Otimização da Reação em Cadeia da Polimerase (PCR) para diferenciação molecular de amebas do complexo Histolytica

Abstract

Intestinal parasites contribute to increased morbidity and mortality rates in the world, with amebiasis being the second leading cause of death among parasitic diseases, with approximately 100,000 deaths per year. To prevent unnecessary treatment of individuals with commensal Entamoeba species, it is extremely important to distinguish them from potentially pathogenic E. histolytica. Optical microscopic examination of feces is not efficient for the differentiation of Entamoeba species, and molecular methods are considered useful and reliable for the identification and differentiation of these species, including conventional PCR, Nested-PCR and Multiplex-PCR. The aim of this study was to optimize PCR techniques for better results in the differentiation of amoeba species from the histolytic complex and Entamoeba hartmanni. For this, 16 positive stool samples were obtained by optical microscopy for Entamoeba histolytica/E. dispar. The results of the present study were similar to those of E. hartmanni, Nested-PCR, and Multiplex-PCR for E. histolytica, E. dispar and E. moshkovskii, with modifications of the original protocols to obtain better results in its standardization. In Conventional PCR two positive samples were observed for E. hartmanni, in the Nested-PCR one sample was positive for E. dispar and for E. moshkovskii species no sample was positive. Although the results of the optimization were not completely satisfactory in all the samples tested, due to the possible degradation of the reagents used, the previous results obtained demonstrate the importance of PCR as an effective tool for the detection and differentiation of species of the genus Entamoeba