title: Prevalence and characterization of enterotoxigenic Bacteroides fragilis and toxigenic Clostridium difficile in a Taipei emergency department.
abstract: OBJECTIVE
  Enterotoxigenic Bacteroides fragilis (ETBF) and toxin-encoding Clostridium difficile (TXCD) are associated with gastroenteritis. Routine anaerobic blood culture for recovery of these anaerobic pathogens is not used for the detection of their toxins, especially for toxin-variant TXCD. The aim of this study was to investigate the prevalence and risk factors of the genotypes of these anaerobes in patients with acute diarrheal illnesses.
  
  
  METHODS
  The data and samples of 513 patients with gastroenteritis were collected in a Taipei emergency department from March 1, 2006 to December 31, 2009. Nonenterotoxigenic B. fragilis (NTBF) and ETBF and the toxin genotypes of TXCD were detected by molecular methods.
  
  
  RESULTS
  The prevalence rates of NTBF, ETBF, and TXCD infections were 33.14%, 1.56%, and 2.34%, respectively. ETBF infections often occurred in the elderly (average age = 67.13 years) and during the cold, dry winters. TXCD infections were widely distributed in age and often occurred in the warm, wet springs and summers. The symptoms of ETBF-infected patients were significantly more severe than those of NTBF-infected patients.
  
  
  CONCLUSIONS
  This study identified and analyzed the prevalence, risk factors, and clinical presentations of these anaerobic infections. Future epidemiologic and clinical studies are needed to understand the role of ETBF and TXCD in human gastroenteritis.
authors: Department of Tropical Medicine, National Yang-Ming University, Taipei, Taiwan, ROC; Research and Diagnostics, Centers for Disease Control, Department of Health, Taiwan, ROC.
authors: Dar-Der
authors: DD
authors: Ji
authors: Department of Microbiology and Immunology, National Cheng Kung University, Tainan, Taiwan, ROC.
authors: I-Hsiu
authors: IH
authors: Huang
authors: Emergency Department, Taipei City Hospital, Ren-Ai Branch, Taiwan, ROC.
authors: Chao-Chih
authors: CC
authors: Lai
authors: Research and Diagnostics, Centers for Disease Control, Department of Health, Taiwan, ROC.
authors: Fang-Tzy
authors: FT
authors: Wu
authors: Field Epidemiology Training Program, Centers for Disease Control, Taiwan, ROC.
authors: Donald Dah-Shyong
authors: DD
authors: Jiang
authors: Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC.
authors: Bing-Mu
authors: BM
authors: Hsu
authors: Department of Parasitology, National Cheng Kung University, Tainan, Taiwan, ROC. Electronic address: wcnikelin@mail.ncku.edu.tw.
authors: Wei-Chen
authors: WC
authors: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001427:Bacterial Toxins / Q000032:analysis* / Q000235:genetics; D001442:Bacteroides Infections / Q000453:epidemiology* / Q000382:microbiology; D001441:Bacteroides fragilis / Q000302:isolation & purification* / Q000378:metabolism; D016360:Clostridioides difficile / Q000302:isolation & purification* / Q000378:metabolism; D003015:Clostridium Infections / Q000453:epidemiology* / Q000382:microbiology; D003967:Diarrhea / Q000453:epidemiology* / Q000382:microbiology; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012621:Seasons; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
chemical_list: D001427:Bacterial Toxins
keywords: acute diarrheal illnesses; enterotoxigenic Bacteroides fragilis; toxigenic Clostridium difficile; toxin genotypes