儿童肺炎支原体感染及耐药检测与分析

The infection of mycoplasma pneumoniae,detection and analysis of drug resistance in children

目的分析肺炎患儿中肺炎支原体(MP)的感染及耐药情况,并探讨其临床特点及基因分型特征,为临床合理选择抗生素提供理论依据。方法收集2015年1月至2015年12月铜川市妇幼保健院儿科以发热、咳嗽等呼吸道症状首诊确定MP感染的住院患儿120例。通过肺炎支原体抗体检测、体外培养及核酸检测了解肺炎支原体感染状况,测定多种抗菌药物的最低抑菌浓度(MIC值),分离出耐药菌株。根据药敏试验鉴定结果分为耐药组(n=98)和非耐药组(n=22),比较耐药组与非耐药组患儿临床特征;将耐药组98例患儿依据初选抗生素种类分为初选阿奇霉素或红霉素组(n=78)和初选头孢或青霉素类(n=20),比较两组患儿的临床特点。将耐药菌株的23SrRNA基因序列与标准珠相比对,研究耐药菌株的23SrRNA基因突变位点。结果 120例经临床诊断为MP肺炎的患儿中,98例体外药敏试验结果提示为耐药支原体肺炎,对大环内酯类药物高度耐药。耐药组发热时间、住院时间及给予大环内酯类药物(阿奇霉素)后发热时间均较非耐药组长(P<0.05),两组间年龄、呼吸道症状时间、白细胞计数(WBC)、中性粒细胞比例、C反应蛋白(CRP)、血沉(ESR)、影像所见好转时间、大环内酯类抗生素(ML)总疗程比较差异均无统计学意义(均P>0.05)。耐药组与非耐药组之间预后比较差异有统计学意义(P<0.05),其中非耐药组痊愈患儿比例高于耐药组。98例耐药支原体肺炎中初选头孢或青霉素类抗生素组20例,治疗中更改为大环内酯类抗生素的平均时间为病程第(5.2±1.8)天。初选不同治疗药物两组在呼吸道症状持续时间、使用大环内酯类抗生素后发热时间、白细胞计数等指标差异有统计学意义(P<0.05)。肺炎支原体核糖体23SrRNA全序列分析:其中约90%耐药MP株发生了2063位A→G(A2063G)的突变,少数MP耐药株发生了A2064G(约5%)、A2063C、C2617G/A的突变。结论铜川地区2015年支原体肺炎患儿对大环内酯类抗生素耐药现象严重,其耐药机制主要与2063位A→G(A2063G)的点突变有关。非耐药组患儿预后好于耐药组。MP快速鉴定培养与直接药敏试验方法标本获取容易,检测技术操作简单,检测结果可为临床诊疗提供科学依据。

Objective To analyze the infection and drug resistance of mycoplasma pneumoniae in children, explore its clinical characteristics and genotyping feature, and provide a theoretical basis for the selection of antibiotic. Methods 120 children of mycoplasma pneumoniae pneumonia were enrolled. The infection of mycoplasma pneumoniae was explored by detection of mycoplasma pneumoniae antibody and nucleic acid. The MIC value of multiple antimicrobial drugs was tested. The drug-resistant strains was isolated. The children were divided into drug resistance group and non- drug resistance group by drug-resistant results. The clinical features drug resistance group and non- drug resistance group were compared. The gene sequence of 23SrRNA of drug-resistant strains and non- drug resistance group were detected. Results 98 cases were drug-resistant pneumonia according to susceptibility test results in vitro, which were highly resistant to macrolides . The time of fever group （P〈0.05）. The age, and hospitalization in drug resistance group were longer than that of non-drug resistance duration of symptoms of respiratory tract, white blood cell count （WBC）, neutrophil percentage, C-reactive protein （CRP）, erythrocyte sedimentation rate （ESR）, the image seen better times, period of treatment with macrolides （ML） showed no statistical significance between the two groups. The prognosis was statistically significant （P〈0.05） between drug resistance group and non-drug resistance group. The proportion of healed cases in non-drug resistance group was higher than that of the drug resistance group. The time of change the treatment with macrolide antibiotics was （5.2 ± 1.8） d. The duration of respiratory symptoms, time of fever, white blood cell counts and other indicators were statistically significant in groups of different treatment. There were 90 % of mutations occurred A2063G in drug-resistant strains and 5% occurred A2064G, A2063C and C2617G/A. Conclusion MP is widely prevalent in children and its resistance to MLs is serious in the region of Tongchuan of the year of 2015. Its principal mechanism of resistance were 2063 A →G （A2063G） of point mutations. Non-drug resistance group of children has a better prognosis than drug resistance groups. Rapid culture identification of MP and drug susceptibility testing meet clinical requires of easy collection and simple handling and provide scientific rationals for clinical diagnosis and treatment.