Antimicrobial resistance and biofilm formation capacity among Acinetobacter baumannii strains isolated from patients with burns and ventilator‐associated pneumonia

BACKGROUND: Acinetobacter baumannii is a pathogen responsible for nosocomial infections, especially in patients with burns and ventilator‐associated pneumonia (VAP). The aims of this study was to compare the biofilm formation capacity, antimicrobial resistance patterns and molecular typing based on PFGE (Pulsed‐Field Gel Electrophoresis) in A. baumannii isolated from burn and VAP patients. MATERIALS AND METHODS: A total of 50 A. baumannii isolates were obtained from burn and VAP patients. In this study, we assessed antimicrobial susceptibility, biofilm formation capacity, PFGE fingerprinting, and the distribution of biofilm‐related genes (csuD, csuE, ptk, ataA, and ompA). RESULTS: Overall, 74% of the strains were multidrug resistant (MDR), and 26% were extensively drug‐resistant (XDR). Regarding biofilm formation capacity, 52%, 36%, and 12% of the isolates were strong, moderate, and weak biofilm producers. Strong biofilm formation capacity significantly correlated with XDR phenotype (12/13, 92.3%). All the isolates harbored at least one biofilm‐related gene. The most prevalent gene was csuD (98%), followed by ptk (90%), ataA (88%), ompA (86%), and csuE (86%). Harboring all the biofilm‐related genes was significantly associated with XDR phenotype. Finally, PFGE clustering revealed 6 clusters, among which cluster No. 2 showed a significant correlation with strong biofilm formation and XDR phenotype. CONCLUSION: Our findings revealed the variable distribution of biofilm‐related genes among MDR and XDR A. baumannii isolates from burn and VAP patients. A significant correlation was found between strong biofilm formation capacity and XDR phenotype. Finally, our results suggested that XDR phenotype was predominant among strong‐biofilm producer A. baumannii in our region.