2012－2017年天津市百日咳鲍特菌耐药情况分析

目的 了解2012 — 2017年天津市百日咳鲍特菌菌株对抗生素敏感性的分布情况及耐药位点变异情况，为百日咳防治提供依据。 方法 以2012年2月至2017年7月天津市分离的18株百日咳鲍特菌菌株作为研究对象，采用纸片扩散法对培养的阳性菌株进行红霉素、阿奇霉素、克拉霉素、左氧氟沙星及克林霉素敏感性进行检测，同时采用E-test法检测菌株对红霉素、阿奇霉素、克拉霉素、左氧氟沙星及复方新诺明的敏感性；对红霉素结合区域23S rRNA domain V基因片段进行扩增、序列测定及分析。 结果 纸片扩散法结果显示，18株菌株中仅1株对5种抗生素均敏感，其余17株对红霉素、阿奇霉素、克拉霉素及克林霉素均耐药，红霉素耐药率最高，达94.44%（17/18），18株菌对左氧氟沙星均敏感；E-test法结果显示，仅1株菌对红霉素、阿奇霉素、克拉霉素的最低抑制浓度（MIC）在敏感范围内，其余17株对红霉素、阿奇霉素、克拉霉素的MIC均＞256 μg/ml，18株菌对左氧氟沙星的MIC为0.19～0.38 μg/ml，复方新诺明的MIC为0.047～1.500 μg/ml；23S rRNA扩增产物序列分析发现，17株菌发生A2047G位点突变。 结论 纸片扩散法和E-test法对红霉素、阿奇霉素、克拉霉素和左氧氟沙星的耐药结果完全符合，17株菌对红霉素、阿奇霉素、克拉霉素同时耐药，耐药株23S rRNA序列均发生A2047G红霉素耐药位点改变。

Analysis on drug resistance of Bordetella pertussis isolated in Tianjin

Objective To understand the susceptibility of Bordetella pertussis to antibiotics and variation of drug resistance sites of the isolates in Tianjin and provide evidence for pertussis prevention and treatment. Methods A total of 18 strains of B. pertussis were isolated in Tianjin from February 2012 to July 2017. The susceptibilities of B. pertussis isolates to erythromycin, azithromycin, clarithromycin, levofloxacin and clindamycin were detected with disk diffusion method, and the susceptibilities of the isolates to erythromycin, azithromycin, clarithromycin, levofloxacin and sulphamethoxazole/trimethoprim were detected with E-test method. A fragment of domain V in the 23S rRNA as binding region to erythromycin was amplified and sequenced. Results The results of disk diffusion showed that only one of the 18 isolates was sensitive to all the tested antibiotics, the remaining 17 isolates were resistant to erythromycin, azithromycin, clarithromycin and clindamycin, the resistant rate to erythromycin was highest (94.44 %, 17/18), and all the 18 isolates were sensitive to levofloxacin; E-test showed that only one isolate was sensitive to erythromycin, azithromycin and clarithromycin indicated by minimum inhibitory concentration (MIC) test. The MICs of all the tested antibiotics to the remaining 17 isolates were ＞ 256 μg/ml. The MICs of levofloxacin to the 18 isolates were 0.19–0.38 μg/ml and those of sulphamethoxazole/trimethoprim were 0.047–1.500 μg/ml. PCR amplification of the 23S rRNA region found that 17 antibiotic resistant isolates had A2047G mutation. Conclusion The disk diffusion method and E-test method were used to detect the drug resistance of B. pertussis isolates in Tianjin. The coincidence rate of the two methods for erythromycin, azithromycin, clarithromycin and levofloxacin was 100%. Seventeen isolates were resistant to erythromycin, azithromycin and clarithromycin at the same time. All the antibiotic resistant isolates showed A2047G mutation in the 23S rRNA region.