Azithromycin to doxycycline switching in children with Mycoplasma pneumoniae pneumonia resistance gene positivity

BackgroundThis study aimed to evaluate whether Mycoplasma pneumoniae resistance gene detection can independently guide antibiotic therapy for Mycoplasma pneumoniae pneumonia in children and to identify key predictors for antibiotic adjustment.MethodsWe conducted a retrospective cohort study of children with Mycoplasma pneumoniae pneumonia who underwent resistance gene testing. Participants were recruited from two centers (Affiliated Hospital of North Sichuan Medical College and People's Hospital of Nanbu County) between January 2023 and October 2025. Resistance gene testing results served as the basis for assigning patients to either the positive or negative group. The expression of Mycoplasma pneumoniae resistance genes was analyzed. The positive group was further divided into a “switch group” (switched to doxycycline) and a “maintenance group” (continued azithromycin). We performed a comparative analysis of demographic, clinical, and laboratory parameters across the groups. Multivariate logistic regression identified factors associated with switching antibiotics, and ROC curves assessed predictive performance.ResultsA total of 150 children were enrolled, with 13 in the macrolide resistance gene-negative group and 137 in the positive group, resulting in a macrolide resistance gene positivity rate of 91.3%. Of these patients, 65 patients were in the switch group and 72 patients were in the maintenance group. Significant differences were observed in baseline characteristics (age), inflammatory markers (CRP, PCT, lymphocyte count), disease severity (severe MPP, pleural effusion, bronchoscopy), and clinical management (peak fever, hospital stay, antibiotic duration) (P