Etiological characteristics and genotypes of Mycoplasma pneumoniae infection in children in Baoding from 2022 to 2024

ABSTRACT To investigate the epidemiology associated with genetic types and macrolide resistance of Mycoplasma pneumoniae (MP) in children during and post-COVID-19 in Baoding. A retrospective analysis was conducted on 13,534 children and adolescents (≤18 years old) with community-acquired pneumonia from January 2022 to December 2024. MP detection and macrolide resistance-associated mutation analysis were performed using multiplex real-time PCR. Multilocus variable-number tandem-repeat analysis (MLVA) was used for genotyping. Mycoplasma pneumoniae pneumonia (MPP) cases rose significantly from 844 (2022) to 6,346 (2024) ( P < 0.01), while the positive rate remained stable (67.68%–77.72%). Patients aged 5–18 years had the highest positive rate. Severe MPP (SMPP) prevalence declined from 22.75% (2022) to 6.16% (2024) ( P < 0.01), with MP infections peaking in the fourth quarter of 2023–2024 and prevailing year-round in 2024. Macrolide-resistant MP (MRMP) prevalence was 95.92% overall (97.27%/2022, 93.85%/2023, 96.56%/2024), with no significant difference between SMPP and non-severe MPP groups. MLVA-type M3562 decreased from 77.10% to 33.13%, while M4572 increased to 56.72% (2024) as the dominant type. Both genotypes had 99.00%–100.00% macrolide resistance. Notably, SMPP was more common in M3562-infected patients (20.63%) than M4572-infected ones (13.97%, P < 0.01). MP infections re-emerged between 2023 and 2024, with persistently high macrolide resistance. There was a genotype shift from M3562 to M4572. These findings highlight the need for strengthened surveillance, rational antibiotic use, and targeted prevention strategies to address MP infections in the post-pandemic period. IMPORTANCE Understanding the epidemiological characteristics of Mycoplasma pneumoniae (MP) is essential for effective management of Mycoplasma pneumoniae pneumonia (MPP). This study examines the epidemiology associated with genetic types and macrolide resistance of MP in children with MPP in Baoding, China, during and after the lifting of non-pharmaceutical interventions (NPIs). Data from 9,728 children diagnosed with MPP from January 2022 to December 2024 were analyzed. MPP cases rose significantly from 844 in 2022 to 6,346 in 2024, while the overall prevalence of macrolide-resistant MP was 95.92%. Notably, a striking genotype shift from M3562 (77.10%/2022–33.13%/2024) to M4572 (15.74%/2022–56.72%/2024) was observed over this period. Severe MPP proportion was significantly higher in patients with M3562 (20.63%) infection than that with M4572 (13.97%). This research underscores the urgent need for strengthened surveillance, rational antibiotic use, and targeted prevention strategies to address MP infections in the post-pandemic period.