In vitro evaluation of anti-inflammatory drugs Ibuprofen and Dexamethasone against Acinetobacter baumannii

Today, the rapid rise in drug resistance and the failure of common antibiotics to treat biofilm-associated infections are major concerns. Acinetobacter baumannii (A. baumannii) is recognized as a severe hospital and community-acquired pathogen. The interaction between A. baumannii and the immune system causes an inflammatory response and tissue damage. Ibuprofen and Dexamethasone are widely utilized therapeutic drugs known for their potent anti-inflammatory effect. However, despite their widespread use in managing inflammation, the antimicrobial impact of these drugs on A. baumannii has not been investigated. To the best of our knowledge, this is the first study to evaluate the antibacterial activity of these drugs, the expression of bap and ompA immune evasion genes, and biofilm formation of A. baumannii. For this purpose, the antimicrobial effects of Ibuprofen and Dexamethasone, along with their impact on the expression of the bap and ompA genes, and biofilm formation, were investigated. The results of this study showed that Ibuprofen at 2048 µg/mL exhibits antimicrobial activity against A. baumannii isolates. Ibuprofen significantly reduces bap gene expression but does not significantly affect ompA gene expression. Moreover, this drug can inhibit biofilm formation at a concentration of 2048 µg/mL. The study of Dexamethasone showed that its antimicrobial activity was at a concentration of 1024 µg/mL. It can significantly reduce bap gene expression. Dexamethasone also does not significantly affect ompA gene expression. Additionally, Dexamethasone inhibits biofilm formation at 256 µg/mL. In conclusion, our findings indicate that although both drugs showed antimicrobial activity, Dexamethasone had a better effect on A. baumannii, particularly in inhibiting biofilm formation.