Genetic diversity of bat rabies viruses in Brazil (original) (raw)
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Archives of Virology, 2017
Bats have aroused growing attention in the public health sphere because they are considered the main reservoir of rabies virus (RABV) in the Americas, in places where canine rabies is under control. Antigenic and genetic studies of RABV isolates have been used to describe the epidemiological profile of rabies and to identify possible hosts/reservoirs for different epidemiological cycles. This study describes the antigenic and genotypic characterization of 19 RABV isolates from central nervous system samples of non-hematophagous bats (Mammalia: Chiroptera). These bats were diagnosed as RABV positive by direct fluorescent antibody and mouse inoculation tests. Antigenic characterization using a panel of eight monoclonal antibodies revealed that 7 of 19 RABV isolates from these bats belonged to variant 3, for which the hematophagous bat species Desmodus rotundus is the main reservoir, and 1 of 19 RABV isolates from an insectivorous bat belonged to variant 4, which is characteristic of these bats. The remaining 11 RABV samples were divided into six non-compatible profiles. The isolates were subjected to reverse transcription polymerase chain reaction for the N gene and partially sequenced. Genetic characterization of these isolates was performed by grouping the sequences obtained with known RABV lineages. The sequences were grouped in clusters by the phylogenetic inference neighborjoining method, together with another 89 homologous sequences obtained from GenBank. This analysis grouped the isolates into four known lineages: Nyctinomops Brazil, Myotis Brazil, Eptesicus Brazil and D. rotundus Brazil, as well as another cluster that may define a RABV lineage not yet characterized, here named Myotis Brazil II, for which bats of the genus Myotis apparently act as reservoirs. This assumption of a new lineage is also based on the observation of amino acid substitutions, with an average intraspecific identity of 99.8%, varying from 99.6 to 100.0% for nucleotides and 100.0% for amino acids.
Journal of Veterinary Medical Science, 2011
The complete genome sequences of two Brazilian wild-type rabies viruses (RABV), a BR-DR1 isolate from a haematophagous bat (Desmodus rotundus) and a BR-AL1 isolate from a frugivorous bat (Artibeus lituratus), were determined. The genomes of the BR-DR1 and BR-AL1 had 11,923 and 11,922 nt, respectively, and both encoded the five standard genes of rhabdoviruses. The complete nucleotide sequence identity between the BR-DR1 and BR-AL1 isolates was 97%. The BR-DR1 and BR-AL1 isolates had some conserved functional sites revealed by the fixed isolates, whereas both isolates had unique amino acid substitutions in the antigenic region IV of the nucleocapsid gene. Therefore, it is speculated that both isolates were nearly identical in virologic character. According to our phylogenetic analysis based on the complete genomes, both isolates belonged to genotype 1, and to the previously defined "vampire batrelated RABV lineage" which consisted of mainly D. rotundus-and A. lituratus-isolates; however, a branch pattern with high bootstrap values suggested that BR-DR1 was more closely related to the 9001FRA isolate, which was collected from a dog bitten by a bat in French Guiana, than to BR-AL1. This result suggests that the vampire bat-related RABV lineage includes Brazilian vampire bat and Brazilian frugivorous bat RABV and is further divided into Brazilian vampire bat and Brazilian frugivorous bat RABV sub-lineages. The phylogenetic analysis based on the complete genomes was valuable in discriminating among very closely related isolates.
Molecular characterization of rabies virus isolated from non-haematophagous bats in Brazil
Revista da Sociedade Brasileira de Medicina Tropical, 2011
Introduction: Rabies is an important zoonosis that causes thousands of deaths worldwide each year. Although the terrestrial cycle, mainly transmitted by dogs, is controlled in Brazil, the aerial cycle remains a serious public health issue, besides the economic problem. In the aerial cycle, the haematophagous bat Desmodus rotundus is the main source of infection, where several different species of non-haematophagous bats can be infected and can transmit the virus. Methods: The aim of this work was to study the epidemiological pattern of rabies using antigenic characterization with monoclonal antibodies and genetic characterization by reversetranscriptase polymerase chain reaction followed by sequencing and phylogenetic analysis of non-haematophagous bats' and herbivorous animals' central nervous system samples from the western region of the State of São Paulo, Brazil. Results: From 27 samples, 3 antigenic variants were identified: AgV-3, AgV-4, and AgV-6; and from 29 samples, 5 different clusters were identified, all belonging to the rabies virus species. Conclusions: Although only nonhaematophagous bats were evaluated in the studied region, the majority of samples were from antigenic and genetic variants related to haematophagous bats Desmodus rotundus. Samples from the same antigenic variant were segregated in more than one genetic cluster. This study demonstrated the diversity of rabies virus genetic lineages presented and circulating in nonhaematophagous bats in the studied region.
Genetic Characterization of Rabies Viruses Isolated from Frugivorous Bat (Artibeus spp.) in Brazil
Journal of Veterinary Medical Science, 2004
In Latin America, rabies cases related to frugivorous bats have been reported since 1930's. Recently, two viruses isolated from Artibeus lituratus were proved to be vampire bat variants by monoclonal antibodies panels [2], but their genetic information is not well known. In this report, four rabies viruses were isolated from frugivorous bats (Artibeus spp.) in Brazil and their nucleoprotein gene sequences were determined. These isolates were found to be genotype 1 of lyssavirus and showed the maximum nucleotide sequence homology of 97.6-99.4% with vampire bat-related viruses in Brazil [6]. These results indicate that the Brazilian frugivorous bat rabies viruses in this study are closely related to vampire bat-related viruses that play a main role in rabies virus transmission to livestock in Brazil.
Brazilian Journal of Microbiology, 2021
In Latin America, hematophagous bats are the main reservoirs of rabies virus (RABV) to livestock, to other mammals and, occasionally, to human. Nonetheless, reports of exposure of human and pets to RABV upon aggression by non-hematophagous bats are increasing, possibly facilitated by the synanthropic habits of these bats. We, herein, report the detection and genetic identification of a RABV recovered from an insectivorous bat found sick in a student housing building at the Federal University of Santa Maria, Southern Brazil. Taxonomic characterization identified the captured bat as a member of the genus Nyctinomops, family Molossidae, the group of insectivorous bats. Brain fragments of the bat were positive for RABV antigens by fluorescent antibody test (FAT) and for sequences of the nucleoprotein (N) gene by RT-PCR. The N amplicon was submitted to nucleotide sequencing and analysis, showing that the consensus sequences (SV 33/19) had high identity with RABV sequences of insectivorous bats deposited in GenBank. At phylogenetic tree, the N gene sequences of SV 33/19 clustered with RABV recovered from Nyctinomops laticaudatus, Molossus molossus, and Tadarida lauticaudata bats, and a part of RABV variant 3, 4, and 6, that correspond to Desmodus rotundus, Tadarida brasiliensis, and Lasiurus cinereus, respectively. Although no direct human or domestic animal exposure has been reported, this case strengthens the need for a continuous rabies vaccination in pets in the surrounding areas, since non-hematophagous bats may serve as source of infection for these animals. These findings also call attention for continuous monitoring of populations of synanthropic bats to avoid/prevent human exposure.
Virology, 2008
We genetically characterize rabies virus (RABV) strains isolated from human cases, domestic and wild animals during a human outbreak of bat-transmitted rabies in Augusto Correa municipality, Pará state, Brazilian Amazon in 2005. Partial nucleotide sequences of the N gene (491 bp) were obtained for all strains, and phylogenetic analysis grouped these into two major clades (Pará and Central-Southeast) and identified them as bat-related viruses genotype I, Desmodus rotundus antigenic variant 3 (AgV3). A molecular clock was used to estimate the time of emergence for each RABV isolate. The molecular data from this study suggest the association of vampire bats with human and domestic animal cases reported in the outbreak, the circulation of at least two predominant lineages in the Pará state, and also a geographic association to lineages dispersion.
2006
Bat rabies and its transmission to humans and other species in Mexico were investigated. Eighty-nine samples obtained from rabid livestock, cats, dogs, and humans in Mexico were studied by antigenic typing and partial sequence analysis. Samples were further compared with enzootic rabies associated with different species of bats in the Americas. Patterns of nucleotide variation allowed the definition of at least 20 monophyletic clusters associated with 9 or more different bat species. Several lineages associated with distinctive antigenic patterns were found in rabies viruses related to rabies in vampire bats in Mexico. Vampire bat rabies virus lineages associated with antigenic variant 3 are widely spread from Mexico to South America, suggesting these lineages as the most likely ancestors of vampire bat rabies and the ones that have been moved by vampire bat populations throughout the Americas. Rabies viruses related to Lasiurus cinereus, Histiotus montanus, and some other not yet identified species of the genus Lasiurus were found circulating in Mexico. Long-range dissemination patterns of rabies are not necessarily associated with migratory bat species, as in the case of rabies in Desmodus rotundus and Histiotus montanus. Human rabies was associated with vampire bat transmission in most cases, and in one case, rabies transmission from free-tailed bats was inferred. The occurrence of rabies spillover from bats to domestic animals was also demonstrated. Genetic typing of rabies viruses allowed us to distinguish trends of disease dissemination and to address, in a preliminary fashion, aspects of the complex evolution of rabies viruses in different host-reservoir species.
BMC Research Notes, 2010
Background: Vampire bat related rabies harms both livestock industry and public health sector in central Brazil. The geographical distributions of vampire bat-transmitted rabies virus variants are delimited by mountain chains. These findings were elucidated by analyzing a high conserved nucleoprotein gene. This study aims to elucidate the detailed epidemiological characters of vampire bat-transmitted rabies virus by phylogenetic methods based on 619-nt sequence including unconserved G-L intergenic region. Findings: The vampire bat-transmitted rabies virus isolates divided into 8 phylogenetic lineages in the previous nucleoprotein gene analysis were divided into 10 phylogenetic lineages with significant bootstrap values. The distributions of most variants were reconfirmed to be delimited by mountain chains. Furthermore, variants in undulating areas have narrow distributions and are apparently separated by mountain ridges.
Revista do Instituto de Medicina Tropical de São Paulo, 2008
Although the main transmitters of rabies in Brazil are dogs and vampire bats, the role of other species such as insectivorous and frugivorous bats deserves special attention, as the rabies virus has been isolated from 36 bat species. This study describes the first isolation of the rabies virus from the insectivorous bat Eumops perotis. The infected animal was found in the city of Ribeirão Preto, São Paulo. The virus was identified by immunofluorescence antibody test (FAT) in central nervous system (CNS) samples, and the isolation was carried out in N2A cell culture and adult mice. The sample was submitted to antigenic typing using a panel of monoclonal antibodies (CDC/Atlanta/USA). The DNA sequence of the nucleoprotein gene located between nucleotides 102 and 1385 was aligned with homologous sequences from GenBank using the CLUSTAL/W method, and the alignment was used to build a neighbor-joining distance-based phylogenetic tree with the K-2-P model. CNS was negative by FAT, and only one mouse died after inoculation with a suspension from the bat's CNS. Antigenic typing gave a result that was not compatible with the patterns defined by the panel. Phylogenetic analysis showed that the virus isolated segregated into the same cluster related to other viruses isolated from insectivorous bats belonging to genus Nyctinomops ssp. (98.8% nucleotide identity with each other).
Archives of Virology, 2010
Rabies virus (RABV) isolates from two species of canids and three species of bats were analyzed by comparing the C-terminal region of the G gene and the G-L intergenic region of the virus genome. Intercluster identities for the genetic sequences of the isolates showed both regions to be poorly conserved. Phylogenetic trees were generated by the neighbor-joining and maximum parsimony methods, and the results were found to agree between the two methods for both regions. Putative amino acid sequences obtained from the G gene were also analyzed, and genetic markers were identified. Our results suggest that different genetic lineages of RABV are adapted to different animal species in Brazil.