Menaquinone (Vitamin K2) Enhancement of <i>Staphylococcus aureus</i> Biofilm Formation

Abstract

During infection, Staphylococcus aureus is exposed to exogenous menaquinone which is essential for the human blood clotting cascade. The effect of exogenous menaquinone on S. aureus phenotypic expression is not known. To test whether menaquinone affects expression of virulence-associated phenotypes, methicillin-sensitive (MSSA) and-resistant (MRSA) S. aureus strains (n = 8) were grown in the presence of menaquinone (0.001-12 µg/ml). Capsule production, biofilm formation (plastic and fibronectin-coated microtiter plates) and carotenoid levels were determined spectrophotometrically after growth in Mueller Hinton broth (MH; 24-hr, 37˚C). All experiments were, at minimum, done in triplicate and repeated twice. Menaquinone at physiologic levels (0.01 µg/ml MH) significantly increased (p < 0.05) biofilm formation on plastic in a manner that was bacterial population size dependent. In addition, menaquinone (0.05-4 µg/ml) significantly increased (p < 0.05) biofilm formation on fibronectin-coated surfaces for four MSSA strains and one MRSA strain by two to six-fold as compared to medium controls. However, menaquinone had no effect on capsule production or cell-associated carotenoid levels. Menaquinone's effect on biofilm formation on fibronectin-coated surfaces appears to be regulated by sarA. These findings are the first to demonstrate that a vitamin at concentrations reported in humans affects S. aureus virulence-associated phenotypes.

Metagenome sequencing-based strain-level and functional characterization of supragingival microbiome associated with dental caries in children

“…Polyamines, for example, are known to play an important role in biofilm formation by many bacteria [47] and may thus have a similar role in formation of dental plaque. 1,4-dihydroxy-2-naphthoate and menaquinols are precursors of vitamin K2 (menaquinone) which, in a recent study, has been shown to enhance biofilm formation by Staphylococcus aureus [48]. Similarly, there is evidence to suggest uric acid boosts biofilm formation by Enterococcus faecalis [49].…”

Effects of Metabolites Derived From Gut Microbiota and Hosts on Pathogens

“…In addition, VK2 have been reported to affect the phenotype expression of pathogens. Different concentrations of VK2 enhance the biofilm formation of S. aureus , and the response to exogenous VK2 signals appears to be under the regulation of sarA in S. aureus (Kirby et al, 2014 ). In these processes, VK2 play a vital role in maintaining the survival strategies of pathogens.…”

Retroviral infection and commensal bacteria dependently alter the metabolomic profile in a sterile organ

“…Of these small molecules, metabolites have been shown to serve as an energy source, modulate diseases and psychiatric disorders, promote intestinal barrier function, and modulate the immune system (5)(6)(7) Metabolites have both positive and negative effect on pathogenic bacteria. These effects include enhanced biofilm formation, increased expression of virulence factors (8)(9)(10), disruption of bacterial cell structures, suppression of bacterial growth, and stimulation of innate immune cell proliferation (8,(11)(12)(13)(14). Viral infections are also impacted by metabolites.…”