Biofilm-Forming Ability of Pathogenic Bacteria

A study published in J. Food Protection (Vol. 83(12) p 203202040) reports on biofilm formation by pathogens. Biofilm formation was assessed by qualitative detection of extracellular polymeric substances on Congo red agar, by adherence to glass with the tube method, by the crystal violet biofilm (CV) assay, and by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Ten strains each of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Bacillus cereus were tested. The incubation conditions and time influenced the amount of biofilm formed as well as did the growth medium.  In the test tubes with Luria-Bertani broth (LBB), 22.5% of the strains were adherent, and 77.5% were slightly adherent. Stronger adhesion was obtained in brain heart infusion (BHI) with 2% sucrose; 60% of the isolates were adherent. In BHI plus 2% sucrose, SBP was noted for 42.5 and 37.6% of the strains after 24 and 48 h, respectively. In the MTT assay with LBB, 15% of the strains showed high metabolic activity after 24 h of incubation, and 25% of the strains showed high activity after 48 h. In BHI plus 2% sucrose, 70 and 85% of the incubated strains were classified as high metabolic activity after 24 and 48 h, respectively. @ https://meridian.allenpress.com/jfp/article-abstract/83/12/2032/440811/Biofilm-Forming-Ability-of-Pathogenic-Bacteria?redirectedFrom=fulltext