Tiamulin and a number of macrolides were evaluated as to their ability in forming metabolic-intermediate (MI) complexes with cytochrome P450 in liver microsomes from rabbits bred for meat production. Complex formation, which occurred only in preparations where the expression of P450 3A was increased as the result of rifampicin pre-treatment and with different kinetics, was in the order tiamulin...

The aim of this study was to examine the antimicrobial susceptibility of 97 Haemophilus parasuis cultured from Australian pigs. As there is no existing standard antimicrobial susceptibility technique available for H. parasuis, methods utilising the supplemented media, BA/SN for disc diffusion and test medium broth (TMB) for a microdilution technique, were initially evaluated with the reference ...

The purpose of this study was to compare the efficacy and cost-effectiveness of florfenicol versus tulathromycin for initial treatment of undifferentiated fever in fall-placed steer calves that received metaphylactic tilmicosin on arrival at the feedlot. No significant differences (P > .10) were observed in undifferentiated fever relapses or the crude case fatality rate. Calves treated with flo...

The purpose of this study was to determine the efficacy and cost-effectiveness of tulathromycin (DRAX) versus tilmicosin (MIC) or oxytetracycline (TET) as a metaphylactic antimicrobial in feedlot calves. Calves that received DRAX had significantly (P<.05) lower initial undifferentiated fever (UF) treatment and relapse rates; lower overall chronicity, overall mortality, and cause-specific mortal...

Tumini M., Nagel O.G., Molina M.P., Althaus R.L. (2016): Microbiological method using Bacillus megaterium with fusidic acid for detection of macrolides in milk. Czech J. Food Sci., 34: 9–15. The microbiological method to attain a sensitive detection of macrolides using Bacillus megaterium in agar medium with fusidic acid was designed. To this aim, Mueller-Hinton medium fortified with glucose at...

Sir, Bovine respiratory disease (BRD) is one of the economically most important diseases in animal production, with global losses of the feedlot industry due to BRD being estimated to be over US$ 3 billion per year. Antimicrobial agents, particularly macrolides, are commonly used to combat bacteria involved in BRD, such as Mannheimia haemolytica, Pasteurella multocida and Histophilus somni. Aft...

A series of 20-deoxo-20-cyclic (alkylamino) derivatives of tylosin, desmycosin, macrocin and lactenocin was prepared by reductive amination of the C-20 aldehyde group. The majority of the compounds were prepared using metal hydrides (sodium cyanoborohydride or sodium borohydride) as the reducing agents and a suitable cyclic alkylamine. Subsequently, a more convenient procedure was developed usi...