The role of opsonization ofStaphylococcus aureus in the development of local inflammation and system response

Abstract

Thein vitro neutrophil-stimulating activities of twoS. aureus strains are compared with theirin vivo cytotoxic activities, including the use of intact heterologous neutrophils. After opsonization with normal autologous serum, clinical isolates ofS. aureus differ in the ability to induce luminol-dependent chemiluminescence of guinea pig peritoneal neutrophils. After opsonization, the opsonin-dependent strain markedly stimulates chemiluminescence in comparison with the opsonin-independent strain. The local inflammation induced in guinea pig by intracutaneous administration of the opsonized opsonin-dependent strain is more intense than that induced by the opsonin-independent strain. Intramuscular administration of opsonin-dependentS. aureus strain increases mortality in mice from 10 to 46% while the addition of normal guinea pig neutrophils to the inoculate has no effect on this process. Opsonization of opsonin-independent strain decreased mortality from 78 to 40%, the effect being potentiated by the addition of neutrophils to inoculate (mortality 14%). Presumably, the opsonin dependence ofS. aureus manifestedin vitro is associated with its pathogenicityin vivo, which may be caused by intense stimulation of the respiratory burst in neutrophils.