Lentinula edodes methanol extract inhibits biofilm formation and autoinducer-2 production by Eikenella corrodens, a periodontopathogenic bacterium

Abstract

Shiitake (Lentinula edodes) is a cultivated edible mushroom species with medicinal properties. We investigated the inhibitory effect of shiitake methanol extract on biofilm formation by the periodontopathogenic bacterium Eikenella corrodens and the underlying mechanism. The extract inhibited biofilm formation by E. corrodens; extract obtained from the pileus part of new fresh shiitake especially had strong inhibitory effects. The biofilm-inhibitory effect was dose-dependent and was not due to bactericidal activity against E. corrodens; this effect was greater against the wild-type strain than the ΔluxS strain. The addition of the extract to E. corrodens culture medium significantly decreased autoinducer-2 production in the culture supernatant. The results suggest that the decrease in autoinducer-2 production by the shiitake methanol extract inhibited biofilm formation by E. corrodens.