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

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