Isolation, characterization and analysis of multi-drug resistant Acinetobacter baumannii isolated from hospital adjacent lake soil in Dhaka city

Abstract

Acinetobacter baumannii is a Gram-negative bacillus that exhibits the features of an obligate aerobe. The observed entity exhibits pleomorphism and lacks motility. Acinetobacter baumannii, a pathogen known for its opportunistic and nosocomial nature, has been classified as a "red alert" organism. The aforementioned pathogen is accountable for the occurrence of ventilator-associated pneumonia, bloodstream infections, urinary tract infections, and meningitis. In recent years, this pathogen has shown a diverse array of virulence characteristics, resulting in its resistance to numerous treatment classes such as Cephalosporin, Carbapenem, and Beta-lactams. The discharge of wastewater originating from healthcare facilities may have a notable impact on the transmission of infections to patients, members of the community, hospital personnel, and the surrounding ecosystem, including soil and water bodies. The potential for transmission and lethality shown by hospital wastewater makes it an especially hazardous reservoir for antibiotic-resistant genes (ARG) and antibiotic-resistant microorganisms (ARB). For our study total 30 samples were collected during January 2023 to June2023 from hospital adjacent lake soil within the range of 50meter, 100meter, 150 meter. Out of 20 suspected isolates, only 4 of them were PCR confirmed as A.baumannii which amounted for around only 13% of the sample size. And all of those positive isolated were acquired from only one sampling site within the range of 50m and 100m from the hospital. Isolates that were obtained from 50meters area range were found to be more resistant to tested antibiotics that the isolates that were obtained from 100meters area range from hospital. Among the four positive isolates of A. baumannii, it was observed that three isolates, accounting for 75% of the total isolates, exhibited resistance to the third generation cephalosporin Ceftazidime. This resistance level was found to be the highest among all the medicines tested. In addition, it was shown that 50% of the isolates exhibited resistance to levofloxacin and piperacillin-tazobactam, whereas the other 50% demonstrated susceptibility to these two drugs.