Isolation, characterization and comparative analysis of multi-drug resistant acinetobacter baumannii & vibrio cholerae from hospital wastewater and its adjacent community supply water in Dhaka north

Abstract

Acinetobacter baumannii is a Gram-negative bacillus which shows characteristics of obligate aerobe. It is pleomorphic and non-motile. An opportunistic and nosocomial pathogen, A. baumannii has been designated as “red alert”. This pathogen is responsible for ventilator-associated pneumonia, bloodstream infections, urinary tract infections and meningitis. As this pathogen possesses a wide range of virulence factors which make this pathogen resistant to multiple drug classes, for instance, Cephalosporins, Carbapenem, Beta-lactams etc. in recent years. On the other hand, Vibrio cholerae is Gram-negative, usually curved or comma-shaped which is the major causative agent of cholera outbreak. It has a distinct history to show resistance against a specific class of drugs (Ampicillin, Tetracycline). Wastewater from hospitals can play a significant role in dispersing pathogens to patients, community members, hospital staff, and the surrounding environment. The contagious and poisonous properties of hospital effluent make it a particularly dangerous source of antibiotic resistant gene or ARGs and antibiotic resistant bacteria or ARBs. From our study, a total of 83 samples were collected from our study sampling sites from June 2022 to January 2023, where 36 Polymerase chain reaction (PCR) confirmed Acinetobacter baumannii were obtained which was 43.37% of the sample size. In comparison to community water, isolates from hospital wastewater showed most resistance against our tested antibiotics. However, isolates from both hospital wastewater and community water showed most resistance to Cefixime (82.35%) and Azithromycin (52.94%) among 11 antibiotics. Again, a total of 75 samples were collected from the exact sampling sites from June 2022 to December 2022, where 20 PCR confirmed vibrio spp. and 17 PCR confirmed Vibrio cholerae were obtained, which accounted for 49.33% in total of the sample size. Moreover, in our study Vibrio cholerae isolates from both HWW (Hospital wastewater) and community water has shown 100% resistance towards Azithromycin and Ampicillin. The findings of our study revealed that the development of ARGs in Acinetobacter baumannii and Vibrio cholerae strains in the community setting has grown dramatically. It was expected that these ARBs and ARGs would spread from hospitals via the untreated effluents.