DIFFERENTIAL HEAT-SHOCK PROTEIN-SYNTHESIS AND RESPONSE TO STRESS IN 3AVIRULENT AND VIRULENT LISTERIA SPECIES

Two strains of Listeria monocytogenes, a virulent (V) and an avirulent (A) strain obtained by repeated in vitro cultivation at 37 degrees C, exhibited differing constitutive syntheses of heat-shock proteins (HS P) at 37 degrees C, the temperature of the infected host, and a differ ential response to heat treatment. These two strains also reacted diff erently to addition of a superoxide ion inducer and acid to treatments . Our observations were not limited to these two strains of L. monocyt ogenes: the level of HSP synthesis at 37 degrees C varied from one spe cies of Listeria to another and was correlated with the thermo-inducib ility of HSP. In an accompanying paper, we will attempt to establish w hether these different biosynthetic properties observed in vitro betwe en A and V L. monocytogenes enable the prediction of their properties/ survival once inside the resident peritoneal murine macrophages.