Biofilm formation and Quorum sensing LasRgene in isolated strains of Pseudomonas aeruginosa from patients at Ain Shams University Hospitals

Abstract

According to the CDC, Pseudomonas aeruginosa is the fifth most common pathogen among hospital microorganisms which causes 10% of all hospital aquired infections. P. aeruginosa is an opportunistic pathogen that causes severe infections in immunocompromised patients including cancer patients, cystic fibrosis patients, patients with human immunodeficiency virus infections and patients with severe burn wounds. P. aeruginosavirulence depends on a large number of virulence factors both cell-associated; pili, flagella, lipopolysaccharide, etc and extracellular virulence factors; exotoxin A,exoenzyme S, elastase, biofilm, etc. One of the reasons that P. aeruginosa is a successful opportunistic pathogen is its ability to form biofilm causing chronic infections and high level of drug resistance. Biofilms are not unstructured, homogeneous deposits of cells and accumulated slime, but complex communities of surface-associated cells enclosed in a polymer matrix containing open water channels. It has been involved in almost every human infection and is particularly resistant to many antibiotics and can persist despite sustained host defences. Biofilm causes considerable problems in medical and industrial settings, because bacteria in biofilms can resist antibiotic treatment, host immune responses, and biocide treatment.