Microbiological and molecular epidemiological analyses of community-associated methicillin-resistant Staphylococcus aureus at a tertiary care hospital in Japan.
Molecular characterization of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is generally conducted referred to staphylococcal cassette chromosome mec (SCCmec) type IV or V. CA-MRSA is now a cause of concern since such strains have been isolated not only from individuals in a community but also from patients in healthcare settings. The aim of this study was to analyze microbiological and molecular epidemiological features of CA-MRSA strains at a Japanese tertiary care hospital using PCR based-open reading frame typing (POT). This technique allows for molecular classification into CA-MRSA (POT-CA) and hospital-associated (HA-) MRSA (POT-HA) with clonal discrimination. Clinical MRSA isolates obtained from consecutive patients between October 1, 2012 and September 30, 2013 at the hospital were analyzed in combination with the clinical definition for CA-MRSA by the Centers for Disease Control and Prevention and POT. Of 219 isolates (76 clonal groups), 64 (29.3%) were clinical-HA/POT-CA isolates (22 clonal groups). Some clones of them accumulated in this hospital and might be involved in nosocomial transmission. Virulent factors of the isolates were analyzed, and only one (1.6%) Panton-Valentine leukocidin gene positive isolate but no arginine catabolic mobile element genes positive isolate were found in clinical-HA/POT-CA. Additionally, clinical-HA/POT-CA isolates showed higher antimicrobial susceptibility than clinical-HA/POT-HA, especially to minocycline, doxycycline, and amikacin. The most frequent genotype of molecular CA-MRSA was multi-locus sequence type 5-SCCmecIV, previously not detected in Japan. Although CA-MRSA at this hospital showed low virulence and higher antimicrobial susceptibility, the risk of nosocomial infection from them should be recognized, requiring stricter infection control measures.
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan. Electronic address: inomata@med.tohoku.ac.jp.
Shinya
S
Inomata
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan; Department of Microbiology and Infectious Diseases, Nara Medical University, 840 Shijouchou, Kashihara, Nara 634-8521, Japan.
Hisakazu
H
Yano
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan; Infection Control Unit, Tohoku University Hospital, 1-1 Seiryoumachi, Aobaku, Sendai, Miyagi 980-8574, Japan.
Koichi
K
Tokuda
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Hajime
H
Kanamori
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan; Infection Control Unit, Tohoku University Hospital, 1-1 Seiryoumachi, Aobaku, Sendai, Miyagi 980-8574, Japan.
Shiro
S
Endo
Infection Control Unit, Tohoku University Hospital, 1-1 Seiryoumachi, Aobaku, Sendai, Miyagi 980-8574, Japan.
Chiyuki
C
Ishizawa
Department of Bacteriology, BML Inc., 1360-1, Matoba, Kawagoe, Saitama 350-1101, Japan.
Miho
M
Ogawa
Department of Bacteriology, BML Inc., 1360-1, Matoba, Kawagoe, Saitama 350-1101, Japan.
Sadahiro
S
Ichimura
Department of Bacteriology, BML Inc., 1360-1, Matoba, Kawagoe, Saitama 350-1101, Japan.
Masahiro
M
Shimojima
Department of Otolaryngology, Head and Neck Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aobaku, Sendai, Miyagi 980-8574, Japan.
Risako
R
Kakuta
Department of Otolaryngology, Head and Neck Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aobaku, Sendai, Miyagi 980-8574, Japan.
Daiki
D
Ozawa
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Tetsuji
T
Aoyagi
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Yoshiaki
Y
Gu
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Masumitsu
M
Hatta
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Kengo
K
Oshima
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Kazutoshi
K
Nakashima
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Mitsuo
M
Kaku
D017714:Community-Acquired Infections; D006801:Humans; D007564:Japan / Q000453:epidemiology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000472:pathogenicity; D017720:Molecular Epidemiology; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D062606:Tertiary Care Centers; D014774:Virulence
CA-MRSA; Molecular epidemiology; Molecular typing; PCR based-open reading frame (ORF) typing (POT); ST5-SCCmecIV clone