Molecular characterization of Mycoplasma pneumoniae infections and the difference in clinical characteristics

To assess the subtypes of Mycoplasma pneumoniae ( M. pneumoniae ) circulated in Henan Province, China during the years 2019–2023 and the proportion changed with time. We were also interested in macrolide resistance (MR) mutation of M. pneumoniae . 2. To see if there is a correlation between the subtypes of M. pneumoniae and clinical characteristics . We conducted multi-locus variable-number tandem repeat analysis (MLVA) typing, multi-locus sequence typing (MLST), and MR mutation test in the 23S rRNA from 417 M. pneumoniae clinical isolates. Our study showed there were two major MLVA types: 4572 and 3562. In general, the main MLST types were 3 and 14. The results of MR mutations showed that 97.4% of the isolates harbored A2063G mutations in the 23S rRNA gene with one isolate carrying an A2064G mutation. Patients infected with the 3562-14 subtype isolates exhibited higher C-reactive protein (CRP) levels compared with those infected with the 4572–3 subtype isolates ( Z = − 1.99; P = 0.047). In 2019–2023, the predominant MLVA types alternated between 4572 and 3562 in Henan Province, China. MLVA typing and MLST typing yielded consistent results. The vast majority of positive samples exhibited MR mutations in the 23S rRNA gene. There were significant differences in CRP levels between children infected with the two dominant Mycoplasma pneumoniae subtypes.