The Leukotoxic Action of Streptococci

Abstract

P r~s 33 ~o 41(Received for publication, January 7, 1957) This is the third study in a series on the interactions between streptococci and host cells. Previous reports have concerned the egestion of streptococci by phagocytic cells (1), and the failure of streptococci to lose their capacity of resisting phagocytosis after being killed with gentle heat or ultraviolet radiation (2). The present work is concerned with one type of outcome following phagocytosis; namely, the destruction of the phagocytizing leukocytes which occurs when certain strains of streptococci are ingested. This injury will be called here "leukotoxic action," and the pertinent attribute of injurious streptococci will be called "leukotoxicity." It was described by Levaditi in 1918 (3), but has received no attention since that time as far as we have been able to discover.The leukotoxic effect is seen only after intact cocci have been phagocytized. It must not be confused with the action of streptococcal leukocidin, a soluble substance elaborated into the medium by growing cocci, which destroys leukocytes even when all coccal cells have been removed by filtration. Todd has presented impressive evidence indicating that leukocidin and streptolysin O are identical (4).In the present report consideration will be given to the biological characteristics of leukotoxicity, to its distribution among streptococci, its relation to other known streptococcal products, its relationship to virulence and its possible significance in streptococcal disease.

Diphosphopyridine Nucleotidase as an Extracellular Product of Streptococcal Growth and Its Possible Relationship to Leukotoxicity

“…It had been shown earlier (6) that culture filtrates of leukotoxic cocci did not injure leukocytes when added to blood and observed microscopically. A purified and concentrated preparation of DPNase, assayed at 34,000 units per ml.…”

“…The hypothetical leukotoxin does not appear to be identifiable with any of the previously studied streptococcal products, as erythrogenic toxin, the streptolysins, streptokinase, leukocidin, etc. (6). The remarkable qualitative correlation between DPNase production and leukotoxicity, presented in Table III, suggests that the two functions are associated and may, perhaps, be identical.…”

“…of leukotoxicity and that of DPNase-forming ability suggested that the two phenomena may be related. A number of strains that had previously been tested for capacity to release DPNase were tested for leukotoxicity by a method described elsewhere (6) and other strains whose leukotoxic status had been established were tested for capacity to release DPNase in broth and in 1 per cent serum broth. The two types of information were obtained for a total of 39 strains (Table III).…”

A simple biological method for detecting streptococcal nicotinamide adenine dinucleotide glycohydrolase.

“…NADG does not appear to be inducible since it is formed in a defined minimal medium free of substrate and the addition of substrate does not influence its production . Streptococcal NADG has been described as cardiotoxic (Van Heyningen, 1962) and postulated as a leucotoxin distinct from the streptolysins Wilson, 1957). Although there is a high correlation between NADG activity and leucotoxicity, subsequent evidence points towards streptolysin S as the substance responsible for leucocyte destruction (Ofek et al, 1970).…”

MORPHOLOGICAL STUDY OF THE IN VITRO CYTOTOXIC EFFECT OF α‐HEMOLYTIC E. COLI BACTERIA AND CULTURE SUPERNATANTS ON HUMAN BLOOD GRANULOCYTES AND MONOCYTES

“…Controls as specified above were incubated simultaneously. The cells were incubated for 2 1/2, 5, 7 1/2, 10, 15,20,30 or 60 rnin at 37 "C in a shaking water-bath. In expedments with bacteria, additional tubes were incubated for I20 min.…”