The influence of different culture media on Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus biofilm formation

Abstract

Microorganisms such as Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus are frequently isolated in samples of urinary, blood, intestinal, and respiratory infections, among others. These bacteria are also associated with microbial biofilm formation. E. coli, P. aeruginosa, and S. aureus biofilm infections are particularly hard to manage and often associated with nosocomial problems. This study investigated the influence of different culture media on E. coli, P. aeruginosa, and S. aureus biofilm formation. Bacterial performance was evaluated in brain heart infusion broth, Mueller-Hinton broth, or tryptic soy broth, with or without supplementing with different glucose levels (1-5%). The study quantified biofilm biomass and the count of viable biofilm colonies. This is the first study that compares the biofilm formation of E. coli, P. aeruginosa and S. aureus in polystyrene using different culture media and with different glucose concentrations. The most robust growth of E. coli, P. aeruginosa, and S. aureus occurred in brain heart infusion broth supplemented with 5% glucose, Mueller-Hinton broth without glucose, and tryptic soy broth with 2% glucose, respectively. Our data demonstrate that behavioral and morphological characteristics of each bacterium require a specific broth to enhance the growth of these microorganisms. These findings will contribute to future tests for therapeutic alternatives with anti-biofilm potential.

Keywords

• adhesion
• gram-negative bacteria
• gram-positive bacteria
• in vitro techniques.