Antibiotic susceptibility testing and plasmid profiles of Escherichia coli isolated from diarrhoeal patients.

The antibiotic resistance pattern and plasmid profiles were studied for a total of 89 Escherichia coli (E. coli) isolates recovered from faecal specimens of children hospitalized with diarrhoea in Rahma hospital for children, Irbid-Jordan. Twenty-four of these were identified as diarrhoeagenic E. coli by the polymerase chain reaction (PCR) procedure. Seventy-one E. coli isolates showed a multiple resistance pattern (to 10 antibiotics) and 13 isolates were susceptible to all antibiotics tested. All the 89 isolates were sensitive to nalidixic acid. Plasmid content and profile studies showed that the 76 E. coli drug resistant isolates (including 6 and 12 isolates that showed single resistance to tetracycline and ampicillin respectively) carried plasmids ranging from 54.0 kb to 1.5 kb in size. The number of plasmids in each of these isolates ranged from one to six of different sizes. All the E. coli isolates contained a common plasmid with a molecular weight of 25.0 kb which proved to confer resistance to ampicillin, kanamycin, tetracycline, and possibly chloramphenicol.