Integrated proteomics and metabolomics reveal novel biomarkers and metabolic pathways in drug-resistant mycoplasma pneumoniae pneumonia

The molecular mechanism of macrolide resistance in Mycoplasma pneumoniae (MRMP) remains unclear. We aimed to systematically compare protein expression profiles and metabolic signatures among three distinct cohorts: children with MRMP, children with macrolide-sensitive strains (MSMP), and age-matched healthy controls. Proteomic and metabolomic profiling was performed using data-independent acquisition LC-MS/MS and UHPLC-MS/MS, respectively. Differential proteins/metabolites were analyzed, followed by pathway enrichment and ROC analyses to identify biomarkers. Metabolomics preliminarily suggested significant downregulation of primary bile acid biosynthesis and cholesterol metabolism in MRMP, whereas proteomics indicated upregulation of estrogen signaling and complement/coagulation cascades. The integrated analysis identified cholesterol metabolism and bile secretion as the central pathways, with APOA4, APOE, LRP1, PRKACA, and ATP1A1 as the core regulators. Glycocholic acid (GCA; AUC = 1.0) emerged as a potential candidate biomarker for distinguishing MRMP, and its depletion in the MRMP directly links disrupted cholesterol catabolism to bile acid dysregulation. This exploratory study preliminarily demonstrates that MRMP is associated with metabolic reprogramming characterized by suppressed cholesterol metabolism and bile acid homeostasis. The identified candidate proteins and GCA represent preliminary findings and require validation in larger cohorts. These results provide hypotheses for future mechanistic research and potential targeted interventions against MRMP.