肺炎支原体突变敏感性分子开关检测对抗菌药物敏感性检测的作用研究

Significance of molecular switch-based detection of mutations to prediction of antimicrobial susceptibility of Mycoplasma pneumoniae

目的分析肺炎支原体突变敏感性分子开关检测对抗菌药物敏感性检测的价值。方法选择2015年1月至2016年2月在河北省儿童医院呼吸科住院收治的450例社区获得性肺炎患儿的肺泡灌洗液标本,进行MP培养与药敏分析,抗菌药物选择红霉素与阿奇霉素,对MP培养阳性菌株使用分子开关技术检测23SrRNA V区2063/2064基因的突变情况,并进行测序分析,最后明确分子开关检测MP耐药基因与其对抗菌药物敏感性的相关性。结果在450例患儿中,MP检测阳性80例,阳性率为17.8%。在80株MP中,72株对红霉素耐药,耐药率为90.0%;31株对阿奇霉素耐药,耐药率为38.8%,为此MP对于红霉素的耐药率明显高于阿奇霉素(χ2=9.134,P=0.000)。76株MP株的23SrRNA的2063/2064位发生了基因突变,其中有70株检测出A2063G的突变,6株有A2064G的突变。而在76株23S rRNA 2063/2064基因位点突变的MP中,有72株MP对红霉素产生高水平耐药,并对阿奇霉素发生交叉耐药,未发生突变的4株MP均对红霉素与阿奇霉素敏感。结论肺炎支原体对红霉素与阿奇霉素都有高度的耐药性,分子开关检测可识别23SrRNA V区基因2063/2064位点突变,有利于反映MP对红霉素与阿奇霉素的敏感性,具有很好的检测价值。

Objective To analyze the values of molecular switch-based detection of mutation to the prediction of antimicrobial susceptibility of Mycoplasma pneumoniae（MP）.Methods Bronchoalveolar lavage fluid of450 children with community-acquired pneumonia admitted in the respiratory department of our hospital from January 2015 to February 2016 were collected and cultured to detect the drug sensitivity to erythromycin and azithromycin.Molecular switch technology was used to detect the mutation of 2063/2064 gene in 23 SrRNA V region of MP,which was then sequenced.The correlation between the resistant genes and antimicrobial drug sensitivity of MP was analyzed.Results 80 out of 450 cases were MP positive（17.8%）,among which72strains（90%）were erythromycin resistant,while 31strains（38.8%）were azithromycin resistant;the resistance rate to erythromycin was significantly higher than that to azithromycin（χ2=9.134,P=0.000）.76 strains had mutation at gene loci 2063/2064 on 23SrRNA,including A2063 G mutation detected in 70 strains and A2064 G mutation detected,in 6strains.And in the 76 strains with 2063/2064 gene mutation in23 SrRNA,72strains were highly resistant to erythromycin while cross-resistant to azithromycin.The 4strains without mutations were sensitive to erythromycin and azithromycin.Conclusion Mycoplasma pneumonia are highly resistant to erythromycin and azithromycin.Molecular switch-based detection of the mutations at gene loci 2063/2064 in V region of 23 SrRNA can help to predict sensitivity of MP to erythromycin and azithromycin.