Molecular diversity for Entamoeba histolytica virulence factor genes isolated from patients with amoebic dysentery

Abstract

Entamoebahistolytica is a parasitic protozoan that caused amoebiasis, a diseases which infects the liver and colon and spread all over the world. E.histolytica is causing the death of human cells and leading to develop invasion, and ulceration of the intestine. However, amoebic liver abscess(ALA) considers as major common extraintestinal disease caused by E.histolytica.The aims of this study, was to detect E. histolytica by polymerase chain reaction (PCR), and to differentiate it from other amoeba species in a stool samples of human. Study the pathogenicity of E. histolytica in human through determining the presence of virulence factors like cysteine protease, amoebapore and Gal/lectin. A total of 100 stool samples were collected from patients with amoebic dysentery and then examined microscopically to confirm the presence of E. histolytica and other Entamoeba species, 72 ( 72%) out of 100 examined samples with E.histolytica were positive by PCR and 28(28%) were negative. The positive samples with PCR have been submitted to detect the virulence factors of E.histolytica by PCR and the results showed that the total of 72(100%)were positive with cysteine proteases gene, shown 62(86.11%) were positive with amoebapore and 65(90.27) were positive with lectin. Gene sequence for cysteine protease, amoebapore and lectin in local E. histolytica human isolates showed the nucleotide alignment similarity and substitution mutations in all of cysteine protease, amoebapore and Gal/GalNAc lectin. Phylogenetic tree analysis based on cysteine protease gene partial sequence in local E.histolytica human isolates that used for genetic variation analysis showed genetic closed related to NCBI-BLAST E.histolytica Japan strain (AK421547.1) at total genetic changes (0.0060-0.0010%), while Phylogenetic tree analysis based on amoebapore B gene partial sequence in local E.histolytica human isolates that used for genetic variation analysis showed genetic closed related to NCBI-BLAST E.histolytica, Germany strain (X76904.1) at total genetic changes (0.0060-0.0010%). Phylogenetic tree analysis based on Gal/GalNAc lectin gene partial sequence in local E. histolytica human isolates that used for genetic variation analysis showed genetic closed related to NCBI-BLAST E.histolytica Bangladesh strain (AF501280.1) at total genetic changes (0.0060-0.0020.