Infectious drug resistance in Thailand. VI. Effect of a small dose of tetracycline on intestinal Escherichia coli

Abstract

Studies carried out reaffirmed the high prevalence of drug resistant E. coli in the intestinal flora of healthy residents of Thailand and confirmed that the organisms often exhibit infectious drug resistance. The regular administration of small doses of tetracycline promoted uniform colonization of the gastrointestinal tract by drug resistant E. coli but did not affect the distribution of smooth and rough bacteria. The findings indicated that smooth E. coli dominated the intestinal E. coli of healthy Thais and that resistance to antimicrobials was more common among the smooth than among the rough bacteria. The 'normal' pattern of the intestinal E. coli was restored within a week after the end of low dose tetracycline administration.