[Differentiation of Entamoeba histolytica from Entamoeba dispar using Gal/GalNAc-lectin and polymerase chain reaction]

Rev Med Chil. 2012 Apr;140(4):476-83. doi: 10.4067/S0034-98872012000400008.
[Article in Spanish]

Abstract

Background: Entamoeba histolytica and Entamoeba dispar are morphologically identical. However, the former is highly pathogenic and the latter is not.

Aim: To differentiate Entamoeba histolytica from Entamoeba dispar through ELISA and PCR techniques in Colombian isolates from feces.

Material and methods: Descriptive study of Colombian fecal samples from 53 males and 47 women, that were positive for the complex E. histolytica/E. dispar on light microscopy. Positive samples were cultured on Robinson medium to isolate trophozoites. The presence of specific Gal/ GalNAc-lectin was determined by ELISA and polymerase chain reaction in genomic DNA, using the combination of three nucleotides that recognize a variable region of 16S small subunit ribosomal RNA, generating a 166 base pair (bp) product for E. histolytica and 752 pb product for E. dispar.

Results: After verification, only eight of the 100 samples were positive for the complex E. histolytica/E. dispar and were cultivated. Isolates were obtained in six cultures, one corresponded to E. histolytica and six to E. dispar.

Conclusions: The presence of E. histolytica/E. dispar complex was largely overestimated with light microscopy. In the few samples where isolates were obtained, the technique described differentiated between both strains.

Publication types

  • English Abstract
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Colombia
  • DNA, Protozoan / genetics
  • Entamoeba / genetics
  • Entamoeba / isolation & purification
  • Entamoeba / metabolism*
  • Entamoeba histolytica / genetics
  • Entamoeba histolytica / isolation & purification
  • Entamoebiasis / diagnosis
  • Entamoebiasis / parasitology*
  • Enzyme-Linked Immunosorbent Assay
  • Feces / parasitology
  • Female
  • Humans
  • Lectins
  • Male
  • Polymerase Chain Reaction / methods
  • Protozoan Proteins
  • RNA, Ribosomal, 16S / genetics
  • Sensitivity and Specificity

Substances

  • DNA, Protozoan
  • Lectins
  • Protozoan Proteins
  • RNA, Ribosomal, 16S
  • N-acetylgalactosamine inhibitable lectin 35-kDa subunit, Entamoeba histolytica