Experimental infectious bursal disease in the ostrich (Struthio camelus)

Clinically severe disease was produced in ostriches aged 4 weeks by oral infection with avirulent strain of infectious bursal disease virus (vIBDV), namely strain Faragher 52/70. Four days after infection the birds were humanely killed and tissue samples, including thymus, bursa of Fabricius (BF), brain and kidney were collected for examination. Histopathologically, the thymus and BF showed severe lymphoid depletion and necrosis, while immunolabelling with a polyclonal antibody demonstrated abundant viral antigen. (C) 2007 Elsevier Ltd. All rights reserved.

Effects of broiler breeder genetic, diet type, and feeding program on maternal antibody transfer and development of lymphoid tissues in chicken progeny

Maternal antibody (MatAb) transfer is important for early chicken survivability. Diet composition and the amount of feed given to breeder pullets during rearing may affect the development of immunity and the transfer of MatAb to progeny, and could affect progeny performance and resistance to disease. The effects of broiler breeder nutrition and feeding management practices were evaluated for the transfer of MatAb to progeny and for spleen and bursa development at hatching in 2 genetic strains (A and B). In this experiment, the levels of MatAb against Newcastle disease virus were assessed by enzyme-linked immunosorbent assays in serum samples taken of pedigreed chicken progeny from hatching to 13 d of age. Chickens were fed corn-and wheat-based diets, as were their parents. The breeder feeding program and diet type altered the Newcastle disease virus MatAb found in progeny at hatching and affected how long these antibodies were maintained in circulation. Bursal follicle size at hatching was influenced by an interaction among all factors evaluated. Percentage of white pulp in the spleen was affected mainly by genetic strain and diet type, but responses varied according to the breeder feeding program. It was concluded that breeder feeding programs influence MatAb transfer and half-life, and may also affect the early development of lymphoid tissues.

Araçatuba virus: A vaccinialike virus associated with infection in humans and cattle

We describe a vaccinialike virus, Araçatuba virus, associated with a cowpoxlike outbreak in a dairy herd and a related case of human infection. Diagnosis was based on virus growth characteristics, electron microscopy, and molecular biology techniques. Molecular characterization of the virus was done by using polymerase chain reaction amplification, cloning, and DNA sequencing of conserved orthopoxvirus genes such as the vaccinia growth factor (VGF), thymidine kinase (TK), and hemagglutinin. We used VGF-homologous and TK gene nucleotide sequences to construct a phylogenetic tree for comparison with other poxviruses. Gene sequences showed 99% homology with vaccinia virus genes and were clustered together with the isolated virus in the phylogenetic tree. Araçatuba virus is very similar to Cantagalo virus, showing the same signature deletion in the gene. Araçatuba virus could be a novel vaccinialike virus or could represent the spread of Cantagalo virus.

Use of reverse transcriptase polymerase chain reaction (RT-PCR) in molecular screening of Newcastle disease virus in poultry and free-living bird populations

The aim of this study was to evaluate a simple molecular method of reverse transcriptase polymerase chain reaction (RT-PCR) to differentiate Newcastle disease virus strains according to their pathogenicity, in order to use it in molecular screening of Newcastle disease virus in poultry and free-living bird populations. Specific primers were developed to differentiate LaSota-LS-(vaccine strain) and Sao Joao do Meriti-SJM-strain (highly pathogenic strain). Chickens and pigeons were experimentally vaccinated/infected for an in vivo study to determine virus shedding in feces. Validation of sensitivity and specificity of the primers (SJM and LS) by experimental models used in the present study and results obtained in the molecular analysis of the primers by BLAST made it possible to generalize results. The development of primers that differentiate the level of pathogenicity of NDV stains is very important, mainly in countries where real-time RT-PCR is still not used as a routine test. These primers were able to determine the presence of the agent and to differentiate it according to its pathogenicity. © 2012 Springer Science+Business Media B.V.

Virus-host interaction in feline immunodeficiency virus (FIV) infection

Feline immunodeficiency virus (FIV) infection has been the focus of several studies because this virus exhibits genetic and pathogenic characteristics that are similar to those of the human immunodeficiency virus (HIV). FIV causes acquired immunodeficiency syndrome (AIDS) in cats, nevertheless, a large fraction of infected cats remain asymptomatic throughout life despite of persistent chronic infection. This slow disease progression may be due to the presence of factors that are involved in the natural resistance to infection and the immune response that is mounted by the animals, as well as due to the adaptation of the virus to the host. Therefore, the study of virus-host interaction is essential to the understanding of the different patterns of disease course and the virus persistence in the host, and to help with the development of effective vaccines and perhaps the cure of FIV and HIV infections. © 2013 Elsevier Ltd. All rights reserved.

Presence of infectious agents and co-infections in diarrheic dogs determined with a real-time polymerase chain reaction-based panel

Background: Infectious diarrhea can be caused by bacteria, viruses, or protozoan organisms, or a combination of these. The identification of co-infections in dogs is important to determine the prognosis and to plan strategies for their treatment and prophylaxis. Although many pathogens have been individually detected with real-time polymerase chain reaction (PCR), a comprehensive panel of agents that cause diarrhea in privately owned dogs has not yet been established. The objective of this study was to use a real-time PCR diarrhea panel to survey the frequencies of pathogens and co-infections in owned dogs attended in a veterinary hospital with and without diarrhea, as well the frequency in different countries. Feces samples were tested for canine distemper virus, canine coronavirus, canine parvovirus type 2 (CPV-2), Clostridium perfringens alpha toxin (CPA), Cryptosporidium spp., Giardia spp., and Salmonella spp. using molecular techniques.Results: In total, 104 diarrheic and 43 control dogs that were presented consecutively at a major private veterinary hospital were included in the study. Overall, 71/104 (68.3%) dogs with diarrhea were positive for at least one pathogen: a single infection in 39/71 dogs (54.9%) and co-infections in 32/71 dogs (45.1%), including 21/32 dogs (65.6%) with dual, 5/32 (15.6%) with triple, and 6/32 (18.8%) with quadruple infections. In the control group, 13/43 (30.2%) dogs were positive, all with single infections only. The most prevalent pathogens in the diarrheic dogs were CPA (40/104 dogs, 38.5%), CPV-2 (36/104 dogs, 34.6%), and Giardia spp. (14/104 dogs, 13.5%). CPV-2 was the most prevalent pathogen in the dual co-infections, associated with CPA, Cryptosporidium spp., or Giardia spp. No statistical difference (P = 0.8374) was observed in the duration of diarrhea or the number of deaths (P = 0.5722) in the presence or absence of single or co-infections.Conclusions: Diarrheic dogs showed a higher prevalence of pathogen infections than the controls. Whereas the healthy dogs had only single infections, about half the diarrheic dogs had co-infections. Therefore, multiple pathogens should be investigated in dogs presenting with diarrhea. The effects of multiple pathogens on the disease outcomes remain unclear because the rate of death and the duration of diarrhea did not seem to be affected by these factors.

Molecular and phylogenetic characterization based on the complete genome of a virulent pathotype of Newcastle disease virus isolated in the 1970s in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Natural compounds isolated from Brazilian plants are potent inhibitors of hepatitis C virus replication in vitro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento e aplicação do Elisa indireto com a nucleoproteína recombinante (NPR) do vírus da doença de Newcastle

Pós-graduação em Medicina Veterinária - FCAV

Fluorescent antibody test, quantitative polymerase chain reaction pattern and clinical aspects of rabies virus strains isolated from main reservoirs in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of short-interfering RNAs treatment in experimental rabies due to wild-type virus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detection of serum antibodies to parainfluenza type 3 virus, respiratory syncytial virus, bovine viral diarrhea virus, and herpes virus type 1 in sheep in the region of Botucatu, São Paulo - Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Intramammary coinfection by vaccinia virus and staphylococcus aureus in a bovine vaccinia outbreak

Introduction: Bovine vaccinia virus (VACV) is a well-known zoonotic agent related to exanthemous lesions in skin and mucous membranes of dairy cattle and humans, characterized by the formation of vesicles, pustules and ulcers. Mastitis is one of the most common infectious diseases of dairy herds. Bovine mammary infections are caused mainly by bacterial microorganisms, especially staphylococci. To the best of our knowledge, intramammary coinfection with VACV and Staphylococcus aureus in cows has not been reported previously. Case presentation: During an outbreak of exanthematic bovine VACV infection with animals showing vesicles, pustules and haemorrhagic ulcers on the teats, milk samples were collected for mastitis detection. Conclusion: The present report describes a case of intramammary coinfection by VACV and S. aureus in a bovine VACV outbreak.