Macrolide resistance is common in pediatric Mycoplasma pneumoniae pneumonia (MPP), but its relationship with clinical phenotype, short-term in-hospital course, and radiographic severity remains uncertain. We aimed to characterize macrolide resistance–associated sites and their clinical correlates in hospitalized children with MPP, focusing on A2063G and pulmonary consolidation. This retrospective study included children aged < 14 years hospitalized with MPP at Shantou Central Hospital, China, from January 1 to December 31, 2024. All patients had undergone throat-swab targeted next-generation sequencing within 24 h of admission as part of routine clinical diagnostic work-up. This retrospective study used secondary data extracted from clinical diagnostic reports and electronic medical records. Four macrolide resistance–associated sites were interrogated: A2063G, A2064G, A2067G, and C2617G. Clinical, laboratory, radiographic, and short-term in-hospital outcome variables were compared by A2063G resistance-site status and by pulmonary consolidation. Multivariable logistic regression was performed for A2063G resistance-site status and pulmonary consolidation. Firth penalized logistic regression was used as a sensitivity analysis for the A2063G model. Among 402 hospitalized children with MPP, A2063G was detected in 362 (90. 0%), whereas A2064G, A2067G, and C2617G were not detected. Monthly case counts peaked during June–August, while the proportion of A2063G remained consistently high throughout the year. Pulmonary consolidation was present in 103 patients (25. 6%) and was less frequent in A2063G-positive than in wild-type cases (23. 2% vs. 47. 5%, P = 0. 002). In multivariable analysis, pulmonary consolidation was independently associated with lower odds of A2063G positivity (OR 0. 370, 95% CI 0. 187–0. 732; P = 0. 004). For pulmonary consolidation, A2063G positivity remained independently associated with lower odds after adjustment for age, Tmax₂4h, and CRP (OR 0. 378, 95% CI 0. 190–0. 752; P = 0. 006). No clear differences were observed by resistance-site status in systemic inflammatory profile, overall clinical course, or in-hospital resource use. Overall, short-term in-hospital outcomes were favorable, with no deaths. In hospitalized children with MPP from the Chaoshan region of southern China in 2024, A2063G was the dominant macrolide resistance–associated site. In this cohort, A2063G positivity was not accompanied by more frequent pulmonary consolidation, a more severe clinical phenotype based on the available indicators, or worse short-term in-hospital outcomes. These findings suggest that, in pediatric MPP, predominance of a resistance-associated site, radiographic severity, and short-term clinical course may not necessarily vary in parallel.
Zhou et al. (Sat,) studied this question.