title: Clinical and microbiological characteristics of tigecycline non-susceptible Klebsiella pneumoniae bacteremia in Taiwan.
abstract: BACKGROUND
  Resistance among Klebsiella pneumoniae to most antibiotics is on the rise. Tigecycline has been considered as one of the few therapeutic options available to treat multidrug-resistant bacteria. We investigated the clinical and microbiological characteristics of tigecycline non-susceptible K. pneumoniae bacteremia.
  
  
  METHODS
  Adult patients with tigecycline non-susceptible K. pneumoniae bacteremia at a medical center in Taiwan over a 3-year period were enrolled. K. pneumoniae isolates were identified by the E-test using criteria set by the US Food and Drug Administration (FDA). Data on the clinical features of patients were collected from medical records. Genes for β-lactamases, antimicrobial susceptibilities and pulsed-field gel electrophoresis (PFGE) results were determined for all isolates.
  
  
  RESULTS
  Of 36 patients, 27 had nosocomial bacteremia. Overall 28-day mortality was 38.9%. The MIC50 and MIC90 of tigecycline were 6 and 8 mg/L, respectively. No carbapenemase was detected among the 36 isolates. Twenty isolates carried extended spectrum β-lactamases and/or DHA-1 genes. No major cluster of isolates was found among the 36 isolates by PFGE. Intensive care unit onset of tigecycline non-susceptible Klebsiella pneumoniae bacteremia was the only independent risk factor for 28-day mortality.
  
  
  CONCLUSIONS
  The high mortality of patients with tigecycline non-susceptible K. pneumoniae bacteremia may suggest a critical problem. Further study to identify the possible risk factors for its development and further investigation of this type of bacteremia is necessary.
authors.affiliation: Division of Infectious Disease, Department of Medicine, Taipei Veterans General Hospital, No, 201, Sec, 2, Shih-Pai Road, Taipei, 112, Taiwan. ytlin8@vghtpe.gov.tw.
authors.forename: Yi-Tsung
authors.initials: YT
authors.lastname: Lin
authors.forename: Fu-Der
authors.initials: FD
authors.lastname: Wang
authors.forename: Yu-Jiun
authors.initials: YJ
authors.lastname: Chan
authors.forename: Yung-Chieh
authors.initials: YC
authors.lastname: Fu
authors.forename: Chang-Phone
authors.initials: CP
authors.lastname: Fung
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents; D016470:Bacteremia / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics; D003428:Cross Infection / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D007711:Klebsiella pneumoniae / Q000302:isolation & purification* / Q000502:physiology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008911:Minocycline / Q000031:analogs & derivatives*; D012189:Retrospective Studies; D013624:Taiwan; D000078304:Tigecycline; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D000078304:Tigecycline; D001618:beta-Lactamases; C063912:carbapenemase; D008911:Minocycline