COMPARATIVE METABOLISM OF VIRULENT AND AVIRULENT STAPHYLOCOCCI *

There is no entirely satisfactory in vitro test for virulent staphylococci. The standard tests (e-g., coagulase, alpha hemolysin) have been closely associated with pathogenicity of isolates for man and animals, but they are subject to variation. Coagulase-negative strains, for example, frequently cause human disease, especially in debilitated individuals (Quinn & Cox, 1963), and coagulase-positive strains can be isolated with ease from healthy individuals (Gillespie et al., 1939). Further, there is a paucity of information regarding the true activity of these bacterial products in viuo. Since virulence, or virulence factors, and pathogenicity are probably intimately related to the metabolic properties of a microorganism, a comparative study of the basic metabolic activities of “pathogenic” and “nonpathogenic” staphylococcal isolates has been initiated in an attempt to uncover fundamental metabolic markers of virulence. The present communication describes the general characteristics of endogenous respiration in coagulase-positive and negative staphylococci and documents the marked difference in the endogenous reserves of these two strains. Data are also presented to demonstrate differences in the oxidative metabolism of amino acids and the effect of glucose in the growth medium upon the oxidative capacity of resting cells.