Avian Viral Diseases Research Articles

New oligonucleotide microarray for rapid diagnosis of avian viral diseases

BackgroundWe developed a new oligonucleotide microarray comprising 16 identical subarrays for simultaneous rapid detection of avian viruses: avian influenza virus (AIV), Newcastle disease virus (NDV), infection bronchitis virus (IBV), and infectious bursal disease virus (IBDV) in single- and mixed-virus infections. The objective of the study was to develop an oligonucleotide microarray for rapid diagnosis of avian diseases that would be used in the course of mass analysis for routine epidemiological surveillance owing to its ability to test one specimen for several infections.Methods and resultsThe paper describes the technique for rapid and simultaneous diagnosis of avian diseases such as avian influenza, Newcastle disease, infectious bronchitis and infectious bursal disease with use of oligonucleotide microarray, conditions for hybridization of fluorescent-labelled viral cDNA on the microarray and its specificity tested with use of AIV, NDV, IBV, IBDV strains as well as biomaterials from poultry.Sensitivity and specificity of the developed microarray was evaluated with use of 122 specimens of biological material: 44 cloacal swabs from sick birds and 78 tissue specimens from dead wild and domestic birds, as well as with use of 15 AIV, NDV, IBV and IBDV strains, different in their origin, epidemiological and biological characteristics (RIBSP Microbial Collection). This microarray demonstrates high diagnostic sensitivity (99.16% within 95% CI limits 97.36–100%) and specificity (100%). Specificity of the developed technique was confirmed by direct sequencing of NP and M (AIV), VP2 (IBDV), S1 (IBV), NP (NDV) gene fragments.ConclusionDiagnostic effectiveness of the developed DNA microarray is 99.18% and therefore it can be used in mass survey for specific detection of AIV, NDV, IBV and IBDV circulating in the region in the course of epidemiological surveillance. Rather simple method for rapid diagnosis of avian viral diseases that several times shortens duration of assay versus classical diagnostic methods is proposed.

Dual function of the hemagglutinin H5 fused to chicken CD154 in a potential strategy of DIVA against avian influenza disease: preliminary study

In this study we demonstrated that the vaccine candidate against avian influenza virus H5N1 based on the hemagglutinin H5 (HA) fused to the chicken CD154 (HACD) can also be used for differentiating infected from vaccinated animals (DIVA). As the strategy of DIVA requires at least two proteins, we obtained a variant of the nucleoprotein (NP49-375) in E. coli. After its purification by IMAC, the competence of the proteins NP49-375 and HACD as coating antigens in indirect ELISA assays were tested by using the sera of chickens immunized with the proteins HA and HACD and the reference sera from several avian influenza subtypes. Together with these sera, the sera from different species of birds and the sera of chickens infected with other avian viral diseases were analyzed by competition ELISA assays coated with the proteins NP49-375 and HACD. The results showed that the segment CD154 in the chimeric protein HACD did not interfere with the recognition of the molecule HA by its specific antibodies. Also, we observed variable detection levels when the reference sera were analyzed in the ELISA plates coated with the protein NP49-375. Moreover, only the antibodies of the reference serum subtype H5 were detected in the ELISA plates coated with the protein HACD. The competition ELISA assays showed percentages of inhibition of 88-91% for the positives sera and less than 20% for the negative sera. We fixed the cut-off value of these assays at 25%. No antibody detection was observed in the sera from different species of birds or the sera of chickens infected with other avian viral diseases. This study supported the fact that the ELISA assays using the proteins NP49-375 and HACD could be valuable tools for avian influenza surveillance and as a strategy of DIVA for counteracting the highly pathogenic avian influenza virus H5N1 outbreaks.

Serological Survey of Major Avian Viral Diseases Related with Egg Production in Commercial Chicken Flocks in Korea

While use of mass rearing systems improved poultry production, chances of exposing to contagious diseases have been increased, making flocks more vulnerable to diseases. Diseases of interest which affects egg production adversely include Low pathogenic avian influenza (LPAI), Infectious bronchitis (IB), Avian meta-pneumoviral infection (aMPV) and Egg drop syndrome’76 (EDS’76). This report collected and analyzed 5,385 serum samples, which were collected from 1,330 different chicken flock, provided by Chungbuk National University, Avian Disease Laboratory at 2009. Serums were analyzed based on rearing stages; 0∼1.3weeks (wks) (maternal antibody period), >1.3∼3 wks (starting period), >3∼10 wks (growing period), >10∼22 wks (developing period), >22∼40 wks (peak laying period), >40∼60 wks (late laying period) and over 60 wks (post-molting period). Results showed the 99.7% of the tested flocks were immunized against ND and73.8%, 97.1%, 78,2% and 78% of the flocks were immunized against other 4 agents (LPAI, IB, EDS’76, aMPV). Maternal antibody was transferred to enough quantity for NDV. Generally, antibody titers which were developed at 22 weeks were stabilized permanently for life. In case of IB and aMPV, infection titer emerged as early as 10 weeks and the titer was increased from 99.4% to 100% for life. EDS76 showed increase in titers, reflecting decreased frequency of vaccination programs. Overall, this study displayed general trends of major viral disease in layers, but considering the trend of development of preventive measures and evolution of pathogens, conducting serological surveys on a regular basis is important.

Role of Virus-Encoded microRNAs in Avian Viral Diseases

With total dependence on the host cell, several viruses have adopted strategies to modulate the host cellular environment, including the modulation of microRNA (miRNA) pathway through virus-encoded miRNAs. Several avian viruses, mostly herpesviruses, have been shown to encode a number of novel miRNAs. These include the highly oncogenic Marek’s disease virus-1 (26 miRNAs), avirulent Marek’s disease virus-2 (36 miRNAs), herpesvirus of turkeys (28 miRNAs), infectious laryngotracheitis virus (10 miRNAs), duck enteritis virus (33 miRNAs) and avian leukosis virus (2 miRNAs). Despite the closer antigenic and phylogenetic relationship among some of the herpesviruses, miRNAs encoded by different viruses showed no sequence conservation, although locations of some of the miRNAs were conserved within the repeat regions of the genomes. However, some of the virus-encoded miRNAs showed significant sequence homology with host miRNAs demonstrating their ability to serve as functional orthologs. For example, mdv1-miR-M4-5p, a functional ortholog of gga-miR-155, is critical for the oncogenicity of Marek’s disease virus. Additionally, we also describe the potential association of the recently described avian leukosis virus subgroup J encoded E (XSR) miRNA in the induction of myeloid tumors in certain genetically-distinct chicken lines. In this review, we describe the advances in our understanding on the role of virus-encoded miRNAs in avian diseases.

Ammonia Disinfection of Hatchery Waste for Elimination of Single-Stranded RNA Viruses

Hatchery waste, an animal by-product of the poultry industry, needs sanitation treatment before further use as fertilizer or as a substrate in biogas or composting plants, owing to the potential presence of opportunistic pathogens, including zoonotic viruses. Effective sanitation is also important in viral epizootic outbreaks and as a routine, ensuring high hygiene standards on farms. This study examined the use of ammonia at different concentrations and temperatures to disinfect hatchery waste. Inactivation kinetics of high-pathogenic avian influenza virus H7N1 and low-pathogenic avian influenza virus H5N3, as representatives of notifiable avian viral diseases, were determined in spiked hatchery waste. Bovine parainfluenza virus type 3, feline coronavirus, and feline calicivirus were used as models for other important avian pathogens, such as Newcastle disease virus, infectious bronchitis virus, and avian hepatitis E virus. Bacteriophage MS2 was also monitored as a stable indicator. Coronavirus was the most sensitive virus, with decimal reduction (D) values of 1.2 and 0.63 h after addition of 0.5% (wt/wt) ammonia at 14 and 25°C, respectively. Under similar conditions, high-pathogenic avian influenza H7N1 was the most resistant, with D values of 3.0 and 1.4 h. MS2 was more resistant than the viruses to all treatments and proved to be a suitable indicator of viral inactivation. The results indicate that ammonia treatment of hatchery waste is efficient in inactivating enveloped and naked single-stranded RNA viruses. Based on the D values and confidence intervals obtained, guidelines for treatment were proposed, and one was successfully validated at full scale at a hatchery, with MS2 added to hatchery waste.

Oral DNA vaccination with the polyprotein gene of infectious bursal disease virus (IBDV) delivered by attenuated Salmonella elicits protective immune responses in chickens

Our previous study showed that vaccination with plasmid DNA containing infectious bursal disease virus (IBDV) gene which encodes complete polyprotein (VP2/4/3) induced protective immune responses. In this study, we examined the efficacy of an oral DNA vaccine carrying the IBDV polyprotein antigen delivered by attenuated Salmonella enterica sv. Typhimurium ( S. typhimurium). The recombinant plasmid pCI-VP2/4/3 was transformed by electroporation into an attenuated S. typhimurium strain (Dam ̄ PhoP ̄) (designated hereafter as SV/pCI-VP2/4/3). The IBDV polyprotein gene was expressed in chicken embryo fibroblast (CEF) cells infected with strain SV/pCI-VP2/4/3, as shown by gene-specific RT-PCR and Western blot. Oral immunization of 7-day-old specific-pathogen-free (SPF) chickens with SV/pCI-VP2/4/3 elicited specific humoral responses as measured by ELISA. Vaccination with the strain SV/pCI-VP2/4/3 at 10 9 CFU per chicken offered 11/15 (73.3%) protection of the chickens against virulent IBDV challenge. Our results have implications in the development of DNA vaccines against avian viral diseases by bacteria-vectored oral delivery system.

Prevalence of antibodies to three avian viral diseases in guinea fowls in Ibadan, Nigeria

Prevalence of antibodies to three avian viral diseases in guinea fowls in Ibadan, Nigeria

Study Of Chick Embryo Vaccination Against Newcastle And Newcastle With Gumboro

This study is considered the first trail study in our country to apply In ovo-vaccination to immunize chicks against avian viral diseases. This method was conducted by using 150 chick embryos classified into three equal groups (50 embryo each group). The first group was inoculated with Newcastle disease virus-NDV (B1-strain). Second group was vaccineted with NDV. and GV( Gambaro virus). All vaccinated groups were inoculated in the amniotic sac, thethird group (control group) was inoculated with sterile phosphate buffered saline. Result should the both vaccine did not reveal any negative effect on the percentage of hatchability and liaviability of the vaccinated chicks.Hemagglutination inhibition (HI) , ELISA and challenge test were used to evaluate the level of immunity in chicks vaccinated with (NDV.) alone and (GV.) & (NDV.) double vaccine beside the control group chicks. The result revealed in spite of lower level of mean antibody titer of HI and ELISA in age of 28 days the two vaccinated group were resistant to challenge with virulent NDV. with 60% mortality rate in the control group.

In vivo macrophage activation in chickens with Acemannan, a complex carbohydrate extracted from Aloe vera

Acemannan (ACM 1), a β-(1,4) -acetylated mannan isolated from Aloe vera, can be used as an effective adjuvant in vaccination against some avian viral diseases. Our results demonstrate a quick and lasting in vivo priming effect of ACM 1 on macrophage response after intramuscular inoculation in chickens (500 μg per 2-month-old bird). In response to IFN-γ in vitro, monocytes from ACM 1-treated chickens exhibited a strong enhancement of NO production from 3 to 9 days p.i., but a weaker effect on MHC II cell surface antigen expression on day 3 p.i.. A stimulating effect of ACM 1 treatment was also observed on spontaneous and inducible NO production for splenocytes only on day 3 p.i.. By that time, splenocytes exhibited a strong higher capacity to proliferate in response to the T cell-mitogen PHA. At the same time, the in vivo capacity to produce NO, measured by the (NO − 2+NO − 3) serum level after intravenous LPS injection, increased greatly from 3 to 9 days p.i.. In conclusion, ACM 1 was able efficiently and durably to increase the activation capacity of macrophages from the systemic immune compartment (in particular from the blood and spleen after an intramuscular injection) in chickens, especially for NO production. These findings provide a better understanding of the adjuvant activity of ACM 1 for viral and tumoral diseases.

A Descriptive Analysis of the Potential Association between Migration Patterns of Bean and White-Fronted Geese and the Occurrence of Newcastle Disease Outbreaks in Domestic Birds

The sightings and migration patterns of 65 bean (Anser fabalis) and 65 white-fronted geese (Anser albifrons) are reported. In the past, these geese were serologically screened for the occurrence of Newcastle disease virus (NDV) and other avian viral diseases by Hlinak et al. (3). Of the 130 birds originally tagged and serologically screened in 1991, 53 birds were resighted between 1991 and 1996. Most of the sightings were reported from main wintering and resting sites in Germany and The Netherlands. It is noteworthy that 19 of the 53 birds sighted had serologic evidence that they had been exposed to NDV before the time of marking in 1991. Although the origin of these infections in bean geese and white-fronted geese is still unknown, the sightings reported in this study indicate that, once infected, wild geese may be involved in the dissemination and spread of avian viral diseases, specifically Newcastle disease. The migration patterns of the wild geese provided further evidence that the main resting and wintering areas of migratory waterfowl are likely to be important for the inter- and intraspecies transmission of avian diseases, thereby representing risk areas for the poultry industry.

An Egg Drop Associated with Splenomegaly in Broiler Breeders

A new disease in broiler breeders known in Australia as Big Liver and Spleen Disease (BLS) is described from field observations, retrospective record analysis, and detailed study of a selected flock. BLS has a predilection for adult birds. It is characterized clinically by a sudden drop in egg production, splenomegaly, hepatomegaly, and increased mortality and histologically by a period of lymphoproliferation followed by a period of lymphoid destruction that coincides with the clinical signs. Epidemiology suggests an infectious cause, though initial attempts at isolation of a causative agent have been unsuccessful, and it is serologically distinct from the common avian viral and mycoplasma diseases.

Microculture Neutralization Test for Serodiagnosis of Three Avian Viral Infections

Quantitative serologic assays are extremely important in diagnosis and control of many avian viral diseases. In recent years microculture methods for serologic analysis have come into frequent use. Microculture systems are generally less expensive and less time-consuming and require less of the specific serum and/or virus samples to be measured. The problem of most cell-culture techniques in use today is that they require a constant source of primary cells, such as specific-pathogen-free embryos or chicks. These sources are not only very expensive but require additional holding facilities. This paper describes a microsystem that uses a commercially available cell line for detecting avian viral antibodies, does not require a constant source of primary cells, and is therefore cheaper and less time-consuming than conventional microculture systems.