【摘要】 目的:探讨DNA载量和基因型检测在肺炎支原体(MP)肺炎患儿抗生素治疗中的临床作用。方法:回顾性分析2016年3月至2019年3月河北省沧州市人民医院收治的124例MP肺炎患儿的临床资料。收集咽拭子标本,以快速培养基培养药敏法测定常用抗生素对MP分离株的药物敏感性,观察MP肺炎患儿耐药情况;实时荧光定量PCR法测定MP-DNA载量,分析MP-DNA载量与不同抗生素耐药性的关系;PCR测序检测MP 23SrRNA V区2063位基因型,分析其与不同抗生素耐药性的关系,并比较23SrRNA V区2063位基因型及突变基因型与MP-DNA载量的关系。结果:124例MP肺炎患儿MP培养及药敏鉴定结果显示,9种抗生素中罗红霉素、红霉素耐药率最高,其次为克林霉素、乙酰螺旋霉素、克拉霉素、阿奇霉素、喹诺酮类抗生素。耐药组MPLI均较非耐药组低,其中红霉素、克林霉素、克拉霉素、阿奇霉素耐药组MPLI均显著低于非耐药组(均P<0.05),罗红霉素、乙酰螺旋霉素、加替沙星、左氧氟沙星耐药组MPLI与非耐药组比较,差异均无统计学意义(均P>0.05)。MP 23SrRNA V区2063位A→G突变对大环内酯类抗生素耐药影响较大,其中产生罗红霉素、红霉素、克林霉素、乙酰螺旋霉素、克拉霉素、阿奇霉素耐药的病例检出2063位点G突变均占64%以上。124例MP肺炎患儿中46例A型(37.10%),4例C型(3.23%),72例G型(58.06%),2例T型(1.61%)。突变型组MPLI显著低于野生型组(P<0.05),23SrRNA V区2063位基因突变为C、G、T的患儿MPLI比较差异无统计学意义(P>0.05)。结论:MP对大环内酯类抗生素的耐药率相对较高,其耐药产生及DNA载量改变可能与23SrRNA V区2063位点基因突变有关,可作为MP肺炎患儿临床用药参考依据。更多还原

【Abstract】 Objective:To study the clinical effect of DNA load and genotype detection in antibiotic therapy of children with Mycoplasma pneumoniae(MP)pneumonia.Methods:124 children with MP pneumonia admitted to our hospital from March 2016 to March 2019 were selected.Pharyngeal swab specimens were collected to determine the drug sensitivity of commonly used antibiotics to MP isolates by rapid culture medium.Drug resistance of children with MP pneumonia was observed.Real-time fluorescence quantitative PCR was used to determine MP-DNA load.The relationship between MP-DNA load and antibiotic resistance was analyzed.2063 genotypes of MP 23 SrRNA V region was detected by PCR sequencing,and their relationship with different antibiotic resistance as well as the relationship between 2063 genotypes and mutant genotypes of 23 SrRNA V region and MP-DNA load were analyzed.Results:The results of MP culture and drug susceptibility test of 124 MP pneumonia children showed that roxithromycin and erythromycin had the highest resistance rate among 9 antibiotics,followed by clindamycin,acetylspiramycin,clarithromycin,azithromycin and quinolone antibiotics.MPLI in drug-resistant group was lower than that in Nondrug-resistant group.MPLI in erythromycin,clindamycin,clarithromycin and azithromycin-resistant group was significantly lower than that in Non-drug-resistant group(P<0.05).MPLI in roxithromycin,acetylspiramycin,gatifloxacin and levofloxacin-resistant group was not significantly different from that in Nondrug-resistant group(P>0.05).The 2063 AG mutation in MP 23 SrRNA V region has a greater impact on the resistance of macrolide antibiotics.The 2063 site G mutation was detected in more than 64% of the cases producing roxithromycin,erythromycin,clindamycin,acetylspiramycin,clarithromycin and azithromycin resistance.Among 124 cases of MP pneumonia,46 cases were type A(37.10%),4 cases were type C(3.23%),72 cases were type G(58.06%)and 2 cases were type T(1.61%).MPLI in mutant group was significantly lower than that in wild type group(P<0.05).There was no significant difference in MPLI between children with mutation of 2063 gene in 23 SrRNA V region and those with mutation of C,G and T(P>0.05).Conclusion:The drug resistance rate of MP to macrolide antibiotics is relatively high,and the drug resistance and DNA load change may be related to the gene mutation at 2063 site of 23 SrRNA V region,which can be used as a reference for the clinical medication of MP pneumonia children.更多还原