RESUMEN
To investigate the emergence and current situation of terrestrial rabies in Cuba, a collection of rabies virus specimens was employed for genetic characterization. These data supported the monophyletic nature of all terrestrial rabies viruses presently circulating in Cuba but additionally delineated several distinct variants exhibiting limited spatial distribution which may reflect the history of rabies spread on the island. The strain of rabies currently circulating in Cuba, which emerged on the island in the early 20th century, has very close evolutionary ties to the Mexican dog type and is a member of the cosmopolitan lineage widely distributed during the colonial period. The Cuban rabies viruses, which circulate predominantly within the mongoose population, are phylogenetically distant from viruses circulating in mongooses in other parts of the world. These studies illustrate, at a global level, the adaptation of multiple strains of rabies to mongoose species which should be regarded as important wildlife hosts for rabies re-emergence. Given the recent emergence of human cases due to bat contact in Cuba, this study also included a single insectivorous bat specimen which was found to most closely resemble the rabies viruses known to circulate in Mexican vampire bats.
Asunto(s)
Quirópteros/virología , Virus de la Rabia/clasificación , Virus de la Rabia/genética , Rabia/epidemiología , Rabia/virología , Animales , Cuba/epidemiología , Humanos , Epidemiología Molecular , Proteínas de la Nucleocápside/genética , Filogenia , ARN Viral/genética , Rabia/veterinaria , Virus de la Rabia/aislamiento & purificación , Zoonosis/virologíaRESUMEN
Fifty Brazilian rabies viruses, collected from many different animal species and several regions of the country, were characterized by partial sequencing of the central, variable region of the P gene, a locus useful for sensitive molecular epidemiological studies. Phylogenetic analysis of the sequences, which included comparison with other rabies strains recovered from throughout the Americas, identified three main groups of Brazilian viruses, arbitrarily designated BRL-1 to BRL-3. BRL-1 was found in terrestrial carnivores and clusters with other American strains of the cosmopolitan lineage. BRL-2 comprised two distinct isolates, recovered from two species of non-haematophagous bats, that had evolutionary links to insectivorous-bat-derived strains of North America. BRL-3 consisted of isolates from vampire bats and from livestock species probably infected via contact with vampire bats. The terrestrial group was further subdivided into three subtypes: BRL-1a was associated exclusively with dogs and cats, while BRL-1b and BRL-1c were found exclusively in hoary foxes. These observations strongly support the role of the Brazilian hoary fox as a rabies reservoir. Screening of representative Brazilian rabies viruses against a collection of anti-rabies monoclonal antibodies (mAbs) identified a small panel of mAbs that could be used to discriminate between all Brazilian subgroups as defined by genetic classification in this study.
Asunto(s)
Variación Antigénica/genética , Antígenos Virales/análisis , Reservorios de Enfermedades/veterinaria , Zorros/virología , Virus de la Rabia/aislamiento & purificación , Rabia/veterinaria , Animales , Animales Domésticos/virología , Animales Salvajes/virología , Brasil , Datos de Secuencia Molecular , Filogenia , Rabia/virología , Virus de la Rabia/clasificación , Virus de la Rabia/genética , Virus de la Rabia/inmunología , Zoonosis/virologíaRESUMEN
Automated indirect immunoperoxidase (avidin-biotin complex) staining using monoclonal antibody #5DF12-3B6, directed against rabies N-protein, was used to detect rabies antigen in tissue samples from animals either naturally or experimentally infected with rabies. This monoclonal antibody recognized all 16 strains of rabies virus tested, as well as rabies-related lyssaviruses including Duvenhage, Lagos Bat, and Mokola. The sample infected with Mokola virus initially showed only weak staining, however, deletion of protease digestion resulted in stronger stain uptake. The test was sensitive and specific, correctly identifying rabies antigen in all but one of the samples tested (37/38), and no apparent staining in any of the negative samples tested (23/23). Tissues from 16 mammalian species were tested, including one rabies infected human tissue sample. The utility of the immunoperoxidase staining method described in this study lies in the ability of one monoclonal to recognize a broad spectrum of lyssaviruses in formalin-fixed tissues.