Prevalence of metallo--lactamases producers among carbapenem-resistant Acinetobacter baumannii strains isolated from diabetic foot ulcers

Abstract

The aim of this work was to detect the prevalence of metallo- beta -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.