The genus Bartonella (Rhizobiales: Bartonellaceae) encompasses facultative intracellular Gram-negative alphaproteobacteria that parasitize mainly erythrocytes and endothelial cells, as well as macrophages, monocytes and dendritic cells. Although they can infect numerous mammal species and arthropod vectors worldwide, reports of Bartonella infections in marsupials are scarce. In fact, such agents have only been detected in marsupials and/or associated ectoparasites in Australia and the United States of America until the present moment. The present study aimed to isolate and characterize molecularly, morphologically and phenotypically Bartonella infecting free-living marsupials sampled in the Brazilian Pantanal, the largest wetland in South America. Two marsupials were captured in December 2018 and six marsupials in February 2019, totaling eight small mammals sampled: five (62.5%) Thylamys macrurus and three (37.5%) Monodelphis domestica. All blood samples were submitted to qPCR for Bartonella spp. based on the nuoG gene, a pre-enrichment liquid culture and a chocolate agar solid culture. Bartonella sp. was isolated from 3 T. macrurus and one M. domestica. One Bartonella isolate obtained from a T. macrurus blood sample (strain 117A) that showed to be closely related to the Bartonella vinsonii complex and Bartonella machadoae was selected for whole genome sequencing using a hybrid approach based on Illumina NovaSeq and Nanopore sequencing platforms. This strain showed a genome of 2.35 Mbp, with an average C + G content of 38.8%, coding for 2013 genes, and a 29 kb plasmid with an average C + G content of 34.5%. In addition, this strain exhibited an average nucleotide identity (ANI) of 85% with Bartonella species belonging to the B. vinsonii group and 91% with B. machadoae. Phylogenomic analysis based on 291 protein coding genes shared by the genomes of 53 Bartonella species positioned this strain closely to B. machadoae. This new isolated species was named Bartonella harrusi sp. nov., which was characterized as having small capnophilic, microaerophilic and aerobic rods with an absence of pili and flagella. In conclusion, the present work describes the biochemical, phenotypic and genomic characteristics of Bartonella harrusi, a new species isolated from the T. macrurus blood samples of the Brazilian Pantanal. Finally, a review of the taxonomic classification of members of the genus Bartonella is proposed, based on the ANI values accessed by whole genome sequencing analyses.

Despite numerous reports of Anaplasmataceae agents in mammals worldwide, few studies have investigated their occurrence in birds. The present study aimed to investigate the occurrence and molecular identity of Anaplasmataceae agents in birds from the Pantanal wetland, Brazil. Blood samples were collected from 93 different species. After DNA extraction, samples positive for the avian β-actin gene were subjected to both a multiplex quantitative real-time (q)PCR for Anaplasma and Ehrlichia targeting the groEL gene and to a conventional PCR for Anaplasmataceae agents targeting the 16S rRNA gene. As a result, 37 (7.4%) birds were positive for Anaplasma spp. and 4 (0.8%) for Ehrlichia spp. in the qPCR assay; additionally, 13 (2.6%) were positive for Anaplasmataceae agents in the PCR targeting the 16S rRNA gene. The Ehrlichia 16S rRNA sequences detected in Arundinicola leucocephala, Ramphocelus carbo, and Elaenia albiceps were positioned closely to Ehrlichia sp. Magellanica. Ehrlichia dsb sequences detected in Agelasticus cyanopus and Basileuterus flaveolus grouped with Ehrlichia minasensis. The 16S rRNA genotypes detected in Crax fasciolata, Pitangus sulphuratus and Furnarius leucopus grouped with Candidatus Allocryptoplasma. The 23S-5S genotypes detected in C. fasciolata, Basileuterus flaveolus, and Saltator coerulescens were related to Anaplasma phagocytophilum. In conclusion, novel genotypes of Anaplasma, Ehrlichia, and Candidatus Allocryptoplasma were detected in birds from the Pantanal wetland.

Bats are considered reservoirs of several emerging zoonotic pathogens. Previous studies on blood parasites such as Anaplasmataceae, hemoplasmas, piroplasmids, and Hepatozoon spp. in South American bats have revealed high genetic diversity. This study investigated the molecular occurrence of these agents in 278 bats of 32 species captured in the state of Acre in the Western Brazilian Amazon. Spleen DNA samples were screened by PCR for different pathogens and tested negative for Anaplasma spp., Ehrlichia spp., Neorickettsia spp., piroplasmids, and Hepatozoon spp. However, 84 of the 208 samples (40.4%) were positive for hemoplasmas based on the 16S rRNA gene, and 15 out of the 84 (17.85%) were positive for the 23S rRNA gene. Seventeen 16S rRNA sequences, corresponding to 12 genotypes, were grouped with hemotropic Mycoplasma sp. previously detected in bats from Brazil, Peru, and Belize. Three 23S rRNA sequences represent three distinct genotypes clustered with hemotropic Mycoplasma sp., previously detected in Desmodus rotundus. This is the first molecular report of hemoplasmas in six bat species, namely Dermanura cinereus, Lophostoma silviculum, Phyllostomus elongatus, Phyllostomus hastatus, Rhinophylla fischerae, and Sturnira tildae.

Representatives of the families Didelphidae, Echimyidae, Cricetidae, and Muridae have been identified as significant reservoirs or amplifiers of zoonotic agents. This study aimed to investigate the molecular occurrence of Bartonella spp., Ehrlichia spp., Anaplasma spp., and hemotropic Mycoplasma spp. (hemoplasmas) in small synanthropic mammals in different urban complexes in Brazil’s northern Amazon region. Between January and August 2022, blood samples were collected from 36 small mammal specimens, belonging to ten different species living in three vegetation fragments located in the metropolitan areas of Macapá, in the state of Amapá, and in Santarém and Marabá, state of Pará, Brazil. After DNA extraction, samples were subjected to real-time quantitative PCR (qPCR) for Bartonella spp. based on the nuoG gene, and to conventional PCR assays for Ehrlichia spp., Anaplasma spp., and hemoplasmas based on the dsb and 16S rRNA genes, respectively. This is the first record of Anaplasma spp. and hemotropic Mycoplasma sp. in marsupials in northern Brazil. Bartonella spp. was detected only in small mammals from Macapá, expanding the list of known hosts. This study describes findings on potentially zoonotic pathogens associated with small mammals living in green areas of large urban complexes in the Brazilian Amazon.