[An opsonin-independent strain of Staphylococcus epidermidis]

Human neutrophils, subjected to stimulation under different conditions (phorbol myristate acetate, opsonized zymosan, formylmethionyl-leucinephenylalanine, nonopsonized staphylococci), produced a factor (denoted as clumping factor, or CF) with a capacity for highly selective clumping and opsonization of staphylococci. Out of 68 strains of different species of staphylococci, only a single strains (S.epidermidis) was sensitive of CF. CF negative staphylococci were capable of inducing the release of CF by neutrophils, but were not bound by this factor. Extracts, obtained by the mechanical destruction of neutrophils (sonication, repeated freezing and thawing), had no clumping activity. CF had a mol. wt. exceeding 100 kD, was positively charged and disintegrated at 100 degrees C. The capacity of S.epidermidis 178 M for binding CF completely disappeared after the treatment of bacteria with pronase and partially disappeared after boiling and treatment with trypsin and periodate. Neuraminidase and heating at 80 degrees C produced no effect. These data are the first demonstration of highly selective (strain-specific) interaction between secretory products of neutrophils and bacteria.