Complete Genome Sequences of Avian Metapneumovirus Subtype B Vaccine Strains from Brazil

Avian metapneumovirus (aMPV) causes a highly contagious upper respiratory and reproductive disease in chickens, turkeys, and ducks. Here, complete genome sequences of aMPV-B vaccine strains BR/1890/E1/19 (PL21, Nemovac; Boehringer Ingelheim Animal Health, Brazil) and BR/1891/E2/19 (1062; Hipraviar, France) were sequenced and compared with the pathogenic field strain VCO3/60616.

Avian metapneumovirus subtype B vaccination in commercial broiler chicks: heterologous protection and selected host transcription responses to subtype A or B challenge

Avian metapneumovirus (aMPV) causes respiratory disease and drops in egg production in chicken, and is routinely controlled by vaccination. However, the host's immune response to virulent challenge in vaccinated or unvaccinated broiler chickens is poorly characterised. We show that subtype B vaccination offers heterologous (subtype A challenge) and homologous (subtype B challenge) protection. Subtype B challenge causes significantly greater humoral antibody titres in vaccinated and unvaccinated chickens. In turbinate and lung tissues of unvaccinated-challenged chickens, IgA and IgY mRNA transcription was significantly up-regulated after subtype B challenge compared to subtype A. Cellular immunity (CD8-α and CD8-β) gene transcripts were significantly up-regulated during early and later stages of infection from subtype B or subtype A respectively. Immune gene transcriptional responses (IL-1β, IL-6 and IL-18) were significantly up-regulated after challenge. Gene transcription results have shown that mRNA expression levels of CD8-α, CD8-β, TLR3 and IL-6, particularly in turbinate and trachea tissues, are useful parameters to include in future aMPV vaccination-challenge studies.

In ovo vaccination with herpesvirus of turkey enhances innate and cellular responses in meat-type chickens: Effect of vaccine dose and strain

In ovo vaccination with herpesvirus of turkey (HVT) or recombinant HVT (rHVT) is commonly used in meat-type chickens. Previous studies showed that in ovo vaccination with HVT enhances innate, cellular, and humoral immune responses in egg-type chicken embryos. This study evaluated if in ovo vaccination with HVT hastens immunocompetence of commercial meat-type chickens and optimized vaccination variables (dose and strain of HVT) to accelerate immunocompetence. A conventional HVT vaccine was given at recommended dose (RD), HVT-RD = 6080 plaque forming units (PFU), double-dose (2x), half-dose (1/2), or quarter-dose (1/4). Two rHVTs were given at RD: rHVT-A = 7380 PFU, rHVT-B = 8993 PFU. Most, if not all, treatments enhanced splenic lymphoproliferation with Concanavalin A and increased the percentage of granulocytes at day of age. Dose had an effect and HVT-RD was ideal. An increase of wing-web thickness after exposure to phytohemagglutinin-L was only detected after vaccination with HVT-RD. Furthermore, compared to sham-inoculated chickens, chickens in the HVT-RD had an increased percentage of CD3⁺ T cells and CD4⁺ T-helper cells, and increased expression of major histocompatibility complex (MHC)-II on most cell subsets (CD45⁺ cells, non-T leukocytes, T cells and the CD8⁺ and T cell receptor γδ T-cell subsets). Other treatments (HVT-1/2 and rHVT-B) share some of these features but differences were not as remarkable as in the HVT-RD group. Expression of MHC-I was reduced, compared to sham-inoculated chickens, in most of the cell phenotypes evaluated in the HVT-RD, HVT-2x and rHVT-A groups, while no effect was observed in other treatments. The effect of in ovo HVT on humoral immune responses (antibody responses to keyhole limpet hemocyanin and to a live infectious bronchitis/Newcastle disease vaccine) was minimal. Our study demonstrates in ovo vaccination with HVT in meat-type chickens can accelerate innate and adaptive immunity and we could optimize such effect by modifying the vaccine dose.

Comparative protective immunity provided by live vaccines of Newcastle disease virus or avian metapneumovirus when co-administered alongside classical and variant strains of infectious bronchitis virus in day-old broiler chicks

This study reports on the simultaneous administration of live NDV or aMPV subtype B vaccines alongside two live IBV (Massachusetts-H120 and 793B-CR88) vaccines in day-old maternal-antibody positive commercial broiler chicks. In the first experiment, chicks were divided into four groups; one unvaccinated and three groups vaccinated with live NDV VG/GA-Avinew, live H120 + CR88, or VG/GA-Avinew + H120 + CR88. In the second experiment, live aMPV subtype B vaccine was used in place of NDV. Clinical signs were monitored daily and oropharyngeal swabs were taken at regular intervals for vaccine virus detection. Blood was collected at 21 dpv for serology. 10 chicks from each group were challenged with virulent strains of M41 or QX or aMPV subtype B. For IBV, after 5 days post challenge (dpc), tracheal ciliary protection was assessed. For aMPV, clinical scores were recorded up to 10 dpc. For NDV, haemagglutination inhibition (HI) antibody titres were assayed as an indicator of protective immunity. In both experiments, ciliary protection for IBV vaccinated groups was maintained above 90%. The protection against virulent aMPV challenge was not compromised when aMPV, H120 and CR88 were co-administered. NDV HI mean titres in single and combined NDV-vaccinated groups remained above the protective titre (>3 log2). Both experiments demonstrated that simultaneous administration of live NDV VG/GA-Avinew or aMPV subtype B alongside H120 and CR88 vaccines does not interfere with protection conferred against NDV, IBV or aMPV.

Effects of copper on the early development of Xenopus laevis: the case of CuSO4 and Bordeaux mixture solutions

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Vaccines as alternatives to antibiotics for food producing animals. Part 2: new approaches and potential solutions

Vaccines and other alternative products are central to the future success of animal agriculture because they can help minimize the need for antibiotics by preventing and controlling infectious diseases in animal populations. To assess scientific advancements related to alternatives to antibiotics and provide actionable strategies to support their development, the United States Department of Agriculture, with support from the World Organisation for Animal Health, organized the second International Symposium on Alternatives to Antibiotics. It focused on six key areas: vaccines; microbial-derived products; non-nutritive phytochemicals; immune-related products; chemicals, enzymes, and innovative drugs; and regulatory pathways to enable the development and licensure of alternatives to antibiotics. This article, the second part in a two-part series, highlights new approaches and potential solutions for the development of vaccines as alternatives to antibiotics in food producing animals; opportunities, challenges and needs for the development of such vaccines are discussed in the first part of this series. As discussed in part 1 of this manuscript, many current vaccines fall short of ideal vaccines in one or more respects. Promising breakthroughs to overcome these limitations include new biotechnology techniques, new oral vaccine approaches, novel adjuvants, new delivery strategies based on bacterial spores, and live recombinant vectors; they also include new vaccination strategies in-ovo, and strategies that simultaneously protect against multiple pathogens. However, translating this research into commercial vaccines that effectively reduce the need for antibiotics will require close collaboration among stakeholders, for instance through public–private partnerships. Targeted research and development investments and concerted efforts by all affected are needed to realize the potential of vaccines to improve animal health, safeguard agricultural productivity, and reduce antibiotic consumption and resulting resistance risks.

Vaccines as alternatives to antibiotics for food producing animals. Part 1: challenges and needs

Vaccines and other alternative products can help minimize the need for antibiotics by preventing and controlling infectious diseases in animal populations, and are central to the future success of animal agriculture. To assess scientific advancements related to alternatives to antibiotics and provide actionable strategies to support their development, the United States Department of Agriculture, with support from the World Organisation for Animal Health, organized the second International Symposium on Alternatives to Antibiotics. It focused on six key areas: vaccines; microbial-derived products; non-nutritive phytochemicals; immune-related products; chemicals, enzymes, and innovative drugs; and regulatory pathways to enable the development and licensure of alternatives to antibiotics. This article, part of a two-part series, synthesizes and expands on the expert panel discussions regarding opportunities, challenges and needs for the development of vaccines that may reduce the need for use of antibiotics in animals; new approaches and potential solutions will be discussed in part 2 of this series. Vaccines are widely used to prevent infections in food animals. Various studies have demonstrated that their animal agricultural use can lead to significant reductions in antibiotic consumption, making them promising alternatives to antibiotics. To be widely used in food producing animals, vaccines have to be safe, effective, easy to use, and cost-effective. Many current vaccines fall short in one or more of these respects. Scientific advancements may allow many of these limitations to be overcome, but progress is funding-dependent. Research will have to be prioritized to ensure scarce public resources are dedicated to areas of potentially greatest impact first, and private investments into vaccine development constantly compete with other investment opportunities. Although vaccines have the potential to improve animal health, safeguard agricultural productivity, and reduce antibiotic consumption and resulting resistance risks, targeted research and development investments and concerted efforts by all affected are needed to realize that potential.

Experimental infection of IS/885/00-like infectious bronchitis virus in specific pathogen free and commercial broiler chicks

Pathogenesis of an IS/885/00-like (IS/885) strain of variant infectious bronchitis virus (IBV) was examined in one day old specific pathogen free (SPF) and commercial broiler chicks. Chicks were humanely euthanized at 3, 6, 9, 12, 15, 21 and 28 days post infection (dpi) for necropsy examination, and tissues were collected for histopathology and virus detection by reverse transcription polymerase chain reaction (RT-PCR). Respiratory clinical signs and gross lesions consisting of tracheal caseous exudate and plugs, and swollen kidneys (with or without) urate deposits were observed in SPF and broiler chicks. The onset of disease developed more slowly and were of lesser severity in broiler compared to SPF chicks, reflecting the inhibitory effects of the IBV maternal-antibodies in the broiler chicks or genetic/strain susceptibility, or both. Head swelling was observed in one infected broiler chick at 15 dpi and the virus was recovered by RT-PCR and isolation. In the IS/885-infected SPF chicks, cystic oviducts were found in two female chicks. IS/885 was isolated from the cystic fluid. Using ELISA, low to moderate levels of the antibodies to IBV was detected in the SPF compared to broiler infected chicks.

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Pathogenesis of IBV IS/885 was examined in one day old SPF and broiler chicks.

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The virus caused respiratory distress, tracheal and kidney lesions in infected chicks.

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Head swelling was observed in one infected broiler chick at 15 dpi.

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Cystic oviducts were found in two female SPF chicks.

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IBV IS/885 examined in this study was pathogenic for both SPF and broiler chicks.

Protection conferred by live infectious bronchitis vaccine viruses against variant Middle East IS/885/00-like and IS/1494/06-like isolates in commercial broiler chicks

The ability of the infectious bronchitis H120 (a Massachusetts strain) and CR88 (a 793B strain) live attenuated vaccine viruses to protect from two Middle East infectious bronchitis virus isolates, IS/885/00-like (IS/885) and IS/1494/06-like (IS/1494) in broiler chicks was investigated. Day-old chicks were separated into three groups, (I) vaccinated with H120 at day-old followed by CR88 at 14 days-old, (II) vaccinated with H120 and CR88 simultaneously at day-old and again with CR88 at 14 days-old, (III) control unvaccinated. At 30 days-old, each of the groups was challenged with virulent IS/885 or IS/1494. Protection was evaluated based on the clinical signs, tracheal and kidney gross lesions and tracheal ciliostasis. Results showed that administering combined live H120 and CR88 vaccines simultaneously at day-old followed by CR88 vaccine at 14 days-old gave more than 80 per cent tracheal ciliary protection from both of the Middle East isolates. In addition, this programme conferred 100 per cent protection from clinical signs and tracheal or kidney lesions. The other vaccination programme, H120 at day-old followed by CR88 at 14 days-old, the tracheal ciliary protection conferred were 60 per cent and 80 per cent from IS/885/00-like and IS/1494/06-like, respectively.

Observation of risk factors, clinical manifestations and genetic characterization of recent Newcastle Disease Virus outbreak in West Malaysia

Background

Newcastle disease virus remains a constant threat in commercial poultry farms despite intensive vaccination programs. Outbreaks attributed to ND can escalate and spread across farms and states contributing to major economic loss in poultry farms.

Results

Phylogenetic analysis in our study showed that eleven of the samples belonged to genotype VIId. All farms were concurrently positive with two immunosuppressive viruses; Infectious Bursal Disease Virus (IBDV) and Marek’s Disease Virus (MDV). Amino acid sequence analysis confirmed that eleven of the samples had sequence motifs for velogenic/mesogenic strains; three were lentogenic.

Conclusion

In conclusion, no new NDV genotype was isolated from the 2011 NDV outbreak. This study suggests that the presence of other immunosuppressive agents such as IBD and MDV could have contributed to the dysfunction of the immune system of the chickens, causing severe NDV outbreaks in 2011. Risk factors related to biosecurity and farm practices appear to have a significant role in the severity of the disease observed in affected farms.

Antioxidant responses of Annelids, Brassicaceae and Fabaceae to pollutants: a review

Pollutants, such as Metal Trace Elements (MTEs) and organic compounds (polycyclic aromatic hydrocarbons, pesticides), can impact DNA structure of living organisms and thus generate damage. For instance, cadmium is a well-known genotoxic and mechanisms explaining its clastogenicity are mainly indirect: inhibition of DNA repair mechanisms and/or induction of Reactive Oxygen Species (ROS). Animal or vegetal cells use antioxidant defense systems to protect themselves against ROS produced during oxidative stress. Because tolerance of organisms depends, at least partially, on their ability to cope with ROS, the mechanisms of production and management of ROS were investigated a lot in Ecotoxicology as markers of biotic and abiotic stress. This was mainly done through the measurement of enzyme activities The present Review focuses on 3 test species living in close contact with soil that are often used in soil ecotoxicology: the worm Eisenia fetida, and two plant species, Trifolium repens (white clover) and Brassica oleracea (cabbage). E. fetida is a soil-dwelling organism commonly used for biomonitoring. T. repens is a symbiotic plant species which forms root nodule with soil bacteria, while B. oleracea is a non-symbiotic plant. In literature, some oxidative stress enzyme activities have already been measured in those species but such analyses do not allow distinction between individual enzyme involvements in oxidative stress. Gene expression studies would allow this distinction at the transcriptomic level. A literature review and a data search in molecular database were carried out on the basis of keywords in Scopus, in PubMed and in Genbank™ for each species. Molecular data regarding E. fetida were already available in databases, but a lack of data regarding oxidative stress related genes was observed for T. repens and B. oleracea. By exploiting the conservation observed between species and using molecular biology techniques, we partially cloned missing candidates involved in oxidative stress and in metal detoxification in E. fetida, T. repens and B. oleracea.

Immune responses and interactions following simultaneous application of live Newcastle disease, infectious bronchitis and avian metapneumovirus vaccines in specific-pathogen-free chicks

Interactions between live Newcastle disease virus (NDV), avian metapneumovirus (aMPV) and infectious bronchitis virus (IBV) vaccines following simultaneous vaccination of day old specific pathogen free (SPF) chicks were evaluated. The chicks were divided into eight groups: seven vaccinated against NDV, aMPV and IBV (single, dual or triple) and one unvaccinated as control. Haemagglutination inhibition (HI) NDV antibody titres were similar across all groups but were above protective titres. aMPV vaccine when given with other live vaccines suppressed levels of aMPV enzyme-linked immunosorbent assay (ELISA) antibodies. Cellular and local immunity induced by administration of NDV, aMPV or IBV vaccines (individually or together) showed significant increase in CD4+, CD8+ and IgA bearing B-cells in the trachea compared to the unvaccinated group. Differences between the vaccinated groups were insignificant. Simultaneous vaccination with live NDV, aMPV and IBV did not affect the protection conferred against aMPV or IBV.

Concomitant turkey herpesvirus-infectious bursal disease vector vaccine and oil-adjuvanted inactivated Newcastle disease vaccine administration: consequences for vaccine intake and protection

Hatchery vaccination protocols in day-old chicks are designed to provide early priming and protection against several poultry diseases including, but not limited to, Marek's disease (MD), infectious bursal disease (IBD), and Newcastle disease (ND). The constraint of concomitant administration of live MD and IBD vaccines plus ND inactivated oil-adjuvanted vaccines (IOAVs) requires improvements in vaccine technology. Single-needle concomitant subcutaneous (SC) application of IBD/MDV and killed NDV vaccine and the use of viral vectors for expression of immunogenic proteins are a current trend in the industry. The objective of this work was to assess the compatibility of a turkey herpesvirus (HVT)-infectious bursal disease (vHVT-IBD) vector vaccine applied simultaneously with IOAV and to evaluate the consequences for vaccine intake, the need for additional immunizations with the respective vaccines, and protection. Five separate trials were performed using double- and/or single-needle injectors. The levels and persistence of vaccine intake, serologic response, vHVT-IBD virus combination with the MD Rispens strain, and/or live NDV vaccination were also assessed. Histopathology and PCR at injection sites showed adequate vaccine intake detected up to 44 days postvaccination. Serologic evidence of vaccine priming was observed, and all vaccinated groups differed (P < 0.05) from the control at different time points. MD, NDV, and IBD protection results after concomitant double-shot single-needle vaccination were near 85%, 95%, and 100%, respectively. Taken together the results indicate no deleterious effects on the efficacy of the vHVT-IBD vaccine monitored by vaccine intake, serologic and challenge results, and combinations after concomitant live/killed vaccination, suggesting the suitability of its use in hatchery vaccination. All types of injectors used as well as injection techniques, vaccines injected separately or together, gave the same results.

Comparison of blood and feather pulp samples for the diagnosis of Marek's disease and for monitoring Marek's disease vaccination by real time-PCR

Comparison of blood and feather pulp (FP) samples for the diagnosis of Marek's disease (MD) and for monitoring Marek's diseases vaccination in chickens (serotypes 2 and 3 vaccines) by real time-PCR was evaluated. For diagnosis of MD, quantification of serotype 1 Marek's disease virus (MDV) DNA load was evaluated in 21 chickens suffering from MD. For each chicken, samples of blood and FP were collected and MDV DNA load was quantified. Solid tumors are the sample of choice for MD diagnosis by real time-PCR and, hence, 14 solid tumors were included in the study as positive controls. Load of MDV DNA in FP was equivalent to that detected in solid tumors (threshold cycle [Ct] ratio above 1.7). MDV DNA load in blood samples was lower than in solid tumors and FP samples. Nonetheless, there was a statistically significant correlation of the results obtained from FP and blood (r = 0.92). Results of the Pearson correlation test showed that Ct ratio values of 1.7 in FP correspond to Ct ratio values of 1.2 in peripheral blood. For monitoring vaccines, serotypes 2 and 3 MDV DNA load was evaluated in blood and FP samples of vaccinated chickens. Serotype 2 MDV DNA load was evaluated in samples of blood and FP from 34 chickens vaccinated with SB-1 strain. Serotype 3 MDV DNA load was evaluated in blood and FP samples from 53 chickens vaccinated with HVT strain. For both serotypes, frequency of positive samples and load of vaccine DNA was higher in FP than in blood samples. There was not a statistically significant correlation between the load of SB-1 DNA (r = 0.17) or HVT DNA (r = -0.04) in FP and blood. Our results show that the load of serotypes 1, 2, and 3 DNA is higher in FP than in blood. Diagnosis of MD could be done using both FP and blood samples. Monitoring of MD vaccination by real time-PCR required the use of FP samples. There were a high percentage of false negative samples when using blood to detect serotypes 2 and 3 MDV by real time-PCR.

DNA damage (comet assay) and 8-oxodGuo (HPLC-EC) in relation to oxidative stress in the freshwater bivalveUnio tumidus

The relationships between DNA damage and oxidative stress in the digestive gland, gills and haemocytes of the freshwater bivalve Unio tumidus were investigated. Two markers of genotoxicity were measured: DNA breaks by means of the comet assay, and oxidative DNA lesions by means of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) measured using high-performance liquid chromatography (HPLC) coupled to electrochemical detection. Lipid peroxidation was evaluated by measuring malondialdehyde (MDA) tissue levels. Effects were studied after exposure of bivalves for 6 days to benzo[a]pyrene (B[a]P) (50 and 100 microg l(-1)) and ferric iron (20 and 40 mg l(-1)), applied alone or in combination. Lipid peroxidation in the digestive gland and gills resulted from exposure to Fe3+ or B[a]P whatever the concentrations tested. DNA oxidatively formed lesions were induced in the two tissues at a higher level after B[a]P exposure than after Fe3+ treatment. No significant dose-response relationship was found with the two compounds and no synergistic effect was observed between Fe3+ and B[a]P. The gills appeared less sensitive than the digestive gland to DNA lesions expressed as 8-oxodGuo and comet results. Good correlations were noted between 8-oxodGuo and comet. MDA and DNA damage did not correlate as well, although it was stronger in the digestive gland than in the gills. Production of mucus by the gills likely served to prevent lesions by reducing the bioavailability of the chemicals tested, which could explain that dose-effect relationships and synergistic effects were not observed.