Reporting macrolide-resistant <i>Mycoplasma pneumoniae</i> : a diagnostic obligation?

ABSTRACT Macrolide-resistant Mycoplasma pneumoniae (MRMP) is increasingly detected worldwide, with increasing prevalence even in the United States. Detection of resistance within M. pneumoniae has meaningful clinical and stewardship implications. Resistance is most commonly mediated by point mutations within 23S rRNA and can be reliably identified by molecular assays, not just on isolates butalso on primary respiratory samples like swabs. Multiple studies associate macrolide resistance with prolonged fever, delayed clinical response, increased healthcare utilization, and greater antibiotic exposure due to delay or treatment failure. The detection of resistance can meaningfully influence the clinical course and overall patient outcomes. Though clinical disease is not any more severe in infections with resistant isolates, failure to report may perpetuate unnecessary macrolide use, leading to delay in transition to effective second-line agents (tetracyclines or fluoroquinolones when appropriate), and contribute to selective pressure. Beyond individual patient care, routine reporting provides valuable local epidemiologic data to inform empiric therapy, support outbreak recognition, and guide antimicrobial stewardship initiatives. Even so, a significant clinical gap remains as most commercially available diagnostic assays do not routinely detect or report resistance markers in Mycoplasma pneumoniae . Moreover, even among assays designed to detect resistance, performance can vary considerably with reduced sensitivity for organism detection and incomplete identification of key 23S rRNA mutations reported in comparative evaluations, as reported by Hénin N, Silvant A, Gardette M, Balcon C, Guiraud J, Bébéar C, Pereyre S, J Clin Microbiol 64: e0149125, 2026, https://doi.org/10.1128/jcm.01491-25 . Focused efforts are, therefore, needed to close existing diagnostic and reporting gaps to ensure resistance detection is more consistently integrated into routine clinical practice.