Inhibition of Biofilm Formation in Some Pathogenic Gram Negative Bacteria by Anti-Quorum Sensing Compounds

Abstract

The present study included collecting of 125 clinical bacterial isolates from different sources such as pus, sputum, nasal polyps, urine and blood. The collected bacterial isolates were preliminary identified by biochemical tests as 44 Pseudomonas spp., 35 Klebsiella spp., 18 E. coli, 17 Acinetobacter spp., 8 Proteus spp. and 3 Enterobacter spp., The test for biofilm formation in these isolates was carried out by using three different methods (congo red agar, microplate assay and tube method) that finally resulted in 27 positive biofilm forming isolates. Production of quorum sensing signal molecules (acyl homoserine lactone) was detected in 20 isolates using gas chromatography mass spectrum (GC/MS), these isolates were 3 Pseudomonas spp., 6 Klebsiella spp., 8 E. coli and 3 Enterobacter spp.