Background: Acinetobacter baumannii (A.baumannii) is an opportunistic pathogen that
causes serious types of infections in human. It shows a wide range of antibiotic
resistance. Objective: to investigate biofilm formation and its relation to biofilm-related
genes in multidrug-resistant (MDR) A.baumannii isolated from patients hospitalized in
Benha University Intensive Care Unit (ICU). Methodology: This study was conducted on
(90) clinical samples obtained from immunocompromised patients with various
symptomatic clinical infections, at least 48 hours after admission to Benha University
ICU. A. baumannii isolates were identified, their antibiotic susceptibility pattern was
detected using VITEK® 2 system. Biofilm-forming capacity of A. baumannii isolates was
determined by tube method. Biofilm-related genes (csuE , omp A, bap , bla PER-1, and aba
I) were detected using polymerase chain reaction(PCR). Results: Out of 60 A.baumannii
isolates, 93.3% were MDR, 76.7% were extensive drug resistant (XDR), and 75% were
biofilm formers. A significant relationship was revealed between the multidrug
resistance and biofilm formation. Detected ratio of csuE, omp A, bap, bla PER-1,, and aba
I genes were 96.7%, 48.3% , 68.3% , 40% and 88.3% respectively. (csu E, bap, aba I,
and bla PER-1) genes were founded to have a statistically significant relation to biofilm
formation. While (omp A) gene was insignificantly related to biofilm formation.
Conclusion: Biofilm formation in A. baumannii is significantly related to multidrug
resistance, with high frequency of biofilm -related genes.