Susceptibility of avian Trichomonas strains to metronidazole

摘要

Genetic variations are possible causes fordifferent sensitivity patterns of protozoa against antiprotozoal compounds. Eleven isolates of T.gallinae identified based on ITS1/5.8S/ITS2 region and 18S rRNA gene including T. gallinae, T.tenax and T. vaginalis strains were subjected to In vitro inhibition by metronidazole after 24hincubation under aerobic and anaerobic conditions. Minimum lethal concentration (MLC) wasset at ≥50 mug/ml under aerobic and ≥12.5 mug/ml under anaerobic condition. MLCs of 8 T. tenax-strains (Type II of ITS1/5.8S/ITS2 region and type I of 18S rRNA gene) varied 1.56-6.25 mug/mland those of other T. tenax (Type III of ITS1/5.8S/ITS2 region and type X of 18S rRNA gene) was1.56 mug/ml under aerobic condition. The MLCs of T. tenax-like strains were less than those ofT.gallinae-like strains in both studies. Under aerobic conditions MLC’s for T. gallinae-likeisolates MR28 and MR30 were 12.5ug/ml, and higher compared with other T. tenax isolates(0.8 to 6.25 mug/ml). Similar results were achieved under anaerobic condition. Results suggestthat T. gallinae-like strains were more resistant to metronidazole than T.tenax-like strains.