title: Increased sensitivity to phagocytosis of Staphylococcus E-46 after growth in artificial media.
abstract: Staphylococcus E-46, which exhibits high virulence in mice mainly due to resistance to phagocytosis, gradually lost its virulence during growth in artificial media [Heart-Infusion (HI) slants]. Staphylococcus E-46 is coagulase-negative and DNase-positive, and has a capsule-like structure, and the less-virulent derivative (LVD) strain seemed not to be changed in this respect. The bacteria which had been exposed to HI slants for more than one year (= LVD strain) became more sensitive to phagocytosis by mouse peritoneal macrophages than bacteria which were kept in a lyophilized state. The chemiluminescent response of macrophages to the LVD strain was remarkably higher than that to the original Staphylococcus E-46. When the LVD or the sera for opsonization were heated, the chemiluminescence to the LVD was as low as that to the original Staphylococcus E-46. Polyacrylamide gel electrophoresis of sonication-released membrane protein from the LVD strain showed a unique band with a molecular weight of about 40,000. The factor concerned with the virulence of Staphylococcus E-46 is discussed based on these results.
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000276:immunology; D008163:Luminescent Measurements; D008264:Macrophages / Q000276:immunology; D008565:Membrane Proteins / Q000276:immunology; D051379:Mice; D010587:Phagocytosis; D013210:Staphylococcus / Q000276:immunology / Q000472:pathogenicity*
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins