Is biofilm formation a virulence factor?

Is biofilm formation a virulence factor?

Biofilm virulence factors underlie chronic infection. Bacteria often employ opposing molecular mechanisms to establish acute and chronic infections, thus requiring different strategies for treatment of acute and chronic (biofilm) infections.

What is the formation of biofilms?

Biofilm formation is a process whereby microorganisms irreversibly attach to and grow on a surface and produce extracellular polymers that facilitate attachment and matrix formation, resulting in an alteration in the phenotype of the organisms with respect to growth rate and gene transcription.

What stimulates biofilm formation?

In many bacterial species, the intracellular signaling molecule, c-di-GMP, stimulates the synthesis of biofilm matrix components, particularly polysaccharides and proteins (4, 5). A common observation is that cells with elevated levels of intracellular c-di-GMP form thicker and more robust biofilms.

Which of the following is considered a virulence factor?

Which of the following is considered a virulence factor? explanation: Virulence factors are encoded by virulence genes, include toxins, attachment proteins, capsules, and other devices used to avoid host innate adaptive immune systems.

What affects biofilm formation?

Among the conditions that affect biofilm development are temperature, pH, O2 levels, hydrodynamics, osmolarity, the presence of specific ions, nutrients, and factors derived from the biotic environment.

What regulates the formation of biofilms?

Our current knowledge suggests that biofilm formation is regulated by cyclic diguanosine-5′-monophosphate (c-di-GMP), small RNAs (sRNA) and quorum sensing (QS) in all these bacterial species.

What promotes biofilm production?

High c-di-GMP levels induce biofilm formation, whereas low c-di-GMP levels induce planktonic growth (Valentini and Filloux, 2016; Liu et al., 2017). Another well-characterized second messenger cAMP, the cofactor of CRP, is primarily involved in carbon catabolite repression in bacteria.

What are the different biofilm-associated and virulence determinants?

The results obtained from molecular analysis of different biofilm-associated and virulence determinants revealed that all isolates harboured clfA, fnbpA,icaA, icaB, icaC, and icaD, while clfB, fnbB, hlg, and pvlwere detected in 99.5%, 42.1%, 97.5%, and 5.6% of isolates, respectively.

How does the Salmonella typhimurium strain affect biofilm formation?

The variation in the formation of biofilm-based on the diversity of Salmonella species was observed with higher percentage of Salmonella Typhimurium strains as strong biofilms producers at 21, 30 and 37 °C under nutrient-deprived and nutrient-rich medium, with either static or dynamic conditions, with the exemption of 37°C TSB static.

How can I evaluate the biofilm in a 96-well assay?

For evaluating the biofilm, we added 300 μl of a provided bacterial suspension to 3 wells of a 96-well microtiter plate and filled the other 3 wells with uninoculated sterile TSB medium as negative control.

What is the hydrophobic capacity of biofilms?

For the relative biofilm-forming capacity, OD ranges from 0.65±0.02–1.66±0.02 for EAOB and from 0.63±0.13–1.60±0.02 on TSB. For surface hydrophobicity using BATH, 25/45 (55.56%) were hydrophilic as values were < 20% while 20/45 (44.44%) were moderately hydrophobic as values were in the range of 20–50%.