Japanese Society for Infection Prevention and Control-Online Journal

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Article in Japanese

Change in the Epidemic Types of Methicillin-resistant Staphylococcus aureus (MRSA) in Japan

Hidemasa NAKAMINAMI
Department of Clinical Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences

Recently, epidemic types of methicillin-resistant Staphylococcus aureus (MRSA) have significantly changed in both hospital and community setting in Japan. Before 2010, about 80% of MRSA strains isolated from hospitals were the typical healthcare-associated MRSA (HA-MRSA) with staphylococcal cassette chromosome (SCC) mec type II. However, USA400-like community-associated MRSA (CA-MRSA) with SCCmec type IV have become dominant since 2014 in hospitals. Meanwhile, skin infections caused by the highly virulent CA-MRSA USA300-clone have been increasing. The USA300-clone is associated with intractable skin infections and necrotizing pneumonia as it carries a cytolytic pore-forming toxin, Panton-Valentine leukocidin (PVL), and arginine catabolic mobile element, which promotes colonization on the skin. For the past decade, the USA300-clone had limited prevalence and was not considered a serious problem in Japan. However, the USA300-clone has been recently spreading both in clinics and hospitals. In this review, the transition and current status of molecular epidemiological features of HA-MRSA and CA-MRSA in Japan are described using our data.

Key words：methicillin-resistant Staphylococcus aureus, healthcare-associated MRSA, community-associated MRSA, USA300 clone, outbreak

e-mail: nakami＠toyaku.ac.jp

Received: May 31, 2022
Accepted: July 6, 2022

37 (5)：164─173,2022