vitamin E improves the action of some antibiotics against MRSA

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J Med Microbiol. 2011 Aug 11. [Epub ahead of print]Vitamin E improves the in vivo efficacy of tigecycline and daptomycin in an animal model of wounds infected with methicillin resistant Staphylococcus aureus.Provinciali M, Cirioni O, Orlando F, Pierpaoli E, Barucca A, Silvestri C, Ghiselli R, Scalise A, Brescini L, Guerrieri M, Giacometti A.Source1 Experimental Animal Models for Aging Unit, Scientific Technological Area, I.N.R.C.A. I.R.R.C.S.;AbstractRelevant bacterial load in cutaneous wound significantly interferes with the normal process of healing. Vitamin E (VE) is known as immunomodulator and immune enhancer. We report that administration of VE plus daptomycin (DAP) or tigecycline (TIG) was efficacy in increasing antimicrobial activity in a mouse model of wound infection due to methicillin-resistant Staphylococcus aureus (MRSA). Wound, established through the panniculus carnosus of mice, was inoculated with MRSA. Mice were assigned to six groups: a VE pretreated group with no antibiotics given after MRSA challenge, two VE pretreated groups plus DAP or TIG given after MRSA challenge; two groups treated with only DAP or TIG after MRSA challenge, and a control group which did not receive any treatment. Main outcome measures were: quantitative bacterial culture and analysis of Natural Killer (NK) cytotoxicity and leukocyte phenotype. Bacterial cultures of mice receiving antibiotics alone showed a -3-log decrease, VE plus TIG determined a -4-log decrease, while VE plus DAP the highest efficacy (-5-log decrease). The higher antimicrobial effect exerted by VE plus antibiotics was associated with increased levels of NK cytotoxicity, with a preferential modulation of leukocyte populations in VE plus DAP treated mice. These data suggest that the combination of VE with antibiotic treatment act in synergy. VE may be useful for the management of infected wounds as an immune enhancer in immunoprophylactic combinations with DAP or TIG.