[Protective effect of a tetracycline-sensitive strain of Escherichia coli on the growth of a tetracyclic-resistant strain in the presence of tetracycline in a coculture].

The addition of tetracycline to a culture of a tetracycline-sensitive strain of Escherichia coli leads to the appearance in the medium of a chemical compound (or compounds) that in part relieve the inhibition of growth of a tetracycline-resistant strain by a high concentration of the antibiotic. An increase in the growth rate can be as high as 50%.