[Extracellular polysaccharides of coagulase-negative staphylococci and their role in pathogenicity]

Coagulase-negative staphylococci have been recognised as important pathogens in biomaterial-associated infections and a number of studies have been carried out to identify virulence factors for these microorganisms. Among them bacterial slime has been most extensively investigated, since it is considered to participate in the staphylococcal adherence and growth on polymer surfaces. It has been shown that on the surface of infected biomaterial bacteria are embedded in a heavy slime layer, that allows them to escape host defence and resist to the antimicrobial action of antibiotics. In this review article the reasons for the growing pathogenicity of coagulase-negative staphylococci are discussed. Also the methods for studying bacterial adherence and slime production are presented and the latest data on chemical composition of coagulase-negative extracellular polysaccharides are reported.