Diversity of Bartonella spp. in wild and domestic mammals and ectoparasites in Northeastern Brazil

• Grant number: 25/00394-6
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2025
• End date: October 31, 2028
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Marcos Rogério André
• Grantee: Marcos Rogério André
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated researchers: Eder Silva Barbier ; Pierre Barnabé Escodro ; Renata Santiago Alberto Carlos ; Victor Fernando Santana Lima

Abstract

The genus Bartonella (Hyphomicrobiales; Bartonellaceae) includes facultative intracellular Gram-negative bacteria that mainly parasitize erythrocytes and endothelial cells of mammals, causing zoonoses with clinical manifestations ranging from moderate to severe. Rodents, bats, marsupials, domestic and wild canids and felids, and several other mammals are important reservoirs of these bacteria. The flea Ctenocephalides felis is a vector of Bartonella henselae, the etiological agent of Cat Scratch Disease (CSD). Despite the significant biodiversity of mammals in Brazil, there are gaps in knowledge about the diversity of Bartonella spp. in domestic and wild animals and associated ectoparasites. This study aims to investigate the molecular occurrence and genetic diversity of Bartonella spp. in blood samples from cats, bats, wild mammals (rodents, marsupials and carnivores) and ectoparasites in Northeastern Brazil, covering the states of Alagoas, Sergipe, Pernambuco, Rio Grande do Norte, Ceará and Bahia. In 2019, the environmental disaster in Maceió that resulted in the evacuation of five neighborhoods due to the reactivation of geological faults by rock salt mining lead to abandonment and an increase in the population of stray cats in the region. A total of 350 cat blood samples will be collected in the state of Alagoas through the Integra Animal Project, in partnership with UFAL. In addition, blood samples were collected from 200 bats belonging to eight different species captured in four caves in the states of Ceará, Pernambuco, Rio Grande do Norte and Sergipe. Blood, spleen (rodents only) and ectoparasite samples will be collected from wild rodents, marsupials and carnivores in the Caatinga biome, state of Sergipe. Additionally, we will analyze 1000 fleas were collected from 82 dogs and 200 fleas from 40 cats in the state of Bahia. Screening and molecular characterization of Bartonella spp. will be performed using real-time quantitative PCR (qPCR - nuoG gene) and conventional PCR (gltA, rpoB, ribC, ftsZ, groEL, pap-31, nuoG genes and 16S-23S rRNA intergenic region [ITS]) assays, respectively. The collected blood samples will be subjected to pre-enrichment in BAPGM (Bartonella AlphaProteobacteria Growth Medium) liquid medium, followed by qPCR and isolation on chocolate agar. Isolates identified as B. henselae will be genotyped using the Multilocus Sequence Typing (MLST) technique, while those suggestive of new species will have their genome sequenced using a hybrid platform (Illumina and Nanopore) in order to perform phylogenomic and average nucleotide identity (ANI) analyses. Putative novel Bartonella species will be characterized biochemically, phenotypically and metabolically, in addition to being subjected to scanning electronic microscopy. Amplicons of Bartonella spp. based on different molecular markers and obtained from blood and ectoparasite samples will be subjected to purification, Sanger sequencing and phylogenetic inferences. The proposal presented herein will contribute to the understanding of the genetic diversity of Bartonella spp. in domestic and wild mammals and ectoparasites in Northeastern Brazil. (AU)