BEHAVIOR AND ENTEROTOXIN PRODUCTION BY STAPHYLOCOCCUS-AUREUS DURING THE MANUFACTURE AND RIPENING OF RAW GOATS MILK LACTIC CHEESES

To study the possible presence of staphylococcal enterotoxin A in raw goats' milk lactic cheese, milli was inoculated with an enterotoxigeni c Staphylococcus aureus strain to a final concentration of 4, 5 and 6 log(cfu/ml). Cheese was prepared following industrial specifications a nd ripened for 42 d. Detection of the enterotoxins was by the Vidas St aph enterotoxin test (BioMerieux) and by an indirect double-sandwich E LISA technique using anti-enterotoxin monoclonal antibodies. Staphyloc occal counts declined markedly after draining, and by the end of ripen ing they had disappeared from some cheeses. In contrast, aerobic mesop hilic organisms grew well. The level of staphylococcal enterotoxin A r ecovered varied from 1 to 2.5 ng/g cheese made with an initial populat ion of 10(5) Or 10(6) cfu/ml. Only traces of enterotoxin A (0.5 ng/g) were detected in cheeses made with the lowest Staph aureus inoculum us ed in this study. Enterotoxin A was also detected in cheeses from whic h Staph. aureus had disappeared.