Biofilm Formation and β-lactamase Enzymes: A Synergism Activity in Acinetobacter baumannii Isolated from Wound Infection

Background and Objective: Biofilm formation plays a crucial role in wound infections and increases the bacteria resistance to treatment. The present study investigated the relationship between the biofilm formation, ESBL, AmpC, and KPC enzymes in Acinetobacter baumannii isolated from the wound specimens. Materials and Methods: Eighty- nine A. baumannii isolates were collected from wound specimens and were confirmed by different biochemical tests. The biofilm-producing strains were identified using the crystal violet method. The producing strains of KPC, ESBL, and AmpC β-lactamase enzymes were detected through phenotypic tests. Further, the PCR method was employed to identify the ESBL, KPC, and AmpC. The Chi-square test and SPSS 16 were used for data analysis. Results: Among 89 wound isolates, 21 and 68 were collected from male and female patients, respectively. The strains resistant to ciprofloxacin (69.66%) and gentamicin (66.29%) were the most frequent strains while ceftazidime (7.86%) and colistin (1.12%) resistant strains had the lowest frequency. Furthermore, 40 isolates were considered as ESBL-producing enzymes, 33 isolates as AmpC, and 26 isolates as KPC-producing enzymes. In addition, the isolates were categorized as strong biofilms with 20 isolates, moderate biofilms with 19 isolates, and weak biofilm-producing strains with 10 isolates. The distribution of the β-lactamase genes in A. baumannii isolates was blaVEB (34.83%), blaPER (32.58%), blaFOX (29.21%), blaADC (30.33%), blaIMP (28.08%), and blaKPC (22.47%). Conclusion: Our results demonstrated that isolates with a higher level of antibiotic resistance tended to form stronger biofilms. Likewise, the results showed that the relationship between biofilm formation and antibiotic resistance might be affected by the type of β-lactamase enzyme in wound infection.