Antimicrobial susceptibility and molecular characteristics of methicillin-resistant Staphylococcus aureus in a Japanese secondary care facility

• Published in: Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy 2016-01, Vol.22 (1), p.14-18
• Main Authors: Kimura, Yumiko, Morinaga, Yoshitomo, Akamatsu, Norihiko, Matsuda, Junichi, Yamaryo, Takeshi, Kawakami, Kenji, Matsuo, Hidenori, Kosai, Kosuke, Uno, Naoki, Hasegawa, Hiroo, Yanagihara, Katsunori
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - therapeutic use; Bacterial Proteins - blood; Bacterial Toxins; Community-acquired methicillin-resistant Staphylococcus aureus; Cross Infection - blood; Cross Infection - drug therapy; Cross Infection - microbiology; Daptomycin - therapeutic use; Dibekacin - analogs & derivatives; Dibekacin - therapeutic use; Exotoxins; Hematology, Oncology and Palliative Medicine; Humans; Japan; Leukocidins; Linezolid - therapeutic use; Methicillin-Resistant Staphylococcus aureus - genetics; Microbial Sensitivity Tests; Multilocus Sequence Typing; Open Reading Frames; Panton-Valentine leukocidin; Phage open reading frame typing; Recombinases - blood; SCCmec type; Secondary Care Centers; Skin - microbiology; Soft Tissue Infections - microbiology; Staphylococcus aureus; Staphylococcus aureus - genetics; Staphylococcus aureus - isolation & purification; Teicoplanin - therapeutic use; Vancomycin - therapeutic use; Virulence Factors
• ISSN: 1341-321X; 1437-7780
• DOI: 10.1016/j.jiac.2015.08.011

Abstract Methicillin-resistant Staphylococcus aureus (MRSA) is prevalent in Japan, and the Staphylococcus cassette chromosome mec (SCC mec ) type II is common among hospital-acquired MRSA isolates. Information pertaining to MRSA characteristics is limited, including SCC mec types, in primary or secondary care facilities. A total of 128 MRSA isolates (90 skin and soft tissue isolates and 38 blood isolates) were collected at a secondary care facility, Kawatana Medical Center, from 2005 to 2011. Antimicrobial susceptibility testing for anti-MRSA antibiotics and molecular testing for SCC mec and virulence genes ( tst , sec , etb , luk S/F-PV) were performed. Strains positive for luk S/F-PV were analyzed by multilocus sequence typing and phage open-reading frame typing. SCC mec typing in skin and soft tissue isolates revealed that 65.6% had type IV, 22.2% had type II, 8.9% had type I, and 3.3% had type III. In blood isolates, 50.0% had type IV, 47.4% had type II, and 2.6% had type III. Minimum inhibitory concentrations, MIC50 /MIC90 , against vancomycin, teicoplanin, linezolid, and arbekacin increased slightly in SCC mec II isolates from skin and soft tissue. MICs against daptomycin were similar between sites of isolation. SCC mec type II isolates possess tst and sec genes at a greater frequently than SCC mec type IV isolates. Four luk S/F-PV-positive isolates were divided into two clonal patterns and USA300 was not included. In conclusion, SCC mec type IV was dominant in blood, skin, and soft tissue isolates in a secondary care facility in Japan. Because antimicrobial susceptibility varies with the SCC mec type, SCC mec typing of clinical isolates should be monitored in primary or secondary care facilities.