title: [Macrolide and linezolid susceptibility testing for Mycobacterium intracellulare isolates].
abstract: OBJECTIVE
  To investigate the susceptibility of Mycobacterium intracellulare isolates to clarithromycin, azithromycin and linezolid, and therefore to explore the possibility of using these drugs to treat Mycobacterium intracellulare diseases.
  
  
  METHODS
  The minimal inhibitory concentrations (MICs) of the 3 antibiotics against 76 Mycobacterium intracellulare isolates were determined by using microplate alamar blue assay (MABA).
  
  
  RESULTS
  The MIC90 of clarithromycin against Mycobacterium intracellulare isolates was 2 mg/L. The proportion of susceptible, intermediate and resistant isolates to clarithromycin was 93.4% (71/76), 0.0% (0/76) and 6.6% (5/76), respectively. The MIC90 of azithromycin against the isolates was 32 mg/L. The proportion of susceptible, intermediate and resistant isolates to azithromycin was 94.7% (72/76), 0.0% (0/76) and 5.3% (4/76), respectively. The MIC90 of linezolid was 64 mg/L. The proportion of susceptible, intermediate and resistant isolates to linezolid was 32.9% (25/76), 22.4% (17/76) and 44.7% (34/76), respectively. Among the 5 isolates resistant to clarithromycin, 4 were resistant to azithromycin, and 2 were resistant to linezolid.
  
  
  CONCLUSIONS
  Most of the Mycobacterium intracellulare isolates were sensitive to clarithromycin. High cross-resistance between clarithromycin and azithromycin was present, but some clarithromycin-resistant isolates were sensitive to linezolid.
authors: Department of Tuberculosis, Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing Chest Hospital affiliated to Capital Medical University, Beijing 101149, China.
authors: Hongfei
authors: H
authors: Duan
authors: Department of Tuberculosis, Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing Chest Hospital affiliated to Capital Medical University, Beijing 101149, China.
authors: Qian
authors: Q
authors: Liang
authors: Department of Tuberculosis, Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing Chest Hospital affiliated to Capital Medical University, Beijing 101149, China.
authors: Naihui
authors: N
authors: Chu
authors: Department of Tuberculosis, Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing Chest Hospital affiliated to Capital Medical University, Beijing 101149, China. Email: hairong.huangcn@gmail.com.
authors: Hairong
authors: H
authors: Huang
mesh_terms: D000081:Acetamides / Q000494:pharmacology*; D006801:Humans; D000069349:Linezolid; D018942:Macrolides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015269:Mycobacterium avium Complex / Q000187:drug effects* / Q000302:isolation & purification; D023303:Oxazolidinones / Q000494:pharmacology*
chemical_list: D000081:Acetamides; D018942:Macrolides; D023303:Oxazolidinones; D000069349:Linezolid