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1.
BMC Vet Res ; 19(1): 1, 2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36597079

RESUMO

BACKGROUND: Avian pathogenic Escherichia coli (APEC) are considered a growing health problem to both poultry and the public, particularly due to its multi-drug resistance. Zinc oxide nanoparticles (ZnO-NPs) are a promising multi-benefit candidate. This study focused on boosting the antimicrobial effect of the chemically synthesized ZnO-NPs using Polyethylene glycol-6000 (PEG-6000) and evaluating their potential to recover the sensitivity of Florfenicol and Streptomycin-resistant APEC to these drugs in a concentration range of 0.1-0.4 mg/mL. Four samples of ZnO-NPs were formulated and tested microbiologically. RESULTS: The physicochemical characterization showed well-crystallized spherical in situ synthesized ZnO-NPs using PEG-6000 (surfactant) and ethanol (co-surfactant) of ∼19-67 nm particle size after coating with PEG-6000 molecules. These ZnO-NPs demonstrated a strong concentration-dependent antibacterial effect against multidrug-resistant APEC strains, with a minimum inhibitory concentration of 0.1 mg/mL, Combining PEG-6000 coated in situ synthesized ZnO-NPs and Florfenicol induced 60% high sensitivity (30 mm inhibitory-zone), 30% intermediate sensitivity, and 10% resistance against APEC strains. The combination with Streptomycin revealed 50% high sensitivity, 30% intermediate sensitivity, and 20% resistance with a 20 mm maximum zone of inhibition using agar well diffusion test. CONCLUSION: In situ preparation of ZnO-NPs using PEG-6000 and ethanol followed by coating with PEG-6000 enhanced its antibacterial activity in minimum inhibitory concentration and regained the efficacy of Florfenicol and Streptomycin against APEC, referring to a non-antibiotic antimicrobial alternative and an effective combination regimen against multidrug-resistant APEC E. coli in veterinary medicine.


Assuntos
Escherichia coli , Óxido de Zinco , Animais , Antibacterianos/farmacologia , Antibacterianos/química , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Testes de Sensibilidade Microbiana/veterinária , Aves , Polietilenoglicóis/farmacologia , Estreptomicina/farmacologia , Tensoativos/farmacologia
2.
BMC Vet Res ; 18(1): 325, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36042468

RESUMO

BACKGROUND: Over the past 10 years, inclusion body hepatitis outbreaks, essentially from commercial broiler flocks, have been detected in different geographic regions highlighting the wide distribution of FAdVs around the world resulting in serious economic losses due to increased mortalities as well as poor performance within poultry farms in Assiut province, Egypt. Thus, this study was achieved to detect fowl adenovirus in broiler chicken flocks in Assiut province, Egypt and to recognize the pathogenicity of the isolated virus. RESULTS: The phylogeny of the L1 loop of the hexon gene exposed that the isolated virus clustered and belonged to the reference strains serotype D FAdV. The isolated virus is closely related to inclusion body hepatitis (IBH) strains causing extensive economic losses. The pathogenicity study of the virus showed typical macroscopic lesions with 6% mortality; furthermore, histopathological inspection exhibited severe hepatitis and degenerative changes after 5d from infection in the immune system.  CONCLUSION: Results in this research support the primary pathogenicity and mortality caused by FADV serotype 2 (IBH) alone without immunosuppressive agents thus robust control measures should be implanted against FAdV to evade the serious economic losses in poultry farms.


Assuntos
Infecções por Adenoviridae , Aviadenovirus , Doenças das Aves Domésticas , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/veterinária , Animais , Aviadenovirus/genética , Galinhas , Egito/epidemiologia , Genótipo , Filogenia , Aves Domésticas , Virulência
3.
Avian Pathol ; 44(5): 333-41, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26023824

RESUMO

Vaccination is the main tool implemented in Egypt since 2007 to control H5N1 avian influenza. The present study aimed at comparing the effectiveness of three avian influenza vaccination regimes in commercial broiler chickens carrying high levels of maternally derived antibodies (MDAs). Day-old chicks were divided into four experimental groups. Group I received only the rHVT-H5 vaccine (recombinant turkey herpesvirus (HVT) which carries a H5 clade 2.2 insert) administered at D1. Group II received only the KV-H5 (an oil emulsion killed vaccine prepared from reassortant HPAI virus (A/duck/Anhui/1/06)) vaccine (inactivated reverse genetic H5N1 clade 2.3.4 virus) administered at D8. Group III received rHVT-H5 and KV-H5 as prime/boost. Group IV served as unvaccinated control. Weekly serological monitoring was conducted using the haemagglutination inhibition test. Two challenge experiments were conducted at D28 and D35 using HPAI H5N1 clade 2.2.1 virus. Birds were monitored daily 14 days post-challenge for morbidity and mortality, and oropharyngeal swabs were collected for virological monitoring. Initially, day-old chicks had high mean MDA titres (9 + 0.9 log2). The MDA half-life was >7 and <7 days, respectively, for unvaccinated and vaccinated birds. Group III showed the highest post-vaccination humoral immune response and seroconversion rate. The highest protection rate against morbidity (80-90%) and mortality (90-90%) was obtained in Group III after challenge at D28 and D35, respectively, as compared to Group I (70-70%) and (80-90%) and Group II (0-0%) and (30-30%). Groups I and III had lower number of shedder birds. The vaccination regime with prime/boost conferred the highest and earliest protection, and can hence be recommended for the broiler production sector in endemic and high HPAI H5N1 challenge areas.


Assuntos
Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/administração & dosagem , Influenza Aviária/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle , Vacinação , Animais , Galinhas , Egito , Testes de Inibição da Hemaglutinação , Vacinas contra Influenza/imunologia , Influenza Aviária/epidemiologia , Influenza Aviária/imunologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/imunologia , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
4.
Avian Pathol ; 43(6): 514-23, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25245772

RESUMO

The effectiveness of recombinant turkey herpesvirus avian influenza (A/swan/Hungary/4999/2006(H5N1)) clade 2.2 virus (rHVT-H5) vaccine was evaluated in two layer chicken breeds (White Bovans [WB] and Brown Shaver [BS]). One dose of rHVT-H5 vaccine was administered at day 1 and birds were monitored serologically (haemagglutination inhibition test) and virologically for 19 weeks. Maternally-derived antibody and post-vaccination H5 antibody titres were measured using the Chinese (A/Goose/Guangdong/1/96(H5N1)) HA and the Egyptian (A/chicken/Egypt/128s/2012(H5N1)) HA as antigens. The challenge was conducted at 19 weeks of age and on six experimental groups: Groups I (WB) and II (BS), both vaccinated and challenged; Groups III (WB) and IV (BS), both vaccinated but not challenged; Groups V and VI, unvaccinated specific pathogen free chickens, serving respectively as positive and negative controls. The challenge virus was the clade 2.2.1 highly pathogenic avian influenza H5N1 A/chicken/Egypt/128s/2012 at a dose of 10(6) median embryo infective dose. For both breeds, complete maternally-derived antibody waning occurred at the age of 4 weeks. The immune response to rHVT-H5 vaccination was detected from the sixth week. The seroconversion rates for both breeds reached 85.7 to 100% in the eighth week of age. Protection levels of 73.3%, 60% and 0% were respectively recorded in Groups I, II and V. No mortalities occurred in the unchallenged groups. Group I showed superior results for all measured post-challenge parameters. In conclusion, a single rHVT-H5 hatchery vaccination conferred a high level of protection for a relatively extended period. This vaccine could be an important tool for future A/H5N1 prevention/control in endemic countries. Further studies on persistence of immunity beyond 19 weeks, need for booster with inactivated vaccines, breed susceptibility and vaccinal response, and transmissibility are recommended.


Assuntos
Galinhas/imunologia , Herpesvirus Meleagrídeo 1/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Influenza Aviária/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Animais , Egito , Feminino , Vacinas contra Influenza/imunologia , Influenza Aviária/imunologia , Influenza Aviária/virologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , Vacinas de Produtos Inativados/imunologia , Vacinas Sintéticas
5.
Anat Cell Biol ; 57(2): 256-270, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38472741

RESUMO

The antidepressant drug trazodone (TRZ) is commonly used for treating depression, anxiety, and insomnia, however, it causes cardiotoxicity, which is one of its limitations. The objective of this work was to investigate the impact of sage (Salvia officinalis) in rats against cardiotoxicity induced by TRZ and to investigate the mechanisms involved in its cardio-protective properties through autophagy and oxidative stress. Fifty male albino rats were split randomly into five experimental groups: control group, sage oil group (100 mg/kg), TRZ group (20 mg/kg), protective group, and curative group. Cardiac function biomarkers (aspartate aminotransferase [AST], creatine kinase-MB [CK-MB], and cardiac troponin T [cTnI]) were assessed in serum. Oxidative stress and inflammatory biomarkers in cardiac tissue (total antioxidant capacity, malondialdehyde, and tumor necrosis factor-α) were evaluated. Heart tissues were subjected to histological, immunohistochemical, and ultrastructural evaluations. DNA damage also evaluated. Significant rise in the levels of AST, CK-MB, and cTnI were observed with enhanced autophagy along with marked histopathological changes in the form of interrupted muscle fibers with wide interstitial spaces with areas of hemorrhage and extravasated blood and interstitial mononuclear cellular infiltration in TRZ group. DNA damage was also significantly increased in TRZ group. However, administration of sage in both protective and curative groups show marked improvement of the cardiac alterations. In conclusion, sage ameliorated the alterations in the heart induced by trazadone through modulation of autophagy and oxidative stress.

6.
Virol J ; 10: 203, 2013 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-23799999

RESUMO

BACKGROUND: The endemic H5N1 high pathogenicity avian influenza virus (A/H5N1) in poultry in Egypt continues to cause heavy losses in poultry and poses a significant threat to human health. METHODS: Here we describe results of A/H5N1 surveillance in domestic poultry in 2009 and wild birds in 2009-2010. Tracheal and cloacal swabs were collected from domestic poultry from 22024 commercial farms, 1435 backyards and 944 live bird markets (LBMs) as well as from 1297 wild birds representing 28 different types of migratory birds. Viral RNA was extracted from a mix of tracheal and cloacal swabs media. Matrix gene of avian influenza type A virus was detected using specific real-time reverse-transcription polymerase chain reaction (RT-qPCR) and positive samples were tested by RT-qPCR for simultaneous detection of the H5 and N1 genes. RESULTS: In this surveillance, A/H5N1 was detected from 0.1% (n = 23/) of examined commercial poultry farms, 10.5% (n = 151) of backyard birds and 11.4% (n = 108) of LBMs but no wild bird tested positive for A/H5N1. The virus was detected from domestic poultry year-round with higher incidence in the warmer months of summer and spring particularly in backyard birds. Outbreaks were recorded mostly in Lower Egypt where 95.7% (n = 22), 68.9% (n = 104) and 52.8% (n = 57) of positive commercial farms, backyards and LBMs were detected, respectively. Higher prevalence (56%, n = 85) was reported in backyards that had mixed chickens and waterfowl together in the same vicinity and LBMs that had waterfowl (76%, n = 82). CONCLUSION: Our findings indicated broad circulation of the endemic A/H5N1 among poultry in 2009 in Egypt. In addition, the epidemiology of A/H5N1 has changed over time with outbreaks occurring in the warmer months of the year. Backyard waterfowl may play a role as a reservoir and/or source of A/H5N1 particularly in LBMs. The virus has been established in poultry in the Nile Delta where major metropolitan areas, dense human population and poultry stocks are concentrated. Continuous surveillance, tracing the source of live birds in the markets and integration of multifaceted strategies and global collaboration are needed to control the spread of the virus in Egypt.


Assuntos
Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Animais , Aves , Cloaca/virologia , Surtos de Doenças , Egito/epidemiologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Virus da Influenza A Subtipo H5N1/genética , Neuraminidase/genética , Aves Domésticas , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Estações do Ano , Traqueia/virologia , Proteínas da Matriz Viral/genética , Proteínas Virais/genética
7.
Animals (Basel) ; 12(22)2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36428412

RESUMO

Avian coccidiosis remains one of the major parasitic diseases that threaten the global poultry industry. Since prevention is superior to treatment, this study focuses on eliminating the infection outside the host. To determine their effect on the viability of Eimeria tenella oocysts in vitro, allicin and alcoholic garlic extract, which are natural, less toxic, and inexpensive products, were compared to KOH 5% (chemical disinfectant) using an in vitro culture system. Three concentrations of allicin (45, 90, and 180 mg/mL) and alcoholic garlic extract (90, 180, and 360 mg/mL, were used. Subsequently, destructive and sporulation-inhibiting effects on Eimeria oocysts were detected using light and electron microscopy. Young chickens were infected with treated sporulated oocysts to determine their effect on infectivity. After 7 days pi, the percentage of excreted oocysts (oocyst shedding) was determined, and the chickens were slaughtered for histopathological examination of the cecal tissues. Under an electron microscope, allicin at a concentration of 180 mg/mL and alcoholic garlic extract at a concentration of 360 mg/mL demonstrate a high oocysticidal activity with severe destruction of the oocyst wall and the appearance of pores. In addition, both concentrations directly affected the infectivity of sporulated oocysts by reducing the shedding of oocysts and the pathological lesions of infected young chickens. We concluded that the ability of Allicin and alcoholic garlic extract to eliminate Eimeria oocysts makes them superior to chemical disinfectants as a disinfectant.

8.
J Dermatolog Treat ; 31(5): 519-523, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30995143

RESUMO

Background: Lipocalin-2 (LCN2) is an adipokine related to insulin resistance and metabolic syndrome (MetS) in addition to its role in innate immunity and apoptosis.Objective: To estimate LCN2 tissue levels (lesional and non-lesional) in psoriasis. To assess the metabolic status of patients and to detect any possible associations between LCN2 and MetS. To evaluate the effect of narrow-band ultraviolet B (NBUVB) on tissue LCN2 in psoriasis.Methods: This case-control study was conducted on 25 psoriatic patients and 25 healthy controls. Dyslipidemia and MetS have been evaluated. Tissue LCN2 was estimated using ELISA technique before and after treatment with NBUVB.Results: Tissue LCN2 was significantly higher in psoriasis, with no significant difference as regards dyslipidemia or metabolic disturbance in these patients. Both lesional and non-lesional LCN2 and PASI score dropped significantly after NBUVB. No significant correlations have been detected between tissue LCN2 and disease extent or PASI score. Significant positive correlations were detected regarding tissue LCN2 levels between lesional and non-lesional samples before and after treatment.Conclusions: Psoriatic patients were at higher risk of metabolic disorders. LCN2 was not related to metabolic disturbances in our patients. NBUVB might exert its therapeutic effect in psoriasis through reduction of tissue LCN2.


Assuntos
Biomarcadores/metabolismo , Lipocalina-2/metabolismo , Psoríase/radioterapia , Terapia Ultravioleta , Adulto , Idoso , Estudos de Casos e Controles , Dislipidemias/patologia , Feminino , Humanos , Masculino , Síndrome Metabólica/patologia , Pessoa de Meia-Idade , Psoríase/patologia , Índice de Gravidade de Doença
9.
Vet World ; 12(1): 97-105, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30936661

RESUMO

AIM: The aim of the current study was to evaluate the efficacy of a trivalent-inactivated oil-emulsion vaccine against challenge by different clades highly pathogenic avian influenza (HPAI) viruses including HPAI-H5N8 and the virulent genotype VII Newcastle disease virus (NDV) (vNDV). MATERIALS AND METHODS: The vaccine studied herein is composed of reassortant AI viruses rgA/Chicken/Egypt/ME1010/2016 (clade 2.2.1.1), H5N1 rgA/Chicken/Egypt/RG-173CAL/2017 (clade 2.2.1.2), and "NDV" (LaSota NDV/CK/Egypt/11478AF/11); all used at a concentration of 108 EID50/bird and mixed with Montanide-ISA70 oil adjuvant. Two-week-old specific pathogen free (SPF) chickens were immunized subcutaneously with 0.5 ml of the vaccine, and hemagglutination inhibition (HI) antibody titers were monitored weekly. The intranasal challenge was conducted 4 weeks post-vaccination (PV) using 106 EID50/0.1 ml of the different virulent HPAI-H5N1 viruses representing clades 2.2.1, 2.2.1.1, 2.2.1.2, 2.3.4.4b-H5N8, and the vNDV. RESULTS: The vaccine induced HI antibody titers of >6log2 against both H5N1 and NDV viruses at 2 weeks PV. Clinical protection against all HPAI H5N1 viruses and vNDV was 100%, except for HPAI H5N1 clade-2.2.1 and HPAI H5N8 clade-2.3.4.4b viruses that showed 93.3% protection. Challenged SPF chickens showed significant decreases in the virus shedding titers up to <3log10 compared to challenge control chickens. No virus shedding was detected 6 "days post-challenge" in all vaccinated challenged groups. CONCLUSION: Our results indicate that the trivalent H5ND vaccine provides significant clinical protection against different clades of the HPAI viruses including the newly emerging H5N8 HPAI virus. Availability of such potent multivalent oil-emulsion vaccine offers an effective tool against HPAI control in endemic countries and promises simpler vaccination programs.

10.
Indian J Dermatol Venereol Leprol ; 82(6): 666-672, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27451927

RESUMO

BACKGROUND: 8-oxoguanine, a major product of DNA oxidation, is considered a key parameter in measuring the carcinogenic effects of ultraviolet radiation. OBJECTIVE: To assess and compare the carcinogenic potential of different photo (chemo) therapeutic modalities in photoresponsive skin diseases by measuring the levels of 8-oxoguanine in dark-skinned individuals before and after photo (chemo) therapy. METHODS: A prospective, randomized controlled pilot study was conducted in 63 patients of skin types III-V with photo-responsive dermatoses including vitiligo, psoriasis and mycosis fungoides. Patients were divided into three groups; Group 1 (received narrowband ultraviolet-B), Group 2 (received psoralen plus ultraviolet-A) and Group 3 (received broadband ultraviolet-A). Biopsies were taken before and after phototherapy to measure 8-oxoguanine levels using enzyme-linked immunosorbent assay. Biopsies were also taken from the sun-protected skin in 21 controls subjects who had no dermatological disease. RESULTS: Regardless of the disease, a significantly higher level of 8-oxoguanine was found after treatment when compared to the pre-treatment baseline levels; however, these levels were comparable to those in control subjects. A weakly significant positive correlation was found between cumulative dose and 8-oxoguanine levels following psoralen plus ultraviolet-A therapy. In controls, comparing the 8-oxoguanine levels between skin types III and IV showed significantly lower 8-oxoguanine in skin type IV. CONCLUSION: Therapeutic doses of ultraviolet radiation are relatively safe in dark skinned patients; however, minimizing the cumulative dose of phototherapeutic modalities (particularly psoralen plus ultraviolet-A) is recommended.


Assuntos
Dano ao DNA/fisiologia , Guanina/análogos & derivados , Estresse Oxidativo/fisiologia , Fototerapia/métodos , Pigmentação da Pele/fisiologia , Adolescente , Adulto , Dano ao DNA/efeitos dos fármacos , Feminino , Guanina/análise , Guanina/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Fototerapia/efeitos adversos , Projetos Piloto , Estudos Prospectivos , Fatores de Risco , Pigmentação da Pele/efeitos dos fármacos , Adulto Jovem
11.
PLoS One ; 11(6): e0156747, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27304069

RESUMO

In Egypt, ducks kept for commercial purposes constitute the second highest poultry population, at 150 million ducks/year. Hence, ducks play an important role in the introduction and transmission of avian influenza (AI) in the Egyptian poultry population. Attempts to control outbreaks include the use of vaccines, which have varying levels of efficacy and failure. To date, the effects of vaccine efficacy has rarely been determined in ducks. In this study, we evaluated the protective efficacy of a live recombinant vector vaccine based on a turkey Herpes Virus (HVT) expressing the H5 gene from a clade 2.2 H5N1 HPAIV strain (A/Swan/Hungary/499/2006) (rHVT-H5) and a bivalent inactivated H5N1 vaccine prepared from clade 2.2.1 and 2.2.1.1 H5N1 seeds in Mulard ducks. A 0.3ml/dose subcutaneous injection of rHVT-H5 vaccine was administered to one-day-old ducklings (D1) and another 0.5ml/dose subcutaneous injection of the inactivated MEFLUVAC was administered at 7 days (D7). Four separate challenge experiments were conducted at Days 21, 28, 35 and 42, in which all the vaccinated ducks were challenged with 106EID50/duck of H5N1 HPAI virus (A/chicken/Egypt/128s/2012(H5N1) (clade 2.2.1) via intranasal inoculation. Maternal-derived antibody regression and post-vaccination antibody immune responses were monitored weekly. Ducks vaccinated at 21, 28, 35 and 42 days with the rHVT-H5 and MEFLUVAC vaccines were protected against mortality (80%, 80%, 90% and 90%) and (50%, 70%, 80% and 90%) respectively, against challenges with the H5N1 HPAI virus. The amount of viral shedding and shedding rates were lower in the rHVT-H5 vaccine groups than in the MEFLUVAC groups only in the first two challenge experiments. However, the non-vaccinated groups shed significantly more of the virus than the vaccinated groups. Both rHVT-H5 and MEFLUVAC provide early protection, and rHVT-H5 vaccine in particular provides protection against HPAI challenge.


Assuntos
Patos/imunologia , Herpesvirus Meleagrídeo 1/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Virais/imunologia , Animais , Patos/virologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Virus da Influenza A Subtipo H5N1/fisiologia , Vacinas contra Influenza/administração & dosagem , Influenza Aviária/imunologia , Influenza Aviária/prevenção & controle , Influenza Aviária/virologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Substâncias Protetoras/administração & dosagem , Fatores de Tempo , Resultado do Tratamento , Perus/virologia , Vacinação/métodos , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Vacinas Virais/administração & dosagem , Eliminação de Partículas Virais/efeitos dos fármacos , Eliminação de Partículas Virais/imunologia
12.
ISRN Vet Sci ; 2014: 916412, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24977049

RESUMO

Ten infectious bursal disease virus (IBDV) field strains were isolated from 15 broiler flocks located in various parts of Asyut, Egypt. Seven strains were subjected to comparative sequencing and phylogenetic analyses to help provide optimal control program for protection against IBDV infection. Sequence analysis of a 530 bp hypervariable region in the VP2 gene revealed that the rate of identity and homology was around 95.6~99.1%. Sequence characterization revealed the 7 strains identified as vvIBDV with the four amino acids residues typical of vvIBDV (242I, 256I, 294I, 299S). The BURSA-VAC vaccine was the nearest vaccine in sequence similarity to the local examined IBDV strains followed by CEVACIBDL then Bursine plus and Nobilis Gumboro indicating its probable success in the face of incoming outbreaks when using these vaccines. Phylogenetic analysis revealed that the presence of three clusters for the examined strains and are grouped with reference very virulent IBDVs of European and Asian origin (Japanese and Hong Kong) strains suggesting the different ancestors of our isolates. The antigenic index showed a number of changes on the major and minor hydrophilic antigenic peaks of the virus surface structures indicating a new genetic evolution of the surface structure epitopes that may lead to vaccination failure and reemergence of the disease.

13.
Vet Microbiol ; 150(1-2): 28-34, 2011 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-21236607

RESUMO

In contrast to chickens, there is a paucity of information on the potency of H5 vaccines to protect turkeys against the highly pathogenic avian influenza (HPAI) H5N1 virus infections. In this study, 4 groups, 10 turkey poults each, were vaccinated at seven days old with one of H5N2 or H5N1 commercial vaccines or one of two prepared H5N1 vaccines from a local Egyptian variant HPAI H5N1 (EGYvar/H5N1) strain. At 35 days age, all vaccinated and 10 non vaccinated birds were challenged intranasal with 10(6) EID(50)/0.1 ml of EGYvar/H5N1. All vaccines used in this study were immunogenic in turkeys. There was no cross reaction between the commercial vaccines and the Egyptian variant H5N1 antigen as obtained by the hemagglutination inhibition test. Birds vaccinated with H5N2 vaccine were died, while other H5N1 vaccinated groups have had 20-40% mortality. The highest virus excretion was found in non-vaccinated infected and H5N2 vaccinated birds. Eleven peculiar amino acid substitutions in H5 protein of the variant strain were existed neither in the vaccine strains nor in the earliest H5N1 virus introduced into Egypt in 2006. In conclusion, single vaccination at seven days old is inadequate for protection of meat turkeys against variant HPAI H5N1 challenge and multi-dose vaccination at older age is recommended. For the foreseeable future, continuous evaluation of the current vaccines in H5N1 endemic countries in the face of virus evolution is a paramount challenge to mitigate the socio-economic impact of the virus.


Assuntos
Vacinas contra Influenza/imunologia , Influenza Aviária/prevenção & controle , Perus/virologia , Vacinação/veterinária , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Substituição de Aminoácidos , Animais , Egito , Testes de Inibição da Hemaglutinação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Virus da Influenza A Subtipo H5N1/imunologia , Vírus da Influenza A Subtipo H5N2/imunologia , Vacinas contra Influenza/administração & dosagem , Influenza Aviária/imunologia , Influenza Aviária/virologia , Perus/imunologia , Vacinas de Produtos Inativados/imunologia , Eliminação de Partículas Virais
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