来自日本奶牛犊牛的牛支原体分离株中，GyrA和ParC中的氨基酸替换与氟喹诺酮耐药性相关。
Amino acid substitutions in GyrA and ParC are associated with fluoroquinolone resistance in Mycoplasma bovis isolates from Japanese dairy calves.
作者信息
Sato Toyotaka, Okubo Torahiko, Usui Masaru, Higuchi Hidetoshi, Tamura Yutaka
机构信息
Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, 582 Bunkyoudai-Midorimachi, Ebetsu, Hokkaido 069-8501, Japan.
出版信息
J Vet Med Sci. 2013;75(8):1063-5. doi: 10.1292/jvms.12-0508. Epub 2013 Mar 15.
We investigated the contribution of quinolone resistance-determining region (QRDR) mutations to fluoroquinolone (enrofloxacin, orbifloxacin and danofloxacin) susceptibility in 58 Mycoplasma bovis isolates from dairy cattle in Japan. Fluoroquinolone non-resistant isolates (fluoroquinolone-MICs≤2 μg/ml) possessed no QRDR mutations (19 isolates) or Ser83Leu in GyrA (32 isolates). Fluoroquinolone-resistant isolates (fluoroquinolone-MICs≥4 μg/ml) possessed Ser83Leu in GyrA and Ser81Pro in ParC (3 isolates) or Ser83Phe in GyrA and Ser80Ile in ParC (4 isolates). Laboratory-derived fluoroquinolone-resistant mutants selected from 2 isolates (possessing Ser83Leu in GyrA) had an amino acid substitution in ParC at the same position (Ser80Ile or Ser81Tyr) as fluoroquinolone-resistant isolates, suggesting a concurrent amino acid substitution in ParC (Ser80 or Ser81) is important in fluoroquinolone resistance in M. bovis isolates.
我们研究了喹诺酮耐药决定区（QRDR）突变对日本58株来自奶牛的牛支原体分离株对氟喹诺酮类药物（恩诺沙星、奥比沙星和达氟沙星）敏感性的影响。氟喹诺酮不耐药分离株（氟喹诺酮-MICs≤2μg/ml）未出现QRDR突变（19株）或gyrA基因中的Ser83Leu突变（32株）。氟喹诺酮耐药分离株（氟喹诺酮-MICs≥4μg/ml）出现gyrA基因中的Ser83Leu和parC基因中的Ser81Pro突变（3株）或gyrA基因中的Ser83Phe和parC基因中的Ser80Ile突变（4株）。从2株分离株（gyrA基因中存在Ser83Leu突变）筛选出的实验室诱导氟喹诺酮耐药突变体在parC基因中的相同位置（Ser80Ile或Ser81Tyr）出现了氨基酸替代，这表明parC基因中（Ser80或Ser81）同时发生的氨基酸替代对牛支原体分离株的氟喹诺酮耐药性很重要。
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