Effect of Different Culture Media on Pseudomonas aeruginosa Biofilm Formation

Abstract

The opportunistic pathogen Pseudomonas aeruginosa (PA) causes nosocomial infections, and it is the most common pathogen that can form biofilm. PA biofilm formation is important as an environmental bacterium in hospital wastewater, in vivo, in the environment, and in infection control. Besides many antibiotic resistance mechanisms, biofilms may play an important role as in PA forming biofilms that have a minimum inhibitory concentration (MIC) for antibiotics up to 1,000-fold higher than that of planktonic bacteria. Multiple biofilm-specific mechanisms contribute to the high levels of antibiotic resistance. Therefore, PA biofilm-associated infections lead to important clinical outcomes. The aim was to investigate the efficacy of four different culture media used in two biofilm formation protocols on the assessment of biofilm production by 11 PA isolated from hospital wastewater. The crystal violet microtiter plate-based method was used to evaluate the quantification of the biofilm formation capacity of PA. Results of culture media used in the formation of biofilm capacity were; TSB with %1 glucose 0.0 %, 63.6%, and 36.4%; BHI 18.2%, 36.4%, and 45.5%; LBB 9.1%, 27.3%, and 63.6% of isolates were strong, moderate, and weak biofilm producers, respectively. However, in MHB, 27.3%, 63.6%, and 9.1% of isolates were moderate, weak, and non-biofilm producers, respectively. The biofilm levels in protocol one were higher than the other protocol used (OD570). PA biofilm formation and quantification in these media used may help to search for antibiofilm agents in laboratories to prevent the spread of antimicrobial resistance, develop effective precautions, and prevent PA infections in hospitals.