title: Multicenter study of antimicrobial susceptibility of anaerobic bacteria in Korea in 2012.
abstract: BACKGROUND
  Periodic monitoring of regional or institutional resistance trends of clinically important anaerobic bacteria is recommended, because the resistance of anaerobic pathogens to antimicrobial drugs and inappropriate therapy are associated with poor clinical outcomes. There has been no multicenter study of clinical anaerobic isolates in Korea. We aimed to determine the antimicrobial resistance patterns of clinically important anaerobes at multiple centers in Korea.
  
  
  METHODS
  A total of 268 non-duplicated clinical isolates of anaerobic bacteria were collected from four large medical centers in Korea in 2012. Antimicrobial susceptibility was tested by the agar dilution method according to the CLSI guidelines. The following antimicrobials were tested: piperacillin, piperacillin-tazobactam, cefoxitin, cefotetan, imipenem, meropenem, clindamycin, moxifloxacin, chloramphenicol, metronidazole, and tigecycline.
  
  
  RESULTS
  Organisms of the Bacteroides fragilis group were highly susceptible to piperacillin-tazobactam, imipenem, and meropenem, as their resistance rates to these three antimicrobials were lower than 6%. For B. fragilis group isolates and anaerobic gram-positive cocci, the resistance rates to moxifloxacin were 12-25% and 11-13%, respectively. Among B. fragilis group organisms, the resistance rates to tigecycline were 16-17%. Two isolates of Finegoldia magna were non-susceptible to chloramphenicol (minimum inhibitory concentrations of 16-32 mg/L). Resistance patterns were different among the different hospitals.
  
  
  CONCLUSIONS
  Piperacillin-tazobactam, cefoxitin, and carbapemems are highly active beta-lactam agents against most of the anaerobes. The resistance rates to moxifloxacin and tigecycline are slightly higher than those in the previous study.
authors.affiliation: Department of Laboratory Medicine, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Yangsoon
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, School of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yeon Joon
authors.initials: YJ
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Mi Na
authors.initials: MN
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Young
authors.initials: Y
authors.lastname: Uh
authors.affiliation: Department of Laboratory Medicine, Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Myung Sook
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea. leekcp@yuhs.ac.
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001421:Bacteria, Anaerobic / Q000187:drug effects* / Q000302:isolation & purification; D001441:Bacteroides fragilis / Q000187:drug effects / Q000302:isolation & purification; D024901:Drug Resistance, Multiple, Bacterial; D008826:Microbial Sensitivity Tests; D056910:Republic of Korea; D062606:Tertiary Care Centers
chemical_list: D000890:Anti-Infective Agents
keywords: Anaerobe; Imipenem; Moxifloxacin; Multicenter; Tigecycline