Novel record of a tick Amblyomma sculptum with detection of piroplasm Rangelia vitalii DNA.

Abstract

Rangelia vitalii is the protozoan responsible for a febrile tick-borne disease known as "Nambiuvú" or "bleeding plague." The only competent vector of this protozoan recognized in Brazil is the tick Amblyomma aureolatum. The aim of this study was to identify R. vitalii using molecular biology in ticks parasitizing Cerdocyon thous from Tijuca and Serra dos Órgãos National Parks, which are areas of the Atlantic Rainforest biome in the municipality of Rio de Janeiro. After taxonomic identification, ticks were crushed and DNA was extracted and examined by polymerase chain reaction (PCR) to verify amplification of a fragment of the 18S rRNA gene of piroplasms. Samples identified as positive in the PCR analysis were subjected to sequencing, which revealed high identity with sequences of R. vitalii. This is the first report of parasitizing nymphs of A. sculptum infected by R. vitalii under natural conditions.