STUDIES ON THE EFFICACY OF COMBINED IMMUNOSTIMULANT-ANTIBIOTIC THERAPY AGAINST EXPERIMENTAL MYCOPLASMA-GALLISEPTICUM INFECTION IN CHICKENS

Josamycin is an antibiotic known to become selectively concentrated in tracellularly and in respiratory organs, the habitate of Mycoplasma ga llisepticum. The aim of this present work was to evaluate the efficacy of josamycin when given alone or combined with an immunostimulant Cor ne-bacterium cutis ultralysate. Groups of chickens were given josamyci n alone or Corynebacterium ultralysate alone or both agents or nothing immediately before induction of Mycoplasma gallisepticum infection. B irds were subjected to pathological examination to evaluate the incide nce and severity of air-sacculitis, bacteriological examination for re -isolation of Mycoplasma gallisepticum and for immunological examinati on to evaluate the humoral immune response to the infection (haemagglu tination inhibiting titre determination). The effect of treatments use d in this study was to decrease the incidence and severity of air sacc ulitis. The magnitude of rise in haemagglutination inhibiting titres w ere greater and faster in birds given Corynebacterium ultralysate. Tre atments failed to achieve complete elimination of Mycoplasma. No speci al advantage was obtained from the use of josamycin, its effects were rather similar to previously used chemotherapy.