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1.
Nat Commun ; 12(1): 765, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33536414

RESUMO

Chickens are the most common birds on Earth and colibacillosis is among the most common diseases affecting them. This major threat to animal welfare and safe sustainable food production is difficult to combat because the etiological agent, avian pathogenic Escherichia coli (APEC), emerges from ubiquitous commensal gut bacteria, with no single virulence gene present in all disease-causing isolates. Here, we address the underlying evolutionary mechanisms of extraintestinal spread and systemic infection in poultry. Combining population scale comparative genomics and pangenome-wide association studies, we compare E. coli from commensal carriage and systemic infections. We identify phylogroup-specific and species-wide genetic elements that are enriched in APEC, including pathogenicity-associated variation in 143 genes that have diverse functions, including genes involved in metabolism, lipopolysaccharide synthesis, heat shock response, antimicrobial resistance and toxicity. We find that horizontal gene transfer spreads pathogenicity elements, allowing divergent clones to cause infection. Finally, a Random Forest model prediction of disease status (carriage vs. disease) identifies pathogenic strains in the emergent ST-117 poultry-associated lineage with 73% accuracy, demonstrating the potential for early identification of emergent APEC in healthy flocks.


Assuntos
Infecções por Escherichia coli/prevenção & controle , Escherichia coli/genética , Evolução Molecular , Genoma Bacteriano/genética , Doenças das Aves Domésticas/prevenção & controle , Animais , Galinhas , Escherichia coli/classificação , Escherichia coli/patogenicidade , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/microbiologia , Genes Bacterianos , Variação Genética , Estudo de Associação Genômica Ampla/métodos , Genótipo , Humanos , Filogenia , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/microbiologia , Virulência/genética
2.
Parasite ; 28: 9, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33544074

RESUMO

Poultry red mites (PRMs, Dermanyssus gallinae) are ectoparasites that negatively affect farmed chickens, leading to serious economic losses worldwide. Acaricides have been used to control PRMs in poultry houses. However, some PRMs have developed resistance to acaricides, and therefore different approaches are required to manage the problems caused by PRMs. Vaccination of chickens is one of the methods being considered to reduce the number of PRMs in poultry houses. In a previous study, a cysteine protease, Deg-CPR-1, was identified as a candidate vaccine against PRMs distributed in Europe. In this study, we investigated the characteristics of Deg-CPR-1. A phylogenetic analysis revealed that Deg-CPR-1 is closely related to the digestive cysteine proteases of other mite species, and it was classified into a cluster different from that of chicken cathepsins. Deg-CPR-1 of PRMs in Japan has an amino acid substitution compared with that of PRMs in Europe, but it showed efficacy as a vaccine, consistent with previous findings. Deg-CPR-1 exhibited cathepsin L-like enzyme activity. In addition, the Deg-CPR-1 mRNA was expressed in the midgut and in all stages of PRMs that feed on blood. These results imply that Deg-CPR-1 in the midgut may have important functions in physiological processes, and the inhibition of its expression may contribute to the efficacy of a Deg-CPR-1-based vaccine. Further research is required to fully understand the mechanisms of vaccine efficacy.


Assuntos
Cisteína Proteases , Infestações por Ácaros , Ácaros , Doenças das Aves Domésticas , Vacinas , Animais , Galinhas , Cisteína Proteases/genética , Cisteína Proteases/imunologia , Europa (Continente) , Japão , Infestações por Ácaros/prevenção & controle , Infestações por Ácaros/veterinária , Ácaros/classificação , Ácaros/enzimologia , Ácaros/imunologia , Filogenia , Doenças das Aves Domésticas/prevenção & controle
3.
Vet Res ; 52(1): 24, 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33596990

RESUMO

Avian coccidiosis caused by Eimeria leads to huge economic losses on the global poultry industry. In this study, microneme adhesive repeat regions (MARR) bc1 of E. tenella microneme protein 3 (EtMIC3-bc1) was used as ligand, and peptides binding to EtMIC3 were screened from a phage display peptide library. The positive phage clones were checked by enzyme-linked immunosorbent assay (ELISA). Competitive ELISA was applied to further verify the binding capability between the positive phages and recombinant EtMIC3-bc1 protein or sporozoites protein. The inhibitory effects of target peptides on sporozoites invasion of MDBK cells were measured in vitro. Chickens were orally administrated with target positive phages and the protective effects against homologous challenge were evaluated. The model of three-dimensional (3D) structure for EtMIC3-bc1 was conducted, and molecular docking between target peptides and EtMIC3-bc1 model was analyzed. The results demonstrated that three selected positive phages specifically bind to EtMIC3-bc1 protein. The three peptides A, D and W effectively inhibited invasion of MDBK cells by sporozoites, showing inhibited ratio of 71.8%, 54.6% and 20.8%, respectively. Chickens in the group orally inoculated with phages A displayed more protective efficacies against homologous challenge than other groups. Molecular docking showed that amino acids in three peptides, especially in peptide A, insert into the hydrophobic groove of EtMIC3-bc1 protein, and bind to EtMIC3-bc1 through intermolecular hydrogen bonds. Taken together, the results suggest EtMIC3-binding peptides inhibit sporozoites entry into host cells. This study provides new idea for exploring novel strategies against coccidiosis.


Assuntos
Galinhas , Coccidiose/veterinária , Eimeria tenella/imunologia , Doenças das Aves Domésticas/prevenção & controle , Proteínas de Protozoários/imunologia , Esporozoítos/imunologia , Animais , Bacteriófagos , Ceco/patologia , Coccidiose/prevenção & controle , Simulação de Acoplamento Molecular , Doenças das Aves Domésticas/parasitologia , Ligação Proteica , Conformação Proteica
4.
Viruses ; 13(2)2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33579009

RESUMO

Highly pathogenic avian influenza (HPAI), a zoonotic disease, is a major threat to humans and poultry health worldwide. In January 2014, HPAI virus subtype H5N8 first infected poultry farms in South Korea, and 393 outbreaks, overall, were reported with enormous economic damage in the poultry industry. We analyzed the spatiotemporal distribution of HPAI H5N8 outbreaks in poultry farms using the global and local spatiotemporal interaction analyses in the first (January to July 2014) and second (September 2014 to June 2015) outbreak waves. The space-time K-function analyses revealed significant interactions within three days and in an over-40 km space-time window between the two study periods. The excess risk attributable value (D0) was maintained despite the distance in the case of HPAI H5N8 in South Korea. Eleven spatiotemporal clusters were identified, and the results showed that the HPAI introduction was from the southwestern region, and spread to the middle region, in South Korea. This spatiotemporal interaction indicates that the HPAI epidemic in South Korea was mostly characterized by short period transmission, regardless of the distance. This finding supports strict control strategies such as preemptive depopulation, and poultry movement tracking. Further studies are needed to understand HPAI disease transmission patterns.


Assuntos
Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/transmissão , Doenças das Aves Domésticas/transmissão , Animais , Análise por Conglomerados , Surtos de Doenças/prevenção & controle , Fazendas , Influenza Aviária/epidemiologia , Influenza Aviária/prevenção & controle , Aves Domésticas , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/prevenção & controle , República da Coreia/epidemiologia , Análise Espaço-Temporal
5.
BMC Vet Res ; 17(1): 51, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33494765

RESUMO

BACKGROUND: Infectious bronchitis virus (IBV), a coronavirus, is one of the most important poultry pathogens worldwide due to its multiple serotypes and poor cross-protection. Vaccination plays a vital role in controlling the disease. The efficacy of vaccination in chicken flocks can be evaluated by detecting neutralizing antibodies with the neutralization test. However there are no simple and rapid methods for detecting the neutralizing antibodies. RESULTS: In this study, a peptide enzyme-linked immunosorbent assay (pELISA) as a possible alternative to the neutralization test for evaluating the immune response to IBV vaccine was developed. The pELISA could indirect evaluate neutralizing antibody titers against different types of IBV in all tested sera. The titers measured with the pELISA had a coefficient of 0.83 for neutralizing antibody titers. CONCLUSIONS: The pELISA could detect antibodies against different types of IBV in all tested sera. The pELISA has the potential to evaluate samples for IBV-specific neutralizing antibodies and surveillance the infection of IBV.


Assuntos
Infecções por Coronavirus/prevenção & controle , Ensaio de Imunoadsorção Enzimática , Vírus da Bronquite Infecciosa/imunologia , Testes de Neutralização , Doenças das Aves Domésticas/prevenção & controle , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Galinhas/imunologia , Galinhas/virologia , Infecções por Coronavirus/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Testes de Neutralização/métodos , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Antiviral Res ; 186: 104998, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33340637

RESUMO

Infectious bronchitis virus (IBV) is a coronavirus, causes infectious bronchitis (IB) with high morbidity and mortality, and gives rise to huge economic losses for the poultry industry. Aminopeptidase N (APN) may be one of the IBV functional receptors. In this study, Gallus gallus APN (gAPN) protein was screened by phage-displayed 12-mer peptide library. Two high-affinity peptides H (HDYLYYTFTGNP) and T (TKFSPPSFWYLH) to gAPN protein were selected for in depth characterization of their anti-IBV effects. In vitro, indirect ELISA showed that these two high-affinity ligands could bind IBV S1 antibodies. Quantitative real-time PCR (qRT-PCR) assay, virus yield reduction assay and indirect immunofluorescence assay results revealed 3.125-50 µg/ml of peptide H and 6.25-50 µg/ml of peptide T reduced IBV proliferation in chicken embryo kidney cells (CEKs). In vivo, high-affinity phage-vaccinated chickens were able to induce specific IBV S1 antibodies and IBV neutralizing antibodies. QRT-PCR results confirmed that high-affinity phages reduced virus proliferation in chicken tracheas, lungs and kidneys, and alleviated IBV-induced lesions. By multiple sequence alignment, motif 'YxYY' and 'FxPPxxWxLH' of high-affinity peptides were identified in IBV S1-NTD, while another motif 'YxFxGN' located in S2. These results indicated that high affinity peptides of gAPN could present an alternative approach to IB prevention or treatment.


Assuntos
Antivirais/farmacologia , Antígenos CD13/química , Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/efeitos dos fármacos , Oligopeptídeos/farmacologia , Doenças das Aves Domésticas/tratamento farmacológico , Motivos de Aminoácidos , Animais , Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Antivirais/química , Antivirais/uso terapêutico , Antígenos CD13/genética , Antígenos CD13/metabolismo , Técnicas de Visualização da Superfície Celular , Células Cultivadas , Embrião de Galinha , Galinhas , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Vírus da Bronquite Infecciosa/imunologia , Vírus da Bronquite Infecciosa/fisiologia , Ligantes , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Oligopeptídeos/uso terapêutico , Biblioteca de Peptídeos , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologia , Receptores Virais/metabolismo , Glicoproteína da Espícula de Coronavírus/imunologia , Replicação Viral/efeitos dos fármacos
7.
Viruses ; 12(12)2020 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-33352791

RESUMO

Worldwide, poultry industry suffers from infections caused by avian pathogenic Escherichia coli. Therapeutic failure due to resistant bacteria is of increasing concern and poses a threat to human and animal health. This causes a high demand to find alternatives to fight bacterial infections in animal farming. Bacteriophages are being especially considered for the control of multi-drug resistant bacteria due to their high specificity and lack of serious side effects. Therefore, the study aimed on characterizing phages and composing a phage cocktail suitable for the prevention of infections with E. coli. Six phages were isolated or selected from our collections and characterized individually and in combination with regard to host range, stability, reproduction, and efficacy in vitro. The cocktail consisting of six phages was able to inhibit formation of biofilms by some E. coli strains but not by all. Phage-resistant variants arose when bacterial cells were challenged with a single phage but not when challenged by a combination of four or six phages. Resistant variants arising showed changes in carbon metabolism and/or motility. Genomic comparison of wild type and phage-resistant mutant E28.G28R3 revealed a deletion of several genes putatively involved in phage adsorption and infection.


Assuntos
Infecções por Escherichia coli/prevenção & controle , Terapia por Fagos , Doenças das Aves Domésticas/prevenção & controle , Animais , Bacteriólise , Bacteriófagos/genética , Biofilmes , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/veterinária , Genoma Viral , Humanos
8.
Poult Sci ; 99(9): 4351-4359, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32867979

RESUMO

The vaccines currently available to control infectious bursal disease (IBD) include live-attenuated and inactivated vaccines, immune-complex vaccines, and vaccines consisting of viral constructs of herpesvirus of turkeys genetically engineered to express VP2 surface protein. To evaluate the impact of vaccines on the chicken immune system, 2 animal trials were performed in specific pathogen-free broiler chickens. In trial 1, birds were either vaccinated when they are one-day old with a dual recombinant herpes virus of turkey construct vaccine, expressing VP2 protein of (IBDV) and F protein of Newcastle disease virus, or an immune-complex IBDV vaccine or birds were not vaccinated. At 14, 28, and 35 D, the bursa of Fabricius was collected for bursa:body weight (B:BW) ratio calculation. In trial 2, birds were vaccinated when they were 1-day old according to the same protocol as trial 1, but at day 14, all groups also received a live infectious bronchitis (IB) vaccine. At 0, 7, 14, 21, and 28 days after IB vaccination, birds were tested by ELISA for IB serology and, soon after the last blood sampling, they were euthanized for collection of Harderian glands, trachea, and spleen and testing by flow cytometry for characterization of mononuclear cells. The immune-complex vaccine groups showed significantly lower B:BW ratio, lower IBV antibody titers, and higher mean percentage of CD8+ T cells in the spleen, trachea, and Harderian glands than those in the other experimental groups. The results of the in vivo trials coupled with a depth analysis of the repertoire of parameters involved in the immune response to IBD and IB vaccinations show one vaccine may influence the immune response of other vaccines included in the vaccination program.


Assuntos
Infecções por Birnaviridae/veterinária , Doenças das Aves Domésticas/imunologia , Vacinas Virais/imunologia , Animais , Infecções por Birnaviridae/imunologia , Bolsa de Fabricius/patologia , Galinhas , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/imunologia , Vírus da Doença Infecciosa da Bursa/imunologia , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , Vacinação/veterinária , Vacinas Atenuadas/imunologia
9.
Arch Virol ; 165(12): 2777-2788, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32964293

RESUMO

Besides the vaccine strains, the Malaysian variant (MV) and QX-like are the predominant IBVs detected on commercial poultry farms. These two virus strains are distinct based on genomic and pathogenicity studies. In this study, we determined the sequence of the S1 gene and compared the pathogenicity of serial passage 70 (P70) of Malaysian QX-like (QX/P70) and MV (MV/P70) strains with that of their respective wild-type viruses. The nucleotide and amino acid sequences of the complete S1 genes of QX/P70 and MV/P70 showed 1.4 to 1.6% and 3.0 to 3.3% variation, respectively, when compared to the wild-type virus. Most of the mutations were insertions and substitutions in the hypervariable regions (HVRs), primarily in HVR 3. Furthermore, selection pressure analysis showed that both viruses are under purifying selection. A pathogenicity study in specific-pathogen-free (SPF) chickens showed a reduction in respiratory and kidney lesions in chickens inoculated with MV/P70, but not with QX/P70, when compared to the respective wild-type viruses. However, MV/P70 is still pathogenic and can cause ciliary damage. In conclusion, the MV IBV strain is more responsive than the QX-like IBV strain following the attenuation process used for the development of a live attenuated IBV vaccine.


Assuntos
Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/genética , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , Animais , Galinhas , Infecções por Coronavirus/virologia , Vírus da Bronquite Infecciosa/patogenicidade , Doenças das Aves Domésticas/prevenção & controle , Análise de Sequência de Proteína , Inoculações Seriadas , Organismos Livres de Patógenos Específicos , Vacinas Atenuadas/imunologia
10.
Exp Appl Acarol ; 82(2): 243-254, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32897464

RESUMO

Four silica-based acaricides were examined in laboratory tests for their effectiveness against poultry red mite, Dermanyssus gallinae. All acaricides resulted in 100% mite mortality. Two groups of active ingredients could be differentiated. The products Silicosec® and Ewazid®, based on naturally occurring diatomaceous earth (DE), killed 100% of adult D. gallinae within 48 h exposure time. The time to kill 50% of the mites (LT50) was calculated to be 31.7 and 34.9 h, respectively. The other two products, containing aggregates and agglomerates of pyrogenic synthetic amorphous silicon dioxide as active ingredients, killed the mites in a significantly shorter time: LT50 was 6.3 h for the liquid product Fossil Shield® Instant White and 11.8 h for the powdery product Fossil Shield 90.0 White. This is more remarkable as the quantities of active ingredients used for the DE treatments were several folds higher. The effectiveness of all tested products was also shown in practical tests. A professional company treated five chicken houses on one farm in the Berlin-Brandenburg region with the test products, three houses with Fossil Shield Instant White and one each with Ewazid and Silicosec. Over a period of 46 weeks after stocking, the mite development in the houses was assessed. Only in one of the houses, treated with Fossil Shield Instant White, the mite population remained permanently low. In two houses treated with Fossil Shield Instant White, small mite colonies appeared in week 36, which were controlled by a follow-up spot treatment in week 41. In the houses treated with DE, the first mite colonies appeared 12 weeks after stocking. The number increased continuously over the experimental period and in week 31 after stocking there were clearly visible colonies (2-3 cm diameter) and the first mites could also be detected on the chicken eggs. At this time both houses were treated again with a follow-up spot-treatment, which only led to a slight improvement in one house and to a stabilization of the infestation in the other house. In week 41, large mite colonies were detected in both houses. A spot treatment at this point was ineffective in reducing the infestation. The tests showed faster acaricidal action of the products with the synthetic active ingredients compared to the natural DE-based products. This matches the shorter killing times under laboratory conditions. The experiments in a commercial chicken farm showed that it is possible to control the mite population for a period of 46 weeks by using physically effective SiO2-based products. These products are therefore an effective alternative to the use of chemical acaricides.


Assuntos
Acaricidas , Infestações por Ácaros/veterinária , Ácaros , Doenças das Aves Domésticas/prevenção & controle , Dióxido de Silício , Animais , Galinhas/parasitologia , Infestações por Ácaros/prevenção & controle , Aves Domésticas/parasitologia , Doenças das Aves Domésticas/parasitologia
11.
PLoS One ; 15(9): e0238815, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32913363

RESUMO

The Philippines confirmed its first epidemic of Highly Pathogenic Avian Influenza (HPAI) on August 11, 2017. It ended in November of 2017. Despite the successful management of the epidemic, reemergence is a continuous threat. The aim of this study was to conduct a mathematical model to assess the spatial transmission of HPAI among poultry farms in Central Luzon. Different control strategies and the current government protocol of 1 km radius pre-emptive culling (PEC) from infected farms were evaluated. The alternative strategies include 0.5km PEC, 1.5km PEC, 2 km PEC, 2.5 km PEC, and 3 km PEC, no pre-emptive culling (NPEC). The NPEC scenario was further modeled with a time of government notification set at 24hours, 48 hours, and 72 hours after the detection. Disease spread scenarios under each strategy were generated using an SEIR (susceptible-exposed-infectious-removed) stochastic model. A spatial transmission kernel was calculated and used to represent all potential routes of infection between farms. We assumed that the latent period occurs between 1-2 days, disease detection at 5-7 days post-infection, notification of authorities at 5-7 days post-detection and start of culling at 1-3 days post notification. The epidemic scenarios were compared based on the number of infected farms, the total number of culled farms, and the duration of the epidemic. Our results revealed that the current protocol is the most appropriate option compared with the other alternative interventions considered among farms with reproductive ratio (Ri) > 1. Shortening the culling radius to 0.5 km increased the duration of the epidemic. Further increase in the PEC zone decreased the duration of the epidemic but may not justify the increased number of farms to be culled. Nonetheless, the no-pre-emptive culling (NPEC) strategy can be an effective alternative to the current protocol if farm managers inform the government immediately within 24 hours of observation of the presence of HPAI in their farms. Moreover, if notification is made on days 1-3 after the detection, the scale and length of the outbreak have been significantly reduced. In conclusion, this study provided a comparison of various control measures for confronting the spread of HPAI infection using the simulation model. Policy makers can use this information to enhance the effectiveness of the current control strategy.


Assuntos
Surtos de Doenças/veterinária , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/virologia , Animais , Surtos de Doenças/prevenção & controle , Epidemias/veterinária , Fazendas , Modelos Biológicos , Modelos Teóricos , Filipinas/epidemiologia , Aves Domésticas , Doenças das Aves Domésticas/prevenção & controle
12.
J Virol ; 94(17)2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32611755

RESUMO

Recently, the disease of hepatitis-hydropericardium syndrome (HPS) caused by serotype 4 fowl adenovirus (FAdV-4) has spread widely and resulted in huge economic losses to the poultry industry. Although the genome of FAdV-4 has two fiber genes (fiber-1 and fiber-2), the exact role of the genes in the infection of FAdV-4 is barely known. In this study, through superinfection resistance analysis and an interfering assay, we found that fiber-1, but not fiber-2, was the key factor for directly triggering the infection of FAdV-4. The truncation analysis further revealed that both of the shaft and knob domains of fiber-1 were required for the infection. Moreover, the sera against the knob domain were able to block FAdV-4 infection, and the knob-containing fusion protein provided efficient protection against the lethal challenge of FAdV-4 in chickens. All the data demonstrated the significant roles of fiber-1 and its knob domain in directly mediating the infection of FAdV-4, which established a foundation for identifying the receptor of FAdV-4 and developing efficient vaccines against FAdV-4.IMPORTANCE Among 12 serotypes of fowl adenovirus (FAdV), FAdV-1, FAdV-4, and FAdV-10 all carry two fiber genes (i.e., fiber-1 and fiber-2), whereas other serotypes have only one. As important viral surface proteins, the fibers play vital roles in the infection and pathogenesis of FAdV. However, the importance of the fibers to the infection and pathogenesis of FAdV may be different from each other. Recent studies reveal that fiber-2 is identified as a determinant of virulence, but which fiber triggers the infection of FAdV-4 remains unknown. In this study, fiber-1 was identified as a key factor for directly mediating the infection of FAdV-4 through its shaft and knob domains, whereas fiber-2 did not play a role in triggering FAdV-4 infection. The results suggest that fiber-1 and its knob domain may serve as a target for identifying the receptor of FAdV-4 and developing efficient drugs or vaccines against FAdV-4.


Assuntos
Infecções por Adenoviridae/virologia , Adenoviridae/genética , Adenoviridae/metabolismo , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Doenças das Aves Domésticas/virologia , Adenoviridae/patogenicidade , Infecções por Adenoviridae/imunologia , Infecções por Adenoviridae/patologia , Infecções por Adenoviridae/prevenção & controle , Animais , Anticorpos Antivirais , Linhagem Celular , Galinhas/virologia , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/prevenção & controle , Domínios Proteicos , Sorogrupo , Vacinas Virais/imunologia
13.
Parasitol Res ; 119(9): 2885-2895, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32715344

RESUMO

Chicken coccidiosis is a protozoan parasitic disease that leads to considerable economic losses in the poultry industry. In this study, we used invasive Lactobacillus plantarum (L.P) expressing the FnBPA protein as a novel bacterial carrier for DNA delivery into epithelial cells to develop a live oral DNA vaccine. A fusion DNA vaccine co-expressing EtMIC2 and chicken IL-18 (chIL-18) was constructed and then delivered to the host by invasive L.P. Its efficacy against Eimeria tenella challenge was evaluated in chickens by examining the relative weight gain rate; caecal lesion score; OPG; anti-coccidial index (ACI); levels of EtMIC2 antibody, FnBPA, IL-4, IL-18, IFN-γ and SIgA; and proliferation ability and percentages of CD4+ and CD8+ splenocytes. The experimental results showed that chickens immunized with invasive L.P carrying the eukaryotic expression vector pValac-EtMIC2 (pValac-EtMIC2/pSIP409-FnBPA) had markedly improved immune protection against challenge compared with that of chickens immunized with non-invasive L.P (pValac-EtMIC2/pSIP409). However, invasive L.P co-expressing EtMIC2 with the chIL-18 vector exhibited the highest protection efficiency against E. tenella. These results indicate that invasive Lactobacillus-expressing FnBPA improved humoural and cellular immunity and enhanced resistance to E. tenella. The DNA vaccine delivered by invasive Lactobacillus provides a new concept and method for the prevention of E. tenella.


Assuntos
Antígeno 12E7/metabolismo , Coccidiose/veterinária , Eimeria tenella/imunologia , Interleucina-18/metabolismo , Lactobacillus plantarum/metabolismo , Vacinas Protozoárias/imunologia , Vacinas de DNA/imunologia , Animais , Ceco/parasitologia , Galinhas/parasitologia , Coccidiose/parasitologia , Eimeria tenella/genética , Imunidade Celular/imunologia , Imunoglobulina A Secretora/genética , Lactobacillus plantarum/genética , Doenças das Aves Domésticas/parasitologia , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Ganho de Peso
14.
Lett Appl Microbiol ; 71(4): 345-350, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32628287

RESUMO

Phage therapy is considered an alternative modality in the treatment of different bacterial diseases. However, their therapeutic and preventive roles against infections caused by Salmonella Kentucky and Escherichia coli O119 were of little attention. In this study, two phages were isolated, characterized and assessed for their potential therapeutic and preventive roles against S. Kentucky and E. coli O119 infections in broilers. Commercial 1-day-old arboacres broiler chicks were assigned to seven groups: Group Ӏ was as a negative control, groups (П and Ш) were assigned as positive controls by the challenge of S. Kentucky and E. coli O119, respectively. The remaining four groups (IV, V, VI and VII) were administrated with five repeated phage doses to determine the effect of multiple doses. Phages were administrated in groups (IV and VI) after challenging with S. Kentucky and E. coli O119, respectively to assess their therapeutic role; moreover, their preventive role was evaluated through administration in groups (V and VII) before challenging with S. Kentucky and E. coli O119, respectively. Sampling was done from different organs at three time points and revealed that phage-treated groups had lower colony forming units of S. Kentucky and E. coli. Our results suggest that bacteriophages are efficient in the treatment and prevention of salmonellosis and colibacillosis in broiler farms.


Assuntos
Bacteriófagos/fisiologia , Terapia Biológica/métodos , Galinhas/microbiologia , Infecções por Escherichia coli/terapia , Infecções por Escherichia coli/veterinária , Doenças das Aves Domésticas/terapia , Salmonelose Animal/terapia , Animais , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Terapia Biológica/veterinária , Escherichia coli/fisiologia , Escherichia coli/virologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Salmonelose Animal/microbiologia , Salmonelose Animal/prevenção & controle , Salmonella enterica/fisiologia , Salmonella enterica/virologia
15.
Exp Parasitol ; 216: 107945, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32615133

RESUMO

Despite decades of investigation to clarify protective mechanisms of anticoccidial responses, one crucial field is neglected, that is, protective memory responses in primed birds. Protective memory immunity is critical for host resistance to reinfection and is the basis of modern vaccinology, especially in developing successful subunit vaccines. There are important differences between the immune responses induced by infections and antigens delivered either as killed, recombinant proteins or as live, replicating vector vaccines or as DNA vaccines. Animals immunized with these vaccines may fail to develop protective memory immunity, and is still naïve to Eimeria infection. This may explain why limited success is achieved in developing next-generation anticoccidial vaccines. In this review, we try to decipher the protective memory responses against Eimeria infection, assess immune responses elicited by various anticoccidial vaccine candidates, and propose possible approaches to develop rational vaccines that can induce a protective memory response to chicken coccidiosis.


Assuntos
Galinhas/parasitologia , Coccidiose/veterinária , Eimeria/imunologia , Memória Imunológica/fisiologia , Doenças das Aves Domésticas/imunologia , Vacinas Protozoárias , Animais , Galinhas/imunologia , Coccidiose/imunologia , Coccidiose/prevenção & controle , Intestinos/imunologia , Intestinos/parasitologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Protozoárias/imunologia , Recidiva , Vacinação/veterinária , Vacinas de Subunidades/imunologia
16.
J Virol ; 94(19)2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669327

RESUMO

Infectious bronchitis (IB) caused by infectious bronchitis virus (IBV) is currently a major threat to chicken health, with multiple outbreaks being reported in the United States over the past decade. Modified live virus (MLV) vaccines used in the field can persist and provide the genetic material needed for recombination and emergence of novel IBV serotypes. Inactivated and subunit vaccines overcome some of the limitations of MLV with no risk of virulence reversion and emergence of new virulent serotypes. However, these vaccines are weakly immunogenic and poorly protective. There is an urgent need to develop more effective vaccines that can elicit a robust, long-lasting immune response. In this study, we evaluate a novel adjuvant system developed from Quil-A and chitosan (QAC) for the intranasal delivery of nucleic acid immunogens to improve protective efficacy. The QAC adjuvant system forms nanocarriers (<100 nm) that efficiently encapsulate nucleic acid cargo, exhibit sustained release of payload, and can stably transfect cells. Encapsulation of plasmid DNA vaccine expressing IBV nucleocapsid (N) protein by the QAC adjuvant system (pQAC-N) enhanced immunogenicity, as evidenced by robust induction of adaptive humoral and cellular immune responses postvaccination and postchallenge. Birds immunized with pQAC-N showed reduced clinical severity and viral shedding postchallenge on par with protection observed with current commercial vaccines without the associated safety concerns. Presented results indicate that the QAC adjuvant system can offer a safer alternative to the use of live vaccines against avian and other emerging coronaviruses.IMPORTANCE According to 2017 U.S. agriculture statistics, the combined value of production and sales from broilers, eggs, turkeys, and chicks was $42.8 billion. Of this number, broiler sales comprised 67% of the industry value, with the production of >50 billion pounds of chicken meat. The economic success of the poultry industry in the United States hinges on the extensive use of vaccines to control infectious bronchitis virus (IBV) and other poultry pathogens. The majority of vaccines currently licensed for poultry health include both modified live vaccine and inactivated pathogens. Despite their proven efficacy, modified live vaccine constructs take time to produce and could revert to virulence, which limits their safety. The significance of our research stems from the development of a safer and potent alternative mucosal vaccine to replace live vaccines against IBV and other emerging coronaviruses.


Assuntos
Bronquite/prevenção & controle , Infecções por Coronavirus/veterinária , Gammacoronavirus/imunologia , Membrana Mucosa/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Virais/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Bronquite/virologia , Galinhas , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Modelos Animais de Doenças , Imunidade Celular , Imunização , Vírus da Bronquite Infecciosa/imunologia , Nucleocapsídeo/imunologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Proteínas Recombinantes/imunologia , Vacinas de DNA/imunologia , Carga Viral
17.
Viruses ; 12(7)2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32674326

RESUMO

The Gammacoronavirus infectious bronchitis virus (IBV) is a highly contagious economically important respiratory pathogen of domestic fowl. Reverse genetics allows for the molecular study of pathogenic determinants to enable rational vaccine design. The recombinant IBV (rIBV) Beau-R, a molecular clone of the apathogenic Beaudette strain, has previously been investigated as a vaccine platform. To determine tissues in which Beau-R could effectively deliver antigenic genes, an in vivo study in chickens, the natural host, was used to compare the pattern of viral dissemination of Beau-R to the pathogenic strain M41-CK. Replication of Beau-R was found to be restricted to soft tissue within the beak, whereas M41-CK was detected in beak tissue, trachea and eyelid up to seven days post infection. In vitro assays further identified that, unlike M41-CK, Beau-R could not replicate at 41 °C, the core body temperature of a chicken, but is able to replicate a 37 °C, a temperature relatable to the very upper respiratory tract. Using a panel of rIBVs with defined mutations in the structural and accessory genes, viral replication at permissive and non-permissive temperatures was investigated, identifying that the Beau-R replicase gene was a determinant of temperature sensitivity and that sub-genomic mRNA synthesis had been affected. The identification of temperature sensitive allelic lesions within the Beau-R replicase gene opens up the possibility of using this method of attenuation in other IBV strains for future vaccine development as well as a method to investigate the functions of the IBV replicase proteins.


Assuntos
Infecções por Coronavirus/prevenção & controle , Vírus da Bronquite Infecciosa/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Vacinas Virais/imunologia , Animais , Linhagem Celular , Embrião de Galinha , Galinhas , Aves Domésticas/virologia , Doenças das Aves Domésticas/virologia , RNA Viral/genética , Temperatura , Vacinas Atenuadas/imunologia , Replicação Viral/genética , Replicação Viral/fisiologia
18.
Avian Dis ; 64(2): 123-129, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32550611

RESUMO

Eimeria spp. are important intestinal pathogens of chickens (Gallus gallus domesticus). Anticoccidial feed additives, chemicals, and ionophores have traditionally been used to control Eimeria infections in broiler production. Thus, the trend toward antibiotic-free and organic production requires new approaches to coccidiosis prevention. Two not mutually exclusive methods are the use of plant extracts with antiparasitic activity and manipulation of the intestinal microbiota by pre- and probiotics. In the present study, birds were inoculated with a combination of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. We profiled the jejunal microbiome at multiple time points postinfection to investigate the changes in jejunum microbiota and to identify the time point of the maximum difference between infected and noninfected birds. Additionally, we assessed the anticoccidial effects of two anecdotal treatment methods, green tea and apple cider vinegar, as well as amprolium. Green tea and apple cider vinegar had no effect on oocyst shedding, but green tea reduced the mild unspecific lesions in coccidia-infected birds; there was no influence on unspecific lesions in uninfected controls. Jejunal contents were collected on the day of the infection and 1, 2, 4, 6, 10, and 14 days postinfection (dpi) for investigation of the intestinal microbiota by 16S ribosomal (r)RNA gene sequencing. Comparison of the untreated-uninfected and the untreated-infected groups showed a maximum community dissimilarity of 10 dpi. From 4 days after infection, Clostridiales were significantly enriched at the expense of Lactobacillales in infected compared with uninfected birds. Interestingly, treatment with green tea prevented proliferation of Clostridiales induced by the coccidia and increased the relative abundance of Melainabacteria.


Assuntos
Galinhas , Coccidiose/veterinária , Coccidiostáticos/farmacologia , Eimeria/fisiologia , Microbioma Gastrointestinal/fisiologia , Doenças das Aves Domésticas/prevenção & controle , Ácido Acético/química , Amprólio/farmacologia , Animais , Coccidiose/parasitologia , Coccidiose/prevenção & controle , Coccidiostáticos/química , Eimeria tenella/fisiologia , Sucos de Frutas e Vegetais , Jejuno/microbiologia , Malus/química , Doenças das Aves Domésticas/parasitologia , Chá/química
19.
Exp Parasitol ; 215: 107901, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32525007

RESUMO

Eimeria tenella (E. tenella) has caused severe economic loss in chicken production, especially after the forbidden use of antibiotics in feed. Considering the drug resistant problem caused by misuse of chemoprophylaxis and live oocyst vaccines can affect the productivity of chickens, also it has the risk to reversion of virulence, the development of efficacious, convenient and safe vaccines is still deeply needed. In this study, the EtMic2 protein of E. tenella was anchored on the surface of Lactobacillus plantarum (L. plantarum) NC8 strain. The newly constructed strain was then used to immunize chickens, followed by E. tenella challenge. The results demonstrated that the recombinant strain could provide efficient protection against E. tenella, shown by increased relative body weight gains, percentages of CD4+ and CD8+ T cells, humoral immune response and inflammatory cytokines. In addition, decreased cecum lesion scores and fecal oocyst shedding were also observed during the experiment. In conclusion, this study proves the possibility to use L. plantarum as a vessel to deliver protective antigen to protect chickens against coccidiosis.


Assuntos
Antígeno 12E7/imunologia , Galinhas/parasitologia , Coccidiose/veterinária , Eimeria tenella/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Protozoárias , Animais , Antígenos de Protozoários/imunologia , Ceco/parasitologia , Coccidiose/economia , Coccidiose/parasitologia , Coccidiose/prevenção & controle , Eimeria tenella/química , Citometria de Fluxo/veterinária , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Imunoglobulina A Secretora/biossíntese , Imunoglobulina G/sangue , Interferon gama/sangue , Interleucina-2/sangue , Intestinos/imunologia , Lactobacillus plantarum/genética , Lactobacillus plantarum/imunologia , Doenças das Aves Domésticas/economia , Doenças das Aves Domésticas/parasitologia , Distribuição Aleatória , Vacinas Sintéticas
20.
PLoS One ; 15(6): e0232831, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497096

RESUMO

The burden of enteric pathogens in poultry is growing after the ban of antibiotic use in animal production. Organic acids gained attention as a possible alternative to antibiotics due to their antimicrobial activities, improved nutrient metabolism and performance. The current study was conducted to evaluate the effectiveness of organic acid blend on broilers cecal microbiota, histomorphometric measurements, and short-chain fatty acid production in Salmonella enterica serovar Typhimurium challenge model. Birds were divided into four treatments, including a negative control, positive control challenged with S. Typhimurium, group supplemented with an organic acid blend, and birds supplemented with organic acid blend and Salmonella challenged. Results illustrate significant differences in feed conversion ratios and production efficiency factor between treatment groups, however, the influence of organic acid supplement was marginal. Organic acid blend significantly increased cecal acetic and butyric acids concentrations when compared to unsupplemented groups and resulted in minor alterations of intestinal bacterial communities.


Assuntos
Acetatos/metabolismo , Ração Animal , Butiratos/metabolismo , Galinhas/microbiologia , Suplementos Nutricionais , Ácidos Graxos/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Doenças das Aves Domésticas/terapia , Salmonelose Animal/terapia , Salmonella typhimurium/efeitos dos fármacos , Animais , Ceco/microbiologia , Galinhas/metabolismo , Ácidos Graxos/administração & dosagem , Ácidos Graxos Voláteis/administração & dosagem , Ácidos Graxos Voláteis/farmacologia , Íleo/metabolismo , Íleo/ultraestrutura , Mananas/administração & dosagem , Microvilosidades/ultraestrutura , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Distribuição Aleatória , Salmonelose Animal/microbiologia , Salmonelose Animal/prevenção & controle , Salmonella typhimurium/isolamento & purificação , Salmonella typhimurium/metabolismo
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