Abstract

The aim of this work was to detect the prevalence of metallo-β-lactamases (MBL) producers among carbapenem-resistant Acinetobacter baumannii strains isolated from diabetic foot ulcers. Out of 290 samples of diabetic foot ulcers, 99 strains of A. baumannii (33%) were isolated and identified by conventional culture methods. Antibiotic sensitivity pattern of the isolated A. baumanni strains was done by disc diffusion method. For A. baumanni strains that was resistant to imipenem and meropenem, MBL production was screened by potentiated disc test and confirmed by multiplex polymerase chain reaction for bla_IMP and bla_VIM genes. Out of 99 strains of A. baumannii, 26 (26%) were found resistant to imipenem and/or meropenem. Of these 26 carpabenem resistant A. baumannii strains 9 (34.61%) were positive for MBL by potentiated disc test, and 6 strains (23.07%) were positive for bla_VIM or bla_IMP by multiplex PCR;  where  bla_VIM gene was detected in 4 strains (15.38%) and bla_IMP was detected in 2 strains (7.69%). The antimicrobial susceptibility profile for the isolated A. baumanni strains showed that the highest sensitivity was to meropenem (74.4%), imepenem (76.55%), amikacin (65%) and the lowest sensitivity was to ceftazidime (11%) and ciprofloxacin (12%). Rapid dissemination of carbapenem-resistant isolates in diabetic foot ulcers is worrisome and calls for judicious use of antibiotics. bla_VIM and bla_IMP genes have a role in carbapenem-resistant in the community. More studies are needed to differentiate MBL from non-metalloenzymes producers.

Key words: Diabetic foot, A. baumanni, metallo-β-lactamases.