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

• Published in: Revista medíca de Chile Vol. 140; no. 4; pp. 476 - 483
• Main Authors: López, Omaira Y, López, Myriam C, Corredor, Vladimir, Echeverri, M Clara, Pinilla, Análida E
• Format: Journal Article
• Language: Spanish
• Published: Chile 01-04-2012
• Subjects: Base pairs; Colombia; Differentiation; DNA, Protozoan - genetics; Entamoeba - genetics; Entamoeba - isolation & purification; Entamoeba - metabolism; Entamoeba dispar; Entamoeba histolytica; Entamoeba histolytica - genetics; Entamoeba histolytica - isolation & purification; Entamoebiasis - diagnosis; Entamoebiasis - parasitology; Enzyme-Linked Immunosorbent Assay; Feces; Feces - parasitology; Female; genomics; Humans; Lead; Lectins; Male; Nucleotides; Polymerase chain reaction; Polymerase Chain Reaction - methods; Protozoan Proteins; RNA, Ribosomal, 16S - genetics; rRNA 16S; Sensitivity and Specificity; Trophozoites; Variable region; Colombia
• ISSN: 0034-9887; 0717-6163
• DOI: 10.4067/S0034-98872012000400008

Entamoeba histolytica and Entamoeba dispar are morphologically identical. However, the former is highly pathogenic and the latter is not.
To differentiate Entamoeba histolytica from Entamoeba dispar through ELISA and PCR techniques in Colombian isolates from feces.
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.
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.
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.