Quantitative Detection of Leishmania in Rhipicephalus microplus and Amblyomma sabanerae in the Peruvian Amazon Basin.

Leishmaniasis is a disease of public importance with a complex transmission cycle. A quantitative PCR was developed by using the small subunit of the ribosomal RNA gene (SSU rRNA) as a DNA target, which is conserved in all Leishmania species. A TaqMan ® probe was designed to have a high specificity. In all, 22 out of 23 (95.7%) ticks classified as R. microplus tested positive for Leishmania sp. The quantification was between 34.1 and 2197.1 parasites per tick in a range of 12 to 769 fg/uL. In addition, 9 out of 10 (90%) ticks classified as Amblyomma sabanerae tested positive for Leishmania sp. The quantification was between 448.6 and 5428.6 parasites per tick in a range of 157 to 1900 fg/µL. Leishmania sp. was identified in very high percentages in Rhipicephalus microplus and Amblyomma sabanerae from wild Pecari tajacu and Chelonoidis denticulata, in quantities of 34.1 and 5428.6 parasites per arthropod, and this could suggest that the ticks were parasitized by sucking blood from the animals from which they were collected. This is the first report about Leishmania parasites found in wild Rhipicephalus microplus and Amblyomma sabanerae, adding new information about the distribution and epidemiology of the parasite in sylvatic areas.

Detection of Leishmania (V) guyanensis in Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) collected from Pecari tajacu.

INTRODUCTION: Previous studies identified the presence of Leishmania infantum in Rhipicephalus sanguineus and indicated the possibility that it could transmit leishmaniasis to a variety of hosts. OBJECTIVE: To identify parasites of Leishmania (Viannia) spp. in ticks collected from wild animals in an endemic area for leishmaniasis. MATERIALS AND METHODS: We performed 81 individual DNA extractions from ticks collected from three Tapirus terrestris and three Pecari tajacu in Madre de Dios, Perú. Ticks were taxonomically identified and they were subsequently prepared to identify Leishmania (Viannia) spp. kDNA by PCR and the species of Leishmania by HRM-PCR. RESULTS: Leishmania (Viannia) kDNA was detected in three wild ticks of the species R. microplus, collected from a collard peccary (P. tajacu) hunted in the forests of Madre de Dios. The HRM-PCR showed that one of the positive samples had a kDNA curve compatible with L. (V) guyanensis. CONCLUSION: The results showed the presence of L. (V) guyanensis DNA in R. microplus possibly acquired after biting a collarde peccary. Therefore, it is important to design future studies to clarify R. microplus involvement in the transmission of leishmaniasis.

Detección de Leishmania (V) guyanensis en ejemplares de Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) recolectados en pecaríes de collar (Pecari tajacu) / Detection of Leishmania (V) guyanensis in Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) collected from Pecari tajacu

Resumen Introducción. En estudios previos se detectó la presencia de Leishmania infantum en Rhipicephalus sanguineus, lo cual planteaba la posibilidad de que R. sanguineus transmitiera la leishmaniasis a una variedad de huéspedes. Objetivo. Identificar Leishmania (Viannia) spp. en garrapatas recolectadas en animales silvestres de una zona endémica para leishmaniasis. Materiales y métodos. Se hicieron 81 extracciones individuales de ADN en las garrapatas recogidas de tres tapires o dantas (Tapirus terrestres) y tres pecaríes de collar (Pecari tajacu) cazados en Madre de Dios, Perú. Las garrapatas recolectadas se identificaron taxonómicamente y se prepararon para la identificación del cinetoblasto (kDNA) de Leishmania (Viannia) spp. mediante reacción en cadena de la polimerasa (PCR), así como de la especie de Leishmania mediante PCR de fusión de alta resolución (High Resolution Melt, HRM). Resultados. Se detectó el kDNA de Leishmania (V) spp. en tres garrapatas silvestres de R. (Boophilus) microplus, Canestrini, 1888, recolectadas en un pecarí de collar cazado en la selva de Madre de Dios. El análisis mediante HRM-PCR evidenció que una de las muestras positivas de kDNA tenía una curva compatible con L. (V) guyanensis. Conclusión. Los resultados evidenciaron la presencia de ADN de L. (V) guyanensis en R. (Boophilus) microplus, probablemente adquirida después de picar al pecarí. Es importante hacer nuevos estudios para aclarar la participación de R. (Boophilus) microplus en la transmisión de la leishmaniasis.

Abstract Introduction: Previous studies identified the presence of Leishmania infantum in Rhipicephalus sanguineus and indicated the possibility that it could transmit leishmaniasis to a variety of hosts. Objective: To identify parasites of Leishmania (Viannia) spp. in ticks collected from wild animals in an endemic area for leishmaniasis. Materials and methods: We performed 81 individual DNA extractions from ticks collected from three Tapirus terrestris and three Pecari tajacu in Madre de Dios, Perú. Ticks were taxonomically identified and they were subsequently prepared to identify Leishmania (Viannia) spp. kDNA by PCR and the species of Leishmania by HRM-PCR. Results: Leishmania (Viannia) kDNA was detected in three wild ticks of the species R. microplus, collected from a collard peccary (P. tajacu) hunted in the forests of Madre de Dios. The HRM-PCR showed that one of the positive samples had a kDNA curve compatible with L. (V) guyanensis. Conclusion: The results showed the presence of L. (V) guyanensis DNA in R. microplus possibly acquired after biting a collarde peccary. Therefore, it is important to design future studies to clarify R. microplus involvement in the transmission of leishmaniasis.