Distribution of adeB and NDM-1 genes in multidrug resistant Acinetobacter baumannii isolated from infected wound of patients admitted in a tertiary care hospital in Bangladesh

ABSTRACT

Background: The adeB gene in Acinetobacter baumannii regulates the bacterial internal drug effluxpump that plays a significant role in drug resistance. The aim of our study was to determine theoccurrence of adeB gene in multidrug resistant and New Delhi metallo-beta-lactamase-1 (NDM-1) gene in imipenem resistant Acinetobacter baumannii isolated from wound swab samples in atertiary care hospital of Bangladesh. Methods: A total of 345 wound swab samples were testedfor bacterial pathogens. Acinetobacter baumannii was identified by culture and biochemical tests.Antimicrobial susceptibility pattern was determined by the disc diffusion method according toCLSI standards. Extended spectrum beta-lactamases were screened using the double disc synergytechnique. Gene encoding AdeB efflux pump and NDM-1 were detected by Polymerase ChainReaction (PCR). Results: A total 22 (6.37%) Acinetobacter baumannii were identified from 345wound swab samples and 20 (91%) of them were multidrug resistant. High resistance rates to someantibiotics were seen namely, cefotaxime (95%), amoxyclavulanic acid (90%) and ceftriaxone (82%).All the identified Acinetobacter baumannii were sensitive to colistin and 82% to imipenem. Two(9%) ESBL producing Acinetobacter baumannii strains were detected. adeB gene was detectedin 16 (80%) out of 20 multidrug resistant Acinetobacter baumannii. 4 (18%) of 22 Acinetobacterbaumannii were imipenem resistant. NDM-1 gene was detected in 2 (50%) of the imipenem resistantstrains of Acinetobacter baumannii. Conclusion: The results of this study provide insight into the roleof adeB gene as a potential regulator of drug resistance in Acinetobacter baumanni in Bangladesh.NDM-1 gene also contributes in developing such resistance for Acinetobacter baumannii.