K-3464. Clinical and Microbiological Analysis of Methicillin-Resistant Staphylococcus aureus Bacteremia in a Japanese University Hospital
Session: Poster Session: Pathogenesis, Management, and Outcome of Staphylococcal Bacteremia
Monday, October 27, 2008: 12:00 AM
Room: Hall C
Background: Staphylococcus aureus bacteremia is a serious infection, particularly, methicillin-resistant S. aureus (MRSA) bacteremia is increasing and associated with greater morbidity and mortality rates. Methods:
We analysed clinical and microbiological characteristics of MRSA bacteremia in a restrospective cohort study in a Japanese university hospital. From 1 April 2004 through 31 August 2007, the clinical data and outcome of patients with MRSA bacteremia were collected for analysis. Microbiological analysis was performed with antimicrobial-sensitivity, and genotyping by Pharge ORF typing (POT) (Suzuki M, et al. J Applied Microbiol. 2006). Results: A total of 63 episodes from 57 patients were identified. 2 patients developed 4 episodes each. Median age was 62 y (range; 0 to 82 y), and 30 (53%) had prior MRSA isolation. Only 1 episode was defined as community-acquired. Among these, 44% were central venous catheter (CVC)-related, and 32% were secondary bacteremia. Diabetes (25%) was the most frequent underlying disease, followed by hemodialysis (23%), malignancy and immunosuppressive therapy (19% each). 44 (77%) patients were treated appropriately within 48 hrs from onset. 38 POT types were identified among 55 stored isolates, 46 (84%) of them were New York/Japan (N/J) clone with SCCmec IIa. Multiple episodes were revealed identical by POT. Strains of N/J clone were less sensitive to glycopeptides, CLDM, and LVFX than the others. The 30-day mortality was 23%. CVC source (p=0.036), hemodialysis (p=0.022), and poor response at 7 days from onset (p=0.0053) were associated with mortality, meanwhile, delayed (> 48hrs) appropriate treatment and N/J clone were not associated. Conclusions: Our study shows that MRSA bacteremia mainly occurred by major nosocomial clone in Japan, and CVC source and hemodialysis were associated with mortality.
Aki Matsushima, MD1, Masahiro Suzuki2, Michinori Shirano, MD1, Miki Nagao, M.D., Ph.D., Satoshi Ichiyama, M.D., Ph.D., Shunji Takakura, M.D., Ph.D., Takashi Saito, MD, PhD4, Yoshitsugu Iinuma, MD, PhD5, Yutaka Ito, MD, PhD and  Y. Iinuma, None., (1)Kyoto Univ. Hosp., Kyoto, Japan, (2)Aichi Prefectural Institute of Public Health, (3)Department of Clinical Laboratory Medicine, Kyoto University, Kyoto, Japan, (4)Department of Clinical Laboratory Medicine,Kyoto University, Kyoto, Japan, Kyoto, Japan