Mycoplasma pneumoniae is an important etiological agent of respiratory tract infections, and the increasing prevalence of macrolide-resistant Mycoplasma pneumoniae has raised concerns regarding its molecular epidemiology and evolutionary characteristics. In this study, 320 M. pneumoniae –positive clinical specimens collected in Yunnan, China, in 2024, including 230 pediatric and 90 adult cases, were analyzed to investigate macrolide resistance–associated mutations and P1 genotype distribution. Macrolide resistance–associated mutations were identified by PCR amplification and Sanger sequencing, and P1 adhesin gene sequencing was performed for genotyping and phylogenetic analysis. A 94% prevalence of macrolide-resistant Mycoplasma pneumoniae was observed in Yunnan, China. The A2063G substitution in the 23S rRNA gene was the predominant mutation, while no mutations were detected at positions 2064, 2067, or 2617, nor in genes associated with fluoroquinolone or tetracycline resistance. P1 genotyping revealed a predominance of the P1–1 genotype (92%), whereas P1–2 accounted for a minority of cases (7.7%). Although genotype distribution and macrolide resistance rates did not differ significantly between pediatric and adult patients, a significant association was identified between the A2063G mutation and the P1–1 genotype. Phylogenetic analysis further demonstrated distinct clustering patterns corresponding to P1 genotypes. These findings provide insight into the molecular epidemiology of macrolide-resistant M. pneumoniae circulating in southwestern China and contribute to a better understanding of the genetic background associated with macrolide resistance. • A 94% prevalence of macrolide-resistant Mycoplasma pneumoniae was observed in Yunnan, China. • The A2063G mutation was the dominant macrolide resistance–associated mutation. • P1–1 genotype was significantly associated with macrolide resistance.
Gao et al. (Sun,) studied this question.