title: Synergistic hemolysis phenomenon shown by an alpha-toxin-producing Clostridium perfingens and streptococcal CAMP factor in presumptive streptococcal grouping.
abstract: A new phenomenon of synergistic hemolysis by Clostridium perfringens alpha-toxin and the streptococcal CAMP factor on human and guinea pig erythrocytes is described. A possible mode of action of the CAMP factors is suggested. On human blood agar all of the tested isolates of group B streptococci gave an arrowhead-shaped zone of hemolysis; 74% of group A gave a crescent-shaped lytic zone, whereas all isolates of groups C and G and the remaining 26% of group A streptococci gave a bullet-shaped lytic zone. By comparison, in the CAMP test incubated aerobically and anaerobically, 70 and 91%, respectively, of streptococci other than group B gave positive, arrowhead-shaped lytic zones. If all intermediate positive reactions in the CAMP tests were read as negative after aerobic incubation, only 89% of group B streptococci would be properly identified. The synergistic hemolysis phenomenon, using an alpha-toxin-producing C. perfringens and human blood agar, provided a reliable test for presumptive identification of group B streptococci, with promising potential to differentiate in the same test group A streptococci from other groups.
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000276:immunology*; D001431:Bacteriological Techniques; D003015:Clostridium Infections / Q000382:microbiology; D003016:Clostridium perfringens / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology*; D006168:Guinea Pigs; D006461:Hemolysis; D006801:Humans; D013211:Staphylococcus aureus / Q000276:immunology; D013290:Streptococcal Infections / Q000382:microbiology; D013291:Streptococcus / Q000145:classification*; D013292:Streptococcus agalactiae / Q000276:immunology*
chemical_list: D001427:Bacterial Toxins