No abstract

Here we present the complete genomic sequence of bovine herpesvirus 5 (BHV-5), an alphaherpesvirus responsible for fatal meningoencephalitis in cattle. The 138,390-bp genome encodes 70 putative proteins and resembles the ␣2 subgroup of herpesviruses in genomic organization and gene content. BHV-5 is very similar to BHV-1, the etiological agent of infectious bovine rhinotracheitis, as reflected by the high level of amino acid identity in their protein repertoires (average, 82%). The highest similarity to BHV-1 products (>95% amino acid identity) is found in proteins involved in viral DNA replication and processing (UL5, UL15, UL29, and UL39) and in virion proteins (UL14, UL19, UL48, and US6). Among the least conserved (<75%) are the homologues of immediate-early (IE) proteins BICP0, BICP4, and BICP22, the three proteins being longer in BHV-5 than in BHV-1. The structure of the BHV-5 latency-related (LR) region departs markedly from that of BHV-1 in both coding and transcriptional regulatory regions. Given the potential significance of IE genes and the LR region in virus-neuron interactions, it is likely these differences contribute to BHV-5 neuropathogenicity.

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Achados epidemiológicos, clínicos, patológicos e microbiológicos de 13 casos de meningoencefalite necrosante pelo Herpesvírus Bovino (BHV), afetando 12 rebanhos bovinos ocorridos no período de março de 1999 a agosto de 2000 em 11 municípios do Estado de Mato Grosso são descritos. Onze surtos ocorreram em sistemas de criação extensiva, afetando com maior freqüência animais da raça nelore, e idade média de 24 meses com uma variação de dois a 72 meses. Os principais sinais clínicos descritos foram as alterações neurológicas, sendo relatados salivação profusa, descarga nasal e ocular serosa, depressão profunda, incoordenação, andar a esmo ou em círculo, cegueira, diminuição do tonus lingual, decúbito lateral com movimentos de pedalagem, opistótono e morte. Ausência de alterações foi o relato mais comum durante a necropsia. Em alguns casos, observou-se congestão encefálica difusa, hemorragias submeningeanas multifocais, achatamento de circunvoluções cerebrais e áreas focais de malacias. Os principais achados microscópicos foram meningoencefalite com corpúsculos de inclusão eosinofílicos, intranucleares em astrócitos. As áreas de malacia afetavam principalmente o córtex cerebral. Foi realizado isolamento e caracterização viral em três de um total de sete amostras encaminhadas Em um dos casos, dos que houve isolamento viral, o diagnóstico histopatológico foi de polioencefalomalacia não se observando meningoencefalite e corpúsculos de inclusão.

Flores, Eduardo F.; Ridpath, Julia F.; Weiblen, Rudi; Vogel, Fernanda S. F.; and Gil, Laura H.V.G., "Phylogenetic analysis of Brazilian bovine viral diarrhea virus type 2 (BVDV-2) isolates: evidence for a subgenotype within BVDV-2" (2002 AbstractPhylogenetic analysis divides bovine viral diarrhea viruses (BVDV) into two different genotypes (BVDV1 and BVDV2). BVDV1 strains have been further subdivided into two to 11 subgenotypes. Phylogenetic analysis of BVDV2 isolates, however, has not been able to identify discrete subgenotypes. In this study, we identified six South American BVDV2 strains and one North American BVDV2 strain that cluster to a separate genetic group within BVDV2, thus representing a distinct subgenotype. The 5% untranslated region (UTR) sequence homology between these six strains and other BVDV2 from North America, Europe and Asia (81.7%) is lower than the homology used to segregate BVDV1 into BVDV1a and BVDV1b (83.6%). Most nucleotide differences observed between the two subgroups of BVDV2 were concentrated in two regions, which also harbor most of the differences seen between BVDV1a and BVDV1b. To determine if this segregation was real, an additional analysis was performed comparing NS2/3 sequences. Analysis of a conserved sequence located between nucleotides 6670 and 7186 of the NS2/3 coding region also segregated these isolates to a separate group. The sequence homology between the two subgroups (86.3%) was higher than the homology in the 5%UTR (81.7%), with mean sequence homologies of 91 and 87.2% within the proposed subgroups. In contrast to the 5%UTR, alignment of the NS2/3 sequences revealed nucleotide differences distributed across the region. These results demonstrate that BVDV2 isolates cluster to two genetically distinct subgroups within BVDV2. The differences in both the 5%UTR and NS2/3 are consistent and justify this segregation. We suggest that BVDV2 may thereafter be subgenotyped into BVDV2a and BVDV2b. The existence of subgroups within the BVDV2 genotype with genetic heterogeneity similar to that seen among BVDV1 subgroups argues against BVDV2 isolates arising from BVDV1 in a recent evolutionary event. Unless the evolutionary clocks for BVDV1 and BVDV2 isolates tick along at different rates, these results indicate that BVDV2 have existed as long as BVDV1.

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Mexican oregano (Lippia graveolens) is a plant found in Mexico and Central America that is traditionally used as a medicinal herb. In the present study, we investigated the antiviral activity of the essential oil of Mexican oregano and its major component, carvacrol, against different human and animal viruses. The MTT test (3-4,5-dimethythiazol-2yl)-2,5-diphenyl tetrazolium bromide) was conducted to determine the selectivity index (SI) of the essential oil, which was equal to 13.1, 7.4, 10.8, 9.7, and 7.2 for acyclovirresistant herpes simplex virus type 1 (ACVR-HHV-1), acyclovir-sensitive HHV-1, human respiratory syncytial virus (HRSV), bovine herpesvirus type 2 (BoHV-2), and bovine viral diarrhoea virus (BVDV), respectively. The human rotavirus (RV) and BoHV-1 and 5 were not inhibited by the essential oil. Carvacrol alone exhibited high antiviral activity against RV with a SI of 33, but it was less efficient than the oil for the other viruses. Thus, Mexican oregano oil and its main component, carvacrol, are able to inhibit different human and animal viruses in vitro. Specifically, the antiviral effects of Mexican oregano oil on ACVR-HHV-1 and HRSV and of carvacrol on RV justify more detailed studies.

The genus Pestivirus is composed of 4 important pathogens of livestock: Bovine viral diarrhea virus 1 and 2 (BVDV-1 and BVDV-2), Classical swine fever virus (CSFV), and Border disease virus of sheep (BDV). BVDV are major pathogens of cattle, and infection results in significant economic loss worldwide. A new putative pestivirus species, tentatively called “HoBi-like,” “BVDV-3,” or “atypical pestiviruses,” was first identified in Europe in fetal bovine serum (FBS) imported from Brazil. HoBi-like viruses are related to BVDV at the genetic and antigenic levels. Further, the disease caused by these new viruses resembles clinical presentations historically associated with BVDV infection, including growth retardation, reduced milk production, respiratory disease, reduced reproductive performance, and increased mortality among young stock. Current BVDV diagnostic tests may fail to detect HoBi-like viruses or to differentiate between BVDV and HoBi-like viruses. Further, commercial tests for BVDV exposure, based on serological response, do not reliably detect HoBi-like virus exposure, and cross protection against HoBi-like viruses conferred by current BVDV vaccines is likely limited. As many HoBi-like viruses, characterized to date, were isolated from FBS originating from Brazil, it is assumed that the agent is probably widespread in Brazilian herds. Nevertheless, reports of natural infection in Southeast Asia and Europe demonstrate that these viruses are not restricted to South America. Increased demand for FBS has led to widespread distribution of FBS originating in HoBi-like virus endemic regions. The contamination of such FBS with HoBi-like viruses may lead to spread of this virus to other regions.