title: Clinical implications of species identification in monomicrobial Aeromonas bacteremia.
abstract: BACKGROUND
  Advances in Aeromonas taxonomy have led to the reclassification of aeromonads. Hereon, we aimed to re-evaluate the characteristics of Aeromonas bacteremia, including those of a novel species, Aeromonas dhakensis.
  
  
  RESULTS
  A retrospective study of monomicrobial Aeromonas bacteremia at a medical center in southern Taiwan from 2004-2011 was conducted. Species identification was based on rpoB sequencing. Of bacteremia of 153 eligible patients, A. veronii (50 isolates, 32.7%), A. dhakensis (48, 31.4%), A. caviae (43, 28.1%), and A. hydrophila (10, 6.5%) were the principal causative species. A. dhakensis and A. veronii bacteremia were mainly community-acquired and presented as primary bacteremia, spontaneous bacterial peritonitis, or skin and soft-tissue infection, whereas A. caviae was associated with hospital-onset bacteremia. The distribution of the AmpC β-lactamase and metallo-β-lactamase genes was species-specific: bla(AQU-1), bla(MOX), or bla(CepH) was present in A. dhakensis, A. caviae, or A. hydrophila, respectively, and bla(CphA) was present in A. veronii, A. dhakensis, and A. hydrophila. The cefotaxime resistance rates of the A. caviae, A. dhakensis, and A. hydrophila isolates were higher than that of A. veronii (39.5%%, 25.0%, and 30% vs. 2%, respectively). A. dhakensis bacteremia was linked to the highest 14-day sepsis-related mortality rate, followed by A. hydrophila, A. veronii, and A. caviae bacteremia (25.5%, 22.2%, 14.0%, and 4.7%, respectively; P = 0.048). Multivariate analysis revealed that A. dhakensis bacteremia, active malignancies, and a Pitt bacteremia score ≥ 4 was an independent mortality risk factor.
  
  
  CONCLUSIONS
  Characteristics of Aeromonas bacteremia vary between species. A. dhakensis prevalence and its associated poor outcomes suggest it an important human pathogen.
authors: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan, Taiwan; Institute of Clinical Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan; Departments of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors: Chi-Jung
authors: CJ
authors: Wu
authors: Institute of Clinical Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan; Departments of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors: Po-Lin
authors: PL
authors: Chen
authors: Departments of Laboratory Medicine, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan; Internal Medicine, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.
authors: Po-Ren
authors: PR
authors: Hsueh
authors: Biochemistry and Molecular Biology Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan.
authors: Ming-Chung
authors: MC
authors: Chang
authors: Medical Laboratory Science and Biotechnology, National Cheng Kung University College of Medicine, Tainan, Taiwan.
authors: Pei-Jane
authors: PJ
authors: Tsai
authors: Emergency Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors: Hsin-I
authors: HI
authors: Shih
authors: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan, Taiwan.
authors: Hsuan-Chen
authors: HC
authors: Wang
authors: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan, Taiwan.
authors: Pei-Hsin
authors: PH
authors: Chou
authors: Departments of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan; Departments of Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan.
authors: Wen-Chien
authors: WC
authors: Ko
mesh_terms: D000328:Adult; D000333:Aeromonas / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D016470:Bacteremia / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics; D015897:Comorbidity; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases