Molecular and parasitological detection ofLeishmania spp. in a dipteran of the speciesTabanus importunus

Abstract

Leishmaniasis is an important chronic zoonosis caused by protozoa of the genus Leishmania spp. The major vectors of this protozoosis are sand flies, and Lutzomyia longipalpis is considered the main species implicated in the transmission of American Visceral Leishmaniasis in Brazil. The presence of the parasite's deoxyribonucleic acid (DNA) in ectoparasites such as ticks and fleas has prompted speculations about the existence of new vectors in the cycle of leishmaniasis. The aim of this paper is to report the molecular detection of Leishmania spp. in a horse fly of the species Tabanus importunus which parasitized an oligosymptomatic dog infected with Leishmania spp. Molecular amplification of the protozoan's DNA in the head, thoracic region and abdomen of the tabanid tested positive for Leishmania complex. This is the first report of the presence of DNA from Leishmania spp. in dipterous insects of the species T. importunus.Keywords: Dogs, canine visceral leishmaniasis, horse fly, PCR, protozoan, vectors. ResumoA leishmaniose é uma importante zoonose, de caráter crônico, causada por protozoários do gênero Leishmania spp. Esta protozoose tem como principal vetor os flebotomíneos, sendo que, no Brasil, o Lutzomyia longipalpis é a principal espécie incriminada na transmissão da leishmaniose Visceral Americana. A presença do ácido desoxirribonucleico (DNA) do parasito em ectoparasitos, como carrapatos e pulgas, tem gerado especulações quanto a existência de novos vetores no ciclo da leishmaniose. Foi objetivo deste estudo relatar a detecção molecular de Leishmania spp. em uma mutuca da espécie Tabanus importunus que parasitava um cão oligossintomático infectado por Leishmania spp. A análise molecular amplificou o DNA do protozoário na cabeça, na região torácica e no abdomen do tabanídeo, resultando como positivo para complexo Leishmania. Este é o primeiro relato da presença de DNA de Leishmania spp. em insetos dipteros da espécie T. importunus.

Histochemical and molecular evaluation of the prevalence of Leishmania spp. in hematophagous insects

“…This fact is noteworthy, given the fact that, in another study by Coelho et al ( Coelho and Bresciani, 2013 ) in the same municipality, the occurrence of coinfection by T. evansi and Leishmania was observed in a dog from the rural area. No phlebotomine sand flies were captured in this region, but it is an area with a high occurrence of horseflies, stable flies, mosquitoes and black flies.…”

“…The presence of amastigote forms of Leishmania spp. in a horsefly in this area was also reported for the first time ( Coelho and Bresciani, 2013 ).…”

“…Although the positive tabanid flies in this study were collected directly in the peri-urban environment, amastigote forms of Leishmania spp. were detected in the same municipality in 2013, in a T. importunus horsefly that was captured on an oligosymptomatic dog positive for this protozoan ( Coelho and Bresciani, 2013 ).…”

Tabanids in South America

“…A specimen of Tabanus importunus was found infected with a Leishmania sp. : the diagnosis was performed using DNA amplification technique, in São Paulo, Brazil [186]. Borrelia burgdorferi was found naturally infecting tabanids on Marambaia Island, Rio de Janeiro, southeast Atlantic Brazilian Forest (no published data from Guimarães et al).…”

Identification of Leishmania spp. promastigotes in the intestines, ovaries, and salivary glands of Rhipicephalus sanguineus actively infesting dogs

“…Conversely, the study by Paz et al (2010) concluded that it was unlikely that Leishmania maintenance and multiplication occurs within R. sanguineus. Our research group has focused upon the study of the epidemiology and diagnosis of canine visceral leishmaniasis, with an interest in the role nontraditional vectors might have in the biological cycle of this disease (Coelho and Bresciani 2013). We utilized immunohistochemistry (IHC) and PCR to test for the presence and prevalence of Leishmania spp.…”