Abstract: Objective To explore the correlation between DNA load of drug-resistance mycoplasma pneumonia(MP) and 23sRNA mutation at 2063 locus in children, in order to provide evidence for the treatment of MP pneumonia. Methods A total of 158 children with MP pneumonia who were treated in Nantong First People's Hospital from December 2017 to December 2019 were enrolled in this study.The drug sensitivity tests were performed on all patients.According to the results of drug-resistance to antibiotics, patients were divided into resistance group(n=112) and non-resistance group(n=46).The MP load index(MPLI) and mutation rate of 23sRNA gene at 2063 locus were compared between resistance group and non-resistance group.The relationship between MPLI and clinical indexes was analyzed.The diagnostic value of MPLI for drug-resistance MP pneumonia was analyzed by ROC curves.The correlation between MPLI and mutation of 23sRNA gene at 2063 locus was analyzed. Results MPLI in resistance group was significantly lower than that in non-resistance group(t=4.373, P<0.001).AUC and cut-off value of MPLI for diagnosis of drug-resistance MP pneumonia were 0.698 and 5.16, respectively.The proportion of cases with defervescence time not shorter than 3 days, disappearance time of cough and expectoration not shorter than 5 days, disappearance time of chest shadow not shorter than 10 days and extrapulmonary complications in positive MPLI group was higher than that in negative MPLI group(χ²=17.584, 19.237, 44.724, 11.075, P<0.001).Multivariate Logistics regression analysis showed that defervescence time ≥3 days, disappearance time of cough and expectoration ≥5 days, disappearance time of chest shadow ≥10 days and extrapulmonary complications were influencing factors of MPLI expression in children with MP pneumonia(OR=1.420, 1.573, 1.670, 1.598, P<0.001).The mutation rate of 23sRNA gene at 2063 locus in resistance group was significantly higher than that in non-resistance group(χ²=52.484, P<0.001).The expression level of MPLI was negatively correlated with 23sRNA gene mutation at 2063 locus(r=-0.538, P<0.001). Conclusions The expression of MPLI is related to clinical indexes such as disappearance time of clinical symptoms in children with MP pneumonia, which is negatively related to the mutation rate of 23sRNA gene at 2063 locus.MPLI expression is of diagnostic value for drug-resistance MP pneumonia.

Key words: drug-resistance mycoplasma pneumonia, children, mycoplasma DNA load, 23sRNA gene mutation locus

摘要： 目的 分析儿童耐药支原体肺炎的肺炎支原体(MP)DNA载量与23sRNA2063位点突变的相关性,以期为MP肺炎的治疗提供参考。方法 选取2017年12月-2019年12月在南通市第一人民医院治疗的MP肺炎患儿158例,对所有患者进行药敏试验,根据抗生素耐药性将患者分为耐药组(n＝112)和非耐药组(n＝46)。比较两组患者咽拭子MPDNA载量指数(MPLI)及23sRNA基因2063位点突变率,分析患者MPLI与临床指标的关系,采用ROC曲线分析MPLI对耐药MP肺炎的诊断价值,并分析患者MPLI与23sRNA基因2063位点突变的相关性。结果 耐药组MPLI低于非耐药组(t=4.373,P<0.001);MPLI诊断耐药MP肺炎的AUC为0.698,截点值为5.16;MPLI阳性组在退热时间≥3 d、咳嗽咯痰消失时间≥5 d、胸部阴影消失时间≥10 d、合并肺外并发症方面的人数比例大于阴性组(χ²=17.584、19.237、44.724、11.075,P<0.001);经多元Logistics回归分析得,退热时间≥3 d、咳嗽咳痰消失时间≥5 d、胸部阴影消失时间≥10 d、合并肺外并发症是影响MP肺炎患儿MPLI表达的相关因素(OR=1.420、1.573、1.670、1.598,P<0.001);耐药组23sRNA基因2063位点基因突变率高于非耐药组(χ²=52.484,P<0.001);MP肺炎患儿MPLI表达水平与23sRNA基因2063位点突变呈负相关(r=-0.538,P<0.001)。结论 耐药肺炎支原体患儿MPLI表达与临床症状消失时间等临床指标有关,与23sRNA基因2063位点突变率呈负相关,且MPLI表达对耐药MP肺炎具有诊断价值。

关键词: 耐药支原体肺炎, 儿童, 支原体DNA载量, 23sRNA基因突变位点