胞内分枝杆菌临床分离株对大环内酯类和利奈唑胺的药物敏感性研究

Macrolide and Linezolid Susceptibility Testing for Mycobacterium intracellulare Isolates

目的研究胞内分枝杆菌对克拉霉素、阿奇霉素和利奈唑胺的敏感性，以初步评价其用于胞内分枝杆菌疾病治疗的价值。方法采用微孔板Alamar Blue法测定克拉霉素、阿奇霉素和利奈唑胺对76株胞内分枝杆菌的MIC。结果克拉霉素对胞内分枝杆菌的MIC90为2mg／L，敏感、中介和耐药的比例分别为93．4％（71／76）、0．0％（0／76）和6．6％（5／76）；阿奇霉素对胞内分枝杆菌的MIC90为32mg／L，敏感、中介和耐药的比例分别为94．7％（72／76）、0．0％（0／76）和5．3％（4／76）；利奈唑胺对胞内分枝杆菌的MIc90为64mg／L，敏感、中介和耐药的比例分别为32．9％（25／76）、22．4％（17／76）和44．7％（34／76）。5株克拉霉素耐药菌株中有4株对阿奇霉素耐药，2株对利奈唑胺耐药。结论胞内分枝杆菌中克拉霉素敏感株占绝大多数，克拉霉素耐药株对阿奇霉素高度交叉耐药，对利奈唑胺部分敏感。

Objective To investigate the susceptibility ofMycobacterium 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 azithromyein 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.