() infection is a primary cause of otitis media (OM), the most common disease for which children are prescribed antibiotics. However, the abuse of antibiotics has led to a global increase in antimicrobial resistance (AMR). Nanozymes, as promising alternatives to traditional antibiotics, are being extensively utilized to combat AMR. Here, we synthesize a series of single-atom nanozymes (metal-CN SANzymes) by loading four metals (Ag, Fe, Cu, Ru) with antibacterial properties onto a crystalline g-CN. These metal-CN display a rob-like morphology and well-dispersed metal atoms. Among them, Ru-CN demonstrates the optimal peroxidase-like activity (285.3 U mg), comparable to that of horseradish peroxidase (267.7 U mg). antibacterial assays reveal that Ru-CN significantly inhibits growth compared with other metal-CN even at a low concentration (0.06 mg mL). Notably, Ru-CN acts as a narrow-spectrum nanoantibiotic with relative specificity against Gram-positive bacteria. Biofilms formed by are easily degraded by Ru-CN due to its high peroxidase-like activity. , Ru-CN effectively eliminates and relieves ear inflammation in OM mouse models. However, untreated OM mice eventually develop hearing impairment. Due to its low metal load, Ru-CN does not exhibit significant toxicity to blood, liver, or kidney. In conclusion, this study presents a novel SANzyme-based antibiotic that can effectively eliminate and treat -induced OM.