Serratia marcescens bacteremia. Clinical observations and studies of precipitin reactions.

Abstract

Sixteen cases of<i>Serratia marcescens</i>bacteremia were seen in three hospitals. Most patients had severe underlying disease and had been treated with antibiotics prior to development of bacteremia. Five patients had organisms other than<i>S marcescens</i>isolated from blood. Portals of entry included intravenous cannulas and pulmonary, urinary, peritoneal, and wound infections. Sera from eight of nine patients tested contained precipitating antibodies against an ultrasonic extract of<i>S marcescens</i>in gel diffusion plates. All sera tested more than seven days after onset of bacteremia contained precipitins. All blood culture isolates tested were sensitive to gentamicin, and isolates from five patients were sensitive to gentamicin alone. Two of three patients treated with gentamicin were cured. Three patients with a urinary portal of entry survived, despite treatment with antibiotics to which their organisms showed in vitro resistance.