Transferable drug resistance among clinical isolates of enterobacteria

Transfer of chemo-antibiotic resistance was carried out on fourteen strains of enterobacteria clinically isolated from Egyptian patients by conjugation into E. coli K.[12] recipient. All 14 strains were resistant to 4 or more antibiotics and transferred all or part of their drug resistance at a rate of 10[-3] - 10[-5]. With only 3 strains, the genetic loci coding for r-markers are located on the same plasmid representing 21.5% of the strains while partial transfer, that is segregated transfer of r-markers was observed in 78.5% of the tested strains. Ap, Cm, Km, Sm and Tc markers were more frequently transferred than Cp marker. On the other hand, Co, Gm, Po, Rif and Sxt markers were not transferred from any of the tested strains