Evaluation of Mastadenovirus and Rotavirus Presence in Phyllostomid, Vespertilionid, and Molossid Bats Captured in Rio Grande do Sul, Southern Brazil.

Bat-borne viruses may affect public health and the global economy. These mammals have a wide geographical distribution and unique biological, physiological, and immunogenic characteristics, allowing the dissemination of many known and unknown viruses. Enteric viruses, such as adeno (AdV) and rotaviruses, are recognized as the main causative agents of disease and outbreaks. In the present study, the presence of viruses from Adenoviridae and Reoviridae families was evaluated in molossid, phyllostomid, and vespertilionid bats captured in Rio Grande do Sul, Southern Brazil, between September 2021 and July 2022. Sixty bat rectal swabs were analyzed by PCR. Eight (13.3%) samples were positive for adenovirus and classified as human mastadenovirus C (HAdV-C) (three samples) and HAdV-E (five samples) by sequencing followed by phylogenetic analysis. All samples were negative in rotavirus specific RT-PCR. This is the first study to describe the presence of HAdV in samples of Glossophaga soricina, Eptesicus brasiliensis, and Histiotus velatus. Furthermore, the presence of HAdV-E in bats was reported, which is unusual and may suggest that other HAdV genotypes, in addition to HAdV-C, may also be harbored by wild animals. The data generated in the present study reinforces the importance of eco-surveillance of viral agents related to diseases in humans and wild animals. In addition, it is essential to identify possible new hosts or reservoirs that increase the risk of spillover and dissemination of infectious pathogens, helping to prevent and control zoonotic diseases.

Rhipicephalus microplus larvae: first report in bats, Molossus rufus.

Cattle are the main hosts of Rhipicephalus microplus; however, this ixodid can also parasitize other animal species. We collected a specimen of R. microplus larvae from one bat Molossus rufus (Mammalia, Chiroptera) from the Cachoeirinha municipality (29° 56' 52'' S and 51° 5' 43'' W), Rio Grande do Sul, Brazil. The specimen was taxonomically identified using identification keys (Vargas 2006). This study reports the first occurrence of this species parasitizing insectivorous bats in Brazil.

Prevalence and molecular detection of Leishmania spp. in bats from Rio Grande do Sul state, Brazil.

This study aimed to detect the occurrence of infection by Leishmania spp.in bats from 34 municipalities of Rio Grande do Sul state (RS; southern Brazil) from 2016 to 2021. A total of 109 bats were provided by the Centro Estadual de Vigilância em Saúde of RS, including six species belonged to Molossidae family, six to Vespertilionidae family, and two to Phyllostomidae family. Leishmania spp. was identified using the nested-PCR method by amplifying the SSU rDNA ribosomal subunit gene into four organ pools: (1) the liver, spleen, and lymph node; (2) heart and lungs; (3) skin; and (4) bone marrow of each bat. Three (3/109, 2.7%) animals tested positive for Leishmania spp. The respective PCR-positive organs came from pools 1 and 3. Two bats (Tadarida brasiliensis) were from the municipality of Canoas, and sequences analysis confirms the species identification as Leishmania infantum. In the third bat (Molossus molossus), from Rio Grande, it was not possible to determine the protozoa species, being considered Leishmania spp. Our results indicate that bats can participate in the biological cycle of Leishmania spp. and perform as host, reservoir, and/or source of infection of the protozoa in different areas of RS. More studies will be needed to elucidate the role of these Chiropteras in the circulation of Leishmania spp. This is the first study reporting the occurrence of Leishmania spp. in bats in Rio Grande do Sul state, southern Brazil.

The virome of the white-winged vampire bat Diaemus youngi is rich in circular DNA viruses.

In the Neotropical region, the white-winged vampire bat (Diaemus youngi) is the rarest of the three species of vampire bats. This bat species feeds preferentially on bird blood, and there is limited information on the viruses infecting D. youngi. Hence, this study aimed to expand the knowledge about the viral diversity associated with D. youngi by sampling and pooling the lungs, liver, kidneys, heart, and intestines of all animals using high-throughput sequencing (HTS) on the Illumina MiSeq platform. A total of three complete and 10 nearly complete circular virus genomes were closely related to gemykrogvirus (Genomoviridae family), smacovirus (Smacoviridae family), and torque teno viruses (TTVs) (Anelloviridae family). In addition, three sequences of bat paramyxovirus were detected and found to be closely related to viruses reported in Pomona roundleaf bats and rodents. The present study provides a snapshot of the viral diversity associated with white-winged vampire bats and provides a baseline for comparison to viruses detected in future outbreaks.

Detection of coronavirus in vampire bats (Desmodus rotundus) in southern Brazil.

The vampire bat (Desmodus rotundus) is a haematophagous animal that feeds exclusively on the blood of domestic mammals. Vampire bat feeding habits enable their contact with mammalian hosts and may enhance zoonotic spillover. Moreover, they may carry several pathogenic organisms, including coronaviruses (CoVs), for which they are important hosts. The human pathogens that cause severe acute respiratory syndrome (SARS-CoV), Middle East respiratory syndrome (MERS-CoV) and possibly coronavirus disease 2019 (SARS-CoV-2) all originated in bats but required bridge hosts to spread into human populations. To monitor the presence of potential zoonotic viruses in bats, the present work evaluated the presence of CoVs in vampire bats from southern Brazil. A total of 101 vampire bats were captured and euthanized between 2017 and 2019 in Rio Grande do Sul state, southern Brazil. The brain, heart, liver, lungs, kidneys and intestines were collected and macerated individually. The samples were pooled and submitted to high-throughput sequencing (HTS) using the Illumina MiSeq platform and subsequently individually screened using a pancoronavirus RT-PCR protocol. We detected CoV-related sequences in HTS, but only two (2/101; 1.98%) animals had CoV detected in the intestines by RT-PCR. Partial sequences of RdRp and spike genes were obtained in the same sample and the RdRp region in the other sample. The sequences were classified as belonging to Alphacoronavirus. The sequences were closely related to alphacoronaviruses detected in vampire bats from Peru. The continuous monitoring of bat CoVs may help to map and predict putative future zoonotic agents with great impacts on human health.

Detection of multiple viruses in oropharyngeal samples from Brazilian free-tailed bats (Tadarida brasiliensis) using viral metagenomics.

In this study, we analyzed the viral population in oropharyngeal samples from T. brasiliensis using a viral metagenomic approach. Genomes corresponding to members of the families Circoviridae, Genomoviridae, Herpesviridae, Paramyxoviridae, Coronaviridae, and Astroviridae were detected. This study provides the first preliminary understanding of the oropharyngeal virome of T. brasiliensis, which may guide the discovery and isolation of novel viruses in the future and highlights the need for continuing investigations in this regard.

Rabies surveillance in wild mammals in South of Brazil.

The sylvatic cycle of rabies, caused by the Rabies lyssavirus (RABV), is maintained in the American Continent by aerial and terrestrial wild mammals. In this study, we combined passive surveillance of rescued wild animals with active serological surveillance in targeting areas at Rio Grande do Sul State and Santa Catarina State, south of Brazil, where bites of humans by wild animals have been reported. Circulation of RABV in Brazilian bats has been extensively demonstrated; however, the observation of such infections in unvaccinated terrestrial mammals is restricted to some regions of the Brazilian territory. The occurrence of rabies infection in unvaccinated animals has been identified by the detection of RABV antigens in brain tissues of dead animals or anti-rabies antibodies in live animals. Such strategies allow the surveillance of rabies and the assessment of spillover risks from infected animals to humans. Our aim included the identification of species of wild mammals that are involved in the sylvatic cycle of rabies virus in Southern Brazil and to assess the risk of rabies infection in patients bitten by wild animals in the state. To assess the anti-rabies seropositivity, sera were submitted to the Rapid Fluorescent Focus Inhibition Test (RFFIT). Among the 100 mammals tested, five animals were seropositive (5%) including three (one primate and two wild canids) with rabies virus neutralizing antibodies titres >0.5 IU/ml. Our results highlight the exposure to RABV of both primates and wild canids in Southern Brazil and suggest the occurrence of RABV exposure without the development of further symptoms. Further research should clarify the dynamics of rabies in wild canids and whether primates are accidental hosts or reservoirs for RABV at this region.

Acidentes com mamíferos silvestres: um risco urbano? / Wild mammal accidents: an urban risk?

Estudo sobre acidentes com animais silvestres e a transmissão do vírus da raiva em ambientes urbanos.

Análise dos acidentes com primatas no Rio Grande do Sul, 2007-2016 / Analysis of primates accidents in Rio Grande do Sul, 2007-2016

Estudo sobre análise de acidentes com primatas no estado do Rio Grande do Sul entre 2007 e 2016.

A Novel Chiropteran Circovirus Genome Recovered from a Brazilian Insectivorous Bat Species.

This report describes the identification and characterization of a novel circovirus using metagenomic approaches in respiratory fluid samples from Brazilian free-tailed bats (Tadarida brasiliensis). The genome and deduced protein sequences share low identity with another circovirus recovered in distantly related bats from China.

Genomic characterization of two novel polyomaviruses in Brazilian insectivorous bats.

Two novel genomes comprising ≈4.9 kb were identified by next-generation sequencing from pooled organs of Tadarida brasiliensis bats. The overall nucleotide sequence identities between the viral genomes characterized here were less than 80% in comparison to other polyomaviruses (PyVs), members of the family Polyomaviridae. The new genomes display the archetypal organization of PyVs, which includes open reading frames for the regulatory proteins small T antigen (STAg) and large T antigen (LTAg), as well as capsid proteins VP1, VP2 and VP3. In addition, an alternate ORF was identified in the early genome region that is conserved in a large monophyletic group of polyomaviruses. Phylogenetic analysis showed similar clustering with group of PyVs detected in Otomops and Chaerephon bats and some species of monkeys. In this study, the genomes of two novel PyVs were detected in bats of a single species, demonstrating that these mammals can harbor genetically diverse polyomaviruses.

Projeto de monitoramento de morcegos: monitoramento de morcegos como estratégia de vigilância da circulação do vírus da raiva no Rio Grande do Sul / Bats monitoring project: bat monitoring as a strategy to monitor rabies virus circulation in Rio Grande do Sul

Estudo sobre a investigação da circulação do vírus rábico em espécies não hematófagas residentes em áreas urbanas, bem como monitoramento do deslocamento de morcegos no Estado do Rio Grande do Sul. (AU)