1 Department of Preventive Veterinary Medicine and Animal Health, FMVZ-USP, Av. Professor Dr Orlando Marques de Paiva 87, 05508-000 Cidade Universitária, São Paulo-SP, Brazil
2 Rabies Centre of Expertise, Canadian Food Inspection Agency, Ottawa Laboratory-Fallowfield, 3851 Fallowfield Road, Ottawa, Canada K2H 8P9
3 Department of Veterinary Medicine - DMV, Centro de Saúde e Tecnologia Rural - CSTR, Federal University of Campina Grande, Caixa Postal 64, 58700-000 Patos-PB, Brazil
Correspondence
S. A. Nadin-Davis
nadindaviss{at}inspection.gc.ca
![]() |
ABSTRACT |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
The GenBank/EMBL/DDBJ accession numbers for the nucleotide sequences determined in this work are AY962047AY962096.
![]() |
INTRODUCTION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
To better understand rabies epidemiology, antigenic and genetic methods of virus characterization are being increasingly applied to collections of Latin American rabies viruses. Most antigenic methods of strain discrimination target the viral nucleoprotein, the product of the N gene, which is expressed in substantial quantities in infected tissues and exhibits sufficient antigenic variation that most strains can be distinguished. In particular, a panel of eight anti-N protein monoclonal antibodies (mAbs), which can differentiate between 11 distinct rabies virus variants harboured by a variety of terrestrial and chiropteran hosts, was reported (Diaz et al., 1994; Delpietro et al., 1997
). Application of this panel to rabies virus collections from many Latin American countries, including Brazil (Diaz et al., 1994
; Roehe et al., 1997
; Morais et al., 2000
; Favoretto et al., 2002
), has identified two major variants, associated with the dog and the vampire bat (Desmodus rotundus), as well as other variants associated with several insectivorous bats, including the free-tailed bat (Tadarida brasiliensis) and the hoary bat (Lasiurus cinereus). In the Ceará state of Brazil, yet another distinct rabies variant associated with a small non-human primate, Callithrix jacchus, commonly referred to as the white-tufted-ear marmoset, has been reported (Favoretto et al., 2001
). In some cases the classification of certain rabies virus isolates by this panel can be confounded by non-typical reactivity patterns not assigned to any known variant, as found for certain Argentinian rabies viruses (Cisterna et al., 2005
). The application of molecular genetic techniques for characterization of viral collections can assist in resolving such typing difficulties; moreover, nucleotide sequencing provides data amenable for prediction of the evolutionary relationships between strains. Several studies, targeting either partial or complete N gene sequences, have been reported for isolates from Brazil (Ito et al., 2001a
, b
, 2003
; Romijn et al., 2003
; Schaefer et al., 2005
), Chile (de Mattos et al., 2000
; Yung et al., 2002
), Colombia (Páez et al., 2003
) and Venezuela (de Mattos et al., 1996
). Another study on Brazilian rabies viruses targeted the more variable G gene, encoding the viral glycoprotein, and the highly variable GL intergenic region (Sato et al., 2004
). All these studies again identified two principal viral types, associated with dog and vampire-bat hosts, and also established the existence of other reservoirs in various species of insectivorous bats. Several species of rabid frugivorous bats of the genus Artibeus were found to harbour the viral strain normally associated with vampire bats, presumably via spillover from this reservoir (Shoji et al., 2004
).
In Brazil, rabies is still endemic in many parts of the country and 29 human rabies cases were reported in 2004 (Ministério Da Saúde, 2004). Up until a few years ago, transmission from dogs was the most frequent means of human exposure, but reports of bat-transmitted rabies are becoming increasingly common (Araújo, 2002
). Indeed, 22 of the human rabies deaths reported in 2004 occurred in the Amazonian state of Para, where the population reports frequent vampire-bat bites (www.promedmail.org, archive number 20040527.1428). In Brazil, diagnosis of animal rabies is conducted using the World Health Organization approved fluorescent antibody test (FAT) and the mouse inoculation test (MIT), by approved state laboratories under the supervision of public or animal health authorities. However, some Northern and North-Eastern states lack their own rabies diagnostic service, so specimens must be sent to laboratories located in other states (Gomes, 2004
), a situation that probably places significant limitations on rabies surveillance and diagnosis in these areas. Laboratory testing is performed primarily on domestic animals; wild animals or captive wild animals are tested only sporadically (OPAS, 2001), and so knowledge of the role of wildlife in maintaining rabies reservoirs is very limited.
The objectives of this study were twofold. First, we wished to examine the molecular epidemiology of vampire-bat rabies in Brazil to explore whether regional variation in isolates could be identified and thereby used to monitor disease spread. Second, we wished to compare isolates taken from domestic animals with those obtained from hoary foxes (Dusicyon vetulus). Up until recently, few positive cases of rabies were diagnosed in Brazilian hoary foxes (Barros et al., 1989), and it was thought that these cases were due to infection by dog bites. However, numerous individuals of this species from the state of Paraiba have recently been diagnosed as rabid, and the possible reservoir role played by this wild species was felt to be worthy of further investigation. To achieve these goals, a molecular epidemiological study of a collection of viruses from Brazil was undertaken by characterization of isolates at their P gene locus, a highly variable region of the genome that previously has been proven useful for sensitive viral typing and phylogenetic studies (Nadin-Davis et al., 2002
, 2003
). Finally, we sought to develop antigenic-typing tools that would allow for the rapid discrimination of rabies virus variants identified by genetic analysis.
![]() |
METHODS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
|
|
Nucleotide sequencing and phylogenetic analysis.
Purified PCR products were sequenced using a Li-Cor 4200L automated sequencing system, a Thermosequenase cycle sequencing kit (Amersham Biosciences) and custom infared (IR)-dye labelled primers (Li-Cor) corresponding in sequence to the nested PCR primers. A 528 bp region in the central part of the P gene was targeted. Eseq v2 software was used for base calling and, after manual review and editing, sequences were saved in FASTA format for subsequent alignment using CLUSTALX v1.8 (Thompson et al., 1997) and phylogenetic analysis using PHYLIP v3.63 (Felsenstein, 1993
). Trees were generated by a neighbour-joining algorithm as detailed previously (Nadin-Davis et al., 2002
), and presented graphically using TREEVIEW software (Page, 1996
).
Antigenic analysis.
Antigenic analysis was undertaken essentially as described previously using an indirect FAT applied to virus propagated in murine neuroblastoma cell culture (Nadin-Davis et al., 2001). Representative rabies viruses (see Table 2
) were grown in murine neuroblastoma cell culture and tested individually with 473 mAbs; most had anti-N specificity but a few were anti-P specific. Those mAbs exhibiting differential reactivities were further examined on all 50 Brazilian rabies samples, and a panel of 10 mAbs capable of differentiating the viruses represented by all phylogenetic clades was assembled.
|
![]() |
RESULTS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
|
The BRL-3 viruses represent the variant that circulates in Brazilian vampire bats with frequent spillover into domestic species, particularly livestock such as bovines and equines. Although this group could be further subdivided into several smaller clusters that segregated with moderate to strong bootstrap support, these subdivisions did not exhibit any obvious trends with respect to either temporal or regional localization of subtypes.
To place the Brazilian strains identified in this report into a more global context, selected viral sequences were compared with representative viruses from throughout the Americas in another phylogenetic analysis. As shown in Fig. 3, all of the BRL-3 viruses clustered within a clade that included vampire-bat rabies viruses from other Latin American countries (Paraguay and Mexico), and Trinidad in the Caribbean. The strongly supported monophyletic nature of this clade indicates that all these vampire-bat-derived viruses have a common origin and a progenitor shared with the free-tailed-bat-derived strain represented in this tree by the V235.FTB isolate from Texas. Notably there was no strong association of any Brazilian vampire-bat-derived isolates to a specific lineage within this clade, further indicating the lack of any clear regional variation within this strain. The two Brazilian insectivorous-bat-derived isolates (group BRL-2) again grouped together and within a region of the tree representing many insectivorous-bat-derived strains recovered primarily in Canada. While the Brazilian variants were not strongly associated with any particular variant from Canada, it is apparent that these viruses are evolutionarily more closely related to the North-American-bat-derived strains than to the vampire-bat-derived strain. The Brazilian BRL-1 viruses all clustered within a clade representing many terrestrial strains of the Americas, including dog-derived isolates from Peru, Paraguay and Mexico, the grey-fox- and coyote-derived strains from Texas in the USA, the western-Canadian-skunk-derived strain, and an isolate representative of mongoose rabies on the island of Puerto Rico. Samples of this clade were previously assigned to a grouping known as the cosmopolitan lineage (Nadin-Davis et al., 2002
).
|
![]() |
DISCUSSION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
In this study, phylogenetic analysis of a collection of Brazilian viruses employed the variable, central region of the P gene. Although the choice of genomic target employed for phylogenetic studies of lyssaviruses does not, in general, greatly impact on the general conclusions of the studies, greater variability within the database provides for a more robust and sensitive analysis, and hence, due to higher bootstrap values, more strongly supported conclusions. The central portion of the P gene is amongst the more variable coding regions of the lyssavirus genome (Le Mercier et al., 1997), second only to the region encompassing the 3' terminus (coding sense) of the G gene which, together with the contiguous, non-coding GL intergenic region, has been used for molecular epidemiological studies (Nel et al., 1997
; Páez et al., 2003
, 2005
). Similarly, use of the P gene for sensitive and robust phylogenetic studies has been previously reported (Nadin-Davis et al., 2003
). An extensive database of lyssavirus P gene sequences is now publicly available to provide comparative data (Nadin-Davis et al., 2002
). Moreover, due to the multifunctional nature of the lyssavirus P protein, including its ability to interact with host-cell proteins (Poisson et al., 2001
), exploration of structural variations that may confer some measure of host adaptation should be continued (Nadin-Davis et al., 2002
).
While two principal rabies cycles, maintained by dogs and vampire bats, have been well established in many parts of Latin America, including Brazil (Ito et al., 2001a), recent reports indicate that the situation is much more complex, particularly with respect to the role played by insectivorous bats, as reported in studies undertaken in Argentina and Chile (de Mattos et al., 2000
; Cisterna et al., 2005
), and also in Colombia (Páez et al., 2003
). Although this study did not focus on the role of insectivorous bats as rabies reservoirs, and our sample set included only two rabies isolates from non-haematophagous bats (H. velatus and M. molossus), which comprised group BRL-2, these isolates were quite distinct from all others, and apparently represented two different viral variants. In a continental context, these isolates were evolutionarily more closely related to specimens from North American insectivorous bats than to Brazilian vampire bats. Further isolation of viruses from these two chiropteran species will be necessary to establish these bats as the reservoirs of these rabies variants. However, it should be noted that a group of rabies isolates recovered from species of the genus Histiotus from Chile and Argentina, and which exhibited a distinctive antigenic profile, formed a monophyletic group that may represent a previously unidentified reservoir (Yung et al., 2002
; Cisterna et al., 2005
). The histiotus-derived specimen in this study may represent this same variant, but unfortunately, since the N gene was targeted in those earlier studies, direct comparison between those histiotus isolates and the one reported in this study was not possible. Moreover, a case of rabies in a M. molossus specimen in Colombia yielded a rabies variant that clearly segregated together with other rabies variants associated with insectivorous bats of the Americas (Páez et al., 2003
), thereby strengthening the possibility that this bat species may act as a rabies reservoir.
The Brazilian isolates representative of the vampire-bat-derived strain were relatively homogeneous, and clustered together with vampire-bat-derived isolates recovered from several other countries in Latin America and the Caribbean, an observation supporting the concept of a common origin of all isolates of this strain despite its extensive geographical range. Despite a fairly extensive sampling of this variant, no obvious temporal or spatial trends with regards to the emergence of Brazilian subvariants were identified. Additionally, no consistent differences in reactivity with a large mAb panel could be discerned for viruses of this group, supporting the conclusion that no clear regional variants of this strain circulate.
Spillover of a rabies virus strain from its reservoir host to other species is not uncommonly reported, as documented, for example, between wildlife in South Africa (Nel et al., 1997), for the raccoon rabies strain to skunks in the United States (Guerra et al., 2003
), and even more recently in Northern Colombia, where cases of rabies in humans, dogs and grey foxes were due to a single genetic variant (Páez et al., 2005
). In addition, there are multiple examples in the literature that clearly indicate the long-term emergence of independent cycles of disease in new reservoir hosts subsequent to such spillover events. For example, Bourhy et al. (1999)
presented evidence that during the westward movement of rabies across Europe during the early 20th century, rabies crossed species from the dog to become established in the red fox population. Johnson et al. (2003)
reported on the apparent recent transmission of rabies virus variants from dogs to foxes in Turkey, while the existence of two independent cycles of transmission involving foxes and domestic animals has been reported within the Federal Republic of Yugoslavia (Stankov, 2001
). Indeed, the present situation in Northern Colombia, which involves dogs and grey foxes, may represent the very initial stages of such a species jump, which, without intervention, might eventually lead to the emergence of a new fox-adapted strain.
Our genetic analysis of all Brazilian isolates of terrestrial-host origin (see Fig. 2) defined one major group (BRL-1) for which further division into three subgroups was strongly supported. All isolates recovered from domestic animals, including V986, which came from a dog of Paraiba state, belonged to subgroup BRL-1a, while subgroups BRL-1b and BRL-1c were associated exclusively with hoary foxes. Despite the limited number of isolates studied, these results clearly support the existence of genetically distinct strains of rabies, derived from a common ancestor, that now circulate independently in dogs and hoary foxes. The phylogenetic analysis presented in Fig. 3
indicates that the Brazilian BRL-1 rabies viruses cluster within the cosmopolitan lineage believed to have been introduced into the Americas during colonial times, probably by transportation of infected dogs from Europe (Nadin-Davis & Bingham, 2004
). Of the specimens included in this study, the isolate most closely related to the Brazilian viruses came from a dog in Paraguay, suggesting a common origin for the viruses circulating in these neighbouring countries. Notably the Brazilian fox-derived strain, represented by isolates V997 and V1001 in Fig. 3
, does not associate closely with the Texas grey-fox-derived strain, represented in this tree by isolate V224.FX, thereby suggesting that these two fox reservoirs have emerged independently from the progenitor of the cosmopolitan lineage. Our identification of the hoary fox of the Paraiba region of Brazil as a rabies reservoir maintaining a viral strain evolutionarily related to the urban rabies variant also circulating in Brazil thus appears to mirror situations reported elsewhere, particularly in Europe, where dog to fox transmission, followed by persistence in the wildlife reservoir, has been documented. While it cannot be inferred from our data whether these dog- and fox-derived strains were originally urban strains that were subsequently transmitted to the sylvatic reservoir, historically transmission from dog to fox appears to be the more common occurrence. The fact that the hoary fox plays a much more extensive role in the maintenance and dissemination of rabies in Brazil than was previously supposed has significant public health implications since in this region, where public awareness of rabies is low and animal vaccination rarely undertaken, hoary foxes are not infrequently raised as pets.
To maximize the effectiveness of rabies-control programmes, strain-typing regimens that identify the reservoirs responsible for disease outbreaks are an essential tool, and several methods currently exist. Genetic methods employing either PCR and nucleotide sequencing (Bordignon et al., 2005), strain-specific RT-PCR and restriction fragment length polymorphism analysis (Ito et al., 2003
), or multiplex PCR (Sato et al., 2005
) have all been applied to collections of Brazilian isolates. However, to date, these methods discriminate only between dog-related and vampire-bat-related virus variants, and these methods require specialized technical facilities and expertise. Systematic typing by genetic methods is time consuming and costly and, even in laboratories of developed countries, is performed on selected cases only. Routine application of antigenic-typing methods, employing a limited panel of mAbs in an indirect FAT procedure, is more practical, especially in developing countries. Thus, there is a need for a rational approach to the development of strain-typing methods in which genetic characterization of representative isolates can be used to direct the identification of mAbs exhibiting reactivity patterns that will differentiate between distinct rabies variants. Such an approach has been described here in which a panel of mAbs, capable of discriminating between the distinct Brazilian viral variants identified by genetic methods, was developed. In particular, the ability to discriminate between the fox- and dog-associated variants may be of considerable importance to future control efforts, where the roles of both species in the continued maintenance of the disease should be clearly established, and the range of the variant associated with fox populations needs to be better defined. The mAbs described here may be a useful addition to the current CDC mAb panel (Diaz et al., 1994
) being employed for strain discrimination. Indeed the utility of the mAbs described in this report to identify other rabies variants unavailable for these studies (e.g. isolates from the marmoset primate of the Ceará region that neighbours Paraiba state, and from other insectivorous bat species) should be the subject of future investigations.
![]() |
ACKNOWLEDGEMENTS |
---|
![]() |
REFERENCES |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Badrane, H. & Tordo, N. (2001). Host switching in Lyssavirus history from the chiroptera to the carnivore orders. J Virol 75, 80968104.
Barros, J. S., de Freitas, C. E. A. A. & de Sousa, F. S. (1989). Raiva em animais silvestres no Estado do Ceará particularmente na raposa (Dusicyon vetulus). Zoonoses Rev Int 1, 913.
Bordignon, J., Brasil-dos-Anjos, G., Bueno, C. R., Salvatiera-Oporto, J., Dávila, A. M. R., Grisard, E. C. & Zanetti, C. R. (2005). Detection and characterization of rabies virus in Southern Brazil by PCR amplification and sequencing of the nucleoprotein gene. Arch Virol 150, 695708.[CrossRef][Medline]
Bourhy, H., Kissi, B. & Tordo, N. (1993). Molecular diversity of the Lyssavirus genus. Virology 194, 7081.[CrossRef][Medline]
Bourhy, H., Kissi, B., Audry, L., Smreczak, M., Sadkowska-Todys, M., Kulonen, K., Tordo, N., Zmudzinski, J. F. & Holmes, E. C. (1999). Ecology and evolution of rabies virus in Europe. J Gen Virol 80, 25452557.
Cisterna, D., Bonaventura, R., Caillou, S. & 10 other authors (2005). Antigenic and molecular characterization of rabies virus in Argentina. Virus Res 109, 139147.[CrossRef][Medline]
Dean, D. J., Ableseth, M. K. & Atanasiu, P. (1996). The fluorescent antibody test. In Laboratory Techniques in Rabies, 4th edn, pp. 8895. Edited by F. X. Meslin, M. M. Kaplan & H. Koprowski. Geneva: World Health Organization.
Delpietro, H. A., Gury-Dhomen, F., Larghi, O. P., Mena-Segura, C. & Abramo, L. (1997). Monoclonal antibody characterization of rabies virus strains isolated in the River Plate Basin. Zentrabl Veterinaermed B 44, 477483.
De Mattos, C. A., De Mattos, C. C., Smith, J. S., Miller, E. T., Papo, S., Utrera, A. & Osburn, B. I. (1996). Genetic characterization of rabies field isolates from Venezuela. J Clin Microbiol 34, 15531558.[Abstract]
De Mattos, C. A., Favi, M., Yung, V., Pavletic, C. & De Mattos, C. C. (2000). Bat rabies in urban centers in Chile. J Wildl Dis 36, 231240.
Diaz, A. M., Papo, S., Rodriguez, A. & Smith, J. S. (1994). Antigenic analysis of rabies-virus isolates from Latin América and Caribbean. Zentralbl Veterinaermed B 41, 153160.
Favoretto, S. R., De Mattos, C. C., Morais, N. B., Alves Araújo, F. A. & De Mattos, C. A. (2001). Rabies in marmosets (Callithrix jacchus), Ceará, Brazil. Emerg Infect Dis 7, 10621065.[Medline]
Favoretto, S. R., Carrieri, M. L., Cunha, E. M. S., Aguiar, E. A. C., Silva, L. H. Q., Sodré, M. M., Souza, M. C. A. M. & Kotait, I. (2002). Antigenic typing of Brazilian rabies virus samples isolated from animals and humans, 1989-2000. Rev Inst Med Trop Sao Paulo 44, 9195.[Medline]
Felsenstein, J. (1993). PHYLIP: phylogeny inference package. (Version 3.52c), Department of Genome Sciences, University of Washington, Seattle, WA, USA.
Fooks, A. R. (2004). The challenge of new and emerging lyssaviruses. Expert Rev Vaccines 3, 333336.[CrossRef][Medline]
Gomes, A. A. B. (2004). Epidemiologia da raiva: caracterização de vírus isolados de animais domésticos e silvestres do semi-árido paraibano da região de Patos, Nordeste do Brasil. (Epidemiology of rabies: characterization of viruses isolated from domestic and wild animals of the semi-arid region of Patos, state of Paraíba, North-Eastern Brazil). 107 f. Doctorate in Veterinary Medicine thesis - Faculty of Veterinary Medicine and Zootechny, University of São Paulo, São Paulo.
Guerra, M. A., Curns, A. T., Rupprecht, C. E., Hanlon, C. A., Krebs, J. W. & Childs, J. E. (2003). Skunk and raccoon rabies in the eastern United States: temporal and spatial analysis. Emerg Infect Dis 9, 11431150.[Medline]
Ito, M., Arai, Y. T., Itou, T., Sakei, T., Ito, F. H., Takasaki, T. & Kurane, I. (2001a). Genetic characterization and geographic distribution of rabies virus isolates in Brazil: identification of two reservoirs, dogs and vampire bats. Virology 284, 214222.[CrossRef][Medline]
Ito, M., Itou, T., Sakai, T., Santos, M. F. C., Arai, Y. T., Takasaki, T., Kurane, I. & Ito, F. H. (2001b). Detection of rabies virus RNA isolated from several species of animals in Brazil by RT-PCR. J Vet Med Sci 63, 13091313.[CrossRef][Medline]
Ito, M., Itou, T., Shoji, Y., Sakai, T., Ito, F. H., Arai, Y. T., Takasaki, T. & Kurane, I. (2003). Discrimination between dog-related and vampire bat-related rabies viruses in Brazil by strain-specific reverse transcriptase-polymerase chain reaction and restriction fragment length polymorphism analysis. J Clin Virol 26, 317330.[CrossRef][Medline]
Johnson, N., Black, C., Smith, J., Un, H., McElhinney, L. M., Aylan, O. & Fooks, A. R. (2003). Rabies emergence among foxes in Turkey. J Wildl Dis 39, 262270.
Kissi, B., Tordo, N. & Bourhy, H. (1995). Genetic polymorphism in the rabies virus nucleoprotein gene. Virology 209, 526537.[CrossRef][Medline]
Koprowski, H. (1996). The mouse inoculation test. In Laboratory Techniques in Rabies, 4th edn, pp. 8087. Edited by F. X. Meslin, M. M. Kaplan & H. Koprowsky. Geneva: World Health Organization.
Krebs, J. W., Wheeling, J. T. & Childs, J. E. (2003). Rabies surveillance in the United States during 2002. J Am Vet Med Assoc 223, 17361748.[Medline]
Le Mercier, P., Jacob, Y. & Tordo, N. (1997). The complete Mokola virus genome sequence: structure of the RNA-dependent RNA polymerase. J Gen Virol 78, 15711576.[Abstract]
Ministério Da Saúde (2004). Programa nacional de profilaxia da raiva. Casos de raiva humana notificados, e percentual de casos transmitidos segundo a espécie animal. Brasília, 2004. Brazilian Ministry of Health annual disease report. http://portal.saude.gov.br/portal/svs/visualizar_texto.cfm?idtxt=21906
Morais, N. B., Rolim, B. N., Chaves, H. H. M., Brito-Neto, J. & Silva, L. M. (2000). Rabies in tamarins (Callithrix jacchus) in the State of Ceará, Brazil, a distinct viral variant? Mem Inst Oswaldo Cruz 95, 609610.[Medline]
Nadin-Davis, S. A. (1998). Polymerase chain reaction protocols for rabies virus discrimination. J Virol Methods 75, 18.[CrossRef][Medline]
Nadin-Davis, S. A. & Bingham, J. (2004). Europe as a source of rabies for the rest of the world. In Historical Perspective of Rabies in Europe and the Mediterranean Basin, pp. 259280. Edited by A. A. King, A. R. Fooks, M. Aubert & A. I. Wandeler. Paris: OIE Press.
Nadin-Davis, S. A., Huang, W., Armstrong, J., Casey, G. A., Bahloul, C., Tordo, N. & Wandeler, A. I. (2001). Antigenic and genetic divergence of rabies viruses from bat species indigenous to Canada. Virus Res 74, 139156.[CrossRef][Medline]
Nadin-Davis, S. A., Abdel-Malik, M., Armstrong, J. & Wandeler, A. I. (2002). Lyssavirus P gene characterization provides insights into the phylogeny of the genus and identifies structural similarities and diversity within the encoded phosphoprotein. Virology 298, 286305.[CrossRef][Medline]
Nadin-Davis, S. A., Simani, S., Armstrong, J., Fayaz, A. & Wandeler, A. I. (2003). Molecular and antigenic characterization of rabies viruses from Iran identifies variants with distinct epidemiological origins. Epidemiol Infect 131, 777790.[CrossRef][Medline]
Nel, L., Jacobs, J., Jaftha, J. & Meredith, C. (1997). Natural spillover of a distinctly canidae-associated biotype of rabies virus into an expanded wildlife host range in southern Africa. Virus Genes 15, 7982.[CrossRef][Medline]
Organización Pan-Americana de la Salud (OPAS) (2001). Boletín: vigilância epidemiológica de la rabia em las Américas. XXXIII, pp. 40. Rio de Janeiro: Organización Pan-Americana de la Salud.
Páez, A., Nnez, C., Garc
a, C. & Bóshell, J. (2003). Molecular epidemiology of rabies epizootics in Colombia: evidence for human and dog rabies associated with bats. J Gen Virol 84, 795802.
Páez, A., Saad, C., Nnez, C. & Bóshell, J. (2005). Molecular epidemiology of rabies in northern Colombia 1994-2003. Evidence for human and fox rabies associated with dogs. Epidemiol Infect 133, 529536.[CrossRef][Medline]
Page, R. D. M. (1996). TREEVIEW: an application to display phylogenetic trees on personal computers. Comput Appl Biosci 12, 357358.
Poisson, N., Real, E., Gaudin, Y., Vaney, M.-C., King, S., Jacob, Y., Tordo, N. & Blondel, D. (2001). Molecular basis for the interaction between rabies virus phosphoprotein P and the dynein light chain LC8: dissociation of dynein-binding properties and transcriptional functionality of P. J Gen Virol 82, 26912696.
Roehe, P. M., Pantoja, L. D., Shaefer, R., Nardi, N. B. & King, A. A. (1997). Analysis of Brazilian rabies isolates with monoclonal antibodies to lyssavirus antigens. Rev Microbiol 28, 288292.
Romijn, P. C., Van der Heide, R., Cattaneo, C. A., Silva, R. D. E. C. & Van der Poel, W. H. (2003). Study of lyssaviruses of bat origin as a source of rabies for other animal species in the State of Rio de Janeiro, Brazil. Am J Trop Med Hyg 69, 8186.
Sato, G., Itou, T., Shoji, Y. & 9 other authors (2004). Genetic and phylogenetic analysis of glycoprotein of rabies virus isolated from several species in Brazil. J Vet Med Sci 66, 747753.[CrossRef][Medline]
Sato, G., Tanabe, H., Shoji, Y., Itou, T., Ito, F. H., Sato, T. & Sakai, T. (2005). Rapid discrimination of rabies viruses isolated from various host species in Brazil by multiplex reverse transcription-polymerase chain reaction. J Clin Virol 33, 267273.[CrossRef][Medline]
Schaefer, R., Batista, H. B. R., Franco, A. C., Rijsewijk, F. A. M. & Roehe, P. M. (2005). Studies on antigenic and genomic properties of Brazilian rabies virus isolates. Vet Microbiol 107, 161170.[CrossRef][Medline]
Shoji, Y., Kobayashi, Y., Sato, G. & 10 other authors (2004). Genetic characterization of rabies viruses isolated from frugivorous bat (Artibeus spp.) in Brazil. J Vet Med Sci 666, 12711273.[CrossRef]
Stankov, S. (2001). Typing of field rabies virus strains in FR Yugoslavia by limited sequence analysis and monoclonal antibodies. Med Pregl 54, 446452.[Medline]
Thompson, J. D., Gibson, T. J., Plewniak, F., Jeanmougin, F. & Higgins, D. G. (1997). The Clustal_X windows interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Res 25, 48764882.
Tordo, N., Poch, O., Ermine, A., Keith, G. & Rougeon, F. (1986). Walking along the rabies genome: is the large G-L intergenic region a remnant gene? Proc Natl Acad Sci U S A 83, 39143918.
Tordo, N., Charlton, K. & Wandeler, A. (1998). Rhabdoviruses: rabies. In Topley and Wilson's Microbiology and Microbial Infections, pp. 666692. Edited by L. H. Collier. London: Arnold Press.
Velasco-Villa, A., Gómez-Sierra, M., Hernández-Rodríguez, G., Juárez-Islas, V., Meléndez-Félix, A., Vargas-Pino, F., Velázquez-Monroy, O. & Flisser, A. (2002). Antigenic diversity and distribution of rabies virus in Mexico. J Clin Microbiol 40, 951958.
Yung, V., Favi, M. & Fernández, J. (2002). Genetic and antigenic typing of rabies virus in Chile. Arch Virol 147, 21972205.[CrossRef][Medline]
Received 31 May 2005;
accepted 4 July 2005.
HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
J MED MICROBIOL | ALL SGM JOURNALS |