ABSTRACT: Our objective was the characterization and staging of histological lesions in different anatomical sites of the central nervous system (CNS) of rabid cattle. The severity of the lesions was compared with the clinical stages of the disease, the variants of viral isolates, and with the load of virus. Thirty-one spontaneously affected rabid cattle the state of Santa Catarina underwent clinical follow-up and were eventually necropsied. CNS tissues were sampled and submitted to direct fluorescent antibody technique (DFAT), immunohistochemistry (IHC), routine histopathology with hematoxylin and eosin stain (HE), reverse transcriptase polymerase chain reaction (RT-PCR), and polymerase chain reaction in quantitative reverse transcriptase in real time (qRT-PCR). Affected cattle were allotted in four groups according to their clinical stage when euthanized: G1, euthanized while standing; G2, euthanized when in sternal recumbence; G3, euthanized when in lateral recumbence; and G4, affected cattle with natural death. In order to evaluate the degree of severity of the lesions and the presence of Negri bodies (NBs), the brain was sectioned at 9 sites. Additionally, spinal cord and trigeminal ganglion sections were examined. The intensity of the lesions was graded as either absent, mild, moderate, or marked, and the presence or absence of the NBs was noted. Histological lesions were characterized by lymphocytic and monocytic meningoencephalitis with NBs in 28 cases. In all analyzed groups, intensities of histological lesions ranging from mild to severe were observed. Brain regions with the highest inflammatory lesion intensity were the medulla at the level of obex, followed by the colliculus and thalamus. NBs were observed in a higher percentage in the cerebellum, followed by medulla at the obex level, striatum complex, and frontal telencephalon. The duration of the clinical course of the disease did not influence the intensity of the inflammatory lesion, but it did influence the presence of NBs, with a higher percentage of these inclusions in cattle that died naturally than in euthanized cattle. All isolated rhabdovirus included in this study were genetically compatible with samples from hematophagous bats Desmodus rotundus. The evaluation by qRT-PCR did not demonstrate a correlation between lesion intensity and the amount of virus.

Bats and dogs are the main reservoirs of rabies virus (RABV) in Latin America and are responsible for the maintenance of different cycles of infection. In the two neighbour and most southern Brazilian states of Rio Grande do Sul (RS) and Santa Catarina (SC), rabies in dogs has been successfully controlled for more than 30 years. However, rabies associated to the rural cycle remains endemic, with a significant, though oscillating-annual incidence of rabies in cattle. Despite the plethora of studies on genetic analyses of Brazilian RABV, isolates from southern Brazil have only scarcely been investigated. This work was performed to identify the genetic lineages of RABVs circulating in states of RS and SC. Fifty-nine RABV cattle isolates from RS and SC were selected and submitted to reverse transcription/polymerase chain reaction (RT-PCR) followed by sequencing of the nucleoprotein gene. In RS, the circulation of two sublineages (1A and 1B) of RABV was detected, both with characteristics of lineages usually detected in vampire bats (Desmodus rotundus). In SC, only one sublineage of RABV (1B) was detected. Nevertheless, the findings reported here are expected to contribute to the understanding of the biology of the virus in the region and its interactions with the natural host D. rotundus. Keywords Rural rabies • Genetic lineages • Rio Grande do Sul • Santa Catarina • BrazilEdited by Zhen F. Fu.

Bats play a significant role in maintaining their ecosystems through pollination, dispersal of seeds, and control of insect populations, but they are also known to host many microorganisms and have been described as natural reservoirs for viruses with zoonotic potential. The diversity of viruses in these animals remains largely unknown, however, because studies are limited by species, location, virus target, or sample type. Therefore, the aim of this study was to detect fragments of viral genomes in bat samples. We performed high-throughput sequencing analysis and specific PCR and RT-PCR on pools of anal and oropharyngeal swabs from Artibeus lituratus and Sturnira lilium collected in southern Brazil. As a result, a member of the family Adenoviridae related to human adenovirus C was detected in anal swabs from S. lilium. In addition, we detected a papillomavirus in an anal swab from A. lituratus. Our analyses also allowed the detection of adenoviruses and parvoviruses in oropharyngeal swabs collected from A. lituratus. These results increase our knowledge about viral diversity and illustrate the importance of conducting virus surveillance in bats.

Os morcegos são mamíferos de grande diversidade, amplamente distribuídos no mundo. Apesar da importância desses animais na manutenção dos ecossistemas, estes também representam uma preocupação na saúde pública, uma vez que atuam como reservatórios ou hospedeiros de diferentes patógenos, principalmente vírus. A identificação das espécies de morcegos é essencial para melhor compreensão da origem e da epidemiologia de diversas doenças. Além disso, o entendimento sobre a interação vírus/hospedeiro e o papel dos morcegos na disseminação das doenças é essencial para a manutenção da diversidade e consequente conservação desses animais, permitindo assim, o controle racional dos patógenos albergados por estes. Desta forma, é imprescindível realizar a identificação correta das espécies de morcegos recebidas nos laboratórios, a fim de implantar medidas adequadas de vigilância. Neste sentido, este estudo teve como objetivo identificar geneticamente as espécies de morcegos enviados para diagnóstico de raiva no Instituto Pasteur através do sequenciamento genético parcial do gene citocromo C oxidase subunidade I (COI). Para este estudo foram selecionadas 127 amostras de pulmão de morcegos negativos para raiva obtidos em 2015. As amostras foram submetidas a extração de DNA e PCR tendo como alvo o COI e sequenciamento genético. Como resultado, foram identificadas oito espécies: Artibeus lituratus, Cynomops planirostris, Eumops glaucinus, Glossophaga soricina, Lasiurus ega, Molossus molossus, Molossus rufus e Myotis riparius, distribuídas em três famílias (Phyllostomidae, Molossidae e Vespertilionidae) comumente encontradas no Brasil. O sequenciamento parcial do gene COI foi eficaz na identificação das espécies de quirópteros podendo ser uma ferramenta auxiliar na identificação morfológica e facilmente implantada em laboratórios de biologia molecular.