Biofilm Formation and Detection of Fluoroquinolone- and Carbapenem-Resistant Genes in Multidrug-ResistantAcinetobacter baumannii

Abstract

Acinetobacter baumanniiis an important opportunistic pathogen that shows resistance to cephalosporins, penicillins, carbapenems, fluoroquinolones, and aminoglycosides, the multiresistance being associated with its ability to form biofilms in clinical environments. The aim of this study was to determine biofilm formation and its potential association with genes involved in antibiotic resistance mechanisms ofA. baumanniiisolates of different clinical specimens. We demonstrated 100% of theA. baumanniiisolates examined to be multidrug resistant (MDR), presenting a 73.3% susceptibility to cefepime and a 53.3% susceptibility to ciprofloxacin. AllA. baumanniiisolates were positive forblaOXA-51, 33.3% being positive forblaOXA-23and ISAba1, and 73.3% being positive forgyrA. We found 86.6% ofA. baumanniistrains to be low-grade biofilm formers and 13.3% to be biofilm negative; culturing on Congo red agar (CRA) plates revealed that 73.3% of theA. baumanniiisolates to be biofilm producers, while 26.6% were not. These properties, combined with the role ofA. baumanniias a nosocomial pathogen, increase the probability ofA. baumanniicausing nosocomial infections and outbreaks as a complication during therapeutic treatments and emphasize the need to controlA. baumanniibiofilms in hospital environments.