Tildipirosin

Tildipirosin, a long-acting macrolide, has antibiotic activity. In Vitro: Tildipirosin exhibits the inhibitory effect on C. coli species, and 23 of 31 (74%) isolates have MICs of 8 or 16 μg/mL while 8 of 31 (26%) have MIC >256 μg/mL. MICs against C. jejuni are 8-64 μg/mL. Tildipirosin against S. enterica and E. coli are 2-8 μg/mL^[1]. Tildipirosin inhibits the treponeme isolates form from CODD lesions from 19 sheep, with MIC90 of 0.0469 mg/L^[3]. The P. multocida B130 clones show the MIC of 0.25 mg/L for tildipirosin. The 10 P. multocida isolates that carry only erm(42) exhibit MIC of 16-32 mg/L for tildipirosin. The single M. haemolytica that harbours only erm(42) shows MIC of 32 mg/L for tildipirosin^[4]. In Vivo: The mean percentage of lung consolidation for tildipirosin (4 mg/kg, s.c.)-treated calves is significantly lower than those for tulathromycin-treated and control calves. Metaphylactic administration of tildipirosin to calves 5 days prior to H somni challenge prevents subsequent culture of the pathogen from bronchial secretions and is more effective in minimizing clinical disease and lung lesions than is metaphylactic administration of tulathromycin^[2].