73 research outputs found
First detection of kobuvirus in farm animals in Brazil and the Netherlands.
Animal kobuviruses have been described in pigs, cattle, sheep and bats in countries in Asia and Europe. The virus can be detected in fecal and serum samples of infected animals with or without diarrhea, but most of the clinical as well as epidemiological features of kobuvirus infection are still unknown. This study reports the first detection of kobuvirus in farm animals from Brazil and the Netherlands and the molecular analysis of the detected strains. In Brazil, 53% (61/115) of the pigs (suckling, weaned and sows) were shedding porcine kobuvirus in feces, while in the Netherlands 16.7% (3/18) of the tested weaned pigs were infected. Kobuviruses detected in fecal samples of pigs in Brazil showed association (p = 0.0002) with diarrhea. In pig serum, kobuvirus was detected at different ages (3, 21, 36, 60, 75, and 180 days), with an overall rate of 76.7% (23/30). The sequencing of amplicons detected in serum of pigs of different ages suggested reinfection and no persistent infection. Kobuvirus was also detected in sheep and cattle feces from Brazil and the Netherlands, respectively. Phylogenetic analyses of Brazilian and Dutch kobuviruses from pig, cattle and sheep revealed genetic variability, particularly in one strain detected in sheep feces, which was more closely related to human Aichi virus. The molecular and phylogenetic analyses performed with other published kobuvirus strains and the strains presented in this study, showed that, in most of the cases, kobuvirus seems to group according to host species, but not to geographical region of origin. The data presented in this study contribute to the comprehension of kobuvirus epidemiology and also to the molecular identification of kobuvirus strains circulating worldwide
EFEITO ADJUVANTE DO CLORETO DE DIMETILDIOCTADECILAMÔNIO EM PREPARAÇÕES DE TOXÓIDE TETÂNICO
Foram formuladas duas vacinas contendo a mesma concentração de toxina,
com o intuito de se avaliar a habilidade do adjuvante cloreto de demetiloctadecilamônio
(DDA cloreto) em potencializar a resposta imune em cobaias imunizada com o toxóide
tetânico. A vacina A foi adsorvida com hidróxido de alumínio e a vacina B cmpreendia a
associação do hidróxido de alumínio e DDA cloreto. Os títulos de antitoxina no soro dos
cobaios imunizados foram quantificados por soroneutralização em camundongos frente a
uma dose contendo 1 Lp/10 (limite paralítico) de toxina tetânica. A inclusão do DDA cloreto
em vacinas constituídas por toxóide tetânico adsorvido com hidróxido de alumínio promoveu
maior ativação das respostas imunes humoral e celular de cobaios, quando comparada à
resposta imune dos animais que receberam o antígeno adsorvido apenas com o hidróxido
de alumínio. Os animais recebedores da vacina B apresentaram títulos de anticorpos
neutralizantes 2,66 vezes maiores que os que recebedores a vacina A, demonstrando a
potencialização da resposta imune humoral promovida pelo DDA cloreto. A resposta imune
celular, avaliada pela reação de hipersensibilidade cutânea tardia, foi 17,8 maior no grupo
B. Esses resultados demonstram que o DDA cloreto é um potente ativador da resposta
imune humoral e celular de cobaios imunizados com o toxóide tetânico.
Adjuvant effect of dimethyl dioctadecyl ammonium chloride in tetanic toxoid preparations
Abstract
Two vaccines were formulated with the same concentration of antigen and different
adjuvants to assess the performance of dimethyl dioctadecyl ammonium chloride (DDA chloride)
in boosting the immune response in guinea pigs immunized with tetanic toxoid. Vaccine A was
adsorbed with aluminum hydroxide and vaccine B contained an association of aluminum hydroxide
and DDA chloride. The antitoxin titres in the immunized guinea pig sera were assessed serum
neutralization in mice using a toxin containing one Lp/10 dose (paralytic limit). The inclusion of
DDA chloride in vaccines made up of tetanic toxoid adsorbed with aluminum hydroxide causes
a greater activation of the humoral and cell immune response in guinea pigs when compared
with the animals which received the antigen adsorbed only with aluminum hydroxide. The animals
which received vaccine B had 2.66 times more neutralizing antibodies than those which received
vaccine A, showing the boosting of the humoral immune response caused by DDA chloride. The
animals from group B also had a strong immune cell response by the delayed type hypersensitivity
reaction, which was 17.8 times higher than group A. These results show that DDA chloride is a
potent activator of the humoral and cell immune response in guinea pigs immunized with tetanic
toxoid
Bovine herpesvirus 1 and bovine viral diarrhea virus impact in the embryo transfer
A transferência de embriões bovinos é uma
biotécnica da reprodução animal, amplamente difundida
no Brasil, que tem possibilitado a produção de embriões
com alto potencial genético. Considerando a difusão
da técnica e o grande número de embriões gerados e
distribuídos, no aspecto sanitário, devem ser avaliados
os riscos da disseminação de agentes infecciosos da
esfera reprodutiva. O herpesvírus bovino 1, responsável
pela rinotraqueíte infecciosa bovina, e o vírus da diarréia
viral bovina, causador da diarréia viral bovina, são dois
vírus capazes de infectar embriões por meio das fêmeas
doadoras e/ou do material biológico relacionado à
técnica.The bovine embryo transfer is an animal
reproduction biotechnique widely diffused in Brazil that
has been allowing the production of embryos with high
genetic potential. Considering the technique diffusion and
the high number of produced and distributed embryos,
in the sanitary aspect its use in wide scale can
contribute with risks of infectious diseases
dissemination. Bovine herpesvirus 1 and bovine viral
diarrhea virus, respectively, the etiological agents of
the infectious bovine rhinotracheitis and bovine viral
diarrhea are two potential viruses able to infect
embryos through donator females and/or biological
materials related to the technique
DETERMINAÇÃO DO SEXO DE EMBRIÕES BOVINOS PRODUZIDOS IN VITRO: UMA REVISÃO DE MÉTODOS COM ÊNFASE PARA A PCR
The development of new animal
reproduction biotechniques has been provided the
obtaining of genetic improvement in cattle herds around
the world. Recently, the ascension of the in vitro
production (IVP) of bovine embryos provided important
development in the technology of bovine embryos.
Although being a consolidated technique, some studies
show disproportion between the sexes of calves born
by means of IVP, being the percentage of males higher
than the theoretically expected rate of 50% for each sex.
This inconvenient opened the perspective for the
development of methods for sex determination for the
embryos before the transference, once the production of
females is desirable in economic terms. This revision will
approach the advantages and disadvantages of the
invasive and non-invasive methods developed for the sex
determination in bovine embryos, with emphasis for PCR
assay that is the technique that displays the best results.O desenvolvimento de novas biotécnicas
em reprodução animal tem proporcionado incrementos
significativos no padrão genético de bovinos em todo o
mundo. A produção in vitro (PIV) de embriões bovinos
ocasionou um salto de qualidade na tecnologia da
produção de embriões. Embora a PIV seja uma técnica
consolidada, alguns estudos têm demonstrado uma
desproporção no sexo de embriões nascidos, onde a
porcentagem de embriões machos tem sido maior do
que a teoricamente esperada de 50% para cada um
dos sexos. Esse inconveniente abriu a perspectiva para
o desenvolvimento de métodos para a determinação
do sexo de embriões bovinos antes da transferência,
uma vez que os produtos do sexo feminino são
economicamente mais valorizados. A presente revisão
abordará as vantagens e desvantagens dos principais
métodos invasivos e não-invasivos, avaliados quanto ao
seu potencial de determinação do sexo de embriões
bovinos, com ênfase para a PCR que é a técnica que
tem apresentado os melhores resultados
Severe diarrhea outbreak in beef calves (Bos indicus) caused by G6P[11], an emergent genotype of bovine rotavirus group A
The episodes of diarrhea caused by neonatal bovine rotavirus group A (BoRVA) constitute one of the major health problems in the calf rearing worldwide. The main G (VP7) and P (VP4) genotypes of BoRVA strains involved in the etiology of diarrhea in calves are G6P[1], G10P[11], G6P[5], and G8P[1]. However, less frequently, other G and P genotypes have been described in BoRVA strains identified in diarrheic fecal samples of calves. This study describes the identification and molecular characterization of an emerging genotype (G6P[11]) in BoRVA strains involved in the etiology of a diarrhea outbreak in beef calves in a cattle herd of high production in extensive management system. The diarrhea outbreak, which showed high morbidity (60%) and lethality (7%) rates, occurred in calves (n= 384) Nelore (Bos indicus) up to 30-day-old from the State of Mato Grosso do Sul, Brazil. BoRVA was identified in 80% (16/20) of the fecal samples analyzed by polyacrylamide gel electrophoresis (PAGE) technique. In all PAGE-positive fecal samples were amplified products with 1,062-bp and 876-bp in the RT-PCR assays for VP7 (G type) and VP4 (VP8*) (P type) of BoRVA, respectively. The nucleotide sequence analysis of VP7 and VP4 genes of four wild-type BoRVA strains showed G6-III P[11]-III genotype/lineage. The G6P[11] genotype has been described in RVA strains of human and animal hosts, however, in calves this genotype was only identified in some cross-sectional studies and not as a single cause of diarrhea outbreaks in calves with high morbidity and lethality rates as described in this study. The monitoring of the G and P genotypes of BoRVA strains involved in diarrhea outbreaks in calves is important for both animal and public health by allowing the identification of the most frequent genotypes, the characterization of novel genotypes and to identify reassortments with genotypes described in animal and human hosts. The results of this study show the importance of the monitoring of the genotypes of BoRVA strains involved in episodes of bovine neonatal diarrhea as for characterization of frequency of occurrence and pathogenic potential of uncommon genotypes as for monitoring of the emergency of different BoRVA genotypes not included in commercial vaccines
Identification of canine papillomavirus type 1 (CPV1) DNA in dogs with cutaneous papillomatosis
Canine oral papillomavirus (COPV), also known as Canine Papillomavirus type 1 (CPV1), induces papillomas at the mucous membranes of the oral cavity and at the haired skin of dogs. The classification of Papillomavirus (PV) types is based on the L1 capsid protein and nucleotide sequence; so far, 14 CPV types have been described in several countries, but the molecular characterization of CPV in Brazil is lacking. This study investigated the presence of the PV in seven papillomas from four mixed breed dogs from Londrina/PR, Southern Brazil, by partial sequencing of the L1 gene. Seven exophytic cutaneous lesions were surgically removed and processed for histopathological and molecular characterization. Histopathology confirmed the lesions as viral papillomas due to typical histological features. Polymerase Chain Reaction (PCR) assay using the FAP59 and FAP64 primers targeted the L1 gene followed by sequence analysis of the amplicons identified CPV1 in all evaluated papilloma samples. This study represents the first description of CPV1 DNA associated with canine papillomatosis in Brazil
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