Ethanol consumption and the susceptibility of mice to Listeria monocytogenes infection

Background: It is well known that excessive alcohol consumption correlates with increased infectious disease. However, the molecular microbiological and immunological bases for ethanol-induced alterations in host defense are largely unknown. Methods: To study the effect of alcohol consumption on the pathogenesis of intracellular bacteria, we examined the relative susceptibility of alcohol-fed mice to a virulent strain of Listeria monocytogenes. Results: Based on lethal dose 50% determinations, survival curve analysis, and bacterial burden, alcohol consumption did not increase the susceptibility of C57BL/6, BALB/c, or A/J mice to systemic infection by strain EGD. Mice fed an ethanol-containing liquid diet showed slightly reduced susceptibility to Listeria. Alcohol consumption modestly decreased bacterial numbers in the spleen but not the liver. We also found that mice fed a typical solid diet were more sensitive to EGD infection than were animals fed a control liquid-containing diet. Conclusions: This study indicates that alcohol consumption may not always increase infectious disease progression.