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1.
Vet Parasitol ; 273: 105-111, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31473449

RESUMO

Diclazuril, which is widely used for the prevention of coccidiosis in chickens, has a lethal effect on asexual and sexual stages of Eimeria spp. However, little is known about its effect on the exogenous stages of Eimeria spp. In this study, we evaluated the effect of in vitro treatment with 0.2% diclazuril on unsporulated and sporulated oocysts of Eimeria spp. For this purpose, a total of 180 male layer chicks aged one day were randomly divided into 5 experimental groups. Each group was divided into 3 replicates of 12 chicks each. Group 1 (G1) and Group 2 (G2) were negative (non-immunized and non-challenged) and positive (non-immunized and challenged) controls, respectively. Group 3 (G3) was immunized per os with 1.0 × 104 non-diclazuril treated-sporulated oocysts. Groups 4 (G4) was immunized per os with 0.2% diclazuril treated-unsporulated oocysts (1.0 × 104) in which diclazzuril didn't affect sporulation. Group 5 (G5) was immunized per os with 0.2% diclazuril treated-sporulated oocysts (1.0 × 104). Chicks of G2, G3, G4, and G5 were challenged with 7.5 × 104 untreated sporulated oocysts at the age of 21 days, while the group 1 chicks remained unchallenged. G4 and G5 animals immunized with 0.2% diclazuril-treated oocysts showed a significant decrease in bloody diarrhea severity, lesion scores, and oocyst counts in comparison to those immunized with untreated oocysts. Furthermore, histopathologic findings showed a low number of parasitic stages in cecal tissues in G4 and G5. A significant increased body weight gain was observed in Gs 4 and 5 in comparison to G2. In addition, expression levels of IL-2, IL-12, and IFN-γ were significantly increased in G4 and G5. In conclusion, diclazuril is effective in attenuating Eimeria oocysts and thus provides an alternative approach for using diclazuril-treated oocysts to protect chicks against Eimeria challenge.


Assuntos
Coccidiose/veterinária , Eimeria/efeitos dos fármacos , Nitrilos/farmacologia , Oocistos/efeitos dos fármacos , Doenças das Aves Domésticas , Triazinas/farmacologia , Animais , Ceco/parasitologia , Galinhas , Coccidiose/parasitologia , Coccidiose/prevenção & controle , Eimeria/patogenicidade , Masculino , Doenças das Aves Domésticas/parasitologia , Doenças das Aves Domésticas/prevenção & controle , Distribuição Aleatória , Virulência/efeitos dos fármacos
2.
Acta Vet Scand ; 61(1): 41, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455410

RESUMO

BACKGROUND: Villegas-Glisson/University of Georgia (VG/GA) strain of Newcastle disease virus (NDV) is recommended for the initial vaccination of commercially reared turkey poults. However, the vaccine-induced antibody responses have not been studied in this species. The level of systemic humoral immune responses against the NDV was investigated in commercial turkey poults vaccinated with the VG/GA vaccine. One hundred eighty-two hybrid strain of turkey poults (Meleagris gallopavo) were divided randomly into vaccinated and unvaccinated groups. The vaccinated group was given the VG/GA vaccine at 10 and 20 days of age. To investigate the vaccine immunity, the level of specific IgY and IgA in serum samples were determined using ELISA and haemagglutination inhibition assays (HI). The biological half-life of maternal antibodies was also determined before the immunization. RESULTS: VG/GA-specific antibodies were detected in the vaccinated turkey poults and were significantly higher in the vaccinated group compared to the unvaccinated group. IgY and IgA antibodies showed a significant increase in titers 14 days after the second vaccination and reached a peak on day 35 of age. The correlation coefficient and intra-rater reliability showed a significant correlation between the HI titers and IgY/IgA ELISA values. Maternal IgY and IgA levels were found to decline in the serum with half-lifes of 7.68 ± 2.35 and 2.18 ± 0.82 days, respectively. CONCLUSIONS: Enterotropic lentogenic VG/GA vaccine induced a marked humoral immune response against the NDV in turkey poults. The positive correlation between IgY and IgA highlights the role of these two antibody classes in controlling the Newcastle disease in turkey poults.


Assuntos
Imunidade Humoral/imunologia , Doença de Newcastle/imunologia , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/imunologia , Perus , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Doença de Newcastle/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle
3.
BMC Vet Res ; 15(1): 271, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370846

RESUMO

BACKGROUND: Fowl adenoviruses (FAdVs) are associated with many diseases, resulting in huge economic losses to the poultry industry worldwide. Since 2015, outbreaks of FAdV infections with high mortality rates have been reported in China. A continued surveillance of FAdVs contributes to understand the epidemiology of the viruses. RESULTS: We isolated 155 FAdV strains from diseased chickens from poultry in China between 2015 and 2018. PCR analysis determined that 123 samples were FAdV species C, 27 were FAdV species E, and five contained two different FAdV strains. The phylogenetic analysis demonstrates that these sequences of hexon regions were clustered into three distinct serotypes: FAdV-4 (79.4%, 123/155), FAdV-8a (13.5%, 21/155) and FAdV-8b (3.9%, 6/155), of which FAdV-4 was the dominant serotype in China. CONCLUSIONS: The characterization of newly prevalent FAdV strains provides valuable information for the development of an effective control strategy for FAdV infections in chickens.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/classificação , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/prevenção & controle , Infecções por Adenoviridae/virologia , Animais , Aviadenovirus/isolamento & purificação , Galinhas , China/epidemiologia , Filogenia , Doenças das Aves Domésticas/prevenção & controle , Sorogrupo
4.
Poult Sci ; 98(9): 3504-3513, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31329978

RESUMO

The nutritional cost of activating B cell-mediated immunity is thought to be low in chickens. However, this assumption is incompletely characterized. Immunoglobulin knockout (Ig-KO) chickens lacking B cells and immunoglobulin may potentially be a robust model to investigate the nutritional cost of immunity. Specifically, comparing the growth of Ig-KO chickens to immunocompetent birds (WT) following activation of the immune system should indicate costs associated with B cell-mediated immunity. A total of 3 experiments were conducted to determine if (1) an antibody response to keyhole limpet hemocyanin (KLH), (2) an intra-abdominal injection with Salmonella enterica serovar Enteritidis (SE), or (3) an oral challenge of SE would affect body weight gain (BWG) in homozygous Ig-KO (KO) chickens and their immunocompetent counterparts. In Experiment 1, a significant genotype*vaccination status interaction was observed (P = 0.03) during the period from 0 to 6 D after initial vaccination in which KLH injection reduced BWG in WT birds, but not in KO birds. A genotype*vaccination status interaction was present (P = 0.002) from 0 to 7 D after the first booster in which KLH injection due to reduced BWG in KO birds, but not WT birds. In Experiment 2, both KO and immunocompetent birds lost body weight during the period from 0 to 2 D after the SE injection, with no significant differences due to genotype (P = 0.92). Experiment 3 demonstrated that KO birds gained less weight than immunocompetent birds, with a tendency for less weight gain after an initial challenge (P = 0.07) and significantly so after a secondary challenge (P = 0.03). The results from these experiments collectively demonstrate that B cell-mediated immunity can affect growth performance in chickens. Furthermore, these effects can either preserve or impair growth performance, likely via mechanisms related to the immune response rather than the discrete nutritional cost of B cell-mediated immunity.


Assuntos
Galinhas/imunologia , Hemocianinas/uso terapêutico , Doenças das Aves Domésticas/prevenção & controle , Salmonelose Animal/prevenção & controle , Vacinação/veterinária , Administração Oral , Animais , Galinhas/crescimento & desenvolvimento , Doenças das Aves Domésticas/imunologia , Salmonelose Animal/imunologia , Salmonella enteritidis/efeitos dos fármacos
5.
Parasit Vectors ; 12(1): 347, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300007

RESUMO

BACKGROUND: Live anticoccidial vaccines have been a tremendous success for disease prevention. The establishment of the reverse genetic manipulation platform has enabled the development of Eimeria parasites, the live anticoccidial vaccine strains, as vaccine vectors. In our previous study, recombinant E. tenella expressing a single immunodominant antigen of E. maxima (Et-EmIMP1) was able to protect chickens against challenge infection with E. maxima. This promising result encouraged us to further explore strategies to improve the protection efficacy of recombinant Eimeria and develop it as a vaccine vector. RESULTS: We constructed a novel recombinant Eimeria line expressing apical membrane antigen 1 of E. maxima (Et-EmAMA1) and then immunized chickens with Et-EmAMA1 and/or Et-EmIMP1. We found that the E. maxima soluble antigen-specific cell-mediated immunity was much stronger in the birds that were co-immunized with Et-EmAMA1 and Et-EmIMP1 than in those that were immunized with Et-EmAMA1 or Et-EmIMP1 alone. The oocyst production after E. maxima infection was significantly reduced in the recombinant Eimeria-immunized birds compared with the wild-type-immunized and naïve birds. The oocyst production in the birds co-immunized with Et-EmAMA1 and Et-EmIMP1 was consistently the lowest among the treatment groups after E. maxima infection. CONCLUSIONS: These results demonstrated that Eimeria is an effective vaccine vector that can carry and deliver heterologous Eimeria antigens to the host immune system and trigger specific immune responses. Our results also suggested that increasing the number of recombinant Eimeria lines is an effective approach to enhance protective immunity against infections with heterologous pathogens.


Assuntos
Coccidiose/veterinária , Eimeria tenella/genética , Eimeria/genética , Imunidade Celular , Doenças das Aves Domésticas/prevenção & controle , Vacinas Protozoárias/imunologia , Animais , Antígenos de Protozoários/imunologia , Galinhas , Coccidiose/prevenção & controle , Eimeria/imunologia , Eimeria tenella/imunologia , Doenças das Aves Domésticas/imunologia , Organismos Livres de Patógenos Específicos , Vacinas Atenuadas , Vacinas Sintéticas
6.
Vet Microbiol ; 233: 118-123, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176397

RESUMO

The vast capacity for maintenance and dissemination in the environment are major challenges for the control of Salmonella spp. in poultry farms. The aim of this study was to assess environmental contamination by non-typhoidal Salmonella in successive broiler flocks in nine commercial broiler farms integrated with three companies in the south of Brazil, for a twelve-month production period. Recycled broiler litter, feed and swabs from the evaporative cooling system pads were analyzed, and the total enterobacteria count in the litter samples was ascertained. Positive broiler houses were identified in two of the three broiler companies studied, in which non-typhoidal Salmonella were detected for the first time in the first or second flock, and recurred in the recycled litter of subsequent flocks. Feed and evaporative cooling pad swab samples were also positive in at least one of the assessed flocks. The majority of the isolates (87.5%) originating from different flocks, broiler houses and companies that were sampled were identified as S. Heidelberg, with the prevalence of one single genotype. The total enterobacteria levels in the litter diminished as the flocks progressed, but the presence of Salmonella spp. was constant over the course of time, indicating that the litter management procedures were not capable of interrupting the cycle of residual contamination. The predominance of S. Heidelberg highlights its emergence and dissemination in this region, as well as its resistance and maintenance in the environment, and reinforces the need to improve prevention and recycled litter management measures.


Assuntos
Galinhas/microbiologia , Microbiologia Ambiental , Aves Domésticas/microbiologia , Salmonelose Animal/epidemiologia , Salmonella/genética , Criação de Animais Domésticos , Animais , Brasil/epidemiologia , Genótipo , Abrigo para Animais/normas , Estudos Longitudinais , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/prevenção & controle , Prevalência , Salmonella/isolamento & purificação , Sorogrupo
7.
BMC Vet Res ; 15(1): 219, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253174

RESUMO

BACKGROUND: Although the poultry sector accounts for a major portion of global antimicrobial consumption, few studies have explored the factors which influence antimicrobial use (AMU) in poultry farms in Europe. We performed a matched case-control study in traditional free-range broiler farms in France during 2016 to evaluate the effect of technical factors and farmers' perceptions of health problems on the probability of AMU. In total, 52 cases (defined as flocks treated with antimicrobials when chickens were between 1 and 42 days old), were included. Another 208 controls (untreated flocks the same ages as the case flocks), were randomly selected and paired with a matching case (same farmer organization and placement date). On-farm questionnaires were administered. Multivariable logistic regression modeling was conducted; seven variables were significant in the final model. RESULTS: Two factors were associated with a lower probability of AMU: the use of chicken paper topped with starter feed (OR = 0.3; 95% CI = [0.1; 0.9]) and the use of herbal drugs as a prophylaxis (OR = 0.1; 95% CI = [0.01; 0.5]). A higher probability of AMU was associated with farmers perceiving the cumulative mortality of chicks between 1 and 10 days old as normal (OR = 10.1; 95% CI = [1.7; 59]) or high (OR = 58.7; 95% CI = [9.6; 372.3]). A higher probability of AMU also was associated with farmers detecting a health problem (OR = 12.5, 95% CI = [4.2; 36.9]) and phone calls between farmers and their technicians (OR = 5.9; 95% CI = [2.3; 14.8]) when chicks are between 11 to 42 days old. Two additional factors (litter thickness and cleaning/disinfecting) were significant and highlighted the importance of technical factors such as biosecurity. CONCLUSIONS: Our results suggest that to reduce AMU, technical training should be provided to farmers to improve how farms are monitored and to reinforce preventive health measures. Training also should address how farmers assess warning criteria like daily mortality rates, which when overestimated often lead to antimicrobial treatment.


Assuntos
Antibacterianos/uso terapêutico , Doenças das Aves Domésticas/tratamento farmacológico , Criação de Animais Domésticos/métodos , Animais , Animais Recém-Nascidos , Galinhas , Fazendeiros/estatística & dados numéricos , Feminino , França , Humanos , Doenças das Aves Domésticas/mortalidade , Doenças das Aves Domésticas/prevenção & controle , Inquéritos e Questionários
9.
Vet Immunol Immunopathol ; 212: 9-14, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213252

RESUMO

Targeting antigens to endocytic receptors on the surface of dendritic cells is a new strategy for increasing the adaptive immune response. The objective of the current study was the construction and bacterial expression of a recombinant antibody single-chain fragment variable (ScFv) directed against chicken DEC 205, an endocytic receptor, for use in the genetic fusion of antigens. In particular, we use as antigen the hemagglutinin-neuraminidase (HN) of Newcastle disease virus. Our results show that inoculation of chickens with HN genetically fused to the ScFv anti-DEC 205 induced an evidently higher immune response against HN, in contrast to inoculation with unconjugated HN. In addition, neutralizing antibodies against Newcastle disease virus were detected only in the serum from chickens immunized with HN fused to ScFv anti-DEC 205. Inoculated fused antigens to ScFv against endocytic receptor DEC 205 resulted in a greater antibody-specific anti-HN production compared with antigens applied alone. The results of this study show that the strategy described here has the potential to be used in the development of more effective vaccines against infectious diseases in chickens.


Assuntos
Antígenos CD/imunologia , Lectinas Tipo C/imunologia , Antígenos de Histocompatibilidade Menor/imunologia , Vírus da Doença de Newcastle/enzimologia , Doenças das Aves Domésticas/prevenção & controle , Receptores de Superfície Celular/imunologia , Anticorpos de Cadeia Única/biossíntese , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Galinhas/imunologia , Escherichia coli/genética , Hemaglutininas Virais/imunologia , Neuraminidase/imunologia , Doenças das Aves Domésticas/imunologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Anticorpos de Cadeia Única/imunologia , Vacinas Virais/imunologia
10.
BMC Vet Res ; 15(1): 205, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208467

RESUMO

BACKGROUND: Poultry farming is widely practiced by rural households in Vietnam and the vast majority of domestic birds are kept on small household farms. However, smallholder poultry production is constrained by several issues such as infectious diseases, including avian influenza viruses whose circulation remains a threat to public health. This observational study describes the demographic structure and dynamics of small-scale poultry farms of the Mekong river delta region. METHOD: Fifty three farms were monitored over a 20-month period, with farm sizes, species, age, arrival/departure of poultry, and farm management practices recorded monthly. RESULTS: Median flock population sizes were 16 for chickens (IQR: 10-40), 32 for ducks (IQR: 18-101) and 11 for Muscovy ducks (IQR: 7-18); farm size distributions for the three species were heavily right-skewed. Muscovy ducks were kept for long periods and outdoors, while chickens and ducks were farmed indoors or in pens. Ducks had a markedly higher removal rate (broilers: 0.14/week; layer/breeders: 0.05/week) than chickens and Muscovy ducks (broilers: 0.07/week; layer/breeders: 0.01-0.02/week) and a higher degree of specialization resulting in a substantially shorter life span. The rate of mortality due to disease did not differ much among species, with birds being less likely to die from disease at older ages, but frequency of disease symptoms differed by species. Time series of disease-associated mortality were correlated with population size for Muscovy ducks (Kendall's coefficient τ = 0.49, p-value < 0.01) and with frequency of outdoor grazing for ducks (τ = 0.33, p-value = 0.05). CONCLUSION: The study highlights some challenges to disease control in small-scale multispecies poultry farms. The rate of interspecific contact and overlap between flocks of different ages is high, making small-scale farms a suitable environment for pathogens circulation. Muscovy ducks are farmed outdoors with little investment in biosecurity and few inter-farm movements. Ducks and chickens are more at-risk of introduction of pathogens through movements of birds from one farm to another. Ducks are farmed in large flocks with high turnover and, as a result, are more vulnerable to disease spread and require a higher vaccination coverage to maintain herd immunity.


Assuntos
Criação de Animais Domésticos/métodos , Galinhas , Patos , Doenças das Aves Domésticas/epidemiologia , Fatores Etários , Animais , Fazendas/estatística & dados numéricos , Dinâmica Populacional , Doenças das Aves Domésticas/mortalidade , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologia , Vietnã
11.
Parasitol Res ; 118(7): 2009-2026, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31152233

RESUMO

Coccidiosis is a parasitic disease of a wide variety of animals caused by coccidian protozoa. The coccidia are responsible for major economic losses of the livestock industry. For example, the annual cost due to coccidiosis to the global poultry industry has been estimated to exceed US$ 3 billion annually. Currently available drugs for the control of this disease are either polyether ionophorous antibiotics that are derived from fermentation products, or synthetic compounds, produced by chemical synthesis. Unfortunately, no new drugs in either category have been approved for use for decades. Resistance has been documented for all those of the drugs currently employed and therefore the discovery of novel drugs with unique modes of action is imperative if chemotherapy is to remain the principal means to control this disease. This chapter aims to give an overview of the efficacy and mode of action of the current compounds used to control coccidiosis in livestock and provides a brief outlook of research needs for the future.


Assuntos
Coccídios/efeitos dos fármacos , Coccidiose/veterinária , Coccidiostáticos/farmacologia , Gado/parasitologia , Doenças das Aves Domésticas/prevenção & controle , Animais , Coccidiose/prevenção & controle , Aves Domésticas , Doenças das Aves Domésticas/parasitologia
12.
Toxicon ; 166: 66-75, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31125619

RESUMO

The amelioration of aflatoxicosis in ducklings was examined by feeding molecular imprinted polymer (MIP) synthesized to target the aflatoxin B1 (AFB1) analog molecule [5, 7-dimethoxycoumarin (DMC)] as a smart and novel toxin binder in comparison to a commercial toxin binder (CTB). MIP was characterized with some techniques, such as scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA) that showed morphology and thermal resistance of MIP, respectively. The SEM showed that more pores and big cavities were formed in the network of the MIP. TGA plots of MIP showed dehydration at temperatures of about 31 °C-200 °C and gradual decomposition until 300 °C. The in vitro and in vivo ability of MIP and CTB to adsorb some minerals (Ca, Cu, Mg, P and Zn) was evaluated. The in vivo efficacy of MIP as an aflatoxins (AFs) binder in duckling exposed to aflatoxin-contaminated feed from 4 to 18 d of age was also compared to that of the CTB. A total of 240 4-d-old ducklings were assigned to experimental diets. Each diet was replicated four times with 10 birds in each pen, and the initial body weight classes were considered as blocks. The experimental treatment diets included: 1- Control (basal diet without any additive or AFs), 2- MIP (5 g/kg diet), 3- CTB (5 g/kg diet), 4- AFs (0.2 mg/kg diet), 5- AFs + MIP (0.2 mg/kg + 5 g/kg diet), and 6- AFs + CTB (0.2 mg/kg + 5 g/kg diet). In vitro study may clearly reflect the possibility of adsorbing minerals by CTB as compared to MIP whilst the results were not confirmed by in vivo study and it seems that reduction in plasma levels of minerals is related to the adverse effects of AFs. Livers showed histopathological alterations, with bile-duct proliferation of all aflatoxin fed ducklings. Macroscopic study indicated liver of birds fed diets containing AFs showed abnormal signs including yellowish, friable and rounded shape without protective effect of MIP and CTB. The results obtained from in vivo study indicate the partial alleviation of the adverse effects of AFs in ducklings by dietary supplementation of MIP and CTB (5 g/kg) on plasma albumin, Zn, Mg and Ca.


Assuntos
Aflatoxina B1/toxicidade , Patos , Minerais/química , Micotoxicose/veterinária , Polímeros/química , Aflatoxina B1/metabolismo , Ração Animal/análise , Animais , Dieta/veterinária , Fígado/efeitos dos fármacos , Minerais/sangue , Impressão Molecular/métodos , Micotoxicose/prevenção & controle , Doenças das Aves Domésticas/induzido quimicamente , Doenças das Aves Domésticas/prevenção & controle , Albumina Sérica
13.
Parasitol Res ; 118(6): 1701-1710, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31065831

RESUMO

Coccidiosis is a major poultry disease which compromises animal welfare and costs the global chicken industry a huge economic loss. As a result, research entailing coccidial control measures is crucial. Coccidiosis is caused by Eimeria parasites that are highly immunogenic. Consequently, a low dosage of the Eimeria parasite supplied by a vaccine will enable the host organism to develop an innate immune response towards the pathogen. The production of traditional live anticoccidial vaccines is limited by their low reproductive index and high production costs, among other factors. Recombinant vaccines overcome these limitations by eliciting undesired contaminants and prevent the reversal of toxoids back to their original toxigenic form. Recombinant vaccines are produced using defined Eimeria antigens and harmless adjuvants. Thus, studies regarding the identification of potent novel Eimeria antigens which stimulate both cell-mediated and humoral immune responses in chickens are essential. Although the prevalence and risk posed by Eimeria have been well established, there is a dearth of information on genetic and antigenic diversity within the field. Therefore, this paper discusses the potential and efficiency of recombinant vaccines as an anticoccidial control measure. Novel protective Eimeria antigens and their antigenic diversity for the production of cheap, easily accessible recombinant vaccines are also reviewed.


Assuntos
Coccidiose/veterinária , Eimeria/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Protozoárias/imunologia , Adjuvantes Imunológicos , Animais , Antígenos/administração & dosagem , Antígenos/genética , Antígenos/imunologia , Galinhas/parasitologia , Coccidiose/imunologia , Coccidiose/parasitologia , Coccidiose/prevenção & controle , Eimeria/genética , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/parasitologia , Vacinas Protozoárias/administração & dosagem , Vacinas Protozoárias/genética
14.
Microb Pathog ; 132: 201-207, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31077753

RESUMO

Subclinical necrotic enteritis (SNE) broadly occurs in boilers, which reduces the growth performance by causing serious economic and social problems. The following study was conducted to better understand the molecular mechanism of the SNE on liver inflammation and to examine the innovative prevention of Lactobacillus johnsonii BS15 upon SNE. The research was based on the regulatory molecular mechanism of Lactobacillus johnsonii BS15, and its effect on liver inflammatory pathways in the broiler with SNE infection. Day old one hundred and eighty (Cobb 500) broiler chickens were distributed into 3 groups (control, SNE and BS15 group) and reared for 28 days. RNA sequencing was used for the analysis of gene expression extracted from liver samples. Gene expression was detected with the help of quantitative real-time PCR (qRT-PCR). RNA-Seq analysis revealed altered expressions of genes involved in liver inflammatory pathway. A total number of 385 genes were found as differentially expressed (DEGs) in the liver samples that belonged to SNE group as compared with the control liver samples (p < 0.05). Out of those 385 genes, 117 were down-regulated and 268 were up-regulated. The DEGs related to liver inflammation between control group and SNE group or SNE and BS15 groups, included cluster of differentiation 80 (CD80), Interleukin 1 beta (IL1B), Phosphoinositide 3- Kinase regulatory subunit 5 (PIK3R5), Toll-like receptor 4 (TLR4), Toll-like receptor 2 A (TLR2A), and proto-oncogene protein (FOS). The RNA-Seq analysis provided DEGs expression and this result was validated by qRT-PCR. Results confirmed that these genes are essential in the regulation of liver inflammation in the SNE infected chickens. Findings of current research indicated that the hepatic inflammation could be induced by SNE in broilers. Simultaneously, effects of SNE infection on liver could be subsided by improved TLRs signaling pathway with the naturally present prophylactic strategy as BS15.


Assuntos
Enterite/metabolismo , Perfilação da Expressão Gênica/métodos , Inflamação/genética , Lactobacillus johnsonii/fisiologia , Fígado/metabolismo , Probióticos/farmacologia , Animais , Antígeno B7-1 , Galinhas , Clostridium perfringens , Regulação para Baixo , Enterite/prevenção & controle , Regulação da Expressão Gênica/efeitos dos fármacos , Genes Reguladores , Inflamação/tratamento farmacológico , Interleucina-1beta , Fígado/efeitos dos fármacos , Fígado/patologia , Doenças das Aves Domésticas/prevenção & controle , Análise de Sequência de RNA , Transdução de Sinais , Transcriptoma , Regulação para Cima
15.
Poult Sci ; 98(8): 3176-3180, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30953077

RESUMO

The purpose of this study was to determine if Eimeria oocysts recovered from litter at the time of chick placement in commercial broiler houses contained oocysts that were infectious for chickens. Over 100 litter samples were collected from 30 poultry farms representing a total of 60 different broiler houses with 9 houses sampled more than once over 1.5 yr. The samples were collected just before the placement of newly hatched chicks and after an anticoccidial drug (ACD) or Eimeria vaccine (VAC) program, and processed for counting oocysts followed by Eimeria species determination using ITS1 PCR. Broiler chicks were inoculated with recovered Eimeria oocysts to determine if the litter oocysts were viable and capable of causing patent infection. At placement, E. maxima (Emax) oocysts were detected in 70 of 75 houses after ACD program and 46 of 47 houses after VAC program. Eimeria acervulina, E. praecox, and/or E. tenella (Eapt) were detected in 75 of 75 houses after ACD program and 47 of 47 houses after VAC program. Viability testing revealed that 33.0% of broiler houses contained viable Emax oocysts, while 46.9% contained viable Eapt oocysts. During VAC programs, the concentration of Emax oocysts at placement and the total number of Emax oocysts shed by chickens in viability studies showed a very strong correlation (r = 0.83). Likewise, during ACD programs, the concentration of Eapt oocysts at placement and the total number of Eapt oocysts shed by chickens in the viability study showed a strong correlation (r = 0.62). In general, Eimeria oocyst levels at placement and number of viable oocysts shed by chickens in the viability study were similar among houses on the same farm. However, the number of Eimeria oocysts shed in the viability studies was considerably less than expected based on the number of oocysts given. These data suggest that nearly 100% of all poultry houses contain Emax and Eapt oocysts at placement with 30 to 50% of the houses containing viable Eimeria oocysts, thus possibly representing a source of the protozoa to newly hatched chicks.


Assuntos
Coccidiose/veterinária , Eimeria/isolamento & purificação , Oocistos/isolamento & purificação , Doenças das Aves Domésticas/transmissão , Animais , Animais Recém-Nascidos , Galinhas , Coccidiose/prevenção & controle , Coccidiose/transmissão , Coccidiostáticos/administração & dosagem , Abrigo para Animais , Doenças das Aves Domésticas/parasitologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Protozoárias/administração & dosagem , Vacinação/veterinária
16.
Environ Sci Pollut Res Int ; 26(16): 16210-16219, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30972680

RESUMO

Tibial dyschondroplasia (TD) is most the common tibiotarsal bone disease in rapidly growing birds throughout the world. There is accumulating evidence that COX-2 abnormal expression in tibia plays an important role in TD progression. So, the regulation of COX-2 is an ever more appealing target for therapeutic intervention in TD. Astragaloside IV has an indispensable role in maintaining COX-2 expression in many diseases. So, we designed this study to use Astragaloside IV (AST-IV) against TD-affected chickens. A total of 180 Arbor Acres chickens were randomly divided in the control group, TD group, and Astr (AST-IV-treated chickens) group. During the experiment, mortality, feed conversion ratio, physiological changes, biochemical criterion, liver antioxidant enzymes, and gene expression of COX-2 were examined in all the chicken groups at various days. The results showed that AST-IV administration restored the growth performance and tibia lesions and decreased the mortality as compared with TD chickens. The biochemical criterion (ALP, AST, and ALT) of serum and liver antioxidant enzymes (SOD, GSH-Px, MDA, and T-AOC) improved after the administration of AST-IV. The COX-2 gene was upregulated significantly (P < 0.05) in TD chickens. Whereas, AST-IV treatment downregulated both gene and protein expression of COX-2 significantly (P < 0.05) in TD-affected chickens. AST-IV recovered tibial dyschondroplasia chickens by increasing the growth performance, ameliorating tibial cartilage damage, and decreasing COX-2 expression. In conclusion, AST-IV can be used to prevent thiram-induced TD in chickens.


Assuntos
Galinhas , Osteocondrodisplasias/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle , Saponinas/farmacologia , Tiram/toxicidade , Triterpenos/farmacologia , Ração Animal , Animais , Antioxidantes/metabolismo , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Enzimas/metabolismo , Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Osteocondrodisplasias/induzido quimicamente , Osteocondrodisplasias/veterinária , Doenças das Aves Domésticas/genética , Substâncias Protetoras/farmacologia , Tíbia/efeitos dos fármacos , Tíbia/fisiopatologia
17.
Vet Microbiol ; 231: 218-225, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955813

RESUMO

Infection with duck Tembusu virus (DTMUV) can cause large economic losses to the duck-rearing industry in China. In this study, we isolated a virulent strain of DTMUV (SDS) from sparrows near a duck farm and attenuated it via serially passaging (alternately for 100 passages) in specific pathogen-free chicken and duck embryos. We attenuated the virus after the 60th passage (SDS-60), based on the production of embryos that were free of visible lesions and still alive. The 70th adapted strain (SDS-70), obtained with a virus titer of 10-2.46 EID50 was chosen to be the live attenuated vaccine. After immunizing ducklings with the SDS-70 strain, they obtained 100% protection against infection by the SDS-10 virulent strain. Our data demonstrate that the vaccine can protect ducks from becoming infected with TMUV. Our study also shows that this newly developed attenuated vaccine candidate provides excellent immunogenicity, is safe, and has the potential to control DTMUV infections in ducks.


Assuntos
Infecções por Flavivirus/veterinária , Flavivirus , Doenças das Aves Domésticas/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Patos/virologia , Infecções por Flavivirus/prevenção & controle , Imunização , Imunogenicidade da Vacina , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , Baço/patologia , Baço/virologia , Vacinas Atenuadas/imunologia , Proteínas do Envelope Viral/imunologia , Carga Viral
18.
Vet Microbiol ; 231: 48-55, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955823

RESUMO

Mycoplasma synoviae (MS) is a major pathogen of poultry globally, causing chronic respiratory disease and arthritis. Vaccination is an effective means for the control of the disease. The MS-H vaccine is an attenuated strain developed through chemical mutagenesis of an Australian field strain, 86079/7NS. Analysis of whole genome of MS-H and its comparison with that of 86079/7NS has revealed a frameshift mutation early in a gene (oppF) that codes for an oligopeptide transporter permease, OppF. Monospecific antibodies raised against peptides upstream and downstream of the mutation in OppF revealed that only N-terminus of the OppF was expressed in MS-H while the full version was expressed in 86079/7NS. Also, examination of the recombinant N- (OppF-N) and C termini (OppF-C) of OppF, upstream and downstream of the mutation site respectively, as well as the full length OppF in Western immunoblotting experiments showed that serum from MS-H vaccinated chicken strongly bound OppF-N while serum from 86079/7NS challenged chicken detected OppF, OppF-N and OppF-C. The potential of the recombinant OppF, OppF-N and OppF-C to discriminate antibody responses to MS-H reisolates with wild or vaccine type OppF was assessed against 88 chicken sera in indirect ELISA and ratios were calculated between optical densities (OD) over those obtained in MS major membrane protein MSPB ELISA. Comparison of the OD ratios revealed that the MSPB/OppF and MSPB/OppF-C OD ratios of the sera against isolates with vaccine type OppF were significantly higher than those against isolates with wild type OppF. These results are in accordance with oppF gene mutation in MS-H and confirms that MS-H does not express OppF beyond the frame shift mutation found in its oppF gene. Also, the indirect ELISA based on OppF-C in combination with the MSPB has the potential to differentiate between MS-H and field strain antibody responses.


Assuntos
Proteínas de Bactérias/genética , Vacinas Bacterianas/imunologia , Mutação , Infecções por Mycoplasma/veterinária , Mycoplasma synoviae/genética , Doenças das Aves Domésticas/imunologia , Animais , Anticorpos Antibacterianos/sangue , Austrália , Proteínas de Bactérias/imunologia , Galinhas , Ensaio de Imunoadsorção Enzimática , Infecções por Mycoplasma/imunologia , Infecções por Mycoplasma/prevenção & controle , Mycoplasma synoviae/imunologia , Doenças das Aves Domésticas/prevenção & controle , Testes Sorológicos , Vacinas Atenuadas/imunologia
19.
Vet Microbiol ; 232: 146-150, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31030839

RESUMO

Newcastle disease virus (NDV) is a major threat to poultry worldwide. Virulent Newcastle disease virus infection can cause 100% morbidity and mortality in chickens. Vaccination is the most effective way to prevent and control NDV outbreaks in poultry. Previously, we demonstrated that a duck enteritis virus (DEV) vaccine strain is a promising vector to generate recombinant vaccines in chickens. Here, we constructed two recombinant DEVs expressing the F protein (rDEV-F) or HN protein (rDEV-HN) of NDV. We then evaluated the protective efficacy of these recombinant DEVs in specific-pathogen-free chickens. rDEV-F induced 100% protection of chickens from lethal NDV challenge after a single dose of 104 TCID50, whereas rDEV-HN did not induce effective protection. rDEV-F may therefore serve as a promising vaccine candidate for chickens. This is the first report of a DEV-vectored vaccine providing robust protection against lethal NDV infection in chickens.


Assuntos
Mardivirus/genética , Doença de Newcastle/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle , Proteínas Virais de Fusão/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais , Galinhas/imunologia , Galinhas/virologia , Patos/virologia , Proteína HN/genética , Proteína HN/imunologia , Doença de Newcastle/imunologia , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , Vacinação , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Proteínas Virais de Fusão/genética , Vacinas Virais/administração & dosagem
20.
Trop Anim Health Prod ; 51(7): 1997-2001, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31020540

RESUMO

The current study investigated the protective efficacy of a formalin-inactivated infectious bronchitis virus (IBV) vaccine derived from the field strain KP729422, which exhibits low S1 spike protein sequence homology (77.1-79.8%) with the currently used vaccine strains in Egypt. Two-week-old, specific-pathogen-free chickens were subcutaneously inoculated with a single dose of the vaccine containing 106.7 50% embryo infective dose (EID50) of the inactivated virus. At 6 weeks of age, the chickens were challenged with 104 EID50 of the same virus strain via the oculonasal route. In comparison with the unvaccinated challenged group, the vaccinated chickens had significantly higher IBV-neutralizing antibody titers and exhibited efficient protection against challenge on the basis of tracheal ciliary activity. However, the challenge virus was recovered from the kidneys and tracheas of these chickens at rates of 40% and 60%, respectively. These findings suggest that a single application of the vaccine may provide sufficient clinical and respiratory protection, but may not ensure complete protection against infection by the challenge virus.


Assuntos
Galinhas , Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Virais/imunologia , Animais , Galinhas/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Egito , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , Vacinas de Produtos Inativados/imunologia
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