The emergence and spread of antimicrobial-resistant (AMR) bacteria have become a major global concern. In Japan, infections caused by AMR pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae (PRSP), extended-spectrum β-lactamase (ESBL)-producing Enterobacterales, carbapenemase-producing Enterobacteriaceae (CPE), and multidrug-resistant Pseudomonas aeruginosa (MDRP), have raised concerns about outbreaks in healthcare facilities and community transmission.

In 2006, the Japanese Society of Chemotherapy (JSC) launched a nationwide surveillance program to monitor respiratory tract infection (RTI) pathogens [1]. Since 2009, this surveillance has been conducted jointly by JSC, the Japanese Association for Infectious Diseases (JAID), and the Japanese Society for Clinical Microbiology (JSCM) to track trends in antimicrobial susceptibility of major RTI pathogens [1], [2], [3], [4], [5], [6]. Long-term, systematic surveillance in clinical settings is essential. Data from these surveys enhance epidemiological understanding of drug resistance and support antimicrobial stewardship efforts.

This study presents findings on the antimicrobial susceptibility of seven major RTI pathogens during, predominantly from tertiary medical centers, the Omicron wave of the COVID-19 pandemic in Japan (2022–2023).