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Ticks are one of the main vectors of pathogens for humans and animals worldwide. However, they harbor non-pathogenic microorganisms that are important for their survival, facilitating both their nutrition and immunity. We investigated the bacterial communities associated with two neotropical tick species of human and veterinary potential health importance from Brazil: Amblyomma aureolatum and Ornithodoros brasiliensis. In A. aureolatum (adult ticks collected from wild canids from Southern Brazil), the predominant bacterial phyla were Proteobacteria (98.68%), Tenericutes (0.70%), Bacteroidetes (0.14%), Actinobacteria (0.13%), and Acidobacteria (0.05%). The predominant genera were Francisella (97.01%), Spiroplasma (0.70%), Wolbachia (0.51%), Candidatus Midichloria (0.25%), and Alkanindiges (0.13%). The predominant phyla in O. brasiliensis (adults, fed and unfed nymphs collected at the environment from Southern Brazil) were Proteobacteria (90.27%), Actinobacteria (7.38%), Firmicutes (0.77%), Bacteroidetes (0.44%), and Planctomycetes (0.22%). The predominant bacterial genera were Coxiella (87.71%), Nocardioides (1.73%), Saccharopolyspora (0.54%), Marmoricola (0.42%), and Staphylococcus (0.40%). Considering the genera with potential importance for human and animal health which can be transmitted by ticks, Coxiella sp. was found in all stages of O. brasiliensis, Francisella sp. in all stages of A. aureolatum and in unfed nymphs of O. brasiliensis, and Rickettsia sp. in females of A. aureolatum from Banhado dos Pachecos (BP) in Viamão municipality, Brazil, and in females and unfed nymphs of O. brasiliensis. These results deepen our understanding of the tick-microbiota relationship in Ixodidae and Argasidae, driving new studies with the focus on the manipulation of tick microbiota to prevent outbreaks of tick-borne diseases in South America., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

We report a series of clinical cases associated with parasitism by the Ornithodoros brasiliensis tick in a group of travelers in the Caxias do Sul municipality, Southern Brazil. These cases draw attention to underdiagnosed noninfectious syndromes caused by ticks with restricted local distributions., (Copyright © 2019 Marketing EDGE.org. Published by Elsevier Inc. All rights reserved.)

Borrelia burgdorferi sensu lato (s.l.) complex includes the agents of Lyme disease/borreliosis in North America, Europe, and Asia, such Borrelia burgdorferi sensu stricto, Borrelia afzelii, Borrelia garinii, Borrelia bavariensis, Borrelia spielmanii, Borrelia bissettiae, and Borrelia mayonii. In 2013 B. burgdorferi s.l. was reported for the first time in the Neotropical region, from Ixodes aragaoi ticks in Uruguayan Pampa. In addition, from 2011 to 2016, 17 suspected human cases of borreliosis-like syndrome were reported in Rio Grande do Sul (RS) state, Brazil, which contains only part of country in the Pampa biome. The goal of this work is to report the results of a state surveillance program conducted in order to investigate the presence of B. burgdorferi s.l. in its classic vector, Ixodes spp. ticks, from the Brazilian Pampa. For this, we searched for Ixodes spp. ticks in 307 rodents from 11 municipalities of RS state. We then tested the ticks for the presence of B. burgdorferi s.l. DNA using PCR analysis. Of 35 Ixodes spp. ticks tested, one larva and one nymph of Ixodes longiscutatus ticks tested positive for Borrelia sp. DNA. The phylogenetic analysis of the flaB fragment grouped our samples (referred as Borrelia sp. haplotype Pampa) into B. burgdorferi s.l. group in a particular branch with other South American haplotypes, and this group was close to Borrelia carolinensis, B. bissettiae, and Borrelia californiensis. This is the first evidence of B. burgdorferi s.l. circulation in ticks of the genus Ixodes in Brazil. These results highlight the need for the implementation of public health policies for the diagnosis and prevention of potential cases of human borreliosis in Brazil. Further studies are needed to fill the gaps in our knowledge of the distribution, pathogenicity, reservoirs, and vectors of these emerging South American B. burgdorferi s.l. haplotypes., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

"Candidatus Rickettsia asemboensis" is an obligate intracellular bacterium of the Rickettsiales order, genetically related to species belonging to the Rickettsia felis group, agents of flea-borne spotted fever. Here we report for the first time the detection of "Ca. R. asemboensis", a flea-associated organism, in Rhipicephalus sanguineus ticks. It is the first occurrence of this emerging bacterium in Brazil, which increases the geographical distribution of this R. felis-like agent., (Copyright © 2016 Elsevier B.V. All rights reserved.)