IN-VIVO AND IN-VITRO SENSITIVITY OF TRICHOMONAS-GALLINAE TO SOME NITROIMIDAZOLE DRUGS

A study was carried out in order to establish the in vivo efficacy of two nitroimidazole drugs against the flagellate Trichomonas gallinae. The results obtained showed a high proportion of therapeutic failures. Thus, carnidazole and dimetridazole failed to eliminate infection in 13 of 17 and 20 of 21 racing pigeons, respectively The in vitro suscep tibility of four T. gallinae isolates to five nitroimidazolic drugs, t hat is, carnidazole, dimetridazole, metronidazole, ornidazole and roni dazole, was also determined. Minimal lethal concentrations (MLCs) of t hese drugs were obtained One of the isolates tested had already proved to be resistant in the first in vivo tests, while the other three had been obtained from wild birds. We were able to confirm in vitro the r esistance of the racing pigeon isolate to all the nitroimidazole drugs tested. For carnidazole, dimetridazole, metronidazole and ornidazole the MLC ranged between 93.75-500 mu g ml. Although ronidazole showed a greater potency than the other nitroimidazole derivatives against thi s isolate (MLC: 15.62-31.25 mu g ml), 8-22 times more drug was necessa ry for efficacy against this isolate compared to the others. These oth er three parasite isolates proved to be sensitive to the five drugs te sted (MLC: 0.97-7.81 mu g ml). (C) 1998 Elsevier Science B.V. All righ ts reserved.