Time-course Analysis of Biofilm Formation in Quorum Sensing-deficient Bacteria

Abstract

Pseudomonas aeruginosa and Vibrio vulnificus are Gram-negative human pathogens, which exert their virulence through quorum sensing (QS) regulation. The infection of these pathogens have been known to be mediated by biofilm formation in many cases and this study carried out the time-course analysis of biofilm formation depending on the QS regulation in P. aeruginosa and V. vulnificus. In P. aeruginosa, our results demonstrated that QS-deficient mutant better attached to surface at initial stage of biofilm formation, but poorly proceeded to the maturation of the biofilm structure, while wild type less attached at initial stage but developed highly structured biofilm at late stage. Because of this, the quantitative comparison of biofilm formation between wild type and the QS mutant showed the reversion; the QS mutant formed more biofilm until 10 h after inoculation than wild type, but wild type formed much more biofilm after 10 h than QS mutant. V. vulnificus has been reported to form more biofilm with the mutation on QS system. When we performed the same time-course analysis of the V. vulnificus biofilm formation, the reversion was not detected even with prolonged culture for 108 h and the QS mutant always forms more biofilm than wild type. These results indicate that the QS regulation negatively affects the attachment at early stage but positively facilitates the biofilm maturation at late stage in P. aeruginosa, while the QS regulation has a negative effect on the biofilm formation throughout the biofilm development in V. vulnificus. Based on our results, we suggest that the developmental stage of biofilm and bacterial species should be considered when the QS system is targeted for biofilm control.

Combatting biofilms in potable water systems: A comprehensive overview to ensuring industrial water safety

“…The journey commences with planktonic microorganisms in the water. Drawn to surfaces like pipelines, tanks or fittings due to physicochemical interactions, these microbes find anchor points, especially on materials like stainless steel, PVC or concrete (Adams & White, 2018; Kim et al, 2021). These surfaces, with their unique micro‐textures and chemical properties, become hotbeds for microbial adhesion.…”

“…Elevated levels of critical nutrients, be it carbon, nitrogen or phosphorus, often foreshadow an impending explosion in biofilm growth. With the advent of state‐of‐the‐art analytical tools, accurate nutrient profiling is now a reality, fortifying our defence against biofilm proliferation (Jones et al, 2019; Kim et al, 2021).…”