The Evaluating Chlorine Dosage for Effective Disinfection and Antimicrobial Resistance Profiling in Drinking Water Under Climate Change Influences

Introduction/Importance of Study:Climate patterns, such as heavy rainfall and flooding, can introduce contaminants into water sources, leading to increased microbial loads. Chlorine disinfection is essential in mitigating these risks by effectively destroying pathogens.Novelty Statement:This study investigates the effectiveness of different chlorine disinfectant dosages in eliminating disease-causing microorganisms and assessing antimicrobial resistance (AMR) in drinking water.Material and Method:A biofilm annular reactor (BAR) setup was utilized to assess the impact of chlorination on pathogenic microorganisms. Three chlorine doses were tested: 0.5 mg/L, 1 mg/L, and 1.5 mg/L. Samples were collected and analyzed for AMR. Five selective bacterial strains were isolated using the membrane filtration method, and antibiotic sensitivity was evaluated using the standardized Kirby-Bauer disc diffusion test.Result and Discussion:The study isolated five gram-negative bacteria on selective agar: E. coli, Salmonella, Shigella, Pseudomonas, and Vibrio cholerae. Their antimicrobial resistance to five antibiotics (amoxicillin, AML 5 μg; ampicillin, AMP 10 μg; Azithromycin, AZM 15 μg; ceftriaxone, CRO 30 μg; and imipenem, IPM 10 μg) was tested on Mueller-Hinton (MH) media. Azithromycin demonstrated the highest activity against all isolates. The optimal chlorine concentration for removing these bacteria from water was 1.5 mg/L, due to chlorine’s high reactivity.Concluding Remarks:The study concludes that a chlorine concentration of 1.5 mg/L is optimal for pathogen removal from water, and Azithromycin exhibited exceptional effectiveness against all resistant gram-negative bacterial isolates