Molecular detection and genetic diversity of Bartonella species in large ruminants and associated ectoparasites from the Brazilian Cerrado

Currently, fiveBartonellaspecies and an expanding number ofCandidatus Bartonellaspecies have globally been reported in ruminants. Likewise, differentBartonellagenotypes were identified. However, studies relating to ruminant-associatedBartonellain Brazil are scarce. The current study aimed to assess the prevalence and genetic diversity ofBartonellain cattle, buffaloes and associated ectoparasites in Brazil. For this purpose, EDTA-blood samples from 75 cattle and 101 buffaloes were sampled. Additionally, 128Rhipicephalus microplusand oneAmblyomma sculptumticks collected from cattle, and 197R. microplus, oneA. sculptumand 170 lice (Haematopinus tuberculatus) collected from buffaloes were included.BartonellaDNA was initially screened through an HRM real-time PCR assay targeting the 16S-23S internal transcribed spacer (ITS), and the positive samples were submitted to an additional HRM assay targeting thessrAgene. The HRM-positive amplicons were sequenced, and the nucleotide identity was assessed by BLASTn.Bartonellaspp.-positive DNA samples were analysed by conventional PCR assays targeting thegltAandrpoBgenes, and then, the samples were cloned. Finally, the phylogenetic positioning and the genetic diversity of clones were assessed. Overall, 21 of 75 (28%) cattle blood samples and 13 of 126 (10.3%) associated ticks were positive forBartonella bovis. Out of 101 buffaloes, 95 lice and 188 tick DNA samples, one (1%) buffalo and four (4.2%) lice were positive forBartonellaspp. Conversely, none of the ticks obtained from buffaloes were positive forBartonella. TheBartonellasequences from buffaloes showed identity ranging from 100% (ITS andgltA) to 94% (ssrA) withB. bovis. In contrast, theBartonellaDNA sequences from lice were identical (100%) to unculturedBartonellasp. detected in cattle tail louse (Haematopinus quadripertusus) from Israel in all amplified genes. The present study demonstrates the prevalence of newB. bovisgenotypes and a cattle lice-associatedBartonellaspecies in large ruminants and their ectoparasites from Brazil. These findings shed light on the distribution and genetic diversity of ruminant- and ectoparasite-relatedBartonellain Brazil.