CROSS INFECTIONS DUE TO COAGULASE-NEGATIVE STAPHYLOCOCCI IN HIGH-RISKPATIENTS

Until recently, infections due to coagulase-negative staphylococci (CN S) have been regarded as endogenous in origin. However, there are now increasingly reports in the literature on the endemic occurrence of di stinct strains of CNS. Several outbreaks due to CNS are reported in ca rdiac surgery or in neonates. The latter seem to be high risk populati ons in regard to CNS infections because of certain risk factors (i. e. degree of immunosupression, routine use of central venous catheters a nd parenteral lipids as well as broad spectrum antibiotic therapy). On the other hand, these newborn babies have no physiological skin flora and are therefore easily colonized by multiresistent bacteria. The pe rsistence of certain well-defined Staphylococcus epidermidis (SE) stra ins in neonatal intensive care units have been demonstrated over perio ds as long as a decade. Specific putative virulence factors (i. e. sli me production and polysaccharide/adhesin PS/A) were more common in end emic strains as compared to single isolates. Pulsed-field gel electrop horesis (PFGE) proves to be a powerful tool in the study of the epidem iology of CNS while other modern typing techniques (ribotyping, plasmi d typing) were also used in the literature to investigate outbreaks of CNS infections.