In vitro-antibacterial properties of tilmicosin against Australian isolates of Pasteurella multocida and Actinobacillus pleuropneumoniae from pigs

The MIC95 of tilmicosin, determined by an agar dilution method, for the 50 A. pleuropneumoniae isolates studied was 6.25 micro g/ml while that for 51 P. multocida isolates was 12.5 micro g/ml. 48 of P. multocida isolates were sensitive to tilmicosin with the remaining 3 isolates showing intermediate sensitivity, whereas all A. pleuropneumoniae were sensitive. It is concluded that the in vitro activity of tilmicosin against Australian porcine isolates of A. pleuropneumoniae and P. multocida is very similar to that reported for isolates of the same bacterial species from pigs in North America