title: Aeromonas stool isolates from individuals with or without diarrhea in southern Taiwan: Predominance of Aeromonas veronii.
abstract: BACKGROUND
  Although aeromonads are important pathogens causing invasive infections in southern Taiwan, Aeromonas-associated intestinal infections have been rarely mentioned.
  
  
  OBJECTIVE
  The aim of this study was to understand the frequency of isolation and clinical significance of aeromonads recovered from adult stool samples in southern Taiwan.
  
  
  METHODS
  During a 15-month study period, 514 adults with diarrhea and 167 asymptomatic controls were prospectively screened for the presence of aeromonads in stools. The identity of Aeromonas species was determined by the rpoD sequencing. Clinical information was retrieved from medical records, and in vitro cytotoxicity assay and polymerase chain reaction detection of putative virulent genes were performed.
  
  
  RESULTS
  Thirteen (2.5 %) of 514 diarrheal patients and six (3.6%) of 167 asymptomatic controls had Aeromonas isolates in their stools. Of 11 diarrheal patients with available clinical information, Aeromonas veronii, the predominant species, was noted in six patients, and another potential enteropathogen was present in four patients. The cytotoxicity of A. veronii isolates to the HT-29 cell line was more potent in the isolates from diarrheal patients than those from asymptomatic controls (p = 0.015). The cytotoxicity of A. veronii isolates was more potent than that of A. caviae from symptomatic patients (p = 0.001). Putative virulence markers, including AHCYTONE, ascV, ascF-ascG, and aexT, were detected exclusively in A. veronii. The presence of the ascV gene was associated with cytotoxicity in A. veronii isolates. All Aeromonas isolates were susceptible to varied antimicrobial agents, except ampicillin/sulbactam.
  
  
  CONCLUSIONS
  A. veronii is the predominant species in stools from individuals with or without diarrhea in southern Taiwan.
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan; Graduate Institute of Clinical Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Po-Lin
authors.initials: PL
authors.lastname: Chen
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan, Taiwan; Research Center of Infectious Disease and Signaling, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Pei-Jane
authors.initials: PJ
authors.lastname: Tsai
authors.affiliation: Department of Biochemistry and Molecular Biology, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chang-Shi
authors.initials: CS
authors.lastname: Chen
authors.affiliation: Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Ying-Chuan
authors.initials: YC
authors.lastname: Lu
authors.affiliation: Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Hung-Mo
authors.initials: HM
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Nan-Yao
authors.initials: NY
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Ching-Chi
authors.initials: CC
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Li
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Ming-Chi
authors.initials: MC
authors.lastname: Li
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan, Taiwan. Electronic address: wu.chijung@msa.hinet.net.
authors.forename: Chi-Jung
authors.initials: CJ
authors.lastname: Wu
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan; Department of Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan. Electronic address: winston3415@gmail.com.
authors.forename: Wen-Chien
authors.initials: WC
authors.lastname: Ko
mesh_terms: D000328:Adult; D000333:Aeromonas / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001427:Bacterial Toxins / Q000378:metabolism; D015415:Biomarkers; D002460:Cell Line; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D024881:Drug Resistance, Bacterial; D005243:Feces / Q000382:microbiology*; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D019073:HT29 Cells; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011446:Prospective Studies; D012808:Sigma Factor / Q000235:genetics; D013624:Taiwan / Q000453:epidemiology; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D015415:Biomarkers; D012808:Sigma Factor; D037521:Virulence Factors; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases
keywords: Aeromonas veronii; Cytotoxicity; Diarrhea; Taiwan