Probiotic adhesion to skin keratinocytes and underlying mechanisms

info:eu-repo/semantics/publishedVersio

Evaluation and insights into chitosan antimicrobial activity against anaerobic oral pathogens

The objective of this study was to assess the antimicrobial capability of non-chemically altered chitosan as an alternative to traditional antimicrobials used in the treatment of oral infections. The action mechanism of chitosan was also ascertained. High and low molecular weight chitosan showed antimicrobial activity at low concentrations for all tested bacteria with the MICs varying between 1 and 7 mg/ ml with a drop of efficacy relatively to the action of LMW chitosan. In addition chitosan showed also to be an effective bactericidal presenting bactericidal effect within 8 h at the latest. Additionally the evaluation of chitosan’s action mechanism showed that both MWs acted upon the bacterial cell wall and were not capable of interacting with the intracellular substances, as showed by the inefficacy obtained in the flocculation assayinfo:eu-repo/semantics/publishedVersio

Chitosan: antimicrobial action upon staphylococci after impregnation onto cotton fabric

Background: High levels of viable Staphylococcus aureus, which are often found on inflamed skin surfaces, are usually associated with atopic dermatitis. Textiles, owing to their high specific surface area and intrinsic hydrophilicity, retain moisture while also providing excellent environmental conditions for microbial growth and proliferation. Recently, a number of chemicals have been added to textiles, so as to confer antimicrobial activity. Aims: To evaluate the antimicrobial action of chitosan upon selected skin staphylococci. Methods and Results: We isolated staphylococci from normal skin of 24 volunteers and studied their survival upon contact with chitosan-impregnated cotton fabric. Low and high molecular weight chitosans were used at two concentrations; all four did effectively reduce the growth of some staphylococci (namely Staph. aureus), by up to 5 log cycles, thus unfolding a potential towards control and even prevention of related skin disorders. Conclusion: Our data suggest an effective, but selective antibacterial action of chitosans towards skin bacteria. Significance and Impact of the Study: The possibility to use a natural biopolymer incorporated in a textile to alleviate and even treat some of the symptoms associated with this skin condition may raise an alternative to existing medical treatments. The selectivity observed prevents full elimination of bacteria from the skin surface, which is an advantage.info:eu-repo/semantics/publishedVersio

A comprehensive study into the impact of a chitosan mouthwash upon oral microorganism's biofilm formation in vitro

Modern dentistry emphasizes the importance of dental plaque control to improve oral health. To that endthe development of oral care formulations has been geared toward the incorporation of antiplaque agentsthat may play a crucial role in oral health maintenance. In later years the research into antiplaque agentshas led to the discovery of compounds with significant capability to affect biofilm formation. Among thesecompounds was chitosan, a polysaccharide which showed great ability to interfere with Streptococcusmutans biofilm formation. As such the aim of this work was to incorporate chitosan into a mouthwashmatrix and assess its effect upon biofilm formation of oral microorganisms. This assessment was per-formed via study of the impact the mouthwash upon microbial adherence, biofilm formation and maturebiofilms. Additionally, the action of the chitosan mouthwash was compared with two commerciallyavailable mouthwashes. The results here obtained show that only the chitosan containing mouthwashwas capable of interfering with all microorganisms’ adherence, biofilm formation and mature biofilmswhile at the same time showing vastly superior activity than both commercial mouthwashes assayed.As such a chitosan mouthwash shows great potential as a natural and efficient alternative to traditionalmouthwashes.info:eu-repo/semantics/publishedVersio

Queijo de minas artesanal da Serra da Canastra: influência da altitude das queijarias nas populações de bactérias acidolácticas

Amostras de queijo de minas artesanal foram coletadas em 18 queijarias localizadas em propriedades rurais da região da Serra da Canastra, Minas Gerais, com o objetivo de avaliar a influência da altitude sobre a população de bactérias acidolácticas. As queijarias estavam distribuídas nas altitudes de 600 a 900m, 900 a 1000m e mais de 1000m. Observaram-se populações mais elevadas de bactérias acidolácticas nas amostras de queijo da altitude de 600 a 900m. Lactobacillus rhamnosus, Lactobacillus casei e Lactobacillus plantarum foram os principais microrganismos isolados e identificados por PCR ARDRA 16S-23S rDNA, além de Enterococcus spp., Lactococcus spp. e outras espécies de Lactobacillus. Sugere-se que estas espécies estejam adaptadas ao ambiente de produção do queijo de minas artesanal produzido na região, o que resultaria em características sensoriais próprias do produto