The antibacterial efficacy of a foam mouthwash and its ability to remove biofilms

Abstract Objectives/Aims To evaluate the antimicrobial activity of a newly developed foam mouthwash containing a modified lactoperoxidase system in vitro. Materials and methods Biofilms of five bacterial species were developed on hydrophobic and hydrophilic surfaces whilst salivary-based biofilm was grown on tooth enamel. Each surface was exposed to the foam mouthwash or saline in vitro. Optical density and scanning electron microscopy (SEM) was used to determine retention of the biofilm following 5 or 30 s exposure time. Results The foam mouthwash was active against biofilms formed by S. aureus, K. rhizophila, M. thailandicus, E. coli, and C. violaceum and eliminated significant amount of biofilm from each surface; immature 4 h biofilm was less resistant than 24 h biofilm. A 30 s rinse showed best performance, with removal of up to 66% of biofilm from the hydrophilic surface. SEM imaging confirmed oral biofilm removal from the enamel surface after a 5 s rinse with the foam mouthwash. Discussion Foam mouthwash demonstrated a significant impact on growing biofilm when compared against saline solution. Growing biofilms were more susceptible to the action of the foam mouthwash, which justifies after-meal use of the mouthwash when traditional dentifrices may not be accessible. Conclusions Foam mouthwash can be a convenient on-the-go format of oral care products that can be used after meals or when needed to reduce the risk of biofilm-associated oral conditions

Regulation of Monospecies and Mixed Biofilms Formation of Skin Staphylococcus aureus and Cutibacterium acnes by Human Natriuretic Peptides

Staphylococcus aureus and Cutibacterium acnes are common representatives of the human skin microbiome. However, when these bacteria are organized in biofilm, they could be involved in several skin disorders such as acne or psoriasis. They inhabit in hollows of hair follicles and skin glands, where they form biofilms. There, they are continuously exposed to human hormones, including human natriuretic peptides (NUPs). We first observed that the atrial natriuretic peptide (ANP) and the C-type natriuretic peptide (CNP) have a strong effect S. aureus and C. acnes biofilm formation on the skin. These effects are significantly dependent on the aero-anaerobic conditions and temperature. We also show that both ANP and CNP increased competitive advantages of C. acnes toward S. aureus in mixed biofilm. Because of their temperature-dependent effects, NUPs appear to act as a thermostat, allowing the skin to modulate bacterial development in normal and inflammatory conditions. This is an important step toward understanding how human neuroendocrine systems can regulate the cutaneous microbial community and should be important for applications in fundamental sciences, medicine, dermatology, and cosmetology

Effect of two cosmetic compounds on the growth, biofilm formation activity, and surface properties of acneic strains of Cutibacterium acnes

International audienc

The Impact of Norepinephrine on Mono-Species and Dual-Species Staphylococcal Biofilms

The effect of norepinephrine (“NE”) on Gram-negative bacteria is well characterized; however, little is known about the impact of NE on cutaneous Gram-positive skin residents, especially staphylococci. In this study, the impact of NE on monospecies and dual-species biofilms of Staphylococcus epidermidis and S. aureus model strains was investigated for the first time. Biofilms were grown in two different models (on polytetrafluoroethylene (“PTFE”) cubes and glass microfiber filters (“GMFFs”)) and additionally kinetic measurements of bacterial growth was performed. We have shown that NE can affect the biofilm formation of both species with a strong dependence on aerobic or anaerobic culture conditions in different models. It was shown that S. epidermidis suppresses S. aureus growth in dual-species biofilms and that NE can accelerate this process, contributing to the competitive behavior of staphylococci

Effect of two cosmetic compounds on the growth, biofilm formation activity, and surface properties of acneic strains of Cutibacterium acnes and Staphylococcus aureus

International audienc

Use of Polyguanidine-Derivatives-Based Biocides for Microbial Growth Inhibition and for the Development of a Novel Polyethylene-Based Composite Material Resistant to the Formation of Multispecies Microbial Biofilms

This study aimed to investigate the dependence of the biocidal activity of polyguanidine (co)polymers on their structure during the formation of biofilms by active PE-degrading cultures of model microorganisms. The Bc-2 copolymer of methacryloyl guanidine hydrochloride (MGHC) and diallyldimethylammonium chloride (DADMAC), which suppressed both the formation of biofilms and the growth of planktonic cultures, exhibited the highest activity. When PE was exposed in tropical soil, the composition of the microbial community on the PE surface differed significantly from that of the community in the surrounding soil. In particular, the proportion of Actinobacteria increased from 7% to 29%, while the proportion of Bacteroidetes decreased from 38% to 8%. Keywords: biofilms, polyhexamethylene guanidine salts, dynamics of biofilm formation, antibiofilm effect, composite material

Draft Genome Sequence of Kytococcus schroeteri Strain H01, Isolated from Human Skin

International audienc

Substance P and Calcitonin Gene-Related Peptide: Key Regulators of Cutaneous Microbiota Homeostasis

International audienceNeurohormones diffuse in sweat and epidermis leading skin bacterial microflora to be largely exposed to these host factors. Bacteria can sense a multitude of neurohormones, but their role in skin homeostasis was only investigated recently. The first study focused on substance P (SP), a neuropeptide produced in abundance by skin nerve terminals. SP is without effect on the growth of Gram-positive (Bacillus cereus, Staphylococcus aureus, and Staphylococcus epidermidis) and Gram-negative (Pseudomonas fluorescens) bacteria. However, SP is stimulating the virulence of Bacillus and Staphylococci. The action of SP is highly specific with a threshold below the nanomolar level. Mechanisms involved in the response to SP are different between bacteria although they are all leading to increased adhesion and/or virulence. The moonlighting protein EfTu was identified as the SP-binding site in B. cereus and Staphylococci. In skin nerve terminals, SP is co-secreted with the calcitonin gene-related peptide (CGRP), which was shown to modulate the virulence of S. epidermidis. This effect is antagonized by SP. Identification of the CGRP sensor, DnaK, allowed understanding this phenomenon as EfTu and DnaK are apparently exported from the bacterium through a common system before acting as SP and CGRP sensors. Many other neuropeptides are expressed in skin, and their potential effects on skin bacteria remain to be investigated. Integration of these host signals by the cutaneous microbiota now appears as a key parameter in skin homeostasis

Epinephrine Affects Ribosomes, Cell Division, and Catabolic Processes in <i>Micrococcus luteus</i> Skin Strain C01: Revelation of the Conditionally Extensive Hormone Effect Using Orbitrap Mass Spectrometry and Proteomic Analysis

In the current study, extensive Orbitrap mass spectrometry analysis was conducted for skin strain Micrococcus luteus C01 planktonic cultures and biofilms after 24 h and 72 h of incubation either in the presence of epinephrine or without any implementations. The investigation revealed the complex and conditionally extensive effect of epinephrine at concentrations closer to normal blood plasma concentrations on both planktonic cultures and biofilms of skin strain M. luteus C01. The concentrations of hundreds of proteins changed during the shift from planktonic growth mode to biofilm and hundreds of proteins were downregulated or upregulated in the presence of epinephrine. Ribosomal, TCA, and cell division proteins appear to be the most altered in their amounts in the presence of the hormone. Potentially, the regulatory mechanism of this process is connected with c-di-GMP and histidine kinases, which were affected by epinephrine in different samples. The phenomenon of epinephrine-based biofilm regulation in M. luteus C01 has wide implications for microbial endocrinology and other research areas

Atrial Natriuretic Peptide Affects Skin Commensal <i>Staphylococcus epidermidis</i> and <i>Cutibacterium acnes</i> Dual-Species Biofilms

The first evidence of the atrial natriuretic peptide (ANP) effect on mono-species and dual-species biofilms of skin commensals Cutibacterium acnes and Staphylococcus epidermidis was obtained in different model systems. Elucidation of the mechanism of action of hormones on the microbial communities of human skin is an important physiological and medical aspect. Under anaerobic conditions, ANP at a concentration of 6.5 × 10−10 M inhibits the growth of S. epidermidis biofilms and stimulates the growth of C. acnes biofilms, and a lesser effect has been demonstrated on planktonic cultures. In biofilms, ANP stimulates aggregation in C. acnes and aggregate dispersion of S. epidermidis, while in S. epidermidis, ANP also stimulates the metabolic activity of cells. Analysis of dual-species biofilms has shown the dominance of S. epidermidis, while ANP increases the ratio of C. acnes biomass in the community. ANP decreases the growth rate of S. epidermidis biofilms and increases that of C. acnes. The effect of ANP is not dependent on the surface type and probably affects other targets in microbial cells. Thus, the potential regulatory effect of human ANP on skin microbe dual-species communities has been shown, and its potential has been demonstrated to change microbiota homeostasis on the skin