Staphylococcus aureus colonizes rough regions of the skin of the hand. Healing of S. aureus-mediated wounds is promoted by the application of RNA III inhibiting peptide, which inhibits the production of S. aureus virulence factors, including δ-toxin. Herein, we investigated the level of hand-skin roughness in healthcare professionals after they used an alcohol-based hand rub containing polyoxyethylene lauryl ether (formulation E), which inhibits S. aureus δ-toxin production. The inhibition rate of S. aureus δ-toxin production by hand rubs, including formulation E, was calculated by quantifying S. aureus δ-toxin concentration in culture medium using high-performance liquid chromatography. Healthcare professionals used formulations E or S (reference alcohol-based hand rub) for 4 weeks. The surface evaluation of the scaliness (SEsc) value was used as an indicator of hand skin roughness. The ΔSEsc value was calculated by subtracting the SEsc value before using the alcohol-based hand rub from the SEsc value 4 weeks after use. The inhibition rates of S. aureus δ-toxin production by formulations E and S were 43% and 10%, respectively. Formulation E significantly reduced ΔSEsc. The difference in ΔSEsc values after using formulations E and S was significant. The inhibitory effect on S. aureus δ-toxin production was higher with formulation E than with formulation S. Compared to formulations S, formulation E was effective at reducing scaliness and alleviating hand-skin roughness. Furthermore, the inhibitory effect of formulation E on S. aureus δ-toxin production could be associated with a reduction in scaliness and alleviation of hand-skin roughness.

Antifungal agents are not always efficient in resolving vulvovaginal candidiasis (VVC), a common genital infection caused by overgrowth of Candida spp., including Candida albicans, or preventing recurrent infections. Although lactobacilli (which are dominant microorganisms constituting healthy human vaginal microbiota) are important barriers against VVC, the Lactobacillus metabolite concentration needed to suppress VVC is unknown. Therefore, we quantitatively evaluated Lactobacillus metabolite concentrations to determine their effect on Candida spp., including 27 vaginal strains of Lactobacillus crispatus, Lactobacillus jensenii, Lactobacillus gasseri, Lacticaseibacillus rhamnosus, and Limosilactobacillus vaginalis, with inhibitory abilities against biofilms of Candida clinical isolates. Lactobacillus culture supernatants suppressed viable bacteria by approximately 24%-92% relative to preformed Candida biofilms, but their suppression differed between strains, not species. Lactate production was necessary to suppress preformed biofilms and hyphal elongation of C. albicans, whereas hydrogen peroxide was not always essential. Both lactic acid and hydrogen peroxide were required to suppress Candida planktonic cell growth. Lactobacillus strains that significantly inhibited biofilm formation in culture supernatant also inhibited Candida adhesion to epithelial cells in an actual live bacterial adhesion competition test. Healthy human microflora and their metabolites may play important roles in the development of new antifungal agent against VVC caused by C. albicans.