implications are critical for various stakeholders, including public health officials, policymakers, environmentalists, and urban planners. [ABSTRACT FROM AUTHOR]