BACKGROUND Quorum sensing is the key regulator of virulence factors of Pseudomonas aeruginosa such as biofilm formation, motility, productions of proteases, hemolysin, pyocyanin, and toxins. The aim of this study was to explore the effect of the extracts from some medicinal plants on quorum sensing and related virulence factors of P. aeruginosa. MATERIAL AND METHODS Quorum sensing inhibitory ...

introduction: pseudomonas aeruginosa is a gram-negative bacterium that considered as important opportunistic human pathogen. one of the mechanisms that help bacteria to tolerate survival in adverse conditions and resistance to antibiotics is biofilm formation through quorum sensing (qs) signals and toxin-antitoxin (ta) systems. qs and ta are two systems that have important roles in biofilm form...

Biofilms are microbial communities that inhabit various surfaces and are surrounded by extracellular matrices (ECMs). Clinical microbiologists have shown that the majority of chronic infections are caused by biofilms, following the introduction of the first biofilm infection model by J. W. Costerton and colleagues (J. Lam, R. Chan, K. Lam, and J. W. Costerton, Infect Immun 28:546-556, 1980). Ho...

It has long been recognised that bacteria can switch from planktonic unicellular organisms to sessile multicellular communities known as biofilms (Costerton et al., 1987; 1995). The transition to surface-attached (biofilm) growth is known to result in diverse changes in gene expression, which causes the attaching cells to become phenotypically and metabolically distinct from their planktonic co...

Biofilm formation by pathogenic bacteria is a hallmark of chronic infections. In many cases, lectins play key roles in establishing biofilms. The pathogen Pseudomonas aeruginosa often exhibiting various drug resistances employs its lectins LecA and LecB as virulence factors and biofilm building blocks. Therefore, inhibition of the function of these proteins is thought to have potential in devel...

Polymeric beta-1,6-N-acetyl-D-glucosamine (poly-beta-1,6-GlcNAc) has been implicated as an Escherichia coli and Staphylococcus epidermidis biofilm adhesin, the formation of which requires the pgaABCD and icaABCD loci, respectively. Enzymatic hydrolysis of poly-beta-1,6-GlcNAc, demonstrated for the first time by chromatography and mass spectrometry, disrupts biofilm formation by these species an...

The objective of this study was to screen for novel quorum-sensing inhibitors (QSIs) from traditional Chinese medicines (TCMs) that inhibit bacterial biofilm formation. Six of 46 active components found in TCMs were identified as putative QSIs based on molecular docking studies. Of these, three compounds inhibited biofilm formation by Pseudomonas aeruginosa and Stenotrophomonas maltophilia at a...

Detailed knowledge of the developmental process from single cells scattered on a surface to complex multicellular biofilm structures is essential in order to create strategies to control biofilm development. In order to study bacterial migration patterns during Pseudomonas aeruginosa biofilm development, we have performed an investigation with time-lapse confocal laser scanning microscopy of bi...

A total of ten seaweeds and four seagrasses were used in the present investigation to study the effect of crude methanol extracts on anti-biofilm activity using a microtiter-plate and anti-larval settlement assay using cyprids of barnacle Balanus amphitrite. Of these fourteen species tested, seagrass Halophila ovalis showed noticeable anti-biofilm activity against Listeria monocytogenes, Vibrio...

Formation of biofilm within a porous matrix reduces the pore size and the total open space of the system, altering the porosity and permeability of the medium. This change in the pore size distribution can be quantified by expressing the porous structure with a proper geometrical model. A set of pertinent multispecies biofilm models is used to arrive at the dynamic biofilm thickness distributio...