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1.
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
2.
PLoS One ; 15(9): e0239450, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32970714

RESUMO

BACKGROUND: Bone abnormality and leg disease in commercial broiler flocks are increasingly prominent, causing serious economic losses to the broiler breeding industry. Valgus-varus deformity (VVD) is a common deformity of the long bone in broilers that manifests as an outward or inward deviation of the tibiotarsus or tarsometatarsus. There is a paucity of studies on the molecular mechanisms of VVD. RESULTS: In this study, 6 cDNA libraries were constructed from spleen samples from VVD birds and normal birds. A total of 1951 annotated lncRNAs, 7943 novel lncRNAs and 30252 mRNAs were identified by RNA-sequencing. In addition, 420 differentially expressed (DE) mRNAs and 124 differentially expressed lncRNAs (adjusted P-value < 0.05) were obtained. A total of 16 dysregulated genes were confirmed by qPCR to be consistent with the results of the RNA-Seq. The functional lncRNA-mRNA co-expression network was constructed using differentially expressed mRNAs and target genes of the differentially expressed lncRNAs. 11 DE genes were obtained from the analysis. In order to gain insight into the interactions of genes, lncRNAs and pathways associated with VVD, we focused on the following pathways, which are involved in immunity and bone development: the Jak-stat signaling pathway, Toll-like receptor signaling pathway, Wnt-signaling pathway, mTOR signaling pathway, VEGF signaling pathway, Notch signaling pathway, TGF-beta signaling pathway and Fanconi anemia pathway. All together, 30 candidate DE genes were obtained from these pathways. We then analyzed the interaction between the DE genes and their corresponding lncRNAs. From these interaction network analyses we found that GARS, NFIC, PIK3R1, BMP6, NOTCH1, ACTB and CREBBP were the key core nodes of these networks. CONCLUSION: This study showed that differentially expressed genes and signaling pathways were related to immunity or bone development. These results increase the understanding of the molecular mechanisms of VVD and provide some reference for the etiology and pathogenesis of VVD.


Assuntos
Doenças Ósseas/genética , Doenças das Aves Domésticas/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Animais , Desenvolvimento Ósseo/genética , Doenças Ósseas/patologia , Galinhas/genética , Cromossomos/genética , Análise por Conglomerados , Regulação para Baixo , Biblioteca Gênica , Redes Reguladoras de Genes , Doenças das Aves Domésticas/patologia , RNA Longo não Codificante/química , RNA Mensageiro/química , Análise de Sequência de RNA , Baço/metabolismo , Transcriptoma , Regulação para Cima
3.
Virology ; 550: 1-7, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32853833

RESUMO

Avian coronavirus infectious bronchitis virus (IBV) is an important pathogen threatening poultry production worldwide. Here, two recombinant IBVs (rYN-1a-aYN and rYN-1b-aYN) were generated in which ORF1a or ORF1b of the virulent YN genome were replaced by the corresponding regions from the attenuated strain aYN. The pathogenicity and virulence of rIBVs were evaluated in ovo and in vivo. The results revealed that mutations in the ORF1a gene during passage in embryonated eggs caused the decreased pathogenicity of virulent IBV YN strain, proven by determination of virus replication in ECEs and CEK cells, the observation of clinical signs, gross lesions, microscopic lesions, tracheal ciliary activity and virus distribution in chickens following exposure to rIBVs. However, mutations in ORF1b had no obvious effect on virus replication in both ECEs and CEK cells, or pathogenicity in chickens. Our findings demonstrate that the replicase 1a gene of avian coronavirus IBV is a determinant of pathogenicity.


Assuntos
Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/patogenicidade , Doenças das Aves Domésticas/patologia , Vírus Reordenados/patogenicidade , Proteínas Virais/genética , Fatores de Virulência/genética , Animais , Linhagem Celular , Embrião de Galinha , Galinhas , Infecções por Coronavirus/patologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Cricetulus , Células Epiteliais/patologia , Células Epiteliais/virologia , Expressão Gênica , Vida Livre de Germes , Vírus da Bronquite Infecciosa/genética , Vírus da Bronquite Infecciosa/crescimento & desenvolvimento , Mutação , Doenças das Aves Domésticas/transmissão , Doenças das Aves Domésticas/virologia , Vírus Reordenados/genética , Vírus Reordenados/crescimento & desenvolvimento , Proteínas Virais/metabolismo , Virulência , Fatores de Virulência/metabolismo , Replicação Viral
4.
Arch Virol ; 165(10): 2249-2258, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32696270

RESUMO

While infectious bursal disease virus (IBDV) mainly targets immature B cells and causes T cell infiltration in the bursa of Fabricius (BF) of chickens, the effect of IBDV infection on the properties of T cells and relevant cytokine production in avian gut-associated lymphoid tissues (GALTs) remains unknown. Here, we show that while the CD8+ T cell subset is not affected, IBDV infection decreases the percentage of CD4+ T cells in the cecal tonsil (CT), but not in esophagus tonsil, pylorus tonsil, and Meckel's diverticulum of GALTs, in contrast to BF and spleen, in which the proportion of CD4+ cells increases upon IBDV infection. Further, IBDV infection upregulates IFN-γ, IL-10, and the T cell checkpoint receptor LAG-3 mRNA expression in BF. In contrast, in CTs, IBDV infection significantly increases the production of IFN-ß and CTLA-4 mRNA, while no significant effect is seen in the case of IFN-γ, IL-10 and LAG-3. Together, our data reveal differential modulation of T cell subsets and proinflammatory cytokine production in different lymphoid tissues during the course of IBDV infection.


Assuntos
Subpopulações de Linfócitos B/imunologia , Infecções por Birnaviridae/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Regulação da Expressão Gênica/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Subpopulações de Linfócitos B/virologia , Infecções por Birnaviridae/genética , Infecções por Birnaviridae/patologia , Infecções por Birnaviridae/virologia , Bolsa de Fabricius/imunologia , Bolsa de Fabricius/virologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Antígeno CTLA-4/genética , Antígeno CTLA-4/imunologia , Galinhas/virologia , Vírus da Doença Infecciosa da Bursa/crescimento & desenvolvimento , Vírus da Doença Infecciosa da Bursa/imunologia , Vírus da Doença Infecciosa da Bursa/patogenicidade , Interferon beta/genética , Interferon beta/imunologia , Interferon gama/genética , Interferon gama/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/virologia , Tonsila Palatina/imunologia , Tonsila Palatina/virologia , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia
5.
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
6.
Avian Dis ; 64(2): 203-209, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32550621

RESUMO

This article outlines pathomorphologic findings of a study involving commercial mule ducks with confirmed influenza A H5N8 infections after a series of outbreaks in Bulgaria. Examinations were carried out after performing necropsy on dead birds from three different age groups (up to 15, 20 to 30, and 40+ days of age) fattened on different farms. Among birds of all ages, gross lesions were present as lesions affecting the heart. Histologically, the myocardium exhibited severe intermyofibrillar edema, moderate to massive hemorrhages, and degenerative changes. All lesions resulted in single or multiple and small to massive myocardial infarctions. Other affected organs included the brain, lungs, liver, spleen, and pancreas. Nonpurulent lymphocytic encephalitis was found postmortem in ducks that had shown prior clinical nervous signs. Among ducks of all ages, a viral antigen in the cardiomyocytes and the epithelium of air capillaries was found through immunohistochemical detection methods. The results of the present study allowed us to conclude that the highly pathogenic avian influenza A H5N8 viral infection may manifest itself as a systemic illness in commercial mule ducks with septicemic lesions, resulting in high morbidity and mortality rates of up to 100%. Pathomorphologic lesions were somewhat different from those previously reported in wild waterfowl.


Assuntos
Patos , Vírus da Influenza A Subtipo H5N8/fisiologia , Influenza Aviária/patologia , Doenças das Aves Domésticas/patologia , Animais , Bulgária
7.
PLoS One ; 15(6): e0232781, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555739

RESUMO

In poultry production, birds are raised under intensive conditions, which can enable rapid spread of infections, with Clostridium perfringens-caused necrotic enteritis (NE) being one of the most devastating for the industry. The current investigation was conducted to evaluate the effectiveness of Bacillus subtilis PB6 probiotic supplementation on bird's post NE recovery, based on chicken performance, cecal microbiota composition, ileum histomorphometric measurements, and short-chain fatty acid production in the cecum of the birds that were challenged with NE mid-production. Birds were split into four groups, including a negative control, positive control challenged with C. perfringens, group supplemented with B. subtilis probiotic, and NE challenged birds supplemented with B. subtilis probiotic. Following NE challenge birds were allowed to reach the end of production time at 40 days, and samples were collected to estimate if probiotic supplementation resulted in better post-NE recovery. Intestinal lesion score across the duodenum, jejunum, and ileum indicated that at the end of production timeline NE challenged birds supplemented with B. subtilis probiotic had lower intestinal lesion scores compared to NE challenged birds without probiotic supplementation implying improved recovery. Probiotic supplementation improved performance of NE challenged birds only in the post-NE recovery stage. NE challenged birds had a significant increase in cecal propionic acid, which was not observed in NE challenged birds supplemented with B.subtilus. Both B. subtilis supplemented groups (challenged and unchanged) were characterized by a significant rise in cecal acetic and butyric acid. Our results demonstrate that B. subtilis supplementation can assist the birds in dealing with NE outbreak and long term recovery.


Assuntos
Bacillus subtilis , Infecções por Clostridium/veterinária , Clostridium perfringens , Enterite/veterinária , Doenças das Aves Domésticas/dietoterapia , Probióticos/administração & dosagem , Animais , Galinhas , Infecções por Clostridium/dietoterapia , Infecções por Clostridium/patologia , Suplementos Nutricionais , Enterite/dietoterapia , Enterite/patologia , Feminino , Microbioma Gastrointestinal , Intestinos/microbiologia , Intestinos/patologia , Masculino , Doenças das Aves Domésticas/patologia , Distribuição Aleatória
8.
PLoS One ; 15(4): e0230423, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236115

RESUMO

Campylobacter jejuni is one of the most prevalent causes of bacterial gastroenteritis worldwide, and it is largely associated with consumption of contaminated poultry. Current Campylobacter control measures at the poultry production level remain insufficient, and hence there is the need for alternative control strategies. We evaluated the potential of the monoterpene (-)-α-pinene for control of C. jejuni in poultry. The antibacterial and resistance-modulatory activities of (-)-α-pinene were also determined against 57 C. jejuni strains. In addition, the anti-quorum-sensing activity of (-)-α-pinene against C. jejuni NCTC 11168 was determined for three subinhibitory concentrations (125, 62.5, 31.25 mg/L) over three incubation times using an autoinducer-2 bioassay based on Vibrio harveyi BB170 bioluminescence measurements. The effects of a subinhibitory concentration of (-)-α-pinene (250 mg/L) on survival of C. jejuni, and in combination with enrofloxacin on fluoroquinolone resistance development in C. jejuni, were determined in a broiler chicken model, by addition of (-)-α-pinene to the broiler water supply. The reduction of C. jejuni numbers by (-)-α-pinene was further determined in broiler chickens that were colonized with either fluoroquinolone-susceptible or -resistant strains, by direct gavage treatment. We observed weak in vitro antimicrobial activity for (-)-α-pinene alone (MIC >500 mg/L), but strong potentiating effects on antibiotics erythromycin and ciprofloxacin against different Campylobacter strains (>512 fold change). After 24 h of treatment of C. jejuni with (-)-α-pinene, its quorum-sensing signaling was reduced by >80% compared to the untreated control. When given in the drinking water, (-)-α-pinene did not show any significant inhibitory effects on the level of C. jejuni in the colonized chickens, and did not reduce fluoroquinolone resistance development in combination with enrofloxacin. Conversely, when (-)-α-pinene was administered by direct gavage, it significantly reduced the number of fluoroquinolone susceptible C. jejuni in the colonized broiler chickens. These results demonstrate that (-)-α-pinene modulates quorum-sensing in Campylobacter, potentiates antibiotics against different Campylobacter strains, and reduces Campylobacter colonization in broiler chickens.


Assuntos
Antibacterianos/farmacologia , Monoterpenos Bicíclicos/farmacologia , Campylobacter jejuni/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Animais , Antibacterianos/uso terapêutico , Monoterpenos Bicíclicos/uso terapêutico , Infecções por Campylobacter/patologia , Infecções por Campylobacter/prevenção & controle , Campylobacter jejuni/fisiologia , Ceco/microbiologia , Galinhas , Ciprofloxacino/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Eritromicina/farmacologia , Fluoroquinolonas/farmacologia , Fluoroquinolonas/uso terapêutico , Testes de Sensibilidade Microbiana , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/prevenção & controle
9.
J Vet Diagn Invest ; 32(3): 389-393, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32233842

RESUMO

Reticuloendotheliosis virus (REV) can cause runting, immunosuppression, acute reticulum cell neoplasia, and chronic lymphoid tumors in a variety of domestic and wild birds. We diagnosed a case of reticuloendotheliosis with obvious tumors in liver and kidney. We isolated and sequenced the virus and performed pathogenicity testing of the REV strain. Immunohistochemistry and PCR confirmed that the diseased layer chickens were infected with REV. The strain, named BJ1503, was successfully isolated from the case by inoculation of tissue homogenates onto chicken embryo fibroblasts. The length of the proviral REV genome is 8,293 nucleotides. The isolate had 99.7% identity with REV-HA9901 (AY842951.1), which was isolated from Jiangsu, China, in 1999. The chickens infected with REV-BJ1503 had depressed weight gain and lymphoid atrophy. Our findings suggest that REV isolate BJ1503 was phylogenetically close to the earlier strain found in China, with minor variations, and the virus was associated with severe production problems.


Assuntos
Galinhas , Doenças das Aves Domésticas/virologia , Vírus da Reticuloendoteliose Aviária/isolamento & purificação , Vírus da Reticuloendoteliose Aviária/patogenicidade , Infecções por Retroviridae/veterinária , Infecções Tumorais por Vírus/veterinária , Animais , China , Feminino , Filogenia , Doenças das Aves Domésticas/patologia , Infecções por Retroviridae/patologia , Infecções por Retroviridae/virologia , Análise de Sequência de RNA/veterinária , Infecções Tumorais por Vírus/patologia , Infecções Tumorais por Vírus/virologia , Virulência
10.
Poult Sci ; 99(4): 1946-1955, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241475

RESUMO

Providing environmental enrichment for broilers is a potential strategy to increase welfare, activity, and health. The aim of this study was to evaluate the effect of environmental enrichment on health and leg bone characteristics of broilers. One control and 8 types of enrichment were included: 2 distances between food and water (7 and 3.5 m), roughage, vertical panels, straw bales, 2 platforms (30 and 5 cm), and a lowered stocking density (34 kg/m2). Birds were kept according to conventional Danish guidelines. The study included 58 pens with approximately 500 birds each. On day 35 of age, 25 birds per pen were killed and included in a postmortem analysis of wooden breast, body condition scores, pathological conditions (femoral head necrosis, arthritis, tenosynovitis, fractures, tibial dyschondroplasia, and twisted tibiotarsus), muscle width of the lower leg, and tibiotarsus properties (bone strength, weight, length, and proximal diameter, middle diameter, and distal diameter). It was predicted that environmental enrichment would have a positive effect on pathology with the exceptions that environmental enrichment that increased activity would pose a risk factor for wooden breast development, and straw bales would be a risk factor for bacterial infections (arthritis, tenosynovitis, and femoral head necrosis). Furthermore, it was hypothesized that enriched groups would have increased muscle width, bone strength, and dimensions of the tibiotarsus. Broilers with 7 m between food and water had a longer distal diameter of the tibiotarsus than those with straw bales (P = 0.04). The birds provided with vertical panels had wider leg muscle than the treatments with roughage (P = 0.045), 3.5 m distance (P = 0.049), and straw bales (P = 0.044). No effects were found for the remaining outcomes. These results suggest that provision of vertical panels and increased distance between resources can result in larger muscle and bone dimension, possibly having a positive effect on leg health. Furthermore, the provision of environmental enrichment does not appear to be a risk factor for wooden breast or bacterial infection.


Assuntos
Bem-Estar do Animal , Desenvolvimento Ósseo , Galinhas/fisiologia , Abrigo para Animais , Animais , Osso e Ossos/patologia , Osso e Ossos/fisiologia , Galinhas/crescimento & desenvolvimento , Doenças das Aves Domésticas/etiologia , Doenças das Aves Domésticas/patologia
11.
PLoS One ; 15(3): e0230676, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32231395

RESUMO

Salmonella Heidelberg is commonly reported in foodborne outbreaks around the world, and chickens and poultry products are known as important source of these pathogen. Multidrug-resistant S. Heidelberg strains are disseminated into poultry production chair, which can lead to severe clinical infections in humans and of difficult to treat. This study aimed at evaluating the ß-lactam susceptibility and genotypic relatedness of Salmonella Heidelberg at Brazilian poultry production chain. Sixty-two S. Heidelberg strains from poultry production chain (poultry, poultry meat and poultry farm) were used. All strains were evaluated to antimicrobial susceptibility by diffusion disk test, as well as ß-lactam resistance genes. Genotypic relatedness was assessed by Pulsed-Field Gel Eletrophoresis, using Xba1 restriction enzyme. Forty-one strains were characterized as multidrug-resistant according to phenotype characterization. The resistance susceptibility revealed 31 distinct profiles, with higher prevalence of streptomycin (61/62), nalidixic acid (50/62), tetracycline (43/62) and ß-lactam drugs (37/62). blaCMY-2 was the more frequent ß-lactamase gene found (38/62); other resistance genes found were blaCTX-M (2/62), blaSHV (3/62) and blaTEM-1 (38/62). No carbapenemase genes was found. The Pulsed-Field Gel Electrophoresis showed 58 different profiles. Strains with a larger number of antimicrobial resistance were grouped into ten major clusters apart from others. The spread of resistance by ampC continues to rise, thereby turning concern to public health, since the ß-lactam antimicrobials are used as a therapeutic treatment in humans.


Assuntos
Farmacorresistência Bacteriana Múltipla , Doenças das Aves Domésticas/microbiologia , Salmonella/enzimologia , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Brasil , Galinhas , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Genótipo , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Doenças das Aves Domésticas/patologia , Salmonella/efeitos dos fármacos , Salmonella/genética , Salmonella/isolamento & purificação , Estreptomicina/farmacologia , beta-Lactamases/metabolismo , beta-Lactamas/farmacologia
12.
Poult Sci ; 99(3): 1724-1733, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32111334

RESUMO

The effects of spaghetti meat (SM) myopathy and sampling location on chicken breast meat physical traits, composition, and protein functionality were investigated using 30 normal (N) and 30 SM boneless fillets. Weight, drip loss, pH, and color traits were determined on intact fillets. Proximate composition, water holding capacity, mineral profile, SDS-PAGE, myofibrillar, and sarcoplasmic protein solubility, and emulsifying properties were assessed on both the superficial (S) and deep (D) layers of the breasts. SM fillets were heavier (P < 0.0001) and exhibited greater drip loss (P = 0.0131) and higher b* index on the skin side of the muscle (P < 0.0001). Muscle condition by layer interaction effect revealed that the superficial portion of SM fillets (SM-S) exhibited the highest moisture (P = 0.0003) and fat contents (P = 0.0011) coupled with the lowest protein (P < 0.0001) and ash contents (P = 0.0458). Total and soluble collagen amounts were higher in N-S and SM-S groups compared with N-D and SM-D (P < 0.0001). SM-S group exhibited the highest calcium (P = 0.0035) and sodium (P < 0.0001) levels. Overall, the myopathy had only minor impacts on protein profiles, while the muscle layer exerted a more remarkable effect. SM fillets exhibited higher pH but a lower myofibrillar protein solubility (P < 0.0001). Salt-induced water uptake, cooking loss, and final yield values suggested a potential impairment of water-holding capacity in SM-affected meat. Sarcoplasmic and myofibrillar emulsion activity indexes were similar between the 2 muscle conditions, but the stability of the emulsions was lower in SM meat. Overall, significant layer and muscle condition by layer effects were not observed in the functional properties of the breast meat. SM exerted a profound and negative impact on breast meat composition that led to detrimental consequences on functionality traits. Given the fundamental role of protein quality for meat processing, these data suggest that a further step toward the understanding of this myopathy should be the investigation of intrinsic protein characteristics.


Assuntos
Carne/análise , Doenças Musculares/veterinária , Músculos Peitorais/patologia , Animais , Galinhas , Culinária , Qualidade dos Alimentos , Carne/normas , Proteínas Musculares , Doenças Musculares/patologia , Doenças das Aves Domésticas/patologia , Proteínas de Aves Domésticas , Água
13.
Res Vet Sci ; 130: 144-152, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32179292

RESUMO

Avian pathogenic Escherichia coli (APEC) can lead to extraintestinal disease in avian species via respiratory tract infection. However, the regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium remains unknown. In this study, we examined pathological changes in chicken trachea at different infection times (4, 8, 12 and 24 h). The RNA sequencing of APEC infection group and the PBS group (negative control) of chicken trachea epithelium were analysed. Our studies revealed that the oedema, heterophil infiltration and hyperaemia appeared at 8 and 12 h post APEC infection. And the hyperaemia phenomenon and heterophilic granulocyte infiltration disappeared at 24 h post infection. Then RNA sequencing showed many genes were dynamically expressed in the APEC infection group. At 4, 8 and 12 h post infection, the mRNA of differentially expressed genes were enriched by cytokine-cytokine receptor interaction and the toll-like receptor signalling pathway. The cell cycle pathway was enriched at 24 h post infection. Altogether, these findings suggest that APEC infection induces pathological change in the chicken trachea, the mRNA of differentially expressed genes participating in inflammation and hyperplasia signalling pathways. Which not only provide more evidence for regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium, but also facilitate the effective management of APEC infections in poultry through trachea.


Assuntos
Proteínas Aviárias/metabolismo , Galinhas , Citocinas/metabolismo , Infecções por Escherichia coli/veterinária , Doenças das Aves Domésticas/patologia , Receptores de Citocinas/metabolismo , Doenças da Traqueia/veterinária , Animais , Ciclo Celular , Escherichia coli/fisiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/fisiopatologia , Feminino , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/fisiopatologia , RNA Mensageiro/metabolismo , Traqueia/patologia , Traqueia/fisiopatologia , Doenças da Traqueia/microbiologia , Doenças da Traqueia/patologia , Doenças da Traqueia/fisiopatologia
14.
J Virol ; 94(11)2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32213616

RESUMO

Different from other subgroups of avian leukosis viruses (ALVs), ALV-J is highly pathogenic. It is the main culprit causing myeloid leukemia and hemangioma in chickens. The distinctiveness of the env gene of ALV-J, with low homology to those of other ALVs, is linked to its unique pathogenesis, but the underlying mechanism remains unclear. Previous studies show that env of ALV-J can be grouped into three species based on the tyrosine motifs in the cytoplasmic domain (CTD) of Gp37, i.e., the inhibitory, bifunctional, and active groups. To explore whether the C terminus or the tyrosine motifs in the CTD of Gp37 affect the pathogenicity of ALV-J, a set of ALV-J infectious clones containing different C termini of Gp37 or the mutants at the tyrosine sites were tested in vitro and in vivo Viral growth kinetics indicated not only that ALV-J with active env is the fastest in replication and ALV-J with inhibitory env is the lowest but also that the tyrosine sites essentially affected the replication of ALV-J. Moreover, in vivo studies demonstrated that chickens infected by ALV-J with active or bifunctional env showed higher viremia, cloacal viral shedding, and viral tissue load than those infected by ALV-J with inhibitory env Notably, the chickens infected by ALV-J with active or bifunctional env showed significant loss of body weight compared with the control chickens. Taken together, these findings reveal that the C terminus of Gp37 plays a vital role in ALV-J pathogenesis, and change from inhibitory env to bifunctional or active env increases the pathogenesis of ALV-J.IMPORTANCE ALV-J can cause severe immunosuppression and myeloid leukemia in infected chickens. However, no vaccine or antiviral drug is available against ALV-J, and the mechanism for ALV-J pathogenesis needs to be elucidated. It is generally believed that gp85 and LTR of ALV contribute to its pathogenesis. Here, we found that the C terminus and the tyrosine motifs (YxxM, ITIM, and ITAM-like) in the CTD of Gp37 of ALV-J could affect the pathogenicity of ALV-J in vitro and in vivo The pathogenicity of ALV-J with Gp37 containing ITIM only was significantly less than ALV-J with Gp37 containing both YxxM and ITIM and ALV-J with Gp37 containing both YxxM and ITAM-like. This study highlights the vital role of the C terminus of Gp37 in the pathogenesis of ALV-J and thus provides a new perspective to elucidate the interaction between ALV-J and its host and a molecular basis to develop efficient strategies against ALV-J.


Assuntos
Vírus da Leucose Aviária/metabolismo , Vírus da Leucose Aviária/patogenicidade , Leucose Aviária/metabolismo , Doenças das Aves Domésticas/metabolismo , Proteínas do Envelope Viral/metabolismo , Motivos de Aminoácidos , Animais , Leucose Aviária/genética , Leucose Aviária/patologia , Vírus da Leucose Aviária/genética , Linhagem Celular , Galinhas , Mutação , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/patologia , Domínios Proteicos , Proteínas do Envelope Viral/genética
15.
Parasitol Int ; 76: 102098, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32120051

RESUMO

Sarcocistys -associated menigoencephalitis is virtually an unrecognized cause of neurological disease in chickens. An undescribed species of Sarcocystis cause fatal infection in two backyard chickens in the Midwest of Brazil. Infected chickens presented anorexia, weight loss, incoordination, ataxia and opisthotonos. Yellow necrotic foci in the gray and white matter of the telencephalon were the main gross lesion. Microscopically, necrotizing granulomatous and heterophilic meningoencephalitis with intralesional Sarcocystis -like schizonts and mezoites were observed in the central nervous system. Molecular analysis of frozen brain samples of the two chickens was identical and the protozoan was named Sarcocystis sp. Chicken-2016-DF-BR. Complete nested PCR- sequence of Sarcocystis sp. Chicken-2016-DF-BR was equally similar to Sarcocystis anasi (EU553477) and Sarcocystis albifronsi (EU502868). This is the first report of Sarcocistys -associated meningoencephalitis with molecular characterization in backyard chickens.


Assuntos
Galinhas , Meningoencefalite/veterinária , Doenças das Aves Domésticas/diagnóstico , Sarcocystis/classificação , Animais , Encéfalo/parasitologia , Encéfalo/patologia , Brasil , Feminino , Masculino , Meningoencefalite/diagnóstico , Meningoencefalite/parasitologia , Meningoencefalite/patologia , Necrose/diagnóstico , Necrose/parasitologia , Necrose/patologia , Necrose/veterinária , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/parasitologia , Doenças das Aves Domésticas/patologia , Sarcocystis/fisiologia
16.
J S Afr Vet Assoc ; 91(0): e1-e4, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32129635

RESUMO

A feather cyst in the cervical region which, through complications of inward growth, resulted in compression of the cervical spinal cord of a Lohmann Brown layer is described. It is postulated that expansion of the cyst exerted pressure on the adjacent cervical vertebra and through bone lysis created an opening through which the cyst protruded, thereby exerting pressure on the spinal cord. The affected spinal cord segment was reduced to a fifth of its normal diameter. The bird most likely died of starvation because of limb and neck paralysis and disorientation. Although the cause of the feather cyst was not conclusively identified, moulting and trauma could have triggered its formation and subsequent growth.


Assuntos
Doenças Ósseas/veterinária , Vértebras Cervicais/patologia , Galinhas , Cistos/veterinária , Doenças das Aves Domésticas , Compressão da Medula Espinal/veterinária , Animais , Doenças Ósseas/complicações , Doenças Ósseas/etiologia , Doenças Ósseas/patologia , Cistos/complicações , Cistos/etiologia , Cistos/patologia , Plumas , Feminino , Doenças das Aves Domésticas/etiologia , Doenças das Aves Domésticas/patologia , Compressão da Medula Espinal/patologia
17.
Poult Sci ; 99(2): 886-892, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32036984

RESUMO

Coccidiosis has been a pervasive disease within the poultry industry, with test parameters used to measure effectiveness of treatment strategies often being subjective or influenced by non-disease-related activity. Four experiments were completed, which examined several test parameters of coccidiosis, including body weight gain (BWG), lesion scores, and oocysts per gram of feces (OPG). Each experiment included at least 2 parameters for measuring coccidial infection in chickens and turkeys. In experiment 1, an inoculated control was measured against 3 anticoccidial groups, whereas in experiments 2 to 4, noninoculated and inoculated controls were compared via BWG and OPG. Lesion scores were also included in experiments 1, 3, and 4. Experiment 4 resulted in high correlation, via Pearson correlation coefficient, between BWG and OPG (r = -0.69), very high correlation between OPG and lesion score (r = 0.86), and moderate correlation between BWG and lesion score (r = -0.49). Lesion scores proved to be effective in confirming Eimeria infection, although they did not correlate well with BWG or OPG. Each parameter tended to provide more useful information when lined up with the Eimeria life cycle. Incorporation of OPG, with BWG and lesion scores, as test parameters to measure coccidiosis intervention strategies, provides a global description of disease that may not otherwise be observed with the 2 latter measurements alone.


Assuntos
Galinhas , Coccidiose/veterinária , Eimeria/fisiologia , Fezes/parasitologia , Doenças das Aves Domésticas/patologia , Perus , Ganho de Peso , Animais , Coccidiose/parasitologia , Coccidiose/patologia , Oocistos/isolamento & purificação , Doenças das Aves Domésticas/parasitologia , Distribuição Aleatória
18.
J Virol ; 94(8)2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-32024774

RESUMO

Tembusu virus (TMUV) is a flavivirus responsible for panzootic outbreaks of severe egg-drop and fatal encephalitis of domestic waterfowl in China. Although TMUV can be attenuated by in vitro passaging, experimental evidence supporting the role of specific genetic changes in virulence attenuation is currently lacking. Here, we performed site-directed mutagenesis on five envelope (E) protein amino acid residues in accordance with the attenuated TMUV generated in our recent study. Our results showed that the Thr-to-Lys mutation of residue 367 in E protein (E367) plays a predominant role in viral cell adaptation and virulence attenuation in ducks compared with mutations in other residues. We further demonstrated that the positively charged basic amino acid substitution at E367 enhanced the viral binding affinity for glycosaminoglycans (GAGs) and reduced viremia levels and the efficiency of replication in major target organs in subcutaneously inoculated ducks. Interestingly, the T367K mutation increased viral neutralization sensitivity to the early immune sera. Together, our findings provide the first evidence that a basic amino acid substitution at E367 strongly impacts the in vitro and in vivo infection of TMUV.IMPORTANCE Outbreaks of Tembusu virus (TMUV) infection have caused huge economic losses in the production of domestic waterfowl since the virus was first recognized in China in 2010. To control TMUV infection, a live-attenuated vaccine candidate of TMUV was developed in our previous study, but the mechanisms of virulence attenuation are not fully understood. Here, we found that the Thr-to-Lys substitution at E367 is a crucial determinant of TMUV virulence attenuation in ducks. We demonstrated that the T367K mutation attenuates TMUV through reducing viral replication in the blood, brain, heart (ducklings), and ovaries. These data provide new insights into understanding the pathogenesis of TMUV and the rational development of novel TMUV vaccines.


Assuntos
Substituição de Aminoácidos , Infecções por Flavivirus/imunologia , Infecções por Flavivirus/virologia , Flavivirus/genética , Proteínas do Envelope Viral/genética , Substituição de Aminoácidos/imunologia , Animais , Anticorpos Neutralizantes , Linhagem Celular , China/epidemiologia , Patos/virologia , Feminino , Infecções por Flavivirus/epidemiologia , Infecções por Flavivirus/patologia , Mutagênese Sítio-Dirigida , Mutação , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/mortalidade , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , Carga Viral , Virulência , Replicação Viral
19.
Arch Virol ; 165(4): 835-843, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32025807

RESUMO

Avian infectious bronchitis virus (IBV) is a coronavirus with great economic impact on the poultry industry, causing an acute and highly contagious disease in chickens that primarily affects the respiratory and reproductive systems. The cellular regulation of IBV pathogenesis and the host immune responses involved remain to be fully elucidated. MicroRNAs (miRNAs) have emerged as a class of crucial regulators of numerous cellular processes, including responses to viral infections. Here, we employed a high-throughput sequencing approach to analyze the miRNA composition of the spleen and the lungs of chicken embryos upon IBV infection. Compared to healthy chicken embryos, 13 and six miRNAs were upregulated in the spleen and the lungs, respectively, all predicted to influence viral transcription, cytokine production, and lymphocyte functioning. Subsequent downregulation of NFATC3, NFAT5, SPPL3, and TGFB2 genes in particular was observed only in the spleen, demonstrating the biological functionality of the miRNAs in this lymphoid organ. This is the first study that describes the modulation of miRNAs and the related host immune factors by IBV in chicken embryos. Our data provide novel insight into complex virus-host interactions and specifically highlight components that could affect the host's immune response to IBV infection.


Assuntos
Infecções por Coronavirus/veterinária , Gammacoronavirus/fisiologia , MicroRNAs/imunologia , Óvulo/virologia , Doenças das Aves Domésticas/imunologia , Animais , Galinhas , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Citocinas/genética , Citocinas/imunologia , Gammacoronavirus/genética , Pulmão/imunologia , Pulmão/patologia , MicroRNAs/genética , Óvulo/imunologia , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , Baço/imunologia , Baço/patologia
20.
Transbound Emerg Dis ; 67(4): 1442-1446, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32068970

RESUMO

Reticuloendotheliosis virus (REV) has a wide range of avian hosts leading to reticuloendotheliosis, and its characteristic of vertical transmission makes it to be one of the most important diseases in breeder avian populations. Up to date, reports on neoplastic disease caused by REV in breeding ducks are few. Here, spontaneously occurring neoplastic disease caused by REV in breeding Muscovy ducks was reported in Guangdong province, China. The most significant gross lesions of sick ducks were tumour-bearing liver and enlarged spleen. Histopathological examination found proliferation of malignant lymphoreticular cells in the liver and reticuloendothelial cells in the spleen. REV strain, CH-GD2019, was successfully isolated using DF-1 cells, and the presence of REV was confirmed by PCR detection and transmission electron microscopy. The length of complete proviral genome is 8,238 nucleotides. Genetic and phylogenetic analyses revealed that CH-GD2019 was closely related to chicken-origin REV strains circulating in China. The results will provide a basic data for better understanding of REV in breeding ducks and suggest that REV from chickens may be a threat to ducks.


Assuntos
Galinhas/virologia , Neoplasias/veterinária , Doenças das Aves Domésticas/virologia , Vírus da Reticuloendoteliose/isolamento & purificação , Animais , Cruzamento , China/epidemiologia , Patos , Neoplasias/epidemiologia , Neoplasias/patologia , Neoplasias/virologia , Filogenia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/patologia , Vírus da Reticuloendoteliose/genética
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