Molecular Identification of E.histolyticaa/E.dispar using Nested Polymerase Chain Reaction

Abstract

Microscopic identification of Enamoeba sp. in stool is insensitive and unable to distinguish the invasive parasite Entamoeba histolytica from the commensal parasite E. dispar. ANested polymerase chain reaction (nest.PCR) technique for the detection of E. histolytica is powerful test for the diagnosis of E.histolyticaa. An eighty-six stool samples were collected from patients severing from digestive tract symptoms (diarrhea, abdominal pain, loss of appetite, weakness) that attending to the Maternity and Childhood Teaching Hospital and Al-Dewania Teaching Hospital in Al-Dewania Governarte, which gave positive microscopy results for Entamoeba sp. using conventional methods. The results of nested-PCR for all stool samples based on amplification of the small subunit rRNA gene of E. histolytica and E. dispar followed by restriction digest analysis of the PCR product revealed that patients infected with E.histolytica mixed with E.dispar were 16/86(18.6%), while a 46 /86(52%) were positive for E.dispar only and 24/86( 27.9%) were negative for Entamoeba sp while antigens detection for E.histolytica/E.dispar using an ELISA technique yielded 28/86(32%) were negative for E.histolytica/E.dispar and 58/86(68%) were positive.. In conclusions, the sensitivity, specificity and accuracy for ELISA were 87.5%, 37.1%, 46.5% respectively in comparing with the molecular diagnosis using nest.PCR were 100%.