Molecular detection and characterization of Bartonella spp. in phlebotomine sand flies (Diptera: Psychodidae) in north and northeast regions of Brazil

Abstract

The Bartonellaceae family is composed of facultative intracellular Gram-negative a-proteobacteria capable of infecting several cell types, mainly erythrocytes and endothelial cells, from a wide variety of hosts. They are the causative agents of bartonellosis, emerging and re-emerging diseases with a wide clinical spectrum and responsible for damage to human and animal health. The main form of transmission of these agents is through hematophagous arthropods, making the search for vectors essential. Phlebotominae sand flies (Diptera, Psychodidae, Phlebotominae) are one of the main groups of arthropods identified as vectors of Bartonellaceae agents, notably for their participation in the transmission cycle of Carrion's Disease, caused by Bartonella bacilliformis, in the andean countries. These insects are widely distributed throughout the Brazilian territory, with a total of 275 different species identified. Thus, the present study aims to investigate, using molecular techniques, the occurrence and genotypic diversity of Bartonella in sand flies captured in Ecological Reserves and National Parks in seven Brazilian states, from the North and Northeast regions (Acre, Alagoas, Bahia, Ceará, Pará, Pernambuco and Roraima). A total of 676 phlebotomine sand flies specimens, belonging to 14 different genera (Bichromomya, Brumptomyia, Evandromyia, Lutzomyia, Micropygomyia, Nyssomyia, Pintomyia, Pressatia, Psathromyia, Psychodopygus, Sciopemyia, Trichophoromyia, Trichopygomyia and Viannamyia), will be submitted to DNA extraction, PCR for the endogenous ¬cox-1 gene and subsequent quantitative real-time PCR (qPCR) for Bartonella spp. based on the nuoG gene. Positive samples will be submitted to conventional PCR assays based on the intergenic region of the 16S-23S ribosomal RNA gene (ITS) and gltA, rpoB, ribC, pap-31, fstZ, groEL and nuoG genes of Bartonella spp., in order to perform molecular characterization by sequencing and phylogenetic analysis. The present study seeks to contribute to the knowledge of the genetic diversity of Bartonellaceae agents in phlebotomine sand flies and to assist in the elucidation of possible transmission cycles between dipterans and human and animal hosts. (AU)