Molecular Biomarkers & Diagnosis

A Highly Sensitive and Specific Conventional Molecular Diagnosis for Leishmania infantum Chagasi Based on a Single Copy Gene

Abstract

Rodrigo Buzinaro Suzuki, Aline Diniz Cabral, Renata Tonhosolo, Arlei Marcili, Camila de Oliveira Campos Camargo Sanches, Luciamare Perinetti Alves Martins and Márcia Aparecida Sperança

Leishmaniasis are zoonotic diseases caused by a protozoa from Trypanosoma family and of the genus Leishmania, being transmitted by sandfly vectors. Leishmania genus comprise 30 species, including 20 species able to cause disease with different clinical manifestations in humans, ranging from asymptomatic, cutaneous and mucocutaneous lesions, to the severe visceral form. According to the World Health Organization, visceral leishmaniasis, caused by Leishmania infantum chagasi in the Americas, is the most severe form of the disease, and is lethal if not treated. Brazil is part of the group of countries with the highest prevalence of this disease, concentrating 90% of the cases registered in Latin America. A rapid and accurate diagnostic method is of great importance to detect and treat specifically L. i. chagasi in the American continent where others trypanosomiasis circulate, making a specific diagnostic difficult, due to cross reaction. In this work, a new conventional molecular diagnostic method was developed, based on the single copy L. infantum chitinase encoding gene, which presented high specificity and showed increased sensitivity when compared to the method based on the gene encoding the internal transcribed spacer 1 of the Leishmania rRNA (rDNA ITS-1) to diagnose L. i. chagasi on human clinical samples.