diagnosis laboratories, molecular analysis by PCR-based assays is the
method of choice for discriminating between the pathogenic species (E.
histolytica) and the nonpathogenic species (E. dispar).
A: Agarose gel (2%) analysis of a PCR diagnostic test for differentiation between
E. histolytica and E. dispar.
- Lanes 1 - 4: Amplification
with the Psp3/Psp51 PCR primer pair specific for E. histolytica. Diagnostic band size - 876 bp.
- Lanes 6 - 9:
Amplification with the NPsp3/NPsp51 PCR primer pair specific for
E. dispar. Diagnostic band size - 876 bp.
- Lanes 1 and 6:
E. histolytica 200:NIH, zymodeme II (positive control for E. histolytica).
- Lanes 2 and 7:
E. dispar 351:IMMiT, zymodeme I (positive control for E. dispar).
- Lanes 3 and 8:
Specimen from a patient with a liver abscess (positive with E. histolytica primers
and negative with E. dispar primers). E. histolytica 333:IMMiT,
- Lanes 4 and 9:
Specimen from an asymptomatic patient (positive with E. dispar
primers and negative with E. histolytica primers). E. dispar 389:IMMiT,
- Lane 5:
Molecular base pair standard, 100-bp ladder (from 600 to 1,000 bp).
Figure A contributed by Assist.
Prof. Przemyslaw Myjak, Ph.D., Institute of Maritime and Tropical Medicine, Gdynia,
real-time PCR approach has been validated at CDC and is used for
differential laboratory diagnosis of amebiasis.2 The
assay targets the 18S rRNA gene with species-specific TaqMan probes in a
duplex format, making it possible to detect both species in the same
here to learn more about TaqMan real-time PCR.
- Clark CG, Diamond LS.
Differentiation of pathogenic Entamoeba histolytica from other intestinal
protozoa by riboprinting. Arch Med Res 1992;23:15-16.
Y, James C, Xayavong M, Holloway B, Moura I, Visvesvara GS, et al.
Comparison of real-time PCR rationales for differential laboratory
diagnosis of amebiasis. J Clin Microbiol 2005;43:5491-5497.