title: Correlation between growth in antibiotic-medium and hemolytic activity of group C and G streptococci.
abstract: The effect of a subminimal inhibitory concentration of penicillin on the production of bound and free hemolysins by streptococci was examined using sheep red blood cells. A marked decrease of a group C cell-free and bound activities was observed with penicillin at a concentration of 1/3 of the MIC whereas an increase was observed with those of a group G strain. Potassium ferricyanide and anti-streptolysin O (group A streptococcus) were strongly inhibitory for the free activities of both strains. The cell-bound activities were stimulated by addition of RNA during bacterial growth in control cultures and also in drug-containing media.
authors.affiliation: Department of Medical Microbiology, Federal University, Rio de Janeiro, Brazil.
authors.forename: A C
authors.initials: AC
authors.lastname: de Castro
authors.forename: B T
authors.initials: BT
authors.lastname: Ferreira
authors.forename: L C
authors.initials: LC
authors.lastname: Benchetrit
mesh_terms: D000818:Animals; D000989:Antistreptolysin / Q000494:pharmacology; D003470:Culture Media; D005292:Ferricyanides / Q000494:pharmacology; D006460:Hemolysin Proteins / Q000096:biosynthesis; D006461:Hemolysis; D006801:Humans; D010406:Penicillins / Q000494:pharmacology; D013291:Streptococcus / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism
chemical_list: D003470:Culture Media; D005292:Ferricyanides; D006460:Hemolysin Proteins; D010406:Penicillins; D000989:Antistreptolysin; C028033:potassium ferricyanide