Exploring the genetic diversity and the association of drug resistance and biofilm production in Acinetobacter baumannii strains isolated from burn wound infections

Sanaz  Khashei; Hossein  Fazeli; Fateh  Rahimi; Vajihe  Karbasizade

doi:10.18502/ijm.v17i4.19228

Sanaz Khashei Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
Hossein Fazeli Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
Fateh Rahimi Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
Vajihe Karbasizade Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

DOI: https://doi.org/10.18502/ijm.v17i4.19228

Keywords: Burns; Acinetobacter baumannii; Drug resistance; Biofilm; Molecular typing

Abstract

Background and Objectives: Acinetobacter baumannii is considered a troublesome cause of infection in burn units, where its capability to form biofilm and resist antibiotics significantly hampers therapeutic success. This study explored the cor- relations between antimicrobial resistance profiles, biofilm-producing capacity, and genetic diversity of A. baumannii strains from patients with burn wound infection in Isfahan, Iran.

Materials and Methods: Ninety-six isolates were analyzed for antibiotic resistance using the disk diffusion technique and for biofilm formation through the microtiter dish assay. The prevalence of ten biofilm-related genes was investigated using specific primers. Clonal relatedness among bacterial strains was defined by Enterobacterial Repetitive Intergenic Consen- sus-Polymerase Chain Reaction (ERIC-PCR).

Results: A vast majority of isolates (99%) exhibited resistance to meropenem, ciprofloxacin, ceftriaxone, cefotaxime, pip- eracillin-tazobactam, and imipenem, qualifying them as extensively drug-resistant (XDR). Twenty-five percent of the strains were strong biofilm formers, while 68% demonstrated moderate or weak biofilm formation. The most commonly identified biofilm-related genes included bfmR (100%), ompA (100%), and bap (99%). A significant association was found between the production of biofilm, resistance to aminoglycosides, and the presence of csuE and bap genes. ERIC-PCR typing showed the presence of 3 clonal types and 7 single types, with biofilm producers predominantly clustering to clonal type 2.

Conclusion: This work highlights a notable prevalence of biofilm-producing XDR A. baumannii in burn patients, underscoring the need for continuous surveillance and enhanced infection control strategies.