ABSTRACT: This study describes the results of the sequencing and analysis of segments of Blocks II and III of the RNA polymerase L gene of Rabies virus isolates from different reservoir species of Brazil. The phylogenetic relations of the virus were determined and a variety of species-specific nucleotides were found in the analyzed areas, but the majority of these mutations were found to be synonymous. However, an analysis of the putative amino acid sequences were shown to have some characteristic mutations between some reservoir species of Brazil, indicating that there was positive selection in the RNA polymerase L gene of Rabies virus. On comparing the putative viral sequences obtained from the Brazilian isolates and other Lyssavirus, it was determined that amino acid mutations occurred in low-restriction areas. This study of the L gene of Rabies virus is the first to be conducted with samples of virus isolates from Brazil, and the results obtained will help in the determination of the phylogenetic relations of the virus.
Virus Genes 04/2012; 45(1):76-83. · 1.85 Impact Factor
ABSTRACT: Insectivorous bats are the main reservoirs of rabies virus (RABV) in various regions of the world. The aims of this study were to (a) establish genealogies for RABV strains from different species of Brazilian insectivorous bats based on the nucleoprotein (N) and glycoprotein (G) genes, (b) investigate specific RABV lineages associated with certain genera of bats and (c) identify molecular markers that can distinguish between these lineages. The genealogic analysis of N and G from 57 RABV strains revealed seven genus-specific clusters related to the insectivorous bats Myotis, Eptesicus, Nyctinomops, Molossus, Tadarida, Histiotus and Lasiurus. Molecular markers in the amino acid sequences were identified which were specific to the seven clusters. These results, which constitute a novel finding for this pathogen, show that there are at least seven independent epidemiological rabies cycles maintained by seven genera of insectivorous bats in Brazil.
Virology 09/2010; 405(2):352-60. · 3.35 Impact Factor
ABSTRACT: To identify the species of bats involved in maintaining the rabies cycle; to investigate the distribution of the rabies virus in the tissues and organs of bats and the time taken for mortality among inoculated mice.
From April 2002 to November 2003, bats from municipalities in the State of São Paulo were screened for the presence of the rabies virus, by means of direct immunofluorescence. The virus distribution in the bats was evaluated by inoculating mice and N2A cells with 20% suspensions prepared from fragments of different organs and tissues, plus the brain and salivary glands. The time taken for mortality among the mice was monitored daily, following intracerebral inoculation.
Out of the 4,395 bats received, 1.9% were found positive for the rabies virus. They belonged to ten genera, with predominance of insectivores. The maximum mean times taken for mortality among the mice following inoculation with brain and salivary gland material were 15.33+/-2.08 days and 11.33+/-2.30 days for vampire bats, 16.45+/-4.48 days and 18.91+/-6.12 days for insectivorous bats, and 12.60+/-2.13 days and 15.67+/-4.82 days for frugivorous bats, respectively.
The species infected with the rabies virus were: Artibeus lituratus, Artibeus sp., Myotis nigricans, Myotis sp., Eptesicus sp., Lasiurus ega, Lasiurus cinereus, Nyctinomops laticaudatus, Tadarida brasiliensis, Histiotus velatus, Molossus rufus, Eumops sp. and Desmodus rotundus. Virus investigation in the different tissues and organs showed that the brain and salivary glands were the most suitable sites for virus isolation.
Revista de Saúde Pública 07/2007; 41(3):389-95. · 1.33 Impact Factor
ABSTRACT: Rabies laboratorial diagnosis is very important since clinical diagnosis is not
precise. Fluorescent Antibody Test (FAT) is the most used test and even though
it is highly sensible, accurate and fast, false negatives results may occur. Thus,
the isolation of rabies virus in mice (VIM) of Central Nervous System (CNS)
samples of suspected animals to be infected is also recommended and,
nowadays, this test has been substituted in many laboratories by viral isolation
in cell culture (VICC). The aim of the present study was to compare the
sensibility of virus isolation in murine neuroblastoma (N2A) cell culture with VIM
test and with FAT, as well as evaluate obtained results in the diagnostic routine
from Pasteur Institute, regarding reduction of costs, time and work. A total of 105
CNS samples of different animal species were analyzed by FAT, VIM and VICC: 50 bats, 32 dogs, 13 foxes and 10 bovines. All bats and bovines
samples presented concordant results for the three tests, while dogs and
foxes samples presented concordance only in 24 samples (69%). Based on
these results, since 2004 it has been instituted that all bat samples sent to
Pasteur Institute Laboratory, after diagnosed by FAT, should be submitted to
viral isolation in cell culture, replacing the use of mice. In the period of January
2004 to September 2007, 11.298 bat samples were analyzed. A total of 67
positive samples for IFD and/or VICC were also submitted to VIM, and 61
samples presented concordant results for the three tests, and showed that
the use of N2A cells is more sensible to “street virus” isolation of bat samples
in laboratorial routine, being faster and lower in costs than VIM
Boletim Epidemiológico Paulista. 01/2007; 4(47):12-18.
ABSTRACT: 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).
Revista do Instituto de Medicina Tropical de São Paulo 50(2):95-9. · 1.00 Impact Factor