Characterization of acinetobacter baumannii from hospital-adjacent waterbodies in Dhaka city

Abstract

Acinetobacter baumannii has become a significant pathogen over the last few decades. It is naturally found in food, soil, and surface water but in clinical settings, it has demonstrated increasing health problems and nosocomial infections with limited antibiotic treatment options. The presence of multidrug-resistantA. baumannii in hospital settings and from clinical samples have been well documented but their spread in the natural environment is still poorly understood. In this study, A. baumannii were isolated from four waterbodies adjacent (within a 100-200 meter range) to four different hospitals. The samples were collected consecutively for four months to observe the prevalence of the organism. Out of 16 samples 21 positive isolates were confirmed by PCR of the blaOXA51 gene. Subsequently, susceptibility test was carried out for 13 antibiotics from seven different antibiotic classes. The test reported that all isolates (95%) except for one (LM2) were resistant to Ceftazidime meanwhile, 95% of the isolates were susceptible to Meropenem and Gentamicin except for MMY4 and LA7 respectively. The resistance pattern for other antibiotics was as follows: Ceftriaxone (48%), Piperacillin (33%), Trimethoprim (28%), and Cefepime (28%). Notedly, 33.33% of the isolates were in the intermediate category for Ciprofloxacin and Piperacillin. Moreover, the MAR index of 7 out of the 21 isolates was higher than 0.28. indicating the sources of these isolates are exposed to antibiotics at a higher level. Finally, among the 21 isolates, 8 isolates (38%) were found to be resistant to three or more categories of antibiotics making them multidrug-resistant.