J Med Microbiol 57 (2008), 1251-1258; DOI: 10.1099/jmm.0.2008/002824-0
© 2008 Society for General Microbiology
ISSN 1473-5644
Molecular epidemiology and antimicrobial susceptibilities of 273 exfoliative toxin-encoding-gene-positive Staphylococcus aureus isolates from patients with impetigo in Japan
Hidemasa Nakaminami1,
Norihisa Noguchi1,
Masami Ikeda2,3,
Mikiko Hasui3,
Minoru Sato3,
Shinji Yamamoto3,
Tomoko Yoshida3,
Takashi Asano3,
Mitsura Senoue3 and
Masanori Sasatsu1
1 Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
2 Department of Dermatology, Takamatsu Red Cross Hospital, 4-1-3 Banchou, Takamatsu, Kagawa 760-0017, Japan
3 Takamatsu Dermatological Research Group, 4-1-3 Banchou, Takamatsu, Kagawa 760-0017, Japan
Correspondence
Norihisa Noguchi
noguchin{at}ps.toyaku.ac.jp
Received 24 April 2008
Accepted 1 July 2008
The molecular epidemiology and antimicrobial susceptibilities of 273 Staphylococcus aureus isolates positive for the exfoliative toxin-encoding gene obtained from patients with impetigo in Japan in 2006 were studied. The mecA gene was detected in 74 meticillin-resistant S. aureus (MRSA) and 23 meticillin-susceptible S. aureus (MSSA) isolates. All isolates with the staphylococcal cassette chromosome (SCC) mec were classified into type IV (92.8 %, 90/97) or V (7.2 %, 7/97). The ET-encoding gene etb was found primarily in strains with mecA (87.7 %, 71/81), whilst eta (86.6 %, 161/186) was detected mainly in strains without mecA. The chromosomal enterotoxin-encoding gene cluster egc was found in 83.0 % of strains with eta, whilst no enterotoxin-encoding gene was detected in strains with only etb. PFGE showed that each strain carrying eta, etb and etd could be classified into distinct groups. The susceptibility profiles of MRSA to antimicrobial agents excluding β-lactams were similar to those of MSSA. Gentamicin- and clarithromycin-resistant strains were frequently found for both MRSA and MSSA. The aminoglycoside-resistance gene aacA–aphD was detected in 97.3 % of MRSA and 85.4 % of MSSA. Additionally, the macrolide-resistance gene ermA or ermC was detected in 67.6 % of MRSA and 71.4 % of MSSA. Therefore, these results suggest that SCCmec types IV or V have spread, particularly in MSSA carrying etb in the community.
Abbreviations: CA, community-acquired; ET, exfoliative toxin; MRSA, meticillin-resistant Staphylococcus aureus; MSSA, meticillin-susceptible Staphylococcus aureus; SCC, staphylococcal cassette chromosome; SE, staphylococcal enterotoxin.
Copyright © 2008 Society for General Microbiology.