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Original Article

The High-Risk CCL14 Lineage Drives Severe Mycoplasma pneumoniae Pneumonia in Children: A Study in Central China

Chunbo Hao¹  , Zijie Li¹  , Yanjuan Yu¹  , Song Wang²  , Genhao Wang²  , Gaijing Jia²  , Tiantian Sun³  , Shouhang Chen¹  , Yang Wu¹  , Yu Tang¹  , Fang Wang¹  , Guangcai Duan²  , Yuefei Jin^1,2,4,5 

¹Henan International Joint Laboratory of Children's Infectious Diseases, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China, Zhengzhou, China
²Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou, China, Zhengzhou, China
³Department of Infection Control, Henan Provincial People's Hospital, Zhengzhou, China, Zhengzhou, China
⁴Key Laboratory of Infection and Immunity of Anhui Higher Education Institutes, Bengbu Medical University, Bengbu, China, Bengbu, China
⁵State Key Laboratory for Zoonotic Diseases, Wuhan, China, Wuhan, China

Correspondence Yuefei Jin ,Email: jyf201907@zzu.edu.cn

Received: November 25, 2025; Revised: January 21, 2026   Accepted: February 10, 2026.

Abstract

Background
The post-pandemic resurgence of Mycoplasma pneumoniae (MP) infections, particularly in China, underscores the need to understand the drivers of disease severity. However, the genotypic landscape of the prevalent strains in central China and its link to clinical outcomes remain poorly characterized.
Purpose
This study aimed to evaluate the associations between predominant circulating strains of MP and disease severity.
Method
We integrated the clinical data of 3,060 pediatric patients and analyzed the epidemiological characteristics of Mycoplasma pneumoniae pneumonia (MPP) in Henan region from 2020 to 2024. Bronchoalveolar lavage fluid (BALF) from 137 patients was analyzed using multilocus sequence typing (MLST) and variable-number tandem-repeat analysis (MLVA) to investigate the correlation between genotype and clinical outcomes.
Results
A significant post-COVID MPP outbreak was predicted in 2023. Genotyping revealed the cocirculation of 2 major genotypes: the prevalent ST3 (57.7%, severe ratio [31.6%]) and the less common but highly virulent ST14 (26.3%, severe ratio [72.2%]). Phylogenetic clustering confirmed ST14/3-5-6-2 as part of a broader hypervirulent lineage, common cluster label 14 (CCL14), which was significantly associated with disease severity (χ2=19.39; P<0.001). Patients infected with CCL14 strains exhibited a distinct hyperinflammatory profile marked by elevated D-dimer levels, complement C4 levels, and platelet count. The mutation ratio of macrolide resistance sites in the MP strains from Henan Province was approximately 75%.
Conclusion
Our findings identified the CCL14 lineage as a key driver of disease severity in macrolide-resistant pediatric MPP in Henan Province, China. This underscores the importance of integrating molecular surveillance with clinical monitoring to mitigate disease burden.

Keywords :Mycoplasma pneumoniae; Mycoplasma pneumoniae pneumonia; MLST; MLVA