[Ice cream of industrial manufacture. Incidence of Staphylococcus aureus and enterotoxigenicity].

A total of 70 samples of ice-creams, milk, milk cream and water or fruit based were obtained from 7 different industrial producers. Of these samples, 14.3% were positive for Staphylococcus aureus in 1 g: 97.2% showed less than 10 St. aureus in 1 g, 1.4% between 101-1,000 and 1.4% between 1,001-10,000. In 21 strains enterotoxigenicity, was investigated, as well as the response to different biochemical tests and the susceptibility to antibiotics: 9.5% of the strains were toxigenic (2 strains), 1 produced enterotoxin A and 1 enterotoxin B. There was no difference between toxigenic and nontoxigenic strains when the biochemical tests were performed (catalase test, coagulase test, thermostable nuclease production, anaerobic utilization of glucose and mannitol, gelatin and casein hydrolysis, production of hemolysins and pigments). All the strains showed a wide susceptibility when they were tested with different antibiotics. Our results confirm the limit introduced to the article 1078 of the Argentine Food Code for ice-creams of industrial production (100 per g) but there is no specification of the count method to be used.