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Borrelia theileri is a tick-borne spirochete causative agent of fever, apathy and reduced food consumption in cattle. Molecular diagnosis has expanded the understanding of Borrelia theileri with new hosts and geographical locations being described. The present study aimed to describe the first molecular detection of B. theileri in wild tapirs (Tapirus terrestris) from South America. Blood DNA samples obtained from 99 tapirs sampled in Pantanal (n = 61) and Cerrado (n = 38) biomes were screened using a qPCR assay based on the 16 S rRNA gene of Borrelia sp. Positive samples in the qPCR assay were subjected to PCR assays to allow characterization of fragments from 16 S rRNA and flaB genes. Two (2/99; 2.0%) animals from Pantanal biome were positive in the qPCR and one sample presented bands of expected size for the flaB protocol. Amplicons from this sample were successfully cloned and sequenced. In the phylogenetic analysis, Borrelia sp. from T. terrestris grouped together with B. theileri sequences previously detected in Rhipicephalus microplus ticks and cattle from Minas Gerais State in Brazil, Rhipicephalus geigyi from Mali, and R. microplus and Haemaphysalis sulcata from Pakistan. This finding contributes to our knowledge regarding susceptible hosts species for B. theileri. More studies are necessary to understand the potential effects of B. theileri on tapir's health., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Simple Summary: Basal values of hematological and serum biochemical parameters are necessary for health and animal production performance evaluation. Therefore, considering the importance of cattle production in the Brazilian savannah area and the lack of regional data, we aimed to know the differences related to age, breed group, the influence of the productive system, and geographic region. We established baseline values for beef calves at weaning age. Jugular blood samples were collected in a single instant from 30 calves from each of the following breeds: Nellore, Senepol, Nellore × Aberdeen Angus cross, Nellore × Senepol cross, and Nellore × Aberdeen Angus × Senepol cross. Hematological and serum biochemical evaluations and a proteinogram were performed according to routine techniques. In conclusion, the available reference intervals for healthy animals can be used routinely without interference from the geographic region for animals produced without nutritional failures since changes are registered in pathological, infectious, metabolic, or nutritional deficiency situations. Furthermore, these results will help to understand the adaptation advantages and the possible physiological processes of those breeds and their crosses in the savannah biome of Brazil. The Brazilian savannah region, characterized by high average temperatures, well-defined rainy and dry seasons, soil with low productive potential, and high pressure for parasitic diseases, is home to the highest percentage of the beef herd, which is the world's largest commercial beef producer. Therefore, breeds that present rusticity combined with productivity are the focus of research in cattle breeding in the region. Considering their geographic particularities and their effects on the animals' blood parameters, the objective was to study the behavior of hematological variables, serum biochemistry, and acute phase proteins in beef calves at weaning age. Jugular blood samples were collected in a single day from 30 weaning calves (about eight months old and 200 kg of body weight) from the following breeds: Nellore, Senepol, Nellore × Aberdeen Angus cross, Nellore × Senepol cross, and Nellore × Aberdeen Angus × Senepol cross. Hematological data were obtained using an automatic cell counter, serum biochemical measurements were obtained using commercial kits, and the electrophoretogram was obtained using the SDS-page technique. In general, the results were consistent with data already published in similar situations regarding health status, age, and level of metabolic activity. However, differences observed between groups can be explained by differences observed in other concurrent variables like temperament. The pure zebu breed was more reactive than pure taurine. While crossbreds showed intermediate values, and parasitic infestation, the pure taurine breed with higher parasite infestation, while the zebu breed had lower values, which produced effects in some laboratory tests, and generated differences between breeds. In conclusion, the reference intervals available for healthy animals can be routinely used without interference from the geographic region for animals produced without nutritional failures as long as changes are recorded in pathological, infectious, metabolic, or nutritional deficiency situations. However, it is suggested that a study covering a larger number of herds may demonstrate a greater geographic effect on the studied variables. [ABSTRACT FROM AUTHOR]

Borrelia theileri is a relapsing fever group Borrelia that is transmitted to cattle by ticks of the genus Rhipicephalus. In this study, we describe the first molecular detection of B. theileri subclinical infection in a cow in Brazil. During the examination of stained blood smears of 10 cows from a farm with a recent history of fatal Trypanosoma vivax trypanosomiasis, spirochete-like structures were incidentally detected in one of the cows. The animal presented good body score, normal hematocrit and normal-colored ocular mucosa. Temperature, heart rate and respiratory rate were all normal. The animal was infested by ticks, which were morphologically identified as Rhipicephalus microplus. The diagnosis was confirmed by testing DNA extracted from a blood sample using a PCR targeting a ≈ 650 bp fragment of the flagellin B (flaB) gene of Borrelia spp. The partial flaB sequence obtained showed 99.83% similarity with B. theileri. Phylogenetically, the flaB partial sequence generated herein clustered with other B. theileri sequences, being separated from B. lonestari. This is the first molecular detection of B. theileri subclinical infection in a cow in Brazil. The possible implications of this finding are discussed., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

The present study aimed to describe the occurrence of Borrelia spp. in cattle in the states of Minas Gerais and Pará in southeastern and northern Brazil, respectively. Bovine whole blood samples were examined by blood smear and polymerase chain reaction (PCR) to detect the flagellin B (flaB) gene of Borrelia spp. Frequencies of positive animals for Borrelia spp. were 1.52% (2/132) in the municipality of Unaí, Minas Gerais, and 14.2% (2/7) in the municipality of Marabá, Pará. Subsequent genetic sequencing confirmed that the detected spirochetes close to the species B. theileri. In both locations, the animals positive for B. theileri were also highly infested by Rhipicephalus microplus ticks. Despite the low frequency of Borrelia spp., the occurrence of this spirochete indicates that further studies are needed to determine the consequences in cattle herds., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)