title: agr dysfunction affects staphylococcal cassette chromosome mec type-dependent clinical outcomes in methicillin-resistant Staphylococcus aureus bacteremia.
abstract: Staphylococcal cassette chromosome mec element (SCCmec) type-dependent clinical outcomes may vary due to geographical variation in the presence of virulence determinants. We compared the microbiological factors and mortality attributed to methicillin-resistant Staphylococcus aureus (MRSA) bacteremia between SCCmec types II/III and type IV. All episodes of MRSA bacteremia in a tertiary-care hospital (South Korea) over a 4.5-year period were reviewed. We studied the microbiological factors associated with all blood MRSA isolates, including spa type, agr type, agr dysfunction, and the genes for Panton-Valentine leukocidin (PVL) and phenol-soluble modulin (PSM)-mec, in addition to SCCmec type. Of 195 cases, 137 involved SCCmec types II/III, and 58 involved type IV. The mortality attributed to MRSA bacteremia was less frequent among the SCCmec type IV (5/58) than that among types II/III (39/137, P = 0.002). This difference remained significant when adjusted for clinical factors (adjusted odds ratio [aOR], 0.14; 95% confidence interval [CI], 0.04 to 0.49; P = 0.002). Of the microbiological factors tested, agr dysfunction was the only significant factor that showed different positivity between the SCCmec types, and it was independently associated with MRSA bacteremia-attributed mortality (aOR, 4.71; 95% CI, 1.72 to 12.92; P = 0.003). SCCmec type IV is associated with lower MRSA bacteremia-attributed mortality than are types II/III, which might be explained by the high rate of agr dysfunction in SCCmec types II/III in South Korea.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Chang Kyung
authors.initials: CK
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Jeong Eun
authors.initials: JE
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Yoon Jeong
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Younghee
authors.initials: Y
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Nak-Hyun
authors.initials: NH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Chung-Jong
authors.initials: CJ
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Taek Soo
authors.initials: TS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Kyoung-Ho
authors.initials: KH
authors.lastname: Song
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Pyoeng Gyun
authors.initials: PG
authors.lastname: Choe
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Wan Beom
authors.initials: WB
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Ji-Hwan
authors.initials: JH
authors.lastname: Bang
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Eu Suk
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyoung Un
authors.initials: KU
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Nam-Joong
authors.initials: NJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Myoung-Don
authors.initials: MD
authors.lastname: Oh
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea hbkimmd@snu.ac.kr.
authors.forename: Hong Bin
authors.initials: HB
authors.lastname: Kim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000382:microbiology* / Q000401:mortality*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001427:Bacterial Toxins / Q000235:genetics; D005098:Exotoxins / Q000235:genetics; D005260:Female; D006801:Humans; D007956:Leukocidins / Q000235:genetics; D008297:Male; D016106:Methicillin Resistance / Q000235:genetics; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D015999:Multivariate Analysis
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin