Leishmania DNA detection and species characterization within phlebotomines (Diptera: Psychodidae) from a peridomicile-forest gradient in an Amazonian/Guianan bordering area

Abstract

In the border region between Brazil and French Guiana, American cutaneous leishmaniasis is a worrisome public health issue, and entomological studies are required there to better identify classical and putative emerging transmission patterns. The present study aimed to detect and characterize Leishmania DNA in the phlebotomine population of Oiapoque (Amapá State, Brazil). Phlebotomines were captured in anthropized and wild environments in the outskirts of Oiapoque municipality, using CDC light traps installed in vertical (ground/canopy level) and horizontal (peridomicile/extradomicile/forest-edge/forest) strata. Captured specimens were identified according to their morphology. Females were processed for Leishmania DNA detection and characterization using a multiplex polymerase chain reaction targeting kinetoplast DNA (kDNA) and the phlebotomine cacophony gene. The kDNA positive samples were characterized by cloning and sequencing the Leishmania 234 bp- hsp70 gene. Among the 3957 phlebotomine specimens captured, 26 pooled female samples were positive for Leishmania ( Viannia ) spp. DNA. Sequencing analysis allowed species-specific identification of L . ( V .) braziliensis DNA in Trichophoromyia ininii , Bichromomyia flaviscutellata , Nyssomyia umbratilis , and Evandromyia infraspinosa , and L . ( V .) guyanensis DNA in Ny . umbratilis . A pooled sample of Ny . umbratilis was positive for both L . ( V .) braziliensis and L . ( V .) guyanensis DNA. The present study provided additional information regarding ACL ecology in Oiapoque, highlighting the presence of L . ( V .) braziliensis DNA in different phlebotomine species. The epidemiological implications of these findings and the determinant incrimination of L . ( V .) braziliensis as proven vectors in that region must be clarified. In this regard, studies on Leishmania spp. infection and suggestive anthropophilic behavior of associated phlebotomines need to be prioritized in entomological surveillance.

Complex ecological interactions across a focus of cutaneous leishmaniasis in Eastern Colombia: novel description of Leishmania species, hosts and phlebotomine fauna

“…This is similar to the results of some studies in Old World settings that found frequencies of between 0.3% to 7.0% in females that had both fed and not fed [ 44 , 45 ]. Our result is in concordance with the findings of several previous studies of vectors in different areas of Brazil where CL is endemic, which described Leishmania frequencies of between 3.4% and 8.1% [ 42 , 46 – 48 ]. In concordance with Souza-Ferreira et al .…”

Diversity of phlebotomine sand flies and molecular detection of trypanosomatids in Brumadinho, Minas Gerais, Brazil

“…braziliensis [62][63][64] and their capacity to support infections with this parasite have been confirmed by Alexandre et al [65]. The genus Evandromyia presented the highest number of species and although there are no proven vector species within this genus, natural infection or Leishmania DNA has been detected in some species [66,67]. In studies conducted in Minas Gerais, Carvalho et al [68] detected Le.…”

Increasing putative vector importance of Trichophoromyia phlebotomines (Diptera: Psychodidae)

“…Kent et al (30) Fouque et al (29) Vasconcelos dos Santos et al (31) Th. brachipyga In an ACL endemic area of Rio Branco, Acre State, where Th.…”

“…; one sample allowed characterisation at species level, with sequence compatible with L. (V.) braziliensis. (31) Trichophoromyia brachipyga Mangabeira, 1942 and/or Th. adelsonsouzai Vasconcelos dos Santos, Silva, Barata, Andrade & Galati, 2013 -In the Belo Monte hydroelectric system affected area in Pará State, Brazil, a program monitoring ACL transmission has been implemented since 2012, providing substantial knowledge on ecology and taxonomy of phlebotomines.…”

“…The raising question on the putative vector importance of Trichophoromyia is also likely to be biased toward the marked increase in the general list of suspected vectors of leishmaniasis in the New World, (1,3,4) which has been supported in the last years, mainly due to the results of PCR-based techniques for diagnosing Leishmania DNA targets within pooled or individually processed phlebotomines. Integrative molecular methodological approaches let us to include suspected vector species from phlebotomine genera with little or even null association with Leishmania, such as Pintomyia, (35) Pressatia, Evandromyia, (25,31) Martinsmyia, and Micropygomyia; (36) in our view, care must be taken on interpreting these intriguing results. Even considering established natural infection, quantification of the parasitic load and/or demonstration of infective forms would certainly present a further step toward improving knowledge on putative Leishmania vectors inferred exclusively through DNA-based findings.…”