Induction of the Release of Prostaglandin E2 from Polymorphonuclear Neutrophil Granulocytes by Bacteroides fragilis: Its Possible Role in the Pathogenesis of Mixed Infections

Abstract

The presence of anaerobic bacteria, especially of Bacteroides (B.) fragilis, in abdominal abscesses, infected decubitus ulcera, and the infected foot of diabetic patients is well documented. The importance, however, of these microorganisms in the pathogenesis of deep tissue infections has still to be evaluated. Therefore, the aim of this study was to evaluate the potency of B. fragilis as compared to aerobic bacteria widely known for causing inflammation, in inducing the release of prostaglandin E2 from polymorphonuclear granulocytes. Prostaglandin E2 is a potent vasodilator and contributes to edema and erythema, which are part of the inflammatory response. Furthermore, the cAMP-content of the neutrophils was determined after stimulation of the cells with the various bacteria. Of the bacterial species tested, B. fragilis proved to be one of the most potent triggers for prostaglandin E2 release from neutrophils indicating a possible major role of this microorganism in the pathogenesis of mixed infections.