Investigation on extracellular slime substance produced by Staphylococcus epidermidis.

The extracellular slime substance produced by Staphylococcus epidermidis was investigated. Slime production was assessed by bacterial agglutination in the presence of concanavalin A (Con A) or poly-L-lysine and by bacterial adherence to polyethylene. Media for slime production was optimized using these criteria. A phenol-saline extract of crude slime was separated into four fractions on a DEAE-sepharose column. Total protein and sugar content and the monosaccharide constituents were determined. Crude slime and the phenol-saline extract showed a strong precipitation reaction with Con A and poly-L-lysine (double diffusion). Fractions I and II containing mannose as the most abundant sugar reacted with Con A and two other mannose-specific lectins (Lens culinaris, Pisum sativum). This reaction could be inhibited by mannose. Fractions III and IV were precipitated by poly-L-lysine, probably due to a reaction with glucuronic acid which was only present in these fractions. Precoating of polyethylene with crude slime, phenol-saline extract and fractions III and IV resulted in a marked inhibition of attachment of staphylococcal cells. Production of the extracellular slime substance was completely inhibited by subinhibitory concentrations of the glycosylation inhibitor tunicamycin, whereas penicillin had no influence. Extracellular slime substance produced by S. epidermidis seems to be a complex of glycoconjugate character and plays an important role in the attachment to synthetic polymers. The production of slime by staphylococci can be easily determined using mannose specific lectins and poly-L-lysine.