Further Observations on the Behavior of Staphylococci Within Human Leukocytes

Abstract

Recent studies by Cohn and Morse have indicated that pathogenic strains of staphylococci are not phagocytosed in systems containing rabbit serum and polymorphonuclear leukocytes in the absence of specific, thermostable opsonin (1). These studies have further suggested that both pathogenic and non-pathogenic strains of staphylococci are equally susceptible to rapid destruction within the cytoplasm of rabbit leukocytes once phagocytosis has been accomplished.Previous studies in our laboratory have demonstrated that there are significant differences in the intracellular disposition of coagulase-positive and coagulase-negative staphylococci following ingestion by human leukocytes (2). Pathogenic, coagulase-positive strains appear to survive within the cytoplasm of human granulocytes while non-pathogenic coagulase-negative strains are rapidly destroyed following ingestion. Observations on the course of staphylococcal bacteriemia in rabbits performed in our laboratory have also suggested that the survival of pathogenic strains within rabbit polymorphonuclear leukocytes may play a role in the persistence of staphylococci in the rabbit blood stream (3,4).In view of the findings of Cohn and Morse, studies on the behavior of staphylococci within human leukocytes have been extended, and the factors in human serum which promote phagocytosis have been explored. The present paper reports these observations. This study supports the thesis that a specific opsonin is required for prompt phagocytosis of pathogenic staphylococci in siliconed glass systems. Human polymorphonuclear leukocytes, like rabbit granulocytes, do not phagocytose coagulase-positive staphylococci in such in vitro systems in the absence of a specific serum factor. The intracellular fate of staphylococci ingested by human leukocytes appears to differ, however, from the fate of staphylococci within

Fate of Staphylococci Within Human Leukocytes

“…These differences were statistically significant with a t value of 3.79 and a p value of 0.0003. This observation was in keeping with the findings previously reported with large populations of the same strains (8).…”

Demonstration of an Inhibitor of the Muller Phenomenon in Human Sera: Its Identification as Antistaphylokinase*

“…Jensen (16) has shown that a precipitin which, in his studies, is universally present in human sera is rarely found in rabbit sera. Similarly, Rogers and Mellvn (17) have shown that most adult human sera contain a thermostabile opsonin that is usually absent from normal rabbits but was occasionally found in rabbits maintained in the rabbit colony for several months. The differences between human and rabbit sera demonstrated in both the previously reported and present studies are probably a reflection of the frequency with which exposure to staphylococcal antigens occurs in the two species.…”

Studies on Bacteriemia

“…The characteristics of this strain have been previously reported (3,4). Inocula ranging from 4.3 X l0 s to 3.1 X I09 culturable bacteria were injected.…”

“…Inocula ranging from 4.3 X l0 s to 3.1 X I09 culturable bacteria were injected. This strain has been shown to survive within granulocytes (4 Production of Reticuloendothdial Blockade.--Reticuloendothelial "blockade" was accomplished by intravenous administration of 8.0 ml. of thorotrast 19 to 24 hours prior to clearance studies using the method described by Martin, Kerby, and Holland (7).…”