The effects of glutaraldehyde on the control of single and dual biofilms ofBacillus cereusandPseudomonas fluorescens

Abstract

Glutaraldehyde (GLUT) was evaluated for control of single and dual species biofilms of Bacillus cereus and Pseudomonas fluorescens on stainless steel surfaces using a chemostat system. The biofilms were characterized in terms of mass, cell density, total and matrix proteins and polysaccharides. The control action of GLUT was assessed in terms of inactivation and removal of biofilm. Post-biocide action was characterized 3, 7, 12, 24, 48 and 72 h after treatment. Tests with planktonic cells were also performed for comparison. The results demonstrated that in dual species biofilms the metabolic activity, cell density and the content of matrix proteins were higher than those of either single species. Planktonic B. cereus was more susceptible to GLUT than P. fluorescens. The biocide susceptibility of dual species planktonic cultures was an average of each single species. Planktonic cells were more susceptible to GLUT than their biofilm counterparts. Biofilm inactivation was similar for both of the single biofilms while dual biofilms were more resistant than single species biofilms. GLUT at 200 mg l(-1) caused low biofilm removal (<10%). Analysis of the post-biocide treatment data revealed the ability of biofilms to recover their activity over time. However, 12 h after biocide application, sloughing events were detected for both single and dual species biofilms, but were more marked for those formed by P. fluorescens (removal >40% of the total biofilm). The overall results suggest that GLUT exerts significant antimicrobial activity against planktonic bacteria and a partial and reversible activity against B. cereus and P. fluorescens single and dual species biofilms. The biocide had low antifouling effects when analysed immediately after treatment. However, GLUT had significant long-term effects on biofilm removal, inducing significant sloughing events (recovery in terms of mass 72 h after treatment for single biofilms and 42 h later for dual biofilms). In general, dual species biofilms demonstrated higher resistance and resilience to GLUT exposure than either of the single species biofilms. P. fluorescens biofilms were more susceptible to the biocide than B. cereus biofilms.

The effects of ferulic and salicylic acids on Bacillus cereus and Pseudomonas fluorescens single- and dual-species biofilms

“…This is a surprising result as in previous studies (Simões et al, 2009b(Simões et al, , 2011 it was found that B. cereus-P. fluorescens association increased antimicrobial resistance to antimicrobial products (an aldehyde-based biocide and a quaternary ammonium compound) comparatively to their single-species biofilms. This study demonstrates that dual-species biofilm formation in the presence of FA, SA, or FSA will increase their susceptibility to a second exposure to the chemicals.…”

Efflux as a Glutaraldehyde Resistance Mechanism in Pseudomonas fluorescens and Pseudomonas aeruginosa Biofilms

“…Biofilms are known to demonstrate increased antimicrobial resistance compared to planktonic cells (21,42). In the present study, we examined the response of P. fluorescens biofilms to glutaraldehyde, a widely used disinfectant in many industries.…”

“…S1), which may be attributed to short exposure time in our experiments. Previously, significant changes in P. fluorescens biofilm biomass were observed following Ն12 h of glutaraldehyde exposure (21).…”

“…Mechanistically, glutaraldehyde is thought to act by cross-linking proteins and lipids on the outer surface of the cell (4,17). Resistance to glutaraldehyde has been reported in several bacterial species (18)(19)(20)(21)(22)(23), and evidence indicates that genetic factors may contribute to glutaraldehyde resistance. For example, a glutaraldehyde-resistant Pseudomonas aeruginosa was recently isolated from endoscopes associated with an outbreak and was shown to acquire a resistance pattern that remained stable over several passages, indicating the involvement of genetic factors (18,19).…”

Effects of Different Times of Glutaraldehyde 2% on Bacillus subtilis Spores (In Vitro)

“…9,10 Simoes et al studied the effect of glutaraldehyde on the control of mono-and dual-species biofilms of Bacillus cereus and pseudomonas in 2011. 11 Another study done in 2008 by Retta and Saripanti showed the structure of a mathematic model for anticipating the activity of glutaraldehyde in destroying spores. In this model, the effect of glutaraldehyde was calculated exactly by changing factors such as the density of glutaraldehyde, the temperature, and the influence time of the substance.…”