Prevalence of multiple antibiotic resistance and R-plasmid inEscherichia coli isolates of hospital sewage of Aligarh city in India.

R-plasmids that transfer antibiotic resistance are common in the non-pathogenicEscherichia coli of the gastro-intestinal tract of human beings and domestic animals, which inturn may enter into sewage. Therefore we have isolated 30Escherichia coli isolates from hospital sewage of Aligarh city. These isolates were tested for their resistance and sensitivity against 10 antibiotics. 90% isolates showed resistance against ampicillin and sulphamethizole. Of the total 30E. coli isolates 86.6% were resistant to erythromycin and rifampicin but none of them was resistant to kanamycin and streptomycin. Plasmids (mol. wt. 16.5 mega daltons) were isolated from five differentE. coli strains which harboured only a single plasmid and were characterized on the basis of antibiogram. Moreover, the transformation experiments were also performed to confirm the resistant character on the plasmid. We conclude that multiple drug resistance among most of theE. coli isolates is plasmid borne.