Targeted next-generation sequencing reveals pathogen mono- and co-detection patterns in pediatric Mycoplasma pneumoniae pneumonia

Following pandemic control optimization, Mycoplasma pneumoniae (MP) has emerged as a predominant pediatric respiratory pathogen in Shenzhen. Understanding its epidemiological patterns and drug resistance is critical for managing severe MP-associated pneumonia. This retrospective study analyzed 607 hospitalized children (February-November 2023) using targeted next-generation sequencing (tNGS) of bronchoalveolar lavage fluid. MP-positive cases were stratified by age, gender, clinical features, drug resistance genes, and co-detection profiles. Pathogens were identified in 605 cases (99.7 %), with MP constituting 85.0 % of detected pathogens. Among 209 cases with resistance genes, A2063G mutation predominated (98.1 %). Patients were categorized into: MP-positive (n = 444), MP-carriage (n = 72), and MP-negative (n = 91) groups. Age stratification revealed significantly older MP-positive patients (median 72 months, IQR 48-96) versus carriages (29.5 months, IQR 14-60) and negatives (36 months, IQR 16-60) (P < 0.001). Gender distribution showed no significant intergroup differences (χ2 = 2.619, p = 0.270). The MP-positive group demonstrated lower co-detection rates of Haemophilus influenzae (12.2 % vs 37.5 %/31.5 %) and Moraxella catarrhalis (10.6 % vs 25.0 %/20.2 %) compared to carriages and negatives (P < 0.001). tNGS uncovered atypical pathogens including Tropheryma whipplei (13.3 %) and Fusobacterium nucleatum (6.3 %). Post-pandemic MP resurgence correlates with increased severe pediatric pneumonia despite declining macrolide resistance rates (23.2 % in 2023 vs historical 80-90 %). MP primarily manifests as monoinfections, while M. catarrhalis and H. influenzae co-detection may confer observed co-detection pattern. These findings underscore tNGS's clinical utility in identifying atypical pathogens and guiding antimicrobial stewardship in pediatric pneumonia management.