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Canine distemper virus (CDV) is a pathogen which affects members of the Canidae family, causing an acute, often fatal, systemic disease. CDV is an RNA virus of the family Paramyxoviridae that contains two envelope glycoproteins: F and HA. In this study, we focused on the envelope glycoprotein F as the main target for neutralizing antibodies produced after infection or vaccination. The complete coding region of the protein (60 kDa) was expressed in the methylotrophic yeast Pichia pastoris, obtained in a recombinant form and secreted to the culture medium. Later, to analyze its immunogenicity, the protein was combined with an oily adjuvant and used to inoculate mice. The results provide evidence supporting a potential application of this recombinant protein as a subunit vaccine.
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Porcine parvovirus (PPV) is one of many pathogens responsible for reproductive failure in pregnant sows. Several studies have reported the appearance of new PPV strains that differ from previous isolates both genetically and antigenically. Thus, the protective effects of commercially inactivated vaccines could not be complete. In South America, the information about PPV is limited. Thus, the aim of the present study was to detect and characterize the PPV strains present in 131 mummies or stillbirths from normal deliveries in sows from a commercial swine farm of Argentina that uses the commercial vaccine. PCR results showed that 17/131 were positive to PPV. Ten of these viruses were isolated and sequenced. All viruses were related to the PPV1 sequence (NADL-2), maintaining the amino acid differences in positions 436 (S-P) and 565 (R-K). This study is the first to report the isolation of PPV in Argentina and the results suggest that PPV can cross the placenta even in vaccinated sows, thus affecting some of the fetuses and being able to cause fetal death in sows without reproductive failure. The results also suggest that vaccination only reduces clinical signs and reproductive disorders and may thus not be a perfect tool to manage PPV infection. This study provides information that needs to be studied in depth to improve strategies to prevent and control PPV infection in swine farms.
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Equine arteritis virus (EAV) induces apoptosis in infected cells. Cell death caused by EAV has been studied mainly using three cell lines, BHK-21, RK-13 and Vero cells. The mechanism of apoptosis varies among cell lines and results cannot be correlated owing to differences in EAV strains used. We evaluated different markers for apoptosis in BHK-21, RK-13 and Vero cell lines using the Bucyrus EAV reference strain. Acridine orange/ethidium bromide staining revealed morphological changes in infected cells, while flow cytometry indicated the extent of apoptosis. We also observed DNA fragmentation, but the DNA ladder was detected at different times post-infection depending on the cell line, i.e., 48, 72 and 96 h post-infection in RK-13, Vero and BHK-21 cells, respectively. Measurement of viral titers obtained with each cell line indicated that apoptosis causes interference with viral replication and therefore decreased viral titers. As an unequivocal marker of apoptosis, we measured the expression of caspase-3 and caspases-8 and -9 as extrinsic and intrinsic markers of apoptosis pathways, respectively. Caspase-8 in BHK-21 cells was the only protease that was not detected at any of the times assayed. We found that Bucyrus EAV strain exhibited a distinctive apoptosis pathway depending on the cell line.
Assuntos
Apoptose/fisiologia , Equartevirus/patogenicidade , Células Vero , Replicação Viral/fisiologia , Animais , Linhagem Celular/virologia , Chlorocebus aethiops/virologia , Cricetinae , HaplorrinosRESUMO
Triatomines (Hemiptera, Reduviidae) are bloodsucking insects involved in the transmission of Trypanosoma cruzi, the causative agent of Chagas disease, an important public health problem in Latin America. The triatomine species found in sylvatic habitats generally play a limited epidemiological role compared to domestic species, but they may act as a reinfestation source of dwellings after insecticide spraying and have to be carefully considered in control strategies of Chagas disease transmission. The objectives of this work were to carry out a survey of the sylvatic triatomine species colonizing Furnariidae nests in a typical area of the Chaco region of Argentina during the winter and to study the parasites and natural enemies associated with the collected triatomines. Sixty-three triatomine specimens were collected from Furnariidae nests (Coryphistera alaudina and Phacellodomus sibilatrix) randomly selected within the study area. Fifty-four were identified as Psammolestes coreodes, seven as Triatoma platensis, and two as Triatoma infestans. Specimens of T. infestans and T. platensis were found in one nest. The first finding of instar nymphs of T. infestans x T. platensis in a sylvatic habitat is reported. For the first time, sylvatic collected specimens of T. platensis were found infected by T. cruzi. Triatoma virus was found in one Ps. coreodes specimen.
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Insetos Vetores/fisiologia , Triatominae/fisiologia , Animais , Argentina , Ecossistema , Feminino , Insetos Vetores/parasitologia , Masculino , Triatominae/parasitologia , Trypanosoma cruzi/patogenicidadeRESUMO
A semen sample from a stallion infected during the 2010 equine arteritis virus (EAV) outbreak was received for viral isolation prior to castration of the animal. The virus was identified using a polyclonal antibody immunofluorescence test. Reverse-transcription polymerase chain reaction (RT-PCR) was used to amplify a region of the GP5 gene with primers GL105F and GL673R. The PCR products were purified and sequences of both strands were determined in a MegaBACE™1000 with inner primers CR2 and EAV32. A phylogenetic dataset was built with the previously reported sequences of five strains isolated in Argentina, together with a group of selected sequences obtained from GenBank. The unrooted neighbour-joining tree was constructed using molecular evolutionary genetic analysis (MEGA) and bootstrap analyses were conducted using 1,000 replicate datasets. Evolutionary distances were computed using the maximum composite likelihood method. A NetNGlyc server analysis at the Technical University of Denmark (www.cbs.dtu.dk/services/NetNGlyc/) was used to predict N-glycosylation in GP5 sequences. The phylogenetic analysis revealed that the new strain GLD-LP-ARG), together with other strains previously isolated, belongs to the European group EU-1 but in a different branch. The new strain shows 99% nucleotide identity with strain Al1and 98.1% with the Belgian strain 08P178. Persistently infected stallions and their cryopreserved semen constitute a reservoir of EAV, which ensures its persistence in the horse population around the world. These findings reinforce the importance of careful monitoring of persistently infected stallions, as well as semen straws, by RT-PCR or test mating, in accordance with national regulations.
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Infecções por Arterivirus/veterinária , Equartevirus/isolamento & purificação , Doenças dos Cavalos/virologia , Sequência de Aminoácidos , Animais , Antígenos Virais/genética , Antígenos Virais/metabolismo , Argentina/epidemiologia , Infecções por Arterivirus/epidemiologia , Infecções por Arterivirus/virologia , Surtos de Doenças/veterinária , Equartevirus/genética , Regulação Viral da Expressão Gênica , Doenças dos Cavalos/epidemiologia , Cavalos , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismoRESUMO
Polymorphisms at Major Histocompatibility Complex (MHC) genes have been associated with resistance/susceptibility to infectious diseases in domestic animals. The aim of this investigation was to evaluate whether polymorphisms of the DRA gene the Equine Lymphocyte Antigen is associated with susceptibility to Equine Arteritis Virus (EAV) infection in horses in Argentina. The equine DRA gene was screened for polymorphisms using Pyrosequencing® Technology which allowed the detection of three ELA-DRA exon 2 alleles. Neither allele frequencies nor genotypic differentiation exhibited any statistically significant (P-values=0.788 and 0.745) differences between the EAV-infected and no-infected horses. Fisher's exact test and OR calculations did not show any significant association. As a consequence, no association could be established between the serological condition and ELA-DRA.
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Infecções por Arterivirus/veterinária , Equartevirus , Doenças dos Cavalos/genética , Complexo Principal de Histocompatibilidade/genética , Animais , Argentina/epidemiologia , Infecções por Arterivirus/epidemiologia , Infecções por Arterivirus/genética , Genótipo , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/virologia , Cavalos , Polimorfismo GenéticoRESUMO
We investigated the association of equine arteritis virus (EAV) infection and three short tandem repeat (STR) polymorphisms located within or in close proximity to equine lymphocyte antigen (ELA) region. We used a case-control design as a first approach before proceeding to select candidate genes. One hundred and sixty-five Silla Argentino horses were taken in 2002 from positive serological detections of EAV in Argentina, to determine whether STR genotypes were correlated to genetic susceptibility to EVA. Allele frequency distribution did not show significant differences between both groups (P = 0.0781). However, in particular alleles, Fisher exact test and odds ratio calculations showed significant values >1 for TKY08 and LEX52, and <1 for UM011, TKY08, LEX52 and VHL20. Interestingly, TKY08 STR is located in ELA class I region.
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Infecções por Arterivirus/genética , Equartevirus , Antígenos de Histocompatibilidade Classe I/genética , Doenças dos Cavalos/genética , Repetições de Microssatélites/genética , Polimorfismo Genético , Alelos , Animais , Argentina , Infecções por Arterivirus/imunologia , Frequência do Gene/genética , Frequência do Gene/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Doenças dos Cavalos/imunologia , Doenças dos Cavalos/virologia , Cavalos , Repetições de Microssatélites/imunologiaRESUMO
Argentinean Suid Herpesvirus 1 isolates were compared with reference strains and sequences available at GenBank and phylogenetically analyzed. A short fragment of the gE gene of the immunodominant epitopes was used for preliminary grouping of isolates by phylogenetic analysis. The analysis of the partial gC gene provided more precise genetic typing and segregation into the main genotypes I and II. Results confirmed that the Argentinean genotype I isolates predominate in our country. The topology of the partial gC gene was similar to that previously reported. The Argentinean type I isolates belonged to one cluster and grouped together with NIA-3 and American and Brazilian genotype I strains. However, the results obtained by the algorithms allow inferring that the Yamagata S-81 and Mer (genotype II) strains are grouped together.
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Herpesvirus Suídeo 1/classificação , Filogenia , Argentina , Sequência de Bases , Genótipo , Herpesvirus Suídeo 1/genética , Herpesvirus Suídeo 1/isolamento & purificação , Alinhamento de Sequência , Análise de Sequência de DNA , Proteínas do Envelope Viral/genéticaRESUMO
The genomic characterization of Suid herpesvirus 1 (SHV-1) isolates from Argentina was accomplished by restriction pattern analysis using the BamHI, BstEII and XhoI enzymes. Type II genome has been described only once in Argentina. This study revealed considerable homogeneity of BamHI endonuclease sites in all the strains analyzed, according to the number and size of the fragments. No deletion of BamHI fragment #7 among the Argentinean isolates suggests that these strains are wild-type. In addition, the main antigenic domain of glycoprotein E of all the Argentinean strains, as well as the reference strains and sequences available in the GenBank, were characterized. The similarity percent oscillated between 99 and 100%.
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Herpesvirus Suídeo 1/classificação , Herpesvirus Suídeo 1/isolamento & purificação , Argentina , HumanosRESUMO
Relatam-se o primeiro isolamento de herpesvirus canino 1 (CaHV-1) e a localização atípica das lesões vesiculares associadas a este vírus na Argentina. A amostra foi recuperada de lesões vesiculares, localizadas na parte interna da coxa direita, em uma fêmea de raça Labrador. A cadela tinha quatro anos de idade e era de propriedade privada. O primeiro diagnóstico foi realizado pela reação em cadeia da polimerase e, posteriormente, o vírus foi isolado e sua identificação confirmada por imunofluorescência indireta e pelo teste de neutralização viral.(AU)