›› 2010, Vol. 37 ›› Issue (9): 43-47.

• 生理生化 • Previous Articles     Next Articles

Characterization of Mutations in DNA Gyrase and Topoisomerase Ⅳ Involved in Quinolone Resistance of Clinical Mycoplasma gallisepticum Isolates

WEI Fei-long, ZHOU Yun-lei,SHEN Xiang-guang,JIANG Hong-xia   

  1. (Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation,College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China)
  • Received:1900-01-01 Revised:1900-01-01 Online:2010-09-20 Published:2010-09-20
  • Contact: JIANG Hong-xia

Abstract: Susceptibilities of 4 isolated M. gallisepticum to common used antimicrobials were determined by broth dilution method. PCR and sequencing were applied for analysis of quinolone resistance-determining regions of the four target genes encoding DNA gyrase and topoisomerase Ⅳ from 4 isolates. The results showed that 4 isolates presented higher susceptible to tylosin, tiamulin, valnemulin and tilmicosin,moderate susceptible to tetracycline and erythromycin, and resistant to lincomycin, florfenicol and 3 fluroquinolone drugs to a certain extent. Several mutations were found in the two fluoroquinolone targets GyrA and ParC. Double mutations within QRDR of GyrA were found among 4 isolated M. gallisepticum, with the same substitution patterns of Ser81→Gly and Ser83→Ile. There was only one alteration existed within QRDR of ParC (Ser80→Leu) among 4 isolates. No mutations were found within QRDR of GyrB and ParE in 4 isolates.

Key words: Mycoplasma gallisepticum; minimum inhibitory concentration; DNA gyrase; topoisomerase Ⅳ

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