Evaluation of oral phytogenic microbeaded Newcastle Disease vaccine delivery in indigenous chicken.

This study describes the evaluation of microbeaded oral vaccine delivery for Newcastle Disease (ND) in village chicken. Microbeads containing vaccine were prepared by ionotropic-gelation technique using aluminum sulfate. Lasota Vaccine strain (2 g) was well mixed with Boswellia caterii gum extract at ratio 1:1. The wet beads were washed twice with distilled water and dried at 37℃ overnight. Microbeads without vaccine were prepared as control. A tablet dissolution machine was used to evaluate peak adhesion time (PAT). Sixty local chickens sourced from a recognized breeder were separated into four groups for in in-vivo evaluation. Group A was administered with the bead-loaded vaccine mixed with their feed, group B had vaccine alone administered in their drinking water, group C had the bead alone mixed with their feed, and group D, which served as negative control received no vaccination against ND nor gum beads.The PAT on both trachea and jejunum was 4 ± 10 hours. Post-vaccination antibody titer revealed higher response in group B than (6.6) in group A (5.3); the micro-beaded vaccine gave delayed but enhanced and prolonged immune response. This noninvasive and easy to administer method may be useful in the prevention of ND outbreaks in backyard poultry production.

Comparative Study of Protection against Newcastle Disease in Young Broilers Administered Natural Chicken Alpha Interferon via Oral and Intramuscular Routes.

Despite extensive vaccination approaches, Newcastle disease (ND) remains a permanent threat to the poultry industry worldwide. Besides vaccination, there is a burgeoning demand for new antivirals for use in interventions to control ND. One strategy is to strengthen the host innate immunity via host-derived innate immune proteins. Type I interferons define one of the first lines of innate immune defense against viral infections. Chicken interferon alpha (chIFN-α) is one of the potent cytokines that trigger antiviral responses. In the current study, we investigated the therapeutic effect of natural chIFN-α administered via oral and intramuscular (i.m.) routes against ND in broiler chickens. Our results showed that the level of protection against ND in response to chIFN-α therapy was dependent on the route and dose of IFN administration. A better therapeutic effect was observed in chickens treated with chIFN-α via the oral route than in those treated via the i.m. route. Regardless of the administration route, double-dose chIFN-α (2,000-U) treatments provided better protection than single-dose (1,000-U) treatments. However, complete protection against ND was achieved in birds treated with repeated doses of chIFN-α via the oral route. Histopathology of trachea, proventriculus, spleen, and liver showed a significant improvement in ND-induced degenerative changes in double-dose IFN-treatment groups compared to single-dose groups. Results of the hemagglutination test demonstrated a decrease in ND virus (NDV) titer in IFN-treated groups. Also, double doses of chIFN-α via oral route resulted in early recovery in weight gain. We propose that chIFN-α therapy via oral route could be an important therapeutic tool to control NDV infection in chicken.IMPORTANCE Newcastle disease (ND) is an economically important contagious disease of wild and domestic birds worldwide. The disease causes severe economic losses in terms of production due to high mortality and morbidity in nonvaccinated chickens. Despite extensive vaccination approaches, Newcastle disease (ND) remains a permanent threat to the poultry industry worldwide. In the current study, we used natural chicken IFN-α as an innate immune modulator to counteract ND in chickens. We report that chIFN-α is effective in protecting the chickens against ND and also prevents shedding of the virus, which can then prevent further spread of the disease. We propose that in addition to vaccination, chIFN-α therapy could be an effective option for controlling ND in areas of endemicity.

Generation and evaluation of a recombinant goose origin Newcastle disease virus expressing Cap protein of goose origin avastrovirus as a bivalent vaccine in goslings.

Currently, both goose astrovirus (GoAstV) and goose-origin Newcastle disease virus (NDV) are widely infectious agents for goslings. There is no vaccine for GoAstV. Capsid protein can elicit a neutralizing antibody in human astroviruses (HAstV). Molecular analysis of the genomic region encoding the capsid protein(ORF2) of goose astrovirus has revealed that it contains neutralizing epitopes. Goose-origin NDV is also an infectious agent. A wide range of NDV strains exist that can be commonly used as vaccine vectors. In the present study, the fusion protein cleavage site RRQKR↓F in a backbone of the virulent goose-origin NDV SH-12 was changed into an avirulent motif GRQGR↓L. The modified goose-origin NDV recombinant vaccine virus expressing the Capsid protein (Cap) of GoAstV was generated as a bivalent vaccine using a reverse-genetics approach. The recombinant virus, rNDV/GoAstV-Cap, was attenuated and similar growth dynamics, cytopathic effects, and virus titers in vitro were maintained when compared to the LaSota strain. Expression of the GoAstV-Cap protein in rNDV/GoAstV-Cap infected cells was detected by an immunofluorescence assay and Western blotting. Goslings inoculated with rNDV/GoAstV-Cap showed no apparent signs of disease and induced GoAstV-Cap-specific immune responses and NDV-specific serum antibody responses to a LaSota vaccination control. Complete protection against a pathogenic GoAstV challenge and avelogenic NDV challenge was conferred. The results of the study suggested that rNDV/GoAstV-Cap viruses have the potential to be the safe, stable, and effective bivalent vaccines.

Can genotype mismatch really affect the level of protection conferred by Newcastle disease vaccines against heterologous virulent strains?

Newcastle disease (ND), caused by virulent class II avian paramyxovirus 1 (Newcastle disease virus, NDV), occurs sporadically in poultry despite their having been immunized with commercial vaccines. These vaccines were all derived from NDV strains isolated around 70 years ago. Since then, class II NDV strains have evolved into 18 genotypes. Whether the vaccination failure results from genotype mismatches between the currently used vaccine strains and field-circulating velogenic strains or from an impaired immune response in the vaccination remains unclear. To test the first hypothesis, we performed a heterologous genotype II vaccine/genotype XI challenge in one-day old specific pathogen free (SPF) chicks and reproduced viral shedding. We then produced two attenuated strains of genotype II and XI by reverse genetics and used them to immunize two-week old SPF chickens that were subsequently challenged with velogenic strains of genotypes II, VII and XI. We found that both vaccines could induce antibodies with hemagglutination inhibition titers higher than 6.5 log2. Vaccination also completely prevented disease, viral shedding in swabs, and blocked viral replication in tissues from different genotypes in contrast to unvaccinated chickens that died shortly after challenge. Taken together, our results support the hypothesis that, in immunocompetent poultry, genotype mismatch is not the main reason for vaccination failure.

Characterisation of genotype VII Newcastle disease virus (NDV) isolated from NDV vaccinated chickens, and the efficacy of LaSota and recombinant genotype VII vaccines against challenge with velogenic NDV.

A Newcastle disease virus (NDV) isolate designated IBS002 was isolated from a commercial broiler farm in Malaysia. The virus was characterised as a virulent strain based on the multiple basic amino acid motif of the fusion (F) cleavage site (112)RRRKGF(117) and length of the C-terminus extension of the hemagglutinin-neuraminidase (HN) gene. Furthermore, IBS002 was classified as a velogenic NDV with mean death time (MDT) of 51.2 h and intracerebral pathogenicity index (ICPI) of 1.76. A genetic distance analysis based on the full-length F and HN genes showed that both velogenic viruses used in this study, genotype VII NDV isolate IBS002 and genotype VIII NDV isolate AF2240-I, had high genetic variations with genotype II LaSota vaccine. In this study, the protection efficacy of the recombinant genotype VII NDV inactivated vaccine was also evaluated when added to an existing commercial vaccination program against challenge with velogenic NDV IBS002 and NDV AF2240-I in commercial broilers. The results indicated that both LaSota and recombinant genotype VII vaccines offered full protection against challenge with AF2240-I. However, the LaSota vaccine only conferred partial protection against IBS002. In addition, significantly reduced viral shedding was observed in the recombinant genotype VII-vaccinated chickens compared to LaSota-vaccinated chickens.

Immune Response of Salmonella Challenged Broiler Chickens Fed Diets Containing Gallipro®, a Bacillus subtilis Probiotic.

This study was conducted to investigate the effect of feeding a probiotic, Bacillus subtilis, on antibody titers against Newcastle and infectious bursal viruses in broiler chickens challenged with Salmonella enterica serotype Enteritidis. One hundred and sixty 1-day-old broiler chicks were randomly assigned to four treatments in a completely randomized design. The treatments were negative control, probiotic-treated group, challenged group, and challenged probiotic treated group. Salmonella challenging decreased (P < 0.05) the relative weights of spleen and bursa. Inclusion of probiotic to diet of challenged chickens increased the relative weight of spleen, but had no effect on the relative weight of bursa. There were no differences for the antibody titers of chickens between negative control and probiotic-treated group. Salmonella challenging decreased (P < 0.05) antibody titers against Newcastle and infectious bursal viruses. Improvements in the antibody titers were observed by the addition of probiotic to diet of these chickens. The results showed that dietary inclusion of probiotic had no significant effect on immune parameters of chickens at non-contaminated environment, display a greater efficacy at environment contaminated with pathogen and can improve immune responses of infected chickens.

Induction of apoptosis in MCF-7 cells by the hemagglutinin-neuraminidase glycoprotein of Newcastle disease virus Malaysian strain AF2240.

Newcastle disease virus (NDV) exerts its naturally occurring oncolysis possibly through the induction of apoptosis. We hypothesized that the binding of the virus to the cell via the hemagglutinin-neuraminidase (HN) glycoprotein may be sufficient to not only induce apoptosis but to induce a higher apoptosis level than the parental NDV AF2240 virus. NDV AF2240 induction of apoptosis in MCF-7 human breast cancer cells was analyzed and quantified. In addition, the complete HN gene of NDV strain AF2240 was amplified, sequenced and cloned into the pDisplay eukaryotic expression vector. HN gene expression was first detected at the cell surface membrane of the transfected MCF-7 cells. HN induction of apoptosis in transfected MCF-7 cells was analyzed and quantified. The expression of the HN gene alone was able to induce apoptosis in MCF-7 cells but it was a less potent apoptosis inducer compared to the parental NDV AF2240 strain. In conclusion, the NDV AF2240 strain is a more suitable antitumor candidate agent than its recombinant HN gene unless the latter is further improved by additional modifications.

Synergistic effects of adjuvants interferon-gamma and levamisole on DNA vaccination against infection with Newcastle disease virus.

Both humoral and cell-mediated immune responses are important to protect animals from initial acute viral infection and establishment of chronic infection. Adjuvants for DNA vaccines can influence the balance between humoral and cell-mediated immunities. In this study, a DNA vaccine encoding the hemagglutinin-neuraminidase and fusion genes of Newcastle disease virus (NDV) incorporated with chicken interferon(provax-chIFN-gamma) cDNA as a molecular adjuvant and levamisole (LMS) as a chemical adjuvant was tested for its efficacy in protection against NDV lethal challenge. Compared with DNA vaccine alone, the DNA vaccine with provax-chIFN-gamma plus LMS induced significantly higher humoral and cell-mediated responses, as shown by higher levels of hemagglutination inhibition (HI) titers and T cell proliferation. In addition, the DNA vaccine with provax-chIFN-gamma plus LMS formulation increased the expression of IFN-gamma, interleukin (IL)-2, IL-4, IL-12, and IL-13, suggesting that the effectiveness of the IFN-gamma and LMS formulation is partly due to the enhancement of balanced cytokine production. Furthermore, the two adjuvants yielded 80% protection in chickens against challenge with a lethal dose of the virulent NDV strain. This study demonstrates that the synergistic effects of provax-chIFN-gamma plus LMS as the adjuvants in NDV DNA vaccination could be used to improve protective efficacy in chickens.

Medical dilemmas associated with rehabilitating confiscated houbara bustards (Chlamydotis undulata macqueenii) after avian pox and paramyxovirus type 1 infection.

Projects to rehabilitate confiscated animals must carefully consider the risks of disease when determining whether to release these animals back into the wild or to incorporate them into captive breeding programs. Avipox and paramyxovirus type 1 (PMV-1) infections are important causes of morbidity and mortality during rehabilitation of confiscated houbara bustards (Chlamydotis undulata macqueenii). This paper presents key findings of an intensive health monitoring program (physical condition, hematology, serology, endoscopy, microbiology, and virology) of two flocks of houbara bustards that survived outbreaks of septicemic avipox and PMV-1 respectively. Mortality in each flock from avipox and PMV-1 infections were 47% and 25% respectively, and the clinicopathologic features and management of each outbreak are presented. Avipox and PMV-1 viruses were not isolated from surviving birds monitored monthly for 11 mo after initial infection nor were septicemic or diptheritic avipox and PMV-1 infections detected in the captive breeding collection into which surviving birds were ultimately integrated up to 24 mo later. Adenovirus was isolated from four birds during the study demonstrating that novel disease agents of uncertain pathogenicity may be carried latently and intermittently shed by confiscated birds. This paper demonstrates the risk of importing pathogens with illegally traded houbara bustards and reinforces the need for surveillance programs at rehabilitation centers for these birds. We recommend that confiscated houbara bustards integrated into captive breeding programs be managed separately from captive-bred stock. Other measures should include separate facilities for adult birds and rearing facilities for offspring derived from different stock lines and strict sanitary measures. Additionally, health monitoring of confiscated birds should continue after birds are integrated into captive flocks.

Tratamiento homeopático en un lote de pollos parrilleros afectados de Enfermedad de Newcastle / Homeopathic treatment in a lot of toasted chicken with Newcastle disease

Dos lotes de igual edad de pollos parrilleros se afectan de enfermedad de Newcastle (enfermedad aguda viral, con tres tipos de sintomatología: digestiva, respiratoria y nerviosa, altamente contagiosa). Uno de los lotes es tratado con terapéutica homeopática, mientras el otro lo fue con un procedimiento convencional. Se evalúan los resultados (AU)

Tratamiento homeopático en un lote de pollos parrilleros afectados de Enfermedad de Newcastle / Homeopathic treatment in a lot of toasted chicken with Newcastle disease

Dos lotes de igual edad de pollos parrilleros se afectan de enfermedad de Newcastle (enfermedad aguda viral, con tres tipos de sintomatología: digestiva, respiratoria y nerviosa, altamente contagiosa). Uno de los lotes es tratado con terapéutica homeopática, mientras el otro lo fue con un procedimiento convencional. Se evalúan los resultados

Experiences in the search for anti-inflammatory agents of microbial origin.

Whole shaken cultures of 20 random, unidentified actinomycetes were extracted with n-butanol at pH 4.5, 7.0 and 8.5, respectively. Residues of butanol-extractable materials (BXM) were reconstituted (100X) in buffers and freeze-dried. BXM were surprisingly well tolerated in animals and were screened against influenza A viral pneumonia in mice. One culture yielded BXM-80 which suppressed both chemical (LPS) and viral (NDV) pneumonia in mice as well as inhibited rat foot pad edema induced by carrageenin. Aspirin, Butazolidin, hydrocortisone, indomethacin, and prednisolone, which are known to inhibit carrageenin-induced rat foot pad edema were tested against chemical (LPS) and viral (NDV) pneumonia in mice. Only hydrocortisone and prednisolone suppressed LPS pneumonia. All of these 5 compounds failed to inhibit NDV pneumonia. Microbial products are suggested as a source for new and unique anti-inflammatory agents.