Biofilm formation, antibiotic-resistance and clonal relatedness among clinical isolates of Acinetobacterbaumannii

Microb Pathog. 2024 Oct:195:106916. doi: 10.1016/j.micpath.2024.106916. Epub 2024 Sep 4.

Abstract

In this work, the antibiotic resistance, biofilm formation capability, and clonal relatedness of 50 A. baumannii isolates collected from three hospitals in Ardabil city, Iran, were evaluated. Antibiotic sensitivity and biofilm formation of isolates were determined by disk diffusion and microtiter-plate methods, respectively. Molecular typing of isolates was also performed using repetitive sequence-based PCR (REP-PCR). The majority of isolates were resistant to cephems, aminoglycosides, and carbapenems, with 80 % classified as multi-drug resistant (MDR). While, only isolates collected from blood and tracheal were resistant to colistin. Additionally, 42 isolates (84 %) had biofilm formation capability. According to rep-PCR results, 34 isolates showed similar banding patterns, while 16 isolates had unique banding patterns. Finally, based on the molecular analysis, there was a direct relationship between biofilm formation and the antibiotic resistance of isolates. In other words, MDR isolates had a higher ability to form biofilm.

Keywords: Acinetobacter baumannii; Antibiotic-resistance; Biofilm formation; REP-PCR.

MeSH terms

  • Acinetobacter Infections* / microbiology
  • Acinetobacter baumannii* / drug effects
  • Acinetobacter baumannii* / genetics
  • Acinetobacter baumannii* / isolation & purification
  • Acinetobacter baumannii* / physiology
  • Adult
  • Anti-Bacterial Agents* / pharmacology
  • Biofilms* / drug effects
  • Biofilms* / growth & development
  • Colistin / pharmacology
  • Drug Resistance, Multiple, Bacterial* / genetics
  • Female
  • Genotype
  • Hospitals
  • Humans
  • Iran
  • Male
  • Microbial Sensitivity Tests*
  • Middle Aged
  • Molecular Typing
  • Polymerase Chain Reaction

Substances

  • Anti-Bacterial Agents
  • Colistin