[Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus (MRSA) by POT Method, Antimicrobial Susceptibility Patterns, and Toxin-Producing Types].

The PCR-based open reading frame typing (POT) is an important method for analyzing outbreak information. Many institutions use POT as a molecular epidemiological method for analyzing horizontal transmission in methicillin-resistant Staphylococcus aureus (MRSA). However, typing and analyzing MRSA only based on POT, with high detection frequency, has some limitations. In this study, we analyzed 62 strains of MRSA, isolated at Ehime University Hospital between January 2018 to December 2018 based on six POT types, toxin type, and antimicrobial susceptibility. Types of POT and strains used were as follows: 106-183-37 (28 strains), 106-137-80 (7 strains), 106-77-113 (7 strains), 106-9-80 (7 strains), 70-18-81 (7 strains), 106-247-33 (6 strains). Based on antimicrobial susceptibility patterns, 5 types of MRSA were detected, including types susceptible to gentamicin (GM), clarithromycin (CAM), and levofloxacin (LVFX). Strains belonging to the same POT type, showed differential antimicrobial susceptibility patterns and had different toxin productivity. These findings suggest that the combination of POT method with antimicrobial susceptibility patterns and toxin type may be a useful technique for MRSA typing.