Biomedical Science Letters (대한의생명과학회지)

The Korean Society for Biomedical Laboratory Sciences (대한의생명과학회)
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Evaluation of Enterotoxigenic Bacteroides fragilis from Colonic Washings from Patients Undergoing Colonoscopy

  • Van, Ni (Department of Medicine, Section of Digestive Diseases & Nutrition, University of Illinois at Chicago) ;
  • Ahlberg, Ned (Department of Medicine, Section of Digestive Diseases & Nutrition, University of Illinois at Chicago) ;
  • Jung, Byung Chul (Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University) ;
  • Lee, Min Ho (Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University) ;
  • Ahn, Seung Ju (Department of Biomedical Laboratory Science, Daegu Health College) ;
  • Lee, In-Soo (Department of Clinical Laboratory Science, Hyejeon College) ;
  • Kim, Yoon Suk (Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University) ;
  • Rhee, Ki-Jong (Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University)
  • Received : 2012.09.26
  • Accepted : 2012.10.04
  • Published : 2012.12.31
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Abstract

Enterotoxigenic Bacteroides fragilis (ETBF) is an intestinal commensal bacterium implicated as a risk factor for colon cancer. The key virulence factor is a secreted toxin called B. fragilis toxin (BFT). In this study we used an in vitro bioassay to examine the prevalence of ETBF in colonic washings from patients with colorectal polyps and normal control patients. We found that 9.3% of polyp patients and 10.9% of non-polyp patients harbored ETBF, respectively. A total of nine ETBF clinical isolates were isolated and confirmed to be positive for the BFT gene by PCR analysis and the ability to induce IL-8 secretion in the colonic epithelial cell line HT29/c1. Two of the ETBF clinical strains were characterized further in vitro and in vivo. We found that the two ETBF clinical isolates induced E-cadherin cleavage in HT29/c1 cells and promoted colonic inflammation in C57BL/6 mice. Our results indicate that the prevalence of ETBF in polyp patients were similar in non-polyp patients suggesting that ETBF carriage does not positively correlate to polyp incidence.

Keywords

References

  1. Akpinar M, Aktas E, Comert F, Kulah C, Sumbuloglu V. Evaluation of the prevalence of enterotoxigenic Bacteroides fragilis and the distribution bft gene subtypes in patients with diarrhea. Anaerobe. 2010. 16: 505-509. https://doi.org/10.1016/j.anaerobe.2010.08.002
  2. Avila-Campos MJ, Liu C, Song Y, Rowlinson MC, Finegold SM. Determination of bft gene subtypes in Bacteroides fragilis clinical isolates. J Clin Microbiol. 2007. 45: 1336-1338. https://doi.org/10.1128/JCM.02108-06
  3. Franco AA, Cheng RK, Goodman A, Sears CL. Modulation of bft expression by the Bacteroides fragilis pathogenicity island and its flanking region. Mol Microbiol. 2002. 45: 1067-1077. https://doi.org/10.1046/j.1365-2958.2002.03077.x
  4. Franco AA, Mundy LM, Trucksis M, Wu S, Kaper JB, Sears CL. Cloning and characterization of the Bacteroides fragilis metalloprotease toxin gene. Infect Immun. 1997. 65: 1007-1013.
  5. Huycke MM, Gaskins HR. Commensal bacteria, redox stress, and colorectal cancer: mechanisms and models. Exp Biol Med (Maywood). 2004. 229: 586-597. https://doi.org/10.1177/153537020422900702
  6. Mundy LM, Sears CL. Detection of toxin production by Bacteroides fragilis: assay development and screening of extraintestinal clinical isolates. Clin Infect Dis. 1996. 23: 269-276. https://doi.org/10.1093/clinids/23.2.269
  7. Myers LL, Shoop DS. Association of enterotoxigenic Bacteroides fragilis with diarrheal disease in young pigs. Am J Vet Res. 1987. 48: 774-775.
  8. Rabizadeh S, Rhee KJ, Wu S, Huso D, Gan CM, Golub JE, Wu X, Zhang M, Sears CL. Enterotoxigenic Bacteroides fragilis: A potential instigator of colitis. Inflamm Bowel Dis. 2007. 13: 1475-1483. https://doi.org/10.1002/ibd.20265
  9. Rhee KJ, Wu S, Wu X, Huso DL, Karim B, Franco AA, Rabizadeh S, Golub JE, Mathews LE, Shin J, Sartor RB, Golenbock D, Hamad AR, Gan CM, Housseau F, Sears CL. Induction of persistent colitis by a human commensal, enterotoxigenic Bacteroides fragilis, in wild-type C57BL/6 mice. Infect Immun. 2009. 77: 1708-1718. https://doi.org/10.1128/IAI.00814-08
  10. Sack RB, Myers LL, Almeido-Hill J, Shoop DS, Bradbury WC, Reid R, Santosham M. Enterotoxigenic Bacteroides fragilis: epidemiologic studies of its role as a human diarrhoeal pathogen. J Diarrhoeal Dis Res. 1992. 10: 4-9.
  11. Sears CL. The toxins of Bacteroides fragilis. Toxicon. 2001. 39: 1737-1746. https://doi.org/10.1016/S0041-0101(01)00160-X
  12. Shanson DC, Singh J. Effect of adding cysteine to brain-heart infusion broth on the isolation of Bacteroides fragilis from experimental blood cultures. J Clin Pathol. 1981. 34: 221-223. https://doi.org/10.1136/jcp.34.2.221
  13. Sharma N, Chaudhry R. Rapid detection of enterotoxigenic Bacteroides fragilis in diarrhoeal faecal samples. Indian J Med Res. 2006. 124: 575-582.
  14. Sinicrope FA. Sporadic colorectal cancer: an infectious disease? Gastroenterology. 2007. 132: 797-801. https://doi.org/10.1053/j.gastro.2007.01.012
  15. Toprak NU, Yagci A, Gulluoglu BM, Akin ML, Demirkalem P, Celenk T, Soyletir G. A possible role of Bacteroides fragilis enterotoxin in the aetiology of colorectal cancer. Clin Microbiol Infect. 2006. 12: 782-786. https://doi.org/10.1111/j.1469-0691.2006.01494.x
  16. Wilkins TD, Chalgren S. Medium for use in antibiotic susceptibility testing of anaerobic bacteria. Antimicrob Agents Chemother. 1976. 10: 926-928. https://doi.org/10.1128/AAC.10.6.926
  17. Wu S, Lim KC, Huang J, Saidi RF, Sears CL. Bacteroides fragilis enterotoxin cleaves the zonula adherens protein, E-cadherin. Proc Natl Acad Sci U S A. 1998. 95: 14979-14984. https://doi.org/10.1073/pnas.95.25.14979
  18. Wu S, Morin PJ, Maouyo D, Sears CL. Bacteroides fragilis enterotoxin induces c-Myc expression and cellular proliferation. Gastroenterology. 2003. 124: 392-400. https://doi.org/10.1053/gast.2003.50047
  19. Wu S, Powell J, Mathioudakis N, Kane S, Fernandez E, Sears CL. Bacteroides fragilis enterotoxin induces intestinal epithelial cell secretion of interleukin-8 through mitogen-activated protein kinases and a tyrosine kinase-regulated nuclear $factor-{\kappa}B$ pathway. Infect Immun. 2004. 72: 5832-5839. https://doi.org/10.1128/IAI.72.10.5832-5839.2004