The Biochemical Activity of Enterotoxin and Non-Enterotoxin Producing Staphylococci

One hundred and sixty-nine staphylococcal strains of human origin have been tested for production of enterotoxin A, B or Ci, coagulase activity, DNase activity, typical growth on ETGP-agar, hemolysin production and the breakdown of mannitol under aerobic conditions. Very good correlation was observed between enterotoxin production and coagulase activity, in that 82 % of the enterotoxin producing strains also synthesized coagulase. The correlation between DNase activity and positive reaction in mannitol to enterotoxin production was also good (80 % of the enterotoxic strains produced both DNase and aerobic acid from mannitol). Of the enterotoxin producing strains 66 % hemolysed bovine erythrocytes and 61 % were ETGP-positive. However, the frequency of hemolysing respectively ETGP-positive but non-enterotoxin producing strains was very high, viz. 46 % respectively 32 %. It is concluded that enterotoxin production can not to a satisfactory degree of security be predicted by means of the other biochemical characters.