Antibiotic resistance pattern of heat-labile enterotoxin (LT) producing escherichia coli isolated from children with diarrhoea in Bangladesh: clonal relationshipamong isolates with different resistants phenotypes

Abstract

Fifty-six heat-labile, enterotoxin- producing (LT+) Escherichia coli isolated from 33 children less than 5 years of age with diarrhoea were analysed for resistance to antibiotics, plasmid contents, and clonal relationships among isolates by ribosomal RNA (jRNA) fingerprinting (ribotyping). Fifty-five (9&2%) of the LT+ isolates were resistant cither to tetracycKne alone (48.2%) or to tetracyclinc and one or more other antibiotic, Le. ampicUlin, streptomycin, chktramphenicol, trimethoprim-sulfametlioxazole, or nafidhdc acid. Most of the isolates harboured one or more plasmid but antibiotic resistance patterns did not always correlate with particular plasmid patterns. Ribotyping of the isolates using the restriction endonudease EcoKI revealed a total of 7 different ribotypes, and ribotypes were shared by E. coli isolates with different antibiotic resistant phenotypes. The results indicate that in Bangladesh at least 7 different clones of LT+ E. coli acquired resistance to one or more different antibiotics in various combinations. However, a similar drug resistance pattern was not mediated by the same set of plasmids in all strains. The mechanism for the emergence and spread of antibiotic resistance among E. coli should be investigated further in Bangladesh, where LT+ £. con is an important agent of early childhood diarrhoea