Aarestrup F M, Friis N F
Danish Veterinary Laboratory, Copenhagen V. Denmark.
Vet Microbiol. 1998 Mar 15;61(1-2):33-9. doi: 10.1016/s0378-1135(98)00169-2.
This study was conducted to compare the Minimal Inhibitory Concentrations (MICs) for enrofloxacin, lincomycin, tetracycline, tiamulin and tylosin, of Mycoplasma hyosynoviae, isolated from pigs at notably different intervals (1968-71 and 1995-96). Each group comprised 21 low passage isolates and a Danish reference strain (M60) and the type strain (S16). MICs were determined in liquid medium with both initial and final readings. Enrofloxacin, lincomycin, tetracycline and tiamulin were active against all isolates, and tiamulin showed the highest activity. For tylosin all the isolates from 1968-71 were highly susceptible, whereas the isolates from 1995-96 could be divided into a highly susceptible (nine isolates) and relatively resistant (12 isolates) group. This difference between old and new strains was statistically significant (p = 0.0000415). The remaining agents, enrofloxacin, lincomycin, tiamulin and tetracycline, showed an unaltered good activity against M. hyosynoviae. The resistance to tylosin seems now to occur so often that this antibiotic cannot be recommended for therapeutic use any more. The most probable explanation for the emergence of resistance is the intensive use of tylosin during many years for therapy and growth promotion.
本研究旨在比较从猪身上分离出的猪滑膜支原体在显著不同时间段（1968 - 1971年和1995 - 1996年）对恩诺沙星、林可霉素、四环素、泰妙菌素和泰乐菌素的最低抑菌浓度（MIC）。每组包括21株低传代分离株以及一株丹麦参考菌株（M60）和标准菌株（S16）。通过液体培养基测定MIC，包括初始读数和最终读数。恩诺沙星、林可霉素、四环素和泰妙菌素对所有分离株均有活性，且泰妙菌素活性最高。对于泰乐菌素，1968 - 1971年的所有分离株均高度敏感，而1995 - 1996年的分离株可分为高度敏感组（9株）和相对耐药组（12株）。新旧菌株之间的这种差异具有统计学意义（p = 0.0000415）。其余药物，恩诺沙星、林可霉素、泰妙菌素和四环素，对猪滑膜支原体仍表现出良好且未改变的活性。现在对泰乐菌素的耐药性似乎经常出现，以至于不再推荐将这种抗生素用于治疗。耐药性出现的最可能原因是多年来泰乐菌素在治疗和促进生长方面的大量使用。
