As amostras foram agrupadas em BVDV-1 (11/19), BVDV-2 (6/19) e num terceiro grupo de amostras denominadas "atípicas" (2/ 19). Das onze amostras genotipadas como BVDV-1, oito amostras foram sub-genotipadas como BVDV-1a, enquanto que a maioria (4/6) das amostras de BVDV-2 foi agrupada como BVDV2b. Duas amostras provenientes de fetos bovinos abortados foram classificadas como atípicas, não BVDV-1 e 2. A presença da diversidade genética de BVDV detectada nas amostras estudadas pode ser responsável por falhas vacinais e de diagnóstico e deve influenciar nas estratégias de controle do BVDV aplicadas nas diferentes regiões brasileiras.TERMOS DE INDEXAÇÃO: BVDV-1, BVDV-2, Pestivirus, Brazil, análise filogenética. INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTIONInfections of cattle by bovine viral diarrhea virus (BVDV) are widespread cause of major economic losses to the cattle industry (Houe 1999). Clinical symptoms may involve the reproductive, respiratory, immune, and gastrointestinal systems, with signs that may range from disease with high mortality rates to asymptomatic infections. The latter is observed in most cases (Pellerin et al. 1994, Ridpath et al.1994, Baker 1995, Fray et al. 2000.BVDV is an enveloped RNA virus that belongs to family Flaviviridae, genus Pestivirus. The viral positive single stranded genome of approximately 12.5 kb in size contains a single open reading frame (ORF) flanked by two non-translating terminal regions, named 5' and 3'-UTR. The single ORF is directly translated and gives rise to a long polyprotein which is co-translationally cleaved, originating 10 to 12 mature viral proteins (Collet et al. 1988, Meyer et al. 1989.Isolates have been subdivided in genotypes BVDV-1 and BVDV-2. These were further split into subgenotypes.

No abstract

No abstract

No abstract

No abstract

No abstract

Thirty rabies virus isolates from cows and vampire bats from different regions of São Paulo State, Southeastern Brazil and three rabies vaccines were studied genetically. The analysis was based on direct sequencing of PCR-amplified products of 600 nucleotides coding for the amino terminus of nucleoprotein gene. The sequences were checked to verify their genealogical and evolutionary relationships and possible implication for health programmes. Statistical data indicated that there were no significant genetic differences between samples isolated from distinct hosts, from different geographical regions and between samples collected in the last two decades. According to the HKA test, the variability observed in the sequences is probably due to genetic drift. Since changes in genetic material may produce modifications in the protein responsible for immunogenicity of virus, which may eventually cause vaccine failure in herds, we suggest that continuous efforts in monitoring genetic diversity in rabies virus field strains, in relation to vaccine strains, must be conducted.

No abstract