Anti-adhesive activity of extracts from edible and medicinal mushrooms against Campylobacter jejuni
Campylobacter jejuni is one of the most common bacterial causes of diarrhoea in the industrialised world , being associated with the occurrence of Guillain-Barré Syndrome (GBS)  and induces diseases partially through intestinal adherence . With increasing reports of C. jejuni drug resistance against standard antibiotics  investigations into anti-adhesive agents for the prevention of bacterial infection  are highly significant, particularly given the possibility of avoiding resistance . Different studies have shown anti-adhesive activity of different plant compounds against a variety of bacteria including C. jejuni . Although two studies report on anti-adhesive effects of fungal compounds/extracts against yeast  and virus , this is the first study that describes anti-adhesive effects of basidiomycetes against any bacteria. Nineteen extracts from 9 edible and medicinal mushroom species (Calvatia gigantea, Flammulina velutipes, Inonotus obliquus, Inonotus hispidus, Inonotus nodulosus, Inonotus dryadeus, Ganoderma lucidum, Ganoderma pfeifferi, Piptoporus betulinus) were screened for anti-adhesive activity against C. jejuni using modifications of previously published anti-adhesion assays [9, 10]. The 2 ethanolic extracts derived from the fruiting bodies of Inonotus nodulosus and Inonotus obliquus showed high anti-adhesive activity (IC50 0.017mg/mL and IC50 0.021mg/mL, respectively). Moreover, the methanolic extracts of the fruiting bodies of Calvatia gigantea and Piptoporus betulinus showed, although not dose dependent, high anti-adhesive activity (81%±13% and 71%±10%, respectively) at 0.002mg/mL. Further investigations need to be conducted to evaluate whether isolated compounds would be candidates for the development of novel drugs against bacterial adhesion.
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