ACTA VETERINARIA ET ZOOTECHNICA SINICA ›› 2011, Vol. 42 ›› Issue (4): 600-604.doi:

• 研究简报 • Previous Articles    

Relationship between Fluoroquinolone Resistance and GeneMutation in Streptococcus suis

RUI Ping1，2, MA Zeng-jun2, DUAN Ling-xin2, LIU Xie-rong2, NI Jing2, SHEN Jian-zhong1*   

  1. 1.College of Veterinary Medicine,China Agricultural University, Beijing 100193, China；2.Key Laboratory of Preventive Veterinary Medicine of Hebei, Hebei Normal University of Science and Technology, Qinhuangdao 066004, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2011-04-20 Published:2011-04-20

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Abstract: To detect the relationship between fluoroquinolone resistance and gyrA and parC gene mutation in Streptococcus suis. The MIC of 34 strains of Streptococcus suis were determined by microdilution. The genes encoding the quinolone-resistance determining region (QRDRs) of parC and gyrA in fluoroquinolone-susceptible and -resistant Streptococcus suis clinical isolates were identified and sequenced. Ser to Phe and Arg to Leu mutation at position 79 and 87 of the parC gene was detected in fluoroquinolone resistance S.suis, and Arg to Ser, or Ser to Arg mutations at the position 66 or 81 of gyrA gene were detected in 4 highly resistance strains; no amino acid changes in gyrA or parC were detected for 9 fluoroquinolonesusceptible strains，the mutations in both genes was found in the strains with MIC of fluoroquinolone higher than 32μg·L-1. Mutations in parC gene result in low level resistance against fluoroquinolone,and high level resistance is resulted from the mutations in gyrA and parC both genes.