title: Influence of antimicrobial regimen on decreased in-hospital mortality of patients with MRSA bacteremia.
abstract: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important causes of bacteremia. Recently, several epidemiological and microbiological changes have become evident in MRSA infections. The purposes of this study were to assess clinical characteristics of patients with MRSA bacteremia and microbiological changes in MRSA. We conducted a retrospective observational study on patients with MRSA bacteremia who were hospitalized between 2008 and 2011. We used univariate and multivariate analysis to evaluate the predictors associated with 30-day mortality. The 7-day and 30-day mortality rates were 12.0% and 25.3%, respectively. According to multivariate analysis, the independent predictors that associated with 30-day mortality were leukopenia, low serum albumin, high sequential organ failure assessment (SOFA) score, and quinolone use within 30 days. Compared to previous data (2003-2007), the SOFA score of the new data set remained unchanged, but in-hospital mortality decreased significantly. In particular, the mortality associated with use of vancomycin (VCM) was significantly lower. Although the minimum inhibitory concentration of VCM required to inhibit the growth of 90% of organisms (MIC90) had not changed, the trough value of VCM changed significantly; a VCM trough value of 10 or greater was significantly higher compared to previous data. Of the staphylococcal cassette chromosome mec (SCCmec) types, SCCmec II values decreased significantly, and SCCmec I and IV values increased significantly. Our results indicate that changes in VCM usage might contribute to decreased in-hospital mortality.
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan; Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Norihito
authors.initials: N
authors.lastname: Kaku
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan; Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. Electronic address: k-yanagi@nagasaki-u.ac.jp.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Yanagihara
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan; Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Morinaga
authors.affiliation: Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan; Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Harada
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan; Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Migiyama
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan; Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Nagaoka
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Matsuda
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Uno
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Hiroo
authors.initials: H
authors.lastname: Hasegawa
authors.affiliation: Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Taiga
authors.initials: T
authors.lastname: Miyazaki
authors.affiliation: Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Izumikawa
authors.affiliation: Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kakeya
authors.affiliation: Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Second Department of Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Bacteremia; MIC; Methicillin-resistant Staphylococcus aureus; Mortality; SCCmec