Growing and Analyzing Static Biofilms

Abstract

Many bacteria can exist as surface‐attached aggregations known as biofilms. Presented in this unit are several approaches for the study of these communities. The focus here is on static biofilm systems, which are particularly useful for examination of the early stages of biofilm formation, including initial adherence to the surface and microcolony formation. Furthermore, most of the techniques presented are easily adapted to the study of biofilms under a variety of conditions and are suitable for either small‐ or relatively large‐scale studies. Unlike assays involving continuous‐flow systems, the static biofilm assays described here require very little specialized equipment and are relatively simple to execute. In addition, these static biofilm systems allow analysis of biofilm formation with a variety of readouts, including microscopy of live cells, macroscopic visualization of stained bacteria, and viability counts. Used individually or in combination, these assays provide useful means for the study of biofilms.

Multiple antibiotic resistance index, fitness and virulence potential in respiratory Pseudomonas aeruginosa from Jamaica

“…Biofilm susceptibility assays against CIP were carried out on a subset of 90 isolates and P. aeruginosa ATCC 27853 control strain using the biofilm assay protocol of Merritt et al (2011) and Khan et al (2010) in 96-well polystyrene microtitre plates. CIP, a broad-spectrum fluoroquinolone used clinically to treat P. aeruginosa infections, was chosen because it exerts significant effect on growth rate and the minimal biofilm eradication concentration is of the order of 4 mg ml 21 (Agarwal et al, 2005).…”

Engineering Microbial Physiology with Synthetic Polymers: Cationic Polymers Induce Biofilm Formation inVibrio choleraeand Downregulate the Expression of Virulence Genes

“…We therefore investigated whether polymer-induced clustering would also affect in vitro biofilm formation. V. cholerae biofilms are mainly composed of Vibrio exopolysaccharide (VPS) 22,34 which can be stained using crystal violet, 35,36 a chromogenic probe that interacts with negatively charged biopolymers. UV-Vis analysis of these polymerinduced clusters revealed an increased retention of the dye in the presence of P1, suggesting higher levels of extracellular exopolysaccharides (Fig.…”

Characterization of the Pseudomonas aeruginosa Glycoside Hydrolase PslG Reveals That Its Levels Are Critical for Psl Polysaccharide Biosynthesis and Biofilm Formation

“…The remaining dye was solubilized by the addition of 200 l of 95% (v/v) ethanol and left for 10 min, after which time the absorbance was measured at 595 nm using a SpectraMax M2 spectrophotometer from Molecular Devices (Sunnyvale, CA). The amount of biofilm is proportional to the absorbance from staining with crystal violet (48).…”