title: [Detection of mutations in the gyrA and gyrB genes associated with fluoroquinolone-resistance among clinical isolates of Mycobacterium abscessus in China].
abstract: OBJECTIVE
  To determine molecular mutations in gyrA and gyrB genes and their association with fluoroquinone-resistance among Mycobacterium abscessus isolates from China.
  
  
  METHODS
  Antimicrobial susceptibility profile of Mycobacterium abscessus isolates was evaluated for resistance to levofloxacin (LFX) and moxifloxacin (MFX). The quinolone resistant determing regions (QRDR) of gyrA and gyrB genes of all the isolates was sequenced and analyzed.
  
  
  RESULTS
  A total 70 Mycobacterium abscessus isolates were analyzed, including 45 (64%) M. abscessus subsp. abscessus and 25 (36%) M. abscessus subsp. massiliense. Analysis of antimicrobial susceptibility profile showed 97% (n=68) of isolates were resistance to LFX and 14.3% (n=10) of isolates were resistance to MFX. All the MFX-resistant strains were resistant to LFX. Cross-resistance to LFX and MFX was noted in 14.3% (n=10) of isolates. Sequencing analysis revealed that the Ser83Ala substitution in the gyrA gene and Lys447Arg and Ser464Asn substitutions in the gyrB gene were found in all the isolates from both M. abscessus subsp. abscessus and M. abscessus subsp. massiliense. No mutation was found to be associated with cross-resistance of M. abscessus to LFX and MFX in the entire gyrA and gyrB gene.
  
  
  CONCLUSIONS
  Our data suggest that there is no clear correlation between the type of mutation in the gene gyrA and gyrB, and the MIC levels of LFX and MFX for resistant M. abscessus strains.
authors.affiliation: National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory on Drug-resistant Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China.
authors.forename: Suting
authors.initials: S
authors.lastname: Chen
authors.affiliation: National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory on Drug-resistant Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Nie
authors.affiliation: National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory on Drug-resistant Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Shang
authors.affiliation: National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory on Drug-resistant Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liang
authors.affiliation: National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory on Drug-resistant Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Fu
authors.affiliation: National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory on Drug-resistant Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Ma
authors.affiliation: National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory on Drug-resistant Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China.
authors.forename: Naihui
authors.initials: N
authors.lastname: Chu
authors.affiliation: National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory on Drug-resistant Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China; Email: haironghuangcn@gmail.com.
authors.forename: Hairong
authors.initials: H
authors.lastname: Huang
mesh_terms: D001372:Aza Compounds; D001483:Base Sequence; D002681:China; D027081:DNA Gyrase; D024841:Fluoroquinolones; D006801:Humans; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D009154:Mutation; D009170:Nontuberculous Mycobacteria
chemical_list: D001372:Aza Compounds; D024841:Fluoroquinolones; D064704:Levofloxacin; D027081:DNA Gyrase; D000077266:Moxifloxacin