Blood proteins do not promote adherence of coagulase-negative staphylococci to biomaterials

Abstract

We studied the effects of in vitro and in vivo coating of catheters with human blood proteins on binding of coagulase-negative staphylococci. Coating resulted in no enhancement of binding. Catheters coated in vitro bound fewer organisms than uncoated catheters. Host proteins do not enhance adherence of coagulase-negative staphylococci to biomaterials.Coagulase-negative staphylococci (CoNS) have become major nosocomial pathogens because of their capacity to colonize plastic biomaterials used in catheters and prosthetic devices (7). Several mechanisms have been proposed to explain this adherence to biomaterials, but the problem is far from solved (6,10,18,20). Recent studies suggest that host proteins coated onto biomaterials promote adherence of CoNS (10, 21).We have proposed that the capsular polysaccharide/adhesin (PS/A) mediates the initial adherence of CoNS to plastic biomaterials. We noted that strains of CoNS which produced PS/A and slime (PS/A' slime') (20) adhered in high numbers to native, uncoated plastics, such as silicon elastomer. PS/Aslime-strains adhere to plastics in much smaller numbers. In the present study, we examined the effect of precoating catheters in vitro with human blood, serum, and purified blood proteins on adherence of both PS/A' slime' and PS/Aslimestrains of CoNS. We also studied adherence of CoNS to catheters coated in vivo with blood proteins after insertion into volunteers or hospitalized patients.CoNS were isolated from patients with clear-cut clinical diagnoses of catheter-related sepsis, dialysis-related peritonitis, endocarditis, or cerebrospinal fluid shunt infection and were identified as Staphylococcus epidermidis by a Sceptor System (Staphylococcus MIC/ID Panel; Becton Dickinson, Towson, Md.). Strains were categorized as PS/A' or PS/Aby enzyme-linked immunosorbent assay inhibition using polyclonal antibody specific for the PS/A antigen purified from S. epidermidis RP62A (ATCC 35984) (20). PS/A' strains showed a mean (+ standard deviation) of 75% + 12% inhibition of binding of PS/A-specific polyclonal rabbit antibody, while PS/Astrains showed a mean of 3.1% + 7% inhibition. Slime production was quantitated by measuring the optical density at 490 nm of the safranin-stained biofilms produced by inoculation of 105 to 106 CFU of CoNS per ml followed by overnight growth at 37°C in tryptic soy broth (TSB) in flat-bottomed 96-well tissue culture plates (Costar, Cambridge, Mass.). PS/A' strains produced a mean optical density of 1.25 ± 0.4, while PS/Astrains produced a mean optical density of 0.34 ± 0.08. Staphylococcus aureus Reynolds, Becker, Wood 46, and Cowan 1 were provided by Jean Lee of Harvard Medical School and were also used in the studies. * Corresponding author.To measure adherence to catheter tubing, CoNS were grown at 37°C overnight in static TSB cultures containing 25 ,uCi of Na [1-'4C]acetate (Du Pont, NEN Research Products, Boston, Mass.). The bacteria were sedimented by centrifugation and suspended in TSB. On the basis of previous reports (10, 21) that a protein ...

Concise review of mechanisms of bacterial adhesion to biomaterial surfaces

“…131 Although only a few coagulase-negative strains. The latter finding strain specific, adherence of clinical staphylococcal isolates was supported by the studies by Muller et al 117 and by to foreign surfaces was significantly increased by Fn, sug-Paulsson et al 135 Recently, Herrmann et al 140 also studied gesting the possible contribution of these proteins to the the mediating role of fibrinogen and fibrin and platelet pathogenesis of iv device infection. 132 integrin on S. aureus adhesion to surface-bound platelets.…”

A RAT MODEL OF POLYPROPYLENE GRAFT INFECTION CAUSED BY STAPHYLOCOCCUS EPIDERMIDIS

“…The second issue is the timing of the infection. It is possible that some host factors, such as fibronectin and albumin, may affect the vulnerability of graft to bacterial colonization 24,25 . It is also known that antibiotic prophylaxis should be started just before the surgical incision or insertion of the material, to be effective 26 .…”

Use of a modified Robbins device to directly compare the adhesion ofStaphylococcus epidermidisRP62A to surfaces

“…In this study, plasma pre-conditioning of glass appears to reduce the adhesion of Staph. epidermidis RP62A compared with glass and this was also found for plasma pre-conditioned biomaterials (Muller et al 1991), NHLBI reference polyethylene (Wang et al 1993) and for albumin pre-conditioned titanium (McDowell et al 1995). This is not the case with other strains of Staph.…”

“…epidermidis than for other bacteria such as Staph. aureus (Muller et al 1991). Dunne and Burd (1992) showed that divalent cation concentration was an important determinant of the adhesion of Staph.…”