Usefulness of a PCR-based method in the detection and species identification of Leishmania from clinical samples

International audience ; The aim of this study is to assess the usefulness of a simple, low-cost method for the detection and species identification of Leishmania isolated by in vitro culture or detected directly from clinical samples. A total of 110 samples were used in this study. Among these, 21 were human and canine peripheral bloods, 63 skin lesion material samples, eight reference strains and 18 Leishmania culture. Detection of Leishmania DNA with PCR using primers designed to amplify the internal transcribed spacer 1 (ITS1) region of the rRNA gene proved sufficiently sensitive at the level of 0.1 parasites per PCR reaction. Furthermore, followed by single-strand conformational polymorphism (SSCP), the PCR-ITS1 allowed the species identification of Leishmania. The inter-specific polymorphism of Leishmania was first validated on reference strains, and then this method was applied on clinical samples and culture. Typing identified all human and canine visceral leishmaniasis samples (21 samples) as L. infantum, 95.23% of the cutaneous leishmaniasis samples as L. major and 3.17% as L. killicki and 1.58% as L. infantum. A scheme of the PCR diagnosis procedure for the detection and identification of Leishmania parasites is proposed in this study. ; Le but de ce travail est d’étudier l’apport d’une technique moléculaire simple, peu coûteuse dans la détection et l’identification des leishmanies isolées par culture in vitro ou directement dans un prélèvement biologique. Au total, 110 échantillons ont été inclus dans cette étude dont 21 prélèvements sanguins (humains et canins), 63 prélèvements cutanés, huit souches de référence de leishmanie et 18 autres cultures de Leishmania. La détection moléculaire de l’ADN leishmanien par PCR, en utilisant des amorces qui ciblent le internal transcribed spacer 1 (ITS1) du gène qui code pour l’ARNr, a montré une bonne sensibilité estimée à 0,1 leishmanie par réaction PCR. En plus, du suivi de l’analyse du polymorphisme de conformation de l’ADN simple brin (single-strand ...