Surface hydrophobicity and opsonic requirements of coagulase-negative staphylococci in suspension and adhering to a polymer substratum.

The opsonic requirements for phagocytosis in suspension of 38 clinical isolates of coagulase-negative staphylococci recovered from neonates with septicemia were found to be related to the degree of surface hydrophobicity of these strains. Sixteen isolates were adequately opsonized only in the presence of complement; this group was significant more hydrophobic (p less than 0.001) than the 22 strains not requiring complement for efficient uptake in suspension. Evidence showed that hydrophobic groups present on the bacterial surface may interfere with IgG opsonization. In contrast, IgG sufficed as an opsonin without complement being required for the efficient uptake of these hydrophobic strains when adhering to a polymer surface.