Significance of the determination of DNA load of drug-resistant mycoplasma pneumoniae and 23sRNA gene mutation locus in children

Abstract

Purpose: To determine the significance of the detection of Mycoplasma pneumoniae (MP)-DNA load and 23sRNA gene mutation locus in children with drug-resistant MP pneumonia. Methods: A total of 158 children with MP pneumonia received drug sensitivity tests. The patients were divided into resistance group and non-resistance group. The MP-DNA load index (MPLI) and mutation rate of 23sRNA gene at 2063 locus were assessed and compared between the two groups: the MPLI-negative group and the MPLI-positive group, based on whether MPLI was greater than 6.12. The association of MPLI of all the patients and the 23sRNA gene mutation at 2063 locus in the resistance group, as well as clinical indicators were analyzed. Results: The MPLI of the resistance group was lower than that of the non-resistance group. In the MPLI-positive group, the duration of disease, defervescence time, disappearance time of cough and expectoration, disappearance time of chest opacity, and length of stay were all longer than those of the MPLI-negative group, while the proportion of cases with extrapulmonary complications and the white blood cell (WBC) count were higher than those of the MPLI-negative group. The mutation rate of 23sRNA gene at 2063 locus in the resistance group was higher than that in non-resistance group (p < 0.05). The defervescence time, disappearance time of cough and expectoration, disappearance time of chest opacity and length of stay were longer in the mutation-positive group than those in the mutation-negative group (p < 0.05). Conclusion: The mutation rate of 23sRNA gene at 2063 locus is higher in children with drug-resistant MP pneumonia. Furthermore, low MPLI and 23sRNA gene mutations at 2063 locus are associated with the duration of disease, disappearance time of clinical symptoms and other clinical indicators.