Tildipirosin

Tildipirosin (TIP) is a novel 16-membered-ring macrolide authorized for the treatment of bovine and swine respiratory disease. The pH dependency of macrolide antimicrobial activity is well known. Considering that the pH in the colon contents of growing beef cattle and pigs is usually below pH 7.0, the minimum inhibitory concentrations (MIC) of TIP against foodborne bacterial pathogens such as Campylobacter (C.) coli, C. jejuni and Salmonella enterica and commensal species including Enterococcus (E.) faecalis, E. faecium and Escherichia coli were determined under standard (pH 7.3 ± 1) or neutral as well as slightly acidic conditions. A decrease in pH from 7.3 to 6.7 resulted in an increase in MICs of TIP. Except for the MICs > 256 μg/mL observed in the resistant subpopulation of the C. coli and the Enterococcus species, the MIC ranges increased from 2-8 μg/mL to 64-> 256 μg/mL for Salmonella enterica and E. coli, from 8-16 μg/mL to 32-128 μg/mL for the two Campylobacter species, and from 4-32 μg/mL to 128-> 256 μg/mL for both Enterococcus species.

This clinical trial evaluated the impact of metaphylactic antimicrobial administration 10 d before experimental inoculation with Mannheimia haemolytica (MH) to mitigate pulmonary lesions. Thirty-three crossbreed heifers were procured as a single group and were randomly allocated to 1 of 3 blocks and to treatment, tildipirosin (ZUP; 4 mg/kg) or tulathromycin (DRX; 2.5 mg/kg) or saline (SAL; 1 mL/45.5 kg), within block on arrival at Kansas State University. All trial procedures were staggered by 7-d intervals for each block, resulting in all animals within a block receiving treatment, challenge, and necropsy on the same dates. Heifers within each block received an endoscopic MH challenge 10 d following treatment administration (d 0) and were housed in individual indoor stalls for 3 d postchallenge. Clinical illness scores (CIS), respiration quality scores, appetite scores, and injection site reactions were recorded on all animals from d 0 through d 13.

Mycoplasma (M.) bovis is frequently implicated in respiratory diseases of young cattle worldwide. Today, to combat M. bovis in Europe, only antimicrobial therapy is available, but often fails, leading to important economical losses. The antimicrobial susceptibility of M. bovis is not covered by antimicrobial resistance surveillance networks. The objectives of this study were to identify resistances that were acquired over the last 30 years in France and to determine their prevalence within contemporary strains. The minimum inhibition concentration (MIC) values of 12 antimicrobials, considered active on M. bovis, were compared, using an agar dilution method, between 27 and 46 M. bovis isolates respectively obtained in 1978-1979 and in 2010-2012 from 73 distinct respiratory disease outbreaks in young cattle all over France. For eight antimicrobials, resistances were proven to be acquired over the period and expressed by all contemporary strains.

In 2011, three newly developed active pharmaceutical ingredients for horses and food producing animals were released on the German market for veterinary drug products. Two of these new products represent different drug classes of antibiotics, the polypeptide antibiotic Bacitracin (Bacivet™) and the macrolide antibiotic Clorsulon (Levatum®). The third product represents an anticestodal antiparasitic (Tildipirosin, Zuprevo®). Furthermore, three established veterinary active pharmaceutical ingredients were modified to allow their application for additional species. Thus the nonsteroidal anti-inflammatory drug sodium salicylate is now additionally authorised for turkeys and both the macrolide antibiotic Tilmicosin and the anticoccidial drug Toltrazuril are currently available for sheep. Additionally, two veterinary drugs with a new formulation as well as a veterinary drug for horses and food producing animals with a resourceful new combination of active pharmaceutical ingredients have recently been released.