Clinical Biofilm Ring Test® Reveals the Potential Role of β-Lactams in the Induction of Biofilm Formation by P. aeruginosa in Cystic Fibrosis Patients

Abstract

Biofilms are characterized by high tolerance to antimicrobials. However, conventional antibiograms are performed on planktonic microorganisms. Through the clinical Biofilm Ring Test® (cBRT), initially aimed to measure the adhesion propensity of bacteria, we discerned a variable distribution of biofilm-producer strains among P. aeruginosa samples isolated from expectorations of cystic fibrosis (CF) patients. Despite a majority of spontaneous adherent isolates, few strains remained planktonic after 5 h of incubation. Their analysis by an adapted protocol of the cBRT revealed an induction of the biofilm early formation by sub-inhibitory doses of β-lactams. Microscopic observations of bacterial cultures stained with Syto 9/Propidium Iodide (PI) confirmed the ability of antimicrobials to increase either the bacterial biomass or the biovolume occupied by induced sessile cells. Finally, the cBRT and its derivatives enabled to highlight in a few hours the potential inducer property of antibiotics on bacterial adhesion. This phenomenon should be considered carefully in the context of CF since patients are constantly under fluctuating antimicrobial treatments. To conclude, assays derived from the Biofilm Ring Test® (BRT) device, not only define efficient doses preventing biofilm formation, but could be useful for the antimicrobial selection in CF, to avoid inducer molecules of the early biofilm initiation.

The value of biofilm testing to guide antimicrobial stewardship in chronic respiratory diseases

“…The lack of differences found in the BPI of patients with BE-COPD and BE is attributed to the fact that mucoid and non-mucoid were similarly distributed between BE-COPD and BE alone. Our findings are in line with previous reports indicating that the presence of BE does not influence mortality in long-term follow-up hospitalized COPD exacerbations ( Olivares et al., 2020 ). Thus, the underlying respiratory disease may not have such a relevant role on PA phenotype and biofilm production which rather responds to the stage of chronic infection.…”

In vitro inhibition of Pseudomonas aeruginosa PAO1 biofilm formation by DZ2002 through regulation of extracellular DNA and alginate production

“…Therefore, we evaluated the effects of DZ2002 on the biological characteristics of P. aeruginosa in the subsequent experiments. The formation of biofilms by P. aeruginosa involves four distinct stages (Kostakioti et al, 2013), including the initial adhesion (Olivares et al, 2020), irreversible adhesion (Thi et al, 2020), maturation (Johnson et al, 2022;Sauer et al, 2022), and dispersal (Kim and Lee, 2016). Olivares, E et al (Olivares et al, 2017) discovered that subminimum inhibitory concentration (sub-MIC) of tobramycin inhibits P. aeruginosa biofilm formation by affecting its early adhesion, which is inconsistent with the results recently described by Tahrioui, A et al (Tahrioui et al, 2019).…”

“…The formation of biofilms by P. aeruginosa involves four distinct stages ( Kostakioti et al., 2013 ), including the initial adhesion ( Olivares et al., 2020 ), irreversible adhesion ( Thi et al., 2020 ), maturation ( Johnson et al., 2022 ; Sauer et al., 2022 ), and dispersal ( Kim and Lee, 2016 ). Olivares, E et al.…”

Exploring the Diversity of Biofilm Formation by the Food Spoiler Brochothrix thermosphacta

“…[1 − ((average BFIs of negative control − three standard deviation)/2)/average BFI of negative control] [47].…”