2 Identification of genes associated with exopolysaccharide production in Actinomyces oris isolated from an odontogenic abscess

Abstract

It is well known that because biofilm-forming bacteria produce a large amount of exopolysaccharides (EPS), they can cause chronic or persistent infections. However the genes associated with EPS production remain poorly understood. To identify gene(s) responsible for EPS production, we performed random mutagenesis against a clinical isolate, Actinomyces oris strain K20, which has considerable ability to continuously produce EPS. SEM observation revealed five EPS production-deficient mutants. One had a transposon insertion within a gene that encodes polysaccharide deacetylase. Extensive analysis around this gene showed the existence of several open reading frames predicted to be associated with the biosynthesis of sugar. Our findings indicated this gene might be implicated in EPS production in A. oris strain K20.