The role of surfactants in inhibition of uropathogenic E. coli biofilm in catheterized patients in Assiut University Hospitals.

Abstract

Background: Escherichia coli (E. coli) represent one of the major pathogens implicated in catheter associated urinary tract infection (CAUTI). Formation of biofilm by uropathogenic E. coli (UPEC) is a major survival and persistence mechanism of bacteria against antibiotics and host immune responses in the bladder. This study was designed aiming to evaluate the role of surfactants [non-anionic: Tween 80, anionic: sodium dodecyl sulfate (SDS), cationic: cetyl trimethyl ammonium (CTMA)] on biofilm forming CsgA gene containing strains of E. coli. Methods: A cross sectional study conducted at Assiut University Hospitals ICUs included 100 patients; 53 males and 47 females, catheterized for at least 3 days. Biofilm production by E. coli isolates was detected phenotypically by culture on Congo red agar plates and confirmed genotypically by detection of CsgA by conventional PCR. Overnight broth culture of each E. coli isolate was incubated with each surfactant at 3 different concentrations (CMC). Subculture on congo red agar plates was done. Inhibition of biofilm formation was indicted by fading or absence of black color of the colonies. Results: Tween 80 showed inhibition of biofilm formation by 15% of all samples at a concentration 0.1% (>CMC). SDS show biofilm inhibition by 23% at concentration 2.32mg/ml (=CMC) and at concentration 3mg/ml (>CMC). CTMA inhibited the biofilm formation by 7% at a concentration 0.4mg/ml (=CMC) and by 38% at a concentration 0.8mg/ml (>CMC). Conclusion: Surfactants have disruptive and inhibitory effect on biofilm formation that provides an alternative for plain and medicated catheters.

Keywords

• biofilm
• e. coli
• curli fibers
• cauti
• surfactants