A Novel Organo-Selenium Bandage that Inhibits Biofilm Development in a Wound by Gram-Positive and Gram-Negative Wound Pathogens.

Biofilm formation in wounds is a serious problem which inhibits proper wound healing. One possible contributor to biofilm formation in a wound is the bacteria growing within the overlying bandage. To test this mechanism, we used bandages that contained a coating of organo-selenium that was covalently attached to the bandage. We tested the ability of this coating to kill bacteria on the bandage and in the underlying tissue. The bandage material was tested with both lab strains and clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa and Staphylococcus epidermidis. It was found that the organo-selenium coated bandage showed inhibition, of biofilm formation on the bandage in vitro (7-8 logs), with all the different bacteria tested, at selenium concentrations in the coating of less than 1.0%. These coatings were found to remain stable for over one month in aqueous solution, 15 min in boiling water, and over 6 years at room temperature. The bandages were also tested on a mouse wound model where the bacteria were injected between the bandage and the wound. Not only did the selenium bandage inhibit biofilm formation in the bandage, but it also inhibited biofilm formation in the wound tissue. Since selenium does not leave the bandage, this would appear to support the idea that a major player in wound biofilm formation is bacteria which grows in the overlying bandage.

Pseudomonas putida F1 has multiple chemoreceptors with overlapping specificity for organic acids.

Previous studies have demonstrated that Pseudomonas putida strains are not only capable of growth on a wide range of organic substrates, but also chemotactic towards many of these compounds. However, in most cases the specific chemoreceptors that are involved have not been identified. The complete genome sequences of P. putida strains F1 and KT2440 revealed that each strain is predicted to encode 27 methyl-accepting chemotaxis proteins (MCPs) or MCP-like proteins, 25 of which are shared by both strains. It was expected that orthologous MCPs in closely related strains of the same species would be functionally equivalent. However, deletion of the gene encoding the P. putida F1 orthologue (locus tag Pput_4520, designated mcfS) of McpS, a known receptor for organic acids in P. putida KT2440, did not result in an obvious chemotaxis phenotype. Therefore, we constructed individual markerless MCP gene deletion mutants in P. putida F1 and screened for defective sensory responses to succinate, malate, fumarate and citrate. This screen resulted in the identification of a receptor, McfQ (locus tag Pput_4894), which responds to citrate and fumarate. An additional receptor, McfR (locus tag Pput_0339), which detects succinate, malate and fumarate, was found by individually expressing each of the 18 genes encoding canonical MCPs from strain F1 in a KT2440 mcpS-deletion mutant. Expression of mcfS in the same mcpS deletion mutant demonstrated that, like McfR, McfS responds to succinate, malate, citrate and fumarate. Therefore, at least three receptors, McfR, McfS, and McfQ, work in concert to detect organic acids in P. putida F1.

Efficacy of aromatherapy (Lavandula angustifolia) as an intervention for agitated behaviours in Chinese older persons with dementia: a cross-over randomized trial.

BACKGROUND: Agitated behaviours among persons with dementia are distressing to both patients and their caregivers. As pharmacological interventions may be limited by their potentially adverse effects, the use of complementary therapies for treatment of agitation has become more popular and aromatherapy is the fastest growing one. OBJECTIVES: This study investigates the effectiveness of lavandula angustifolia (lavender) in treating agitated behaviours of demented people in Hong Kong. METHODS: It was a cross-over randomized trial. Seventy Chinese older adults with dementia were recruited; half were randomly assigned to the active group (lavender inhalation) for three weeks and then switched to control group (sunflower inhalation) for another three weeks; the other half did the opposite. Clinical response was evaluated using the Chinese versions of Cohen-Mansfield Agitation Inventory (CCMAI) and Neuropsychiatric Inventory (CNPI). RESULTS: The mean CCMAI total scores decreased from 24.68 to 17.77(t=10.79, df=69, p<0.001). The CNPI scores changed from 63.17 (SD=17.81) to 58.77 (SD=16.74) (t=14.59, df=69, p<0.001) after receiving Treatment A (Lavandula Angustifolia). There were no period and sequential effects noted. CONCLUSION: In summary, lavender is effective as an adjunctive therapy in alleviating agitated behaviours in Chinese patients with dementia. In a patient population particularly vulnerable to side effects of psychotropic medications, aromatherapy using lavender may offer an alternative option.