Plasmid profile of multidrug resistant Acinetobacter baumannii strains from wounds of patients attending Federal Medical Centre, Abeokuta, Southwest, Nigeria

Abstract

Acinetobacter baumannii which was once considered non-pathogenic Gram-negative bacteria has emerged as a stubborn nosocomial pathogen. The study was conducted to investigate prevalence, antimicrobial resistance and profile plasmids carried by Acinetobacter baumannii from wounds of patients attending Federal Medical Centre, Abeokuta, Nigeria. Wound swabs of 140 patients were collected from the Bones and Plastic Surgery Department from November 2018 to March 2019. Swabs collected were cultured on Leeds Acinetobacter media. Isolates were identified by biochemical method using Oxoid Microbact™ Gram-negative identification system. Polymerase chain reaction was used to investigate the presence of bla-OXA-51-like gene intrinsic to A. baumannii in isolates observed for authentication. Antimicrobial susceptibility test was performed by the agar disc diffusion method and inhibition zones were interpreted following Clinical and Laboratory Standard Institute guidelines. Isolates were cured using Sodium Dodecyl Sulphate and subjected to second antimicrobial susceptibility test. A total of 18 (12.8%) isolates were identified as Acinetobacter baumannii from 140 patients. All the isolates (100%) were resistant to at least three antimicrobial agents. Cured A. baumannii isolates showed that 11 (61%) of the multi-drug resistant isolates were plasmid-mediated, with plasmid sizes ranging from 60-1,333 bp. This study revealed high rate of resistance to multiplicity of antimicrobial agents by plasmids carried on strains of Acinetobacter bauamannii.