TETRACYCLINE REDUCES FLUOROQUINOLONES-INDUCED BLEACHING OF EUGLENA-GRACILIS

Inhibitory activity of tetracycline against ofloxacin- and fleroxacin- induced bleaching of green and etiolized Euglena gracilis was examined . Tetracycline hydrochloride in concentrations of 83-2079 mu M in the light partially inhibited the bleaching activity of 83 mu M ofloxacin and of 162 mu M fleroxacin. In the dark, the TC inhibition of the fluo roquinolones-induced bleaching activity was most obvious, the white co lony counts were all decreased. The total inhibition of bleaching was observed in 43 mu M ofloxacin and 81 mu M fleroxacin both in light and darkness. Cell growth was not significantly influenced by ofloxacin, fleroxacin and tetracycline in the light or darkness. Inhibition of of loxacin-induced euglena bleaching by tetracycline was more effective i n etiolized cells. TC at 0-416 mu M did not influence the growth of of loxacin (2.15 mu M)-induced Salmonella typhimurium revertants.