Coupon position does not affect Pseudomonas aeruginosa and Staphylococcus aureus biofilm densities in the CDC biofilm reactor.

The CDC Biofilm Reactor method is the standard biofilm growth protocol for the validation of US Environmental Protection Agency biofilm label claims. However, no studies have determined the effect of coupon orientation within the reactor on biofilm growth. If positional effects have a statistically significant impact on biofilm density, they should be accounted for in the experimental design.

Simulated aging of draught beer line tubing increases biofilm contamination.

Craft brewing is continually gaining popularity in the United States. Craft brewers are committed to producing a wide variety of products and have a vested interest in product quality. Therefore, these brewers have the expectation that the beer poured at the tap will match the quality product that left the brewery.

Imaging and plate counting to quantify the effect of an antimicrobial: A case study of a photo-activated chlorine dioxide treatment.

Aim: To assess removal versus kill efficacies of antimicrobial treatments against thick biofilms with statistical confidence.

Methods And Results: A photo-activated chlorine dioxide treatment (Photo ClO ) was tested in two independent experiments against thick (>100 μm) Pseudomonas aeruginosa biofilms. Kill efficacy was assessed by viable plate counts.

Harvesting and Disaggregation: An Overlooked Step in Biofilm Methods Research.

Biofilm methods consist of four distinct steps: growing the biofilm in a relevant model, treating the mature biofilm, harvesting the biofilm from the surface and disaggregating the clumps, and analyzing the sample. Of the four steps, harvesting and disaggregation are the least studied but nonetheless critical when considering the potential for test bias. This article demonstrates commonly used harvesting and disaggregation techniques for biofilm grown on three different surfaces.

Drip flow reactor method exhibits excellent reproducibility based on a 10-laboratory collaborative study.

A standard method for growing Pseudomonas aeruginosa biofilm in the Drip Flow Biofilm Reactor was assessed in a 10-laboratory study. The mean log density was 9.29 Log(CFU/cm).

Development, standardization, and validation of a biofilm efficacy test: The single tube method.

Methods validated by a standard setting organization enable public, industry and regulatory stakeholders to make decisions on the acceptability of products, devices and processes. This is because standard methods are demonstrably reproducible when performed in different laboratories by different researchers, responsive to different products, and rugged when small (usually inadvertent) variations from the standard procedure occur. The Single Tube Method (ASTM E2871) is a standard method that measures the efficacy of antimicrobials against biofilm bacteria that has been shown to be reproducible, responsive and rugged.

Revisiting an agar-based plate method: what the static biofilm method can offer for biofilm research.

The development of biofilms in static plates was monitored. Glass coupons were placed on agar covered with filter paper, which was inoculated with suspended bacteria. The viable cell density, biofilms matrix and biomass were quantified.

Checking the validity of the harvesting and disaggregating steps in laboratory tests of surface disinfectants.

A chemical disinfectant against surface-associated bacteria typically uses carriers (e.g., glass disks) that are purposely contaminated with bacteria prior to disinfection.

A method for growing a biofilm under low shear at the air-liquid interface using the drip flow biofilm reactor.

This protocol describes how to grow a Pseudomonas aeruginosa biofilm under low fluid shear close to the air-liquid interface using the drip flow reactor (DFR). The DFR can model environments such as food-processing conveyor belts, catheters, lungs with cystic fibrosis and the oral cavity. The biofilm is established by operating the reactor in batch mode for 6 h.

Comparative evaluation of biofilm disinfectant efficacy tests.

Regulatory agencies are receiving registration applications for unprecedented, antibiofilm label claims for disinfectants. Reliable, practical, and relevant laboratory biofilm test methods are required to support such claims. This investigation describes the influence of fluid dynamics on the relevancy of a laboratory test.

Spatial patterns of DNA replication, protein synthesis, and oxygen concentration within bacterial biofilms reveal diverse physiological states.

It has long been suspected that microbial biofilms harbor cells in a variety of activity states, but there have been few direct experimental visualizations of this physiological heterogeneity. Spatial patterns of DNA replication and protein synthetic activity were imaged and quantified in staphylococcal biofilms using immunofluorescent detection of pulse-labeled DNA and also an inducible green fluorescent protein (GFP) construct. Stratified patterns of DNA synthetic and protein synthetic activity were observed in all three biofilm systems to which the techniques were applied.

Monitoring of microbial souring in chemically treated, produced-water biofilm systems using molecular techniques.

The identification of bacteria in oil production facilities has previously been based on culture techniques. However, cultivation of bacteria from these often-extreme environments can lead to errors in identifying the microbial community members. In this study, molecular techniques including fluorescence in situ hybridization, PCR, denaturing gradient gel electrophoresis, and sequencing were used to track changes in bacterial biofilm populations treated with nitrate, nitrite, or nitrate+molybdate as agents for the control of sulfide production.

Development of a laboratory model to assess the removal of biofilm from interproximal spaces by powered tooth brushing.

Purpose: To develop an interproximal laboratory model to compare the potential effectiveness of powered brushing to remove biofilm plaque from interproximal spaces beyond the reach of bristles.

Materials And Methods: Streptococcus mutans biofilms were first grown on glass microscope slides in a drip-flow reactor. The slides were removed and positioned in the interproximal model.