Enterotoxin gene content in Staphylococcus aureus from the human intestinal tract.

Enterotoxigenic Staphylococcus aureus has been associated with staphylococcal food poisoning, which in a number of patients is accompanied by gastroenteritis. It has also been found to persist asymptomatically in the human intestinal tract, being considered one of the sources of pathogen transmission to manually handled food. However, very little is known about the incidence and enterotoxigenicity of intestinal S. aureus not associated with enteritis. There are practically no data on the frequency of some enterotoxin genes in intestinal S. aureus. Six thousand six hundred and twenty-one fecal swabs from 6-month- to 8-year-old children were analyzed for S. aureus. Growth of S. aureus was found in 347 samples. Two hundred and eight S. aureus isolates (4.2% of 4900 swabs) were from patients with sporadic enteritis and 139 isolates (8% of 1721 swabs) from patients who did not develop diarrhea during hospitalization. The genes encoding 16 members of the enterotoxin family (sea-see, seg-selp, and selu) and tst were present in 174 (83%) S. aureus isolates accompanying enteritis and in 101 (72%) isolates derived from patients with no enteritis symptoms. The genes of the classical enterotoxins (sea-see) and tst were present in 56% and 59% of the enteritis-associated and nonenteritic isolates, respectively.