Looking for the diversity of Bartonella spp. in mammals, birds and hematophagous dipterans in Brazil

Abstract

The genus Bartonella (Rhizobiales; Bartonellaceae) encompasses facultative intracellular Gram-negative bacteria that mainly parasitize erythrocytes and endothelial cells of mammals, and can cause zoonoses with clinical manifestations ranging from moderate to severe, depending on the Bartonella species involved and the immune status of the animal. Cats, rodents and bats act as reservoirs for a great diversity of Bartonella species, many of which are zoonotic. Despite this, the genetic diversity of Bartonella spp. in bats in Brazil is still poorly studied. Likewise, only one study to date aimed to genotype B. henselae isolates from blood samples from cats in Brazil, showing the occurrence of Sequence Types (ST) 9 and 37 in cats in the states of São Paulo and Minas Gerais, respectively. With regard to the occurrence and diversity of Bartonella spp. that infect dogs in Brazil, studies are even scarcer. There are no studies on the occurrence of Bartonella spp. in wild birds in Brazil. Although they are mainly transmitted by hematophagous arthropod vectors (fleas, ticks, mosquitoes, flies and lice), the relationship between this group of bacteria and hematophagous dipterans is poorly studied. Although dipterans of the genus Lutzomyia are the main vectors of Bartonella bacilliformis in Peru, there are no studies on the occurrence and molecular identity of this group of bacteria in sandflies in Brazil, which harbors a huge diversity of Psychodidae dipterans. Additionally, blood transfusion from infected and asymptomatic donors is a possible and neglected form of transmission of these agents. The present study aims to investigate the genetic diversity of Bartonella spp. in blood or spleen samples from dogs, cats, bats, wild birds and in specimens of Psychodidae and Ceratopogonidae dipterans in Brazil. Blood samples from dogs (n=200) and cats (n=200) submitted to routine clinical pathology tests and from blood donors in the Federal District will be cultured for Bartonella spp. using an approach that combines enrichment in liquid BAPGM (Bartonella Alpha Proteobacteria Growth Medium) and isolation on chocolate agar, followed by real-time (qPCR) and conventional (PCR) PCR assays for Bartonella spp. based on numerous molecular markers. B. henselae isolates from blood samples from dogs and cats will be genotyped by the Multilocus Sequence Typing (MLST) technique. Blood samples from dogs and cats from the Federal District, birds (n=817) from the Pantanal from Mato Grosso and from Mato Grosso do Sul, spleen samples from bats from the states of Acre (n=353) and Pará (n=229), and samples of Psychodidae (n=976) and Ceratopogonidae (n=300) dipterans from several states in the North and Northeast regions of the country will be subjected to DNA extraction and qPCR and PCR assays for Bartonella spp. based on several gene targets, followed by sequencing by the Sanger Method and phylogenetic inferences. The present proposal will contribute to the understanding of the genetic diversity of Bartonella spp. in dogs, cats, bats, wild birds and Psychodidae and Ceratopogonidae dipterans in Brazil. (AU)