[Staphylococcal binding with immobilized proteins in the bacteriosorption reaction]

The affinity binding of staphylococci with fibronectin (FN), fibrinogen (FG) and IgG was studied by means of the bacteriosorption test developed by the authors. For this purpose, the suspensions of staphylococci of the strains under study in physiological saline containing 0.1% of Tween-20 was applied in drops onto the areas of polystyrene Petri dishes sensitized with consecutive dilutions of FN, FG, gamma globulin (GL) and ovalbumin (control). The results of the test, manifested as spots formed by the adsorption of staphylococci, were evaluated by visual examination. The test showed that all 62 strains of coagulase-positive staphylococci (S. aureus) were adsorbed on immobilized FG and FN, and 49 of them (79%) were also adsorbed on immobilized GL. The specificity of adsorption was confirmed by negative controls and by the inhibition of the reaction with the solutions of 4 above-mentioned proteins. Out of 32 strains of coagulase-negative staphylococci (S. saprophyticus and S. epidermidis), 20 strains (62.5%) were not adsorbed on any of the proteins, and the remaining 12 strains were nonspecifically adsorbed on all 4 proteins. This new test is proposed for use as an auxiliary method for the identification and typing of micro-organisms.