Parasitology Research

, Volume 107, Issue 3, pp 679–684 | Cite as

Blastocystis hominis and Dientamoeba fragilis in patients fulfilling irritable bowel syndrome criteria

  • Javed YakoobEmail author
  • Wasim Jafri
  • Mohammad Asim Beg
  • Zaigham Abbas
  • Shagufta Naz
  • Muhammad Islam
  • Rustam Khan
Original Paper


Studies have suggested a possible role for Blastocystis hominis and Dientamoeba fragilis in the etiology of irritable bowel syndrome (IBS). We studied the prevalence of B. hominis and D. fragilis in patients with IBS-diarrhea (IBS-D). Three hundred and thirty patients were enrolled, 171 (52%) with IBS-D and 159 (48%) were controls, respectively. Stool microscopy, culture, and polymerase chain reaction (PCR) for B. hominis and D. fragilis were done. B. hominis was positive by stool microscopy in 49% (83/171) of IBS compared to 24% (27/159) in control (p < 0.001). B. hominis culture was positive in 53% (90/171) in IBS compared to 16% (25/159) in control (p < 0.001). B. hominis PCR was positive in 44% (75/171) in IBS compared to 21% (33/159) in control (p < 0.001). D. fragilis microscopy was positive in 3.5% (6/171) in IBS-D compared to 0.6% (1/159) in control (p = 0.123). D. fragilis culture was positive in 4% (7/171) in IBS compared to 1.3% (2/159) in control (p = 0.176). D. fragilis PCR was positive in 4% (6/171) in IBS-D compared to 0% (0/159) in control (p = 0.030). B. hominis is common, while D. fragilis was less prevalent in our patients with IBS-D. B. hominis and D. fragilis culture had a better yield compared to stool microscopy and PCR.


Polymerase Chain Reaction Irritable Bowel Syndrome Irritable Bowel Syndrome Patient Stool Specimen Irritable Bowel Syndrome Group 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This study was supported by the Higher Educational Commission Grant Ref: 20-774/R&D/06/267 to JY. We are thankful to Dr. C. Graham Clark (Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, England) for providing us the controlled DNA of D. fragilis cultures and to Dr. JJ Windsor (NPHS Microbiology Aberystwyth, Bronglais Hospital, Ceredigion, UK) for his valuable comments.

Conflict of interest

The authors declare they have no conflict of interests.


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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Javed Yakoob
    • 2
    Email author
  • Wasim Jafri
    • 2
  • Mohammad Asim Beg
    • 1
  • Zaigham Abbas
    • 2
  • Shagufta Naz
    • 2
  • Muhammad Islam
    • 2
  • Rustam Khan
    • 2
  1. 1.Department of Microbiology and PathologyThe Aga Khan UniversityKarachiPakistan
  2. 2.Department of MedicineAga Khan University HospitalKarachiPakistan

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