title: Production of staphylococcal pyrogenic exotoxin type C: influence of physical and chemical factors.
abstract: Physical and chemical factors that may affect the growth of strains of Staphylococcus aureus that are associated with toxic-shock syndrome were examined for their effect on expression of pyrogenic exotoxin type C (PE-C). Significantly more PE-C was made when cultures were incubated at 37 C rather than at 30 C, although bacterial growth was similar at the two temperatures. Furthermore, 32-fold more toxin was made aerobically versus anaerobically for the seven strains tested, whereas only a twofold difference in bacterial growth was seen. Maximal toxin production occurred at pH 7 and pH 8, although the strains grew well in the range of pH 6 to pH 8. Glucose had little effect on growth and toxin production at levels from 0 to 0.3% but suppressed bacterial growth and, more extensively, toxin production at a level of 3%. Significant amounts of PE-C were made in beef-heart medium, brain-heart infusion broth, and Todd-Hewitt broth, but lesser amounts were made in trypticase soy broth.
mesh_terms: D000332:Aerobiosis; D000818:Animals; D003470:Culture Media; D005098:Exotoxins / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011817:Rabbits; D012772:Shock, Septic / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature
chemical_list: D003470:Culture Media; D005098:Exotoxins; D005947:Glucose