Effect of antibiotics on the prevalence of enterotoxigenic Escherichia coli in two populations in the Philippines.

Hostesses and restaurant employees in the Philippines were studied to determine whether an increased use of antibiotics was associated with a higher point prevalence of enterotoxigenic Escherichia coli. Of 1,030 hostesses and 628 restaurant employees, 28 and 4%, respectively, said that they had taken antibiotics within a week of being cultured (P less than 0.001). Of hostesses and restaurant employees, 10% (103 of 1,030) and 2% (14 of 628), respectively, had antibiotics detectable in their urine (P less than 0.001). Enterotoxigenic E. coli strains were isolated from 1.2% (12 of 1,030) of hostesses and 1.7% (11 of 628) of restaurant employees. In both populations, enterotoxigenic E. coli strains were never found in subjects who had antibacterial activity in their urine. Although resistance to two or more antibiotics was found more frequently in E. coli isolated from hostesses than in that isolated from restaurant workers (48 versus 33%; P less than 0.01), antibiotic selective pressure did not increase the prevalence of enterotoxigenic E. coli in these two populations.