Exploring Leishmania infantum cathepsin as a new molecular marker for phylogenetic relationships and visceral leishmaniasis diagnosis

Author(s)

da Silva, Ryan Emiliano ^[1] ; Sampaio, Bruna Matarucco ^[1] ; Tonhosolo, Renata ^[2] ; Ra da Costa, Andrea Perei ^[3] ; da Silva Costa, Luiz Eduardo ^[1] ; Ap Nieri-Bastos, Fernanda ^[1] ; Speranca, Marcia Aparecida ^{[3, 4]} ; Marcili, Arlei ^{[5, 1]}

Affiliation

^[1] Univ Sao Paulo, Fac Med Vet & Zootecnia, Dept Med Vet Prevent & Saude Anim, Ave Prof Dr Orlando Marques de Paiva 87, BR-05508270 Sao Paulo, SP - Brazil

^[2] Univ Santo Amaro, Fac Med, Sao Paulo, SP - Brazil

^[3] Univ Estadual Maranhao, Ciencia Anim, Sao Luis, MA - Brazil

^[4] Fed Univ ABC, Ctr Ciencias Nat & Humanas, Sao Bernardo Do Campo, SP - Brazil

^[5] Univ Santo Amaro, Med Vet & Bem Estar Anim, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: BMC INFECTIOUS DISEASES; v. 19, n. 1 OCT 28 2019.
• Web of Science Citations: 0

Abstract

Background: Leishmania infantum, the etiological agent of visceral leishmaniasis, is a neglected zoonosis that requires validation and standardization of satisfactory diagnostic methodologies. Thus, the aim of the present study was to evaluate the effectiveness of cathepsin L-like protease as a target for making molecular diagnoses and as a phylogenetic marker enabling to understand the intraspecies variations and evolutionary history of L. infantum in Brazil. Methods: We used 44 isolates of L. infantum. The cathepsin L-like gene fragments were amplified, sequenced, manually aligned and analyzed using inference methods. The sequences generated were used to search and design oligonucleotide primers to be used in reactions specific to the target parasite. Results: The cathepsin L-like gene did not show any intraspecies variability among the isolates analyzed. The pair of primers proposed amplified the target deoxyribonucleic acid (DNA) of L. infantum isolates and were effective for DNA amplification at concentrations of as low as 10(-11) ng/mu l. The proposed marker did not present cross-reactions with other hemoparasites. When used for making the diagnosis in a panel of clinical samples from dogs, a positivity rate of 49.03% (102/208) was obtained, versus 14.42% (30/208) for a ribosomal internal transcribed spacer (ITS) marker. In samples from sandflies, the rate was 6.25% and from humans, 14.28%. Conclusions: The results described in this work allow us to infer that CatLeish-PCR is a sensitive and specific marker for use in diagnostic trials of L. infantum and in clinical and epidemiological surveys. (AU)

• FAPESP's process: 10/50886-7 - Isolation and morphological, biological and molecular characterization and multigenes phylogeography from species causing visceral leishmaniasis
• Grantee: Arlei Marcili
• Support Opportunities: Research Grants - Young Investigators Grants