Antimicrobial resistance and enterotoxin production among isolates of Escherichia coli in the Far East.

The frequency of association between transferable extrachromosomal D.N.A. (plasmid) mediated antibiotic resistance and enterotoxin productin is unknown. The antimicrobial susceptibility of 176 enterotoxigenic Escherichia coli from 57 children and adults in the Philippines, Korea, Taiwan, and Indonesia has been examined. 126 isolates (72%) were resistant to one or more antibiotic(s); 77 (44%) were resistant to four or more antibiotics. 43 E. coli which produced both heat-labile and heat-stable toxin, 110 isolates which produced only heat-labile toxin, and 23 which produced only heat-stable toxin were frequently resistant to multiple antibiotics. 25 of 31 resistant isolates tested, 80% transferred antibiotic resistance in bacterial mating experiments. In 35% of the matings transferring antibiotic resistance, the ability to produce enterotoxin was also conferred on the recipients. This in-vitro observation suggests that the widespread use of antibiotics could increase the distribution of enterotoxigenic E. coli, as genes coding for antibiotic resistance and enterotoxin production are frequently transferred together.