Microbiological and molecular epidemiological analyses of community-associated methicillin-resistant Staphylococcus aureus at a tertiary care hospital in Japan

Shinya Inomata; Hisakazu Yano; Koichi Tokuda; Hajime Kanamori; Shiro Endo; Chiyuki Ishizawa; Miho Ogawa; Sadahiro Ichimura; Masahiro Shimojima; Risako Kakuta; Daiki Ozawa; Tetsuji Aoyagi; Yoshiaki Gu; Masumitsu Hatta; Kengo Oshima; Kazutoshi Nakashima; Mitsuo Kaku

doi:10.1016/j.jiac.2015.07.005

Microbiological and molecular epidemiological analyses of community-associated methicillin-resistant Staphylococcus aureus at a tertiary care hospital in Japan

J Infect Chemother. 2015 Oct;21(10):729-36. doi: 10.1016/j.jiac.2015.07.005. Epub 2015 Aug 10.

Authors

Shinya Inomata¹, Hisakazu Yano², Koichi Tokuda³, Hajime Kanamori⁴, Shiro Endo³, Chiyuki Ishizawa⁵, Miho Ogawa⁶, Sadahiro Ichimura⁶, Masahiro Shimojima⁶, Risako Kakuta⁷, Daiki Ozawa⁷, Tetsuji Aoyagi⁴, Yoshiaki Gu⁴, Masumitsu Hatta⁴, Kengo Oshima⁴, Kazutoshi Nakashima⁴, Mitsuo Kaku⁴

Affiliations

¹ 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.
² 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.
³ 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.
⁴ 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.
⁵ Infection Control Unit, Tohoku University Hospital, 1-1 Seiryoumachi, Aobaku, Sendai, Miyagi 980-8574, Japan.
⁶ Department of Bacteriology, BML Inc., 1360-1, Matoba, Kawagoe, Saitama 350-1101, Japan.
⁷ Department of Otolaryngology, Head and Neck Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryoumachi, Aobaku, Sendai, Miyagi 980-8574, Japan.

PMID: 26271590
DOI: 10.1016/j.jiac.2015.07.005

Abstract

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.

Keywords: CA-MRSA; Molecular epidemiology; Molecular typing; PCR based-open reading frame (ORF) typing (POT); ST5-SCCmecIV clone.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Community-Acquired Infections
Humans
Japan / epidemiology
Methicillin-Resistant Staphylococcus aureus* / genetics
Methicillin-Resistant Staphylococcus aureus* / isolation & purification
Methicillin-Resistant Staphylococcus aureus* / metabolism
Methicillin-Resistant Staphylococcus aureus* / pathogenicity
Molecular Epidemiology
Polymerase Chain Reaction
Staphylococcal Infections / epidemiology
Staphylococcal Infections / microbiology*
Tertiary Care Centers
Virulence