Differences in Entamoeba histolytica Cysteine Proteinase 5 Gene Isolated From Bandar Abbas and Tabriz, Iran

Background: Amebiasis with up to 100 000 human deaths each year is the third cause of human deadly parasitic disease. With regard to the fact that cysteine protease 5 is known to be one of the most important pathogenicity factors of the Entamoeba histolytica and also, CP5 gene has been observed only in E. histolytica, hence we discriminated E. histolytica from E. dispar on CP5 gene by polymerase chain reaction (PCR) and characterized CP5 gene variation in E. histolytica isolated from patients in both cold regions and tropical regions of Iran at molecular level. Materials and Methods: In the present study, a total of 2332 stool samples (1550 from Tabriz and 782 from Bandar Abbas) were studied microscopically. DNA extraction and PCR method were performed on the positive specimens, infected with E. histolytica/E. dispar. Finally we characterized CP5 gene in E. histolytica isolates from 10 positive samples in the cold regions (Tabriz) and 10 positive samples in the tropical regions (Bandar Abbas) by sequencing and studied the polymorphism of the gene. Results: Of 1550 subjects studied from Tabriz and 782 from Bandar Abaas, 83/1550 (8.3%) and 65/782 (5.35%) persons were infected with E. histolytica/E. dispar, respectively. The molecular results on 20 E. histolytica PCR positive isolates from both regions revealed that nucleotides substitution and polymorphism on CP5 gene was more in samples from Bandar Abbas than those from Tabriz. Conclusion: Prevalence of amebiasis was high in the tropical region (Bandar Abbas) compared with the cold region (Tabriz). In this study, CP5 gene variation in the pathogenicity and virulence of this parasite in the tropical region was higher than that in the cold region.