[4-Nitroquinoline-1-oxide induced adaptive and cross resistance to ultraviolet rays and nalidixic acid in Enterococcus faecalis].

The resistance of Enterococcus faecalis to exposure to 4-nitroquinoline-1-oxide (4-NQO) as well as to UV irradiation and nalidixic acid was shown to increase as a result of reinoculations in medium containing 4-NQO. Irradiation of cells with UV254 (20, 60, or 100 J/m2) did not increase their resistance to 4-NQO. The desmutagenic activity of 4-NQO-adapted cells in the case of mutagenesis induced by 4-NQO was higher than in control cells. The mechanism of induced resistance is discussed.