Synergistic efficacy of tiamulin/doxycycline combination to porcine respiratory bacterial pathogens
The purpose of this studies were to determine the value of minimal inhibitory concentration (MIC) respiratory bacterial pathogens, 11 Haemophilus(H.) parasuis, 7 Actinobacillus pleuropneumoniae (APP), 5 Pasteurella(P.) multocida and 5 Streptococcus sp. against tiamulin and doxycycline by serial microdilution method and to evaluate an efficacy of their combination by microdilution checkerboard method. The MIC50 of H. parasuis, Streptococcus sp. and APP against doxycycline was 16 μg/ml and was 4 μg/ml for P. multocida (breakpoint ≤ 4). For tiamulin, the MIC50 was 8 μg/ml for APP and 16 μg/ml for the others (breakpoint ≤16 for APP and H. parasuis and breakpoint ≤ 4 for Streptococcus sp.and P. multocida). Fractional Inhibitory Concentration (FIC index) was used for evaluation of an efficacy of the combination. Doxycycline and tiamulin had an in vitro synergistic interaction for H. parasuis and APP. For all tested Streptococcus sp. and P. multocida, the effect was indifference. In conclusion, the incidences of bacteria resistant to tiamulin and doxycycline were observed in 10％ and 64.28％, respectively which most of them were Streptococcus sp. This synergistic combination between tiamulin/doxycycline may be a potential usefulness of the pathogen control in a conventional pig farm.
microdilution checkerboard method minimal inhibitory concentration synergism bacterial respiratory pathogens.
Nuvee Prapasarakul Navapon Techakriengkrai Jitrada Vasuvat Anurak Sae-Ue Wantanee Neramitmansook Pussadee Klakai Metta Makhanon
Faculty of Veterinary Science, Chulalongkorn University National Institute of Animal Health, Department of Livestock Development Novartis(Thailand), Co.Ltd., Bangkok.Thailand
国际会议
亚洲猪病学会第三届学术会议(Proceedings the 3rd Congress of the Asian Pig Veterinary Society)
武汉
英文
390-391
2007-04-22（万方平台首次上网日期，不代表论文的发表时间）