Slime production, adherence and hydrophobicity in coagulase-negative staphylococci causing peritonitis in peritoneal dialysis

Attachment of coagulase-negative staphylococci to plastic surfaces by means of hydrophobic interaction and slime production may be important in producing catheter associated infections. In continuous ambulatory peritoneal dialysis (CAPD), the relationship between these properties and disease is unclear and the effect of dialysate fluid is not considered. For a collection of coagulase-negative staphylococci from CAPD patients, slime production and adherence were measured by colorimetric methods and hydrophobicity was determined by autoaggregation in ammonium sulphate solution. Comparison of 73 nasal isolates with 69 isolates from peritonitis showed no significant differences with respect to three properties, with the exception of a greater adherence of peritoneal isolates in dialysate because of a greater proportion of staphylococcal species other than Staphylococcus epidermidis. Fewer strains showed adherence in dialysate ( 8·5%) than in broth ( 66%) but the proportion of strains producing slime was similar. The milieu of the bacteria rather than the organisms themselves may be of greater importance in the establishment of infection.