Evaluation of Topical Antiseptics against Biofilm Formation of Staphylococcus Aureus and Pseudomonas Aeruginosa in Chronic Suppurative Otitis Media

Abstract

Background & Objective(s): Chronic suppurative otitis media (CSOM) is a common chronic disease that is often difficult to treat. Biofilms have been demonstrated in bacteria causing CSOM infections contributing to its pathogenesis and resistance to treatment. Antiseptics have a nonspecific mode of action and this gives them the advantage of a broader spectrum of antibacterial activity and a lesser risk of resistance The present study aimed to compare the effect of three antiseptics; 4%boric acid, Lugol’s iodine and tetrasodium ethylenediaminetetraacetic acid t(EDTA) solutions against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) and their biofilm forming ability. Methods: Bactericidal effect of antiseptics was examined using disk diffusion method on Müeller Hinton agar plates and the effect on biofilm formation was examined using biofilm-oriented antiseptics test. Results: The best antiseptic agent for planktonic cells of both bacterial species was Lugol’s iodine (mean±SD= 2.00±0.68), followed by tEDTA (mean±SD= 1.48±0.62) then boric acid (mean±SD= 0.20±0.47).The tested antiseptics had very close results when measuring the mean inhibition zones of S. aureus and P. aeruginosa isolates. All tested antiseptics reduced biofilm formation, but tEDTA was the most effective antiseptic in reducing the biofilm formation compared to Lugol’s iodine and boric acid (Mean OD= 0.055±0.012 versus 0.145±0.137 and 0.122±0.071 respectively, p< 0.001). Conclusion: Lugol’s iodine had a better bactericidal effect on isolates, while tEDTA had a better effect on biofilm formation. Further in vivo studies are needed regarding both their efficacy and ototoxic effects to assess their possible use as local treatment of CSOM patients.

Keywords

• boric acid
• lugol’s iodine
• biofilm
• edta
• staphylococcus aureus
• pseudomonas aeruginosa