An in vitro test of the efficacy of silver-containing wound dressings against Staphylococcus aureus and Pseudomonas aeruginosa in simulated wound fluid

An isothermal microcalorimetric assay was used to quantify the efficacy of a silver-containing wound dressing against two common wound pathogens, Pseudomonas aeruginosa and Staphylococcus aureus. The growth patterns of the two species were unique and varied depending on the environment in which the organisms were grown. Addition of non-silver-containing dressing altered the growth kinetics while addition of silver (contained either in a dressing or as AgNO3 solution) was seen to elicit inhibition and/or kill depending on concentration. Tests were conducted in nutrient broth and simulated wound fluid. It was found that minimum inhibitory and minimum bactericidal concentration values were higher in simulated wound fluid and under anaerobic conditions. Bioavailability of silver from the wound dressing was 35% against S. aureus in nutrient broth and 68% against both species in simulated wound fluid. The data highlight the importance of developing and conducting in vitro assays in biorelevant media

Influence of probiotic bacteria on gut microbiota composition and gut wall function in an in-vitro model in patients with Parkinson's disease

We report here the potential role of a 4-strain probiotic suspension for use with patients with Parkinson's disease (PD). Stool samples from a group of three patients with diagnosed PD were used to create microbiotas in an in-vitro gut model. The effects of dosing with an oral probiotic suspension (Symprove) on bacterial composition and metabolic activity in the microbiotas was evaluated over 48 h and compared with healthy controls. Additionally, the effect of probiotic dosing on epithelial tight-junction integrity, production of inflammatory markers and wound healing were evaluated in cell culture models. In general, the relative proportions of the main bacterial phyla in the microbiotas of PD patients differed from those of healthy subjects, with levels of Firmicutes raised and levels of Bacteroidetes reduced. Dosing with probiotic resulted in a change in bacterial composition in the microbiotas over a 48 h period. Several other indicators of gut health changed upon dosing with the probiotic; production of short chain fatty acids (SCFAs) and lactate was stimulated, levels of anti-inflammatory cytokines (IL-6, IL-10) increased and levels of pro-inflammatory cytokines and chemokines (MCP-1 and IL-8) decreased. Tight junction integrity was seen to improve with probiotic dosing and wound healing was seen to occur faster than a control. The data suggest that if development and/or progression of PD is influenced by gut microbiota dysbiosis then supplementation of the diet with a properly formulated probiotic may be a useful adjunct to standard treatment in clinic

An in vitro test of the efficacy of silver-containing wound dressings against Staphylococcus aureus and Pseudomonas aeruginosa in simulated wound fluid

An isothermal microcalorimetric assay was used to quantify the efficacy of a silver-containing wound dressing against two common wound pathogens, Pseudomonas aeruginosa and Staphylococcus aureus. The growth patterns of the two species were unique and varied depending on the environment in which the organisms were grown. Addition of non-silver-containing dressing altered the growth kinetics while addition of silver (contained either in a dressing or as AgNO3 solution) was seen to elicit inhibition and/or kill depending on concentration. Tests were conducted in nutrient broth and simulated wound fluid. It was found that minimum inhibitory and minimum bactericidal concentration values were higher in simulated wound fluid and under anaerobic conditions. Bioavailability of silver from the wound dressing was 35% against S. aureus in nutrient broth and 68% against both species in simulated wound fluid. The data highlight the importance of developing and conducting in vitro assays in biorelevant media