[Effect of the conjugative plasmids of S. typhimurium antibiotic resistance on the growth indices of E. coli].

The antibiotic resistance conjugative plasmids of Salm. typhimurium prolonged the lag-phase of coli bacteria. It was shown that the plasmids had a significant effect on the generation period either prolonging or shortening it. No correlation between the number of the antibiotic resistance determinants and resistance to separate antibiotics and the growth indices was found. The chromosome mutations of resistance to rifampicin and nalidixic acid in the strain of E. coli studied had no effect on duration of the lag-phase but resulted in shortening of the generation period.