The effect of splenectomy on gram-negative bacteremia

Both clinical and laboratory studies have demonstrated an increased risk of fatal sepsis after splenectomy. The importance of the spleen in clearing a bacterial challenge from pneumococci or other encapsulated organisms is now well accepted. The role of the spleen in handling a bacteremia due to nonencapsulated (Gram negative) organisms is not well established. Rats were subjected to either sham operation or splenectomy. Two weeks after surgery, all animals received 10(6) E. coli by intraperitoneal injection. Tail vein blood samples for quantitative culture were obtained at multiple time intervals after the bacterial challenge. All animals developed a bacteremia. Initially, the mean bloodstream bacterial counts were comparable in the sham and splenectomy groups. Sham-operated rats cleared all bacteria from the bloodstream within 240 minutes. In contrast, 240 minutes after bacterial injection, E. coli could still be recovered from the blood of asplenic rats at levels comparable to those noted at the start of the experiment. The present study shows that splenectomy does impair the animal's ability to clear a Gram-negative bacteremia.