A method of optimising slime production produced by Staphylococcus epidermis and its quantitative assay was developed, which gave a preliminary indication of its identity and an assessment of the correlation between slime production and adherence of the organism to implants. After inducing vigorous growth in brain heart infusion broth to stationary phase, all nutrients were removed by washing and the organisms resuspended in sterile deionised water with added magnesium. After

Extracellular slime (Ecs) from three strains of Staphylococcus epidermidis was prepared and added to fresh suspensions of polymorphonuclear neutrophils. Phagocytic ingestion and killing of opsonised and unopsonised S. epidermidis strains was assessed over time using slide preparations stained by the Gram's method and microbiological culture. Both phagocytic ingestion and killing were inhibited. Investigation as to one possible mechanism of action of Ecs on phagocytes was performed using 1 mu polystyrene spheres which were incubated overnight with Ecs. It was found that the surface tension was altered with Ecs making the beads more hydrophilic, a factor which may interfere with the phagocytic response to infection.

Seven cases of ventriculoatrial shunt infection with immune complex disease are reported in order to demonstrate the usefulness of measurement of levels of specific antibody to Staphylococcus epidermidis in diagnosis. Blood and cerebrospinal fluid cultures gave misleading results, and there was initial doubt about the diagnosis in all seven cases. All showed grossly elevated titres of antibody to Staphylococcus epidermidis, with raised serum C-reactive protein levels and depressed complement levels. Measurement of antibody to Staphylococcus epidermidis enables the diagnosis of chronic ventriculoatrial shunt infection to be made rapidly and reliably.

Extracellular slime (Ecs) from three strains of Staphylococcus epidermidis was prepared and added to fresh suspensions of polymorphonuclear neutrophils. Phagocytic ingestion and killing of opsonised and unopsonised S. epidermidis strains was assessed over time using slide preparations stained by the Gram's method and microbiological culture. Both phagocytic ingestion and killing were inhibited. Investigation as to one possible mechanism of action of Ecs on phagocytes was performed using 1 mu polystyrene spheres which were incubated overnight with Ecs. It was found that the surface tension was altered with Ecs making the beads more hydrophilic, a factor which may interfere with the phagocytic response to infection.

Sera and dialysis effluent from 20 patients on continuous ambulatory peritoneal dialysis (CAPD) with coagulase-negative staphylococcal (CNS) peritonitis were examined by immunoblotting for antibody activity against CNS. Immunoblotting was highly sensitive and demonstrated significantly greater antibody activity in serum and dialysate of infected patients compared with that of uninfected CAPD patients or healthy volunteers. Fourteen of 20 infected CAPD patients had strong antibody activity (> 7 bands); one patient had equivocal activity. Five patients had weak antibody activity, two of whom suffered from recurrent peritonitis with distinguishable CNS strains despite a satisfactory CAPD technique. One patient with a poor CAPD technique had strong antibody activity, but suffered from recurrent peritonitis. Examination of sequential sera suggested that seroconversion occurred soon after insertion of the Tenckhoff catheter, possibly in the absence of clinical infection. Antibody activity against a 25 kDa staphylococcal protein was significantly associated with peritonitis.