Quorum sensing-regulated functions of Serratia marcescens are reduced by eugenol

Abstract

Background and Objectives: Serratia marcescens has emerged as a nosocomial pathogen responsible for human infections, where antibiotic resistance further complicates the treatments. In S. marcescens, biofilm formation and virulence factor production are controlled via quorum sensing (QS) system. QS is a signaling system that enables gene regulation to control diverse physiological functions in bacteria. Essential oils have shown to be potential in diminishing the pathogenicity and virulence of drug-resistant bacteria. This study was performed to determine whether eugenol would affect QS system, biofilm formation and virulence factor production of S. marcescens. Materials and Methods: Biofilm formation, extracellular virulence factor production (hemolysin and protease), swarming motility and pigment formation of S. marcescens ATCC 13880 and S. marcescens Sm2 were assessed after eugenol exposure at 1.25 and 2.5 µg/ml concentrations. The expression of genes involved in motility (flhD), attachment (fimC), biofilm formation (bsmB, bsmA), and QS regulatory (swrR) were also evaluated. Results: Eugenol treatment at 1.25 and 2.5 µg/ml concentrations caused a significant reduction in biofilm formation. The pigment, hemolysin and protease production of two studied S. marcescens strains, also reduced significantly by eugenol treatments (p<0.05). The bsmA, bsmB, flhD and fimC genes were down-regulated after eugenol treatment. The swrR gene expression was also reduced significantly by eugenol in both S. marcescens strains (p<0.05). Conclusion: Eugenol inhibited quorum sensing-regulated functions of two studied S. marcescens strains.

Reduction of disinfection efficacy of contact lens care products on the global market in the presence of contact lenses and cases

“…[20][21][22][23][24] Numerous studies have shown that ATCC 9027, ATCC 6538 and ATCC 13880 are similarly susceptible to antibacterial activity as other strains and species, 22 25-32 and that these strains have similar virulence or virulence factors when used in other species or with human cells. [33][34][35][36][37][38][39] As we expected, and similar to results we have reported previously for products on the American market, 9 most CLCs meet or exceed the primary criteria set forth by the ISO standard. The only exception found in this study was when renu Multiplus, All Clean Soft, and Kombilösung Super were challenged with Serratia marcescens.…”

“…However, these strains are a critical and commonly used piece of evidence when testing for sterility and microbial contamination, as well as biofilms 20–24. Numerous studies have shown that ATCC 9027, ATCC 6538 and ATCC 13880 are similarly susceptible to antibacterial activity as other strains and species,22 25–32 and that these strains have similar virulence or virulence factors when used in other species or with human cells 33–39. As we expected, and similar to results we have reported previously for products on the American market,9 most CLCs meet or exceed the primary criteria set forth by the ISO standard.…”

Antibacterial and Anti-Quorum Sensing Studies of Extracellularly Synthesized Silver Nanoparticles from Azadirachta indica (Neem) Leaf Extract

“…QS signal molecules N-acylhomoserinelactones( AHL ,C4 and C6) regulate different genes responsible for production of various virulence factors, secondary metabolite, prodiogosin and biofilm formation in Serratia [33][34][35] . Eugenol, a plant metabolite could prevent the production of QS-controlled virulence factors like pigment prodigiosin, protease and hemolysin.The QSmediated biofilm formation stages such as swarming motility, formation of microcolony and extracellular polysaccharide production were inhibited and expression of genes responsible for QS system, adhesion, motility, and biofilm formation were down-regulated 36 .…”

Anti-Biofilm Strategies: A Focused Review on Innovative Approaches

“…Another plant metabolite able to prevent the production of QS-controlled virulence factors and related to BF formation is eugenol [141]. Fekrirad et al indicated that this catechol was able to prevent the production of QS-controlled virulence factors, such as pigment prodigiosin, protease, and hemolysin in Serratia marcescens [142]. Specifically, they found that eugenol affected swarming motility, the formation of the microcolony, and extracellular polysaccharide via the downregulation of correlated genes.…”