Egyptian Field Research Articles

Evaluation of CIMMYT Wheat Lines under Egyptian Field Conditions to Identify New Sources of Resistance to Leaf Rust

Leaf rust caused by Puccinia triticina Eriks. is a fungal disease of wheat (Triticum aestivum L.), which causes considerable yield loss. Host resistance is the most effective and economical method to minimize yield losses caused by leaf rust. The current research was planned to evaluate the response of 93 wheat genotypes lines selected from 716 wheat genotypes delivered to Egypt by International Maize and Wheat Improvement Center (CIMMYT). These genotypes were evaluated against leaf rust resistance under field conditions at two locations i.e. Behira governorate (Itay El-Baroud Agricultural Research Station) and Menoufia governorate during three successive growing seasons i.e. 2017/2018, 2018/2019 and 2019/2020. Results of the current study showed that 47 wheat genotypes were resistant and had the lowest values of final rust severity (FRS %), average coefficient of infection (ACI) and area under disease progress curve (AUDPC). Also, these genotypes showed desirable/acceptable relative resistance index (RRI) at the two locations during the three growing seasons of the study. Therefore, we can select these genotypes as resistant lines in the breeding program for the resistance of leaf rust.

Assessment and Mapping of Soil Salinization Risk in an Egyptian Field Using a Probabilistic Approach

The assessment of soil salinization risk at the field scale requires modeling of the spatial variability of soil salinity. This paper presents a probabilistic approach to estimate and map a risk index using all available auxiliary information. A probabilistic methodology is proposed to estimate the conditional probability of exceeding the assigned threshold value of a generic indicator of soil salinity. A geostatistical non-parametric technique, probability kriging, was used to assess the risk of soil salinization and delineate different hazard zones within a field. The technique relies on indicator coding of information. The approach was applied to soil electrical conductivity measurements collected in an experimental field located in the Nile Delta region in Egypt, and submitted over time to trials with different fertilization treatments. The application of the method allowed delineation of a north-eastern zone in the field with a high risk of soil salinization due to its lack of cultivation for a long time and nearness to buildings that prevent water infiltration. The method proved to be quite promising from the perspective of precision agriculture and it is easily extendable to any sort of remote and proximal sensing auxiliary information, including information on the deepest layers of soil.

Effectiveness Of The Pigeon Pox Vaccine On The Chicken Vaccinated With Avian Influenza Vaccine

Evaluation of the effectiveness of pigeon pox (PP) vaccine in improvement the required immunity to avian influenza (AI) virus vaccine in birds and reducing its shedding after challenge was the object of this study.Specific pathogen free chicks were vaccinated with PP and AI in 10 groups at 5 and/or 8 days of age and/or boosted after 35 days then challenged after 28 days with virulent highly pathogenic AI virus local Egyptian field isolate. The development of immune responses to AI haemagglutinine was recorded and also AI virus shedding after challenge.Vaccinated 10 groups induced protective immune responses; especially in the groups which were boosterly vaccinated with PP vaccine. All birds vaccinated and experimentally challenged 28 days later were protected against virulent AI (H5N1); mild clinical signs of infection developed in few number of vaccinated birds. In contrast, all unvaccinated birds died within 72 hours of challenge. Vaccination of chicks with PP and AI vaccines provided good effectiveness of the PP vaccine on the immune response of vaccinated birds with AI vaccine and showed decreasing in shedding after challenge; especially in the groups which take a booster vaccination of PP and AI vaccine. Although eradication still remain the 1st of choice for controlling the AI in the circumstances of a continuing and wide spread outbreak, but also the availability of new designing future vaccination regime by using avipox virus vaccine should be applied.

Phylogenetic Analysis of Infectious Bronchitis Viruses Currently Circulating in the Egyptian Field

One of the major problems of infectious bronchitis virus (IBV) is the frequent emergence of new variants in the Egyptian field. In the present study, 42 broiler chicken flocks suffered from respiratory troubles were investigated for infectious bronchitis virus in 10 Governorates in Egypt during 2016-2018. Ten out of 42 examined flocks revealed variable degrees of embryo lesions after 3-5 passages with negative heamagglutination (HA) activity. From these 10 flocks, IBV was confirmed in six flocks using reverse transcriptase polymerase chain reaction (RT-PCR) assay. Four IBV-positive isolates were selected for further sequence analysis. Partial sequencing of S1 gene revealed four IBV variant-2 isolates circulating among chickens in Egypt. These isolates are IB-Beh-Ch-F2-2016, IB-Sh-Ch-F25-2017, IB-Sh-Ch-F41-2018 and IB-Sh-Ch-F42-2018 and submitted on Gen Bank with accession numbers MH460643, MH460644, MK408615 and MK408616, respectively. The IB-Sh-Ch-F25-2017 isolate had only one amino acid substitution while IB-Beh-Ch-F2-2016, IB-Sh-Ch-F41-2018 and IB-Sh-Ch-F42-2018 isolates had much higher genetic diversity. The similarity between classic viruses of vaccine origin used in Egypt (H120, Ma5) and our four filed isolates ranged between 75.7 and 80.4%. It could be concluded that IB variant-2 strains still circulate in the Egyptian field in spite of vaccination. Therefore we need to revise the IBV vaccines used in Egypt and try to prepare local vaccines with periodic evaluation of cross protection of such vaccines.

Consumer safety evaluation of pyraclostrobin residues in strawberry using liquid chromatography tandem mass spectrometry (LC-MS/MS): An Egyptian profile

The dissipation rates of pyraclostrobin, a methoxyacrylate strobilurin group fungicide, along with its final residues and dietary exposure in strawberry were studied under Egyptian field conditions. Extraction was performed using a QuEChERS method, while residue determination was performed using liquid chromatography tandem mass spectrometry (LC-MS/MS) with limits of quantitation of 0.001 mgkg−1. At three different fortification levels (1.0, 10 and 100 ng/g) of pyraclostrobin applied to untreated strawberry samples, the recoveries ranged between 97 and 104% with relative standard deviation (RSD) of 1–6% (n = 6). The reported analytical method fulfills the standard requirements with regard to specificity, repeatability, limit of quantitation and recoveries. The half-life (t1/2) of pyraclostrobin after one single application of the recommended rate was 5 days. Risk assessment study was carried out by comparing the national estimated daily intake (NEDI) against acceptable daily intake (ADI) under good agricultural practice (GAP) conditions. Results indicated that strawberry treated with pyraclostrobin at the recommended dosage, are safe for human consumption three days after two successive applications with 14 days interval between each application. The present research should pave the way for the establishment of the safe and proper use of pyraclostrobin in strawberry in Egypt.

Emergence and genetic analysis of variant pathogenic 4/91 (serotype 793/B) infectious bronchitis virus in Egypt during 2019.

Infectious bronchitis virus (IBV) affects both vaccinated and unvaccinated flocks worldwide, with a significant impact on the poultry industry. The aim of the present study is to characterize an emerging variant pathogenic IBV originating from field outbreaks in vaccinated Egyptian layer flock. Samples were collected from disease-suspected flock with a history of administration of live and inactivated IBV vaccines (Ma5 type). Virus propagation in embryonated chicken eggs (ECEs), after three successive passages, revealed typical IBV lesions such as curling and dwarfism. The reported isolate was identified by a real-time reverse transcriptase PCR assay targeting nucleocapsid (N) gene and, further characterized by full-length spike (S1) gene sequencing. Phylogenetic analysis revealed clustering of the isolated virus within 4/91 genotype of GI-13 lineage. Deduced amino acid sequences identity revealed 75–76% and 88–90% similarity with the currently used classic (H120, Ma5, and M41) and variant vaccine strains (4/91 and CR88) in Egypt, respectively. Recombination analysis gave an evidence for distinct patterns of origin for the studied isolate providing another example of intra-genotypic recombination among IBVs and the first example of recombination within the GI-13 lineage in the Egyptian field. The studied isolate (IBV/CK/EG/Fadllah-10/2019) emerged as a result of recombination between the variant group (Egy/var I genotype, GI-23 lineage) as a major parent and the CR88 variant vaccine strain (4/91 genotype, GI-13 lineage) as minor parent. Our data suggest that both mutation and recombination may be contributing to the emergence of IBV variants which ascertain the importance of disease monitoring in vaccinated flocks as well as re-appropriation for the current vaccine strategies.Electronic supplementary materialThe online version of this article (10.1007/s11262-019-01693-9) contains supplementary material, which is available to authorized users.

La modernità nel teatro egiziano: l’esempio di Naǧīb al-Rīḥānī

Abstract Arab modernity, in theatre, is characterized by the foundational discourse that grew out of the encounter with European theatre and culture. Traditional types of dramatic representation, some even going back to the pre-Islamic period, were largely neglected by authors and critics, between the end of the 19th and the beginning of the 20th century. They preferred to overlook the influence of popular Arabic theatre and reconnect to the ‘Italian’ theatre. Egyptian playwrights imported the structure of the plays, but they adapted it to the Arabic social context and used it for their own cultural project. This study deals with the themes, the reference samples and the characters, in their relationships with the Egyptian cultural field. After a presentation of the major models in the modern Arab theatre, I will focus on Naǧīb al-Rīḥānī in order to investigate which were the paradigmatic references and characters for one of the main actor and playwright of Egyptian modernity.

Molecular Identification And Pathogenicity Assessment Of Avian Reovirus In Egypt

The avian reoviruse (AVR) induces various manifestations in chickens. They are associated with disease conditions including malabsorption syndrome and tenosynovitis. RT-PCR is a rapid, sensitive and specific diagnostic test for ARV detection and avoiding economic losses. Five broiler poultry farms in Behera province with reovirus like symptoms were screened for ARV. Results revealed the successful identification of one ARV isolate. the pathogenicity of the obtained isolate was assessed by experimental infection of 7-day-old commercial chicks and results revealed various post-mortem lesions in the liver, pancreas liver, and proventiculus. The serological follow up of maternally derived antibodies against ARV in the negative control group revealed that the ELISA antibody titers were declined till becoming negative (ELISA titers less than 395) at 21 day old. Meanwhile, the experimentally infected group showed a significant increase in the ELISA antibody titers following infection. Our results confirm the continuous circulation of ARV in the Egyptian field as well as raise the concern toward ARV and its incrimination in retarded growth rate and arthritis among chicken flocks that consequently have great drawbacks on the poultry industry in Egypt.

Effect of experimental Ornithobacterium rhinotracheale infection along with live infectious bronchitis vaccination in broiler chickens

Ornithobacterium rhinotracheale (ORT), a bacterium causing respiratory tract infection, has led to a significant problem in the intensive poultry production in Egypt. Polymerase chain reaction-amplified 784-bp specific ORT DNA fragments were found in 7 ORT isolates from lungs, air sacs, and tracheas of commercial broilers or layers in Egypt in 2015. The objective of this study was to investigate the role of the live variant IBV 4/91 with ORT infection. A total of 120 14-d-old broiler chickens (Cobb 500) were equally divided into 4 groups for experimental infection in a complete randomized design. Group 1 was infected with ORT strain and live infectious bronchitis vaccine (IBV 4/91) simultaneously; group 2 was infected with the bacterial strain alone; group 3 was vaccinated only with IBV 4/91, and group 4 was the non-vaccinated and non-infected control group. The respiratory signs, post-mortem lesions (tracheitis and pneumonia) and histopathological findings of lungs, trachea, and air sacs in the experimentally infected broiler chickens appeared to be more prominent in the chickens of group 1 than group 2. With respect to body weight, weight gain, feed conversion rate, and Ornithobacterium re-isolation, there was a difference (P ≤ 0.05) among the chickens of group 1 and the other groups. This reveals that the use of live infectious bronchitic vaccines, which is a common practice in the local Egyptian field of production, may concomitantly increase the pathogenicity of ORT in broiler chickens.

Adult Plant Resistance to Stem Rust and Molecular Marker Analysis of some Egyptian and Exotic Bread Wheat Genotypes

Stem rust caused by Puccinia graminis f. sp. tritici is the most dangerous and common disease among global wheat cultivars. Twelve local Egyptian and four exotic genotypes of bread wheat (Triticum aestivum L.) obtained from the International Maize and Wheat Improvement Center (CIMMYT) were evaluated under Egyptian field conditions for adult plant resistance (APR) levels to stem rust at Sakha location during the two successive growing seasons (2015/16 and 2016/17). Also, DNA characterization for genotypes by specific markers were tested to determine the presence of the effective resistance genes (Sr's); Sr22, Sr24, Sr25 and Sr26. Out of the tested genotypes, four Egyptian bread wheat cultivars; (Misr3, Sakha94, Gemmeiza9 and Gemmeiza11), and four of CIMMYT lines (Line6043, Line6091, Line6107 and Line6197) show high levels of adult plant resistance to stem rust. Among the tested genotypes, Sr22 found to be the most frequent gene, present in most of them. While, Sr24 was present only in one local wheat cultivar and two exotic lines. Sr25 was present in five local wheat cultivars and two exotic lines. In addition, a resistance gene Sr26 was present in three exotic lines. The obtained results in this study evince that a combination of two or more resistance genes in one cultivar confer high adult plant resistance level in this cultivar, under field condition.

The Relation Between Developmental Stages of the Predator, Rodalia cardinals (Mulsant) Reared on Icerya purchasi Maskell and the Required Thermal Units

Laboratory experiments were carried out in the Insectary of Economic Entomology Department Faculty of Agriculture, Mansoura University study the relationship betweenthe developmental stages of the predator, Rodalia cardinals (Mulsant)and the required thermal units at threeconstant temperatures, (15, 25 and 30˚C) on the third nymphal instar of Icerya purchasi Maskell. The results indicated that, the duration of the predator was longer at 15˚C. As temperature increased from 15 to 30˚C the developmental aspects of R. cardinals decreased. The lower thermal threshold for thedifferent stages were 10.5, 8.5, 5.3, 5.2, 5.4, 6.9, 0.8 and 1.3˚Cfor egg stage, larval stage, pupal stage, preoviposition period, oviposition period, postoviposition period, adult female longevity and adult male longevity, respectively. The heat units required for the development of eggs was 56.2 DD unite, while for larvae, pupae, adult female and adult male were 211.3, 114.7, 969.3 and 664.4, consecutively. The results revealed that, the longevity of the predator adult stage decreased with increasing the temperature degrees. The highest consumption rate per female was at 15 ˚C comparing with the other temperature degrees. The highest number of deposited eggs per female was 25 ˚C with the value of 443.71 eggs/ female. Obtained results provide essential information for predicting the field population of the predator R. cardinals, releasing time on certain mealybug species for controlling this pest and it's recommended to be an item of integrated pest management programs in Egyptian field designed to control certain mealybug species.

Saponin-adjuvanted vaccine protects chickens against velogenic Newcastle disease virus.

Despite extensive vaccination campaigns, Newcastle disease virus (NDV) remains endemic in many countries worldwide, and factors that contribute to this failure include mismatched vaccines, partial immunization, and poor husbandry practices. In order to overcome the problem of genetic divergence between circulating field strains and vaccine strains, we saponin-adjuvanted an Egyptian field strain and assessed its safety and immunogenicity in chickens. Immunization of chickens with the vaccine followed by challenge with a velogenic reference strain revealed the potential of the saponin-adjuvanted vaccine to induce a strong immune response that resulted in complete protection of chickens. Importantly, in vaccinated chickens, virus shedding was abolished, providing an added advantage over the currently available commercial live-attenuated and inactivated vaccines, which are unable to prevent shedding. A histopathological investigation demonstrated that the vaccinated chickens had less-severe lesions than challenged unvaccinated and mock-vaccinated chickens. We propose using this formulation as an alternative and improved NDV vaccine platform that can be exploited to control disease not only in Egypt but also in other disease-endemic countries.

Insecticides and Their Mixtures for Controlling Tuta Absoluta Infesting Tomato under Egyptian Field Conditions

Insecticides and Their Mixtures for Controlling Tuta Absoluta Infesting Tomato under Egyptian Field Conditions

Genetic Stability of Wheat Stem Rust Resistance Genes under Egyptian Field Conditions

Genetic Stability of Wheat Stem Rust Resistance Genes under Egyptian Field Conditions

Characterization of full genome sequences of chicken anemia viruses circulating in Egypt reveals distinct genetic diversity and evidence of recombination

Chicken anemia virus (CAV) is one of the commercially important diseases of poultry worldwide. In Egypt, CAV has been reported to be a potential threat to the commercial poultry sectors. Hence, this study was aimed at isolation and full genomic analysis of CAVs circulating in chicken populations in different geographical location in Egypt. A total of 42 samples were collected from broiler chicken flocks in 9 governorates in Egypt from 12 to 42 days of age. The mortality rate observed among chickens was ranging from 3% to 22%. Nineteen out of 42 farms were found positive for the CAV genome by polymerase chain reaction (PCR).Full genome sequencing was conducted for 18 positive samples. Genetic analysis revealed a high similarity of >99% in 11 viruses with the vaccine strain Del-Ros; while the other seven samples shared close similarity to CAV field strains isolated from China, Taiwan, and Brazil. The data also indicated Q139 and Q144 amino acids substitutions among the VP1 of Egyptian field strains, which are known to be important in virus replication and spread. Phylogenetic analysis of the sequenced viruses (n = 18) based on either the full gene nucleotide sequence or VP1 coding sequence, suggested the circulation of four distinct genotypes in Egypt designated as group A, B, C and D. Moreover, evidence of recombination was detected among four Egyptian CAVs located within group A. The findings of this study succeeded to elucidate the epidemiological and genetic features of CAVs circulating in Egypt, and underscores the important of CAVs surveillance.

SAYYID QUTB AND THE CRISIS OF CULTURE IN LATE 1940S EGYPT

AbstractThis article focuses on the writings and literary networks of the Egyptian intellectual and activist Sayyid Qutb during the late 1940s. Scholars have tended to explain Qutb's political radicalization and joining of the Muslim Brotherhood during the subsequent decade via aspects of his personality or personal life, such as his quick temper, conservatism, or frustration over unfulfilled aspirations to become a writer. Drawing on three periodicals published respectively by leftist, Islamist, and independent aspiring writers, I instead place Qutb's criticism of political, economic, and cultural elites in the context of an emerging generation of critical intellectuals. By shedding light on intellectual cooperation between Qutb, Muslim Brothers, Marxists, and independent writers, this article challenges established scholarly narratives that locate the Islamist project outside the Egyptian intellectual field.

Virulence of some Puccinia triticina races to the effective wheat leaf rust resistant genes Lr 9 and Lr 19 under Egyptian field conditions

Leaf rust (Puccinia triticina Eriks.) is one of the most widespread disease of wheat (Triticum aestivum L.) in Egypt and worldwide. The two leaf rust resistance genes i.e. Lr 9 and Lr 19 were previously highly effective against the predominant Puccinia triticina races in Egypt. In 2015/2016 growing season, susceptible field reaction was recorded on these two genes, where rust severity reached to 40% for Lr 9 and 5% for Lr 19 under Egyptian field conditions at the four locations i.e. El-Behira, El-Minufiya, El-Qalubiya and El-Fayom governorates. In this study, eight leaf rust field samples were collected from these governorates (four from each of Lr 9 and Lr 19). Forty single isolates were derived from the collected samples of Lr 9 and Lr 19 (each with 20 isolates). Eight pathotypes were identified from Lr 9, while only two pathotypes were identified from Lr 19. Also, 39 leaf rust monogenic lines (Lr,s) and 16 commercial wheat cultivars were tested for their seedling reaction against ten leaf rust pathotypes isolated from Lr 9 and Lr 19. While, 12 leaf rust monogenic lines and the same 16 wheat cultivars were evaluated at adult plant stage. The most frequent pathotype (virulent to Lr 9) was KTSPT (30% frequency), followed by TTTMS (25% frequency). The other pathotypes ranged from only 5%–10% frequency. Whereas, the most frequent pathotype (virulent to Lr 19) was CTTTT (85% frequency), but the lowest frequent one was PKTST (15% frequency). Pathotypes i.e. PRSTT, NTKTS and TTTMS (identified from Lr 9) were more aggressive pathotypes on most of the tested leaf rust monogenic lines than others. Also, the two pathotypes; PKTST and CTTTT (identified from Lr 19) were more aggressive pathotypes on most of the tested leaf rust monogenic lines. The leaf rust resistance gene Lr 2a was the most effective gene against almost all of the tested pathotypes at adult plant stage. On the other hand, the three wheat cultivars; Misr 1, Misr 2 and Nubariya 1 proved to be of highly resistance against all of the tested leaf rust pathotypes at adult plant stage.

Relationship Between Developmental Stages of Predator nephus includens (kisch) (coleoptera: coccinellidae) Reared on Certain Mealy Bug Species and the Required Thermal Units.

The present work was conducted to study the relationship between the developmental stages of the predator Nephus includens (Kisch) (Coleoptera: Coccinellidae) and the required thermal units at three constant temperatures, (20, 25 and 30oC) on certain mealy bug species (Planococcus citri Risso, Icerya seychellarum (Westwood) and Maconellicoccus hirsutus (Green). The results indicated that, the duration of the predator was longer at 20oC. As temperature increased from 20-30oC the longevity decreased, the lower thermal threshold for the development of N. includens 10.9, 10.6 and 11.1oC for eggs , 6.4, 2.1 and 0.7oC for larvae, 8.4, 5.6 and 11.9oC for pupa while it were 0.1, 3.2 and 1.9oC for the total duration from (egg to adult). The heat units requirement for the development of eggs were 90.1, 92.4 and 91.5 DD's , for larvae were 387.7, 328.1 and 382.5 DD's, for the pupa 325.8, 308.1 and 390.1 DD's while it were 713.8, 674.2 and 765.3 DD's for the development period of P. citri, I. seychellarum and M. hirtsutus respectively. The lower thermal threshold for longevity (female and male) of N. includens were 12.8 & 18.4, 10.9 and 13.2& 22.8 & 48.7, meanwhile, the heat units requirement for longevity of (female and male) were 2779.8 & 2513.7, 2709.9 and 2380.7 & 2432.4 & 4206.2 on the same mealy bug species, respectively. The average of total consumption per larva was the highest at 25 + 1oC and when this predator fed on the mealy bug species P. citri during its larval stage. The results revealed that, the longevity of the predator adult stage decreased with increasing the temperature degrees. The highest consumption rate per female was at 30 + 1oC comparing with the other temperature degrees. The number of deposited eggs per female was the highest (185.74 + 1.92 eggs) when female reared on P. citri at 25 + 1oC. Obtained results provide essential information for predicting the field population of the predator N. includens, releasing time on certain mealy bug species for controlling these pests and it's recommended to be an item of Integrated Pest Management Programs in Egyptian field designed to control certain mealy bug species.

Evolutionary insights into the fusion protein of Newcastle disease virus isolated from vaccinated chickens in 2016 in Egypt

Newcastle disease virus (NDV) infections are one of the most devastating causes of economic losses in the poultry industry and despite extensive vaccination, outbreaks are being reported around the globe especially from developing and tropical countries. Analysis of NDV field strains from vaccinated flocks would highlight essential areas of consideration not only to design effective immunization strategies but also to devise vaccines that provide sterile immunity. For this purpose, 91 NDV suspected outbreaks were investigated and screened for NDV genetic material. A total of 16 NDV-positive isolates were examined using biological, genetics and bioinformatics analysis to assess the epidemiological association and to identify motifs that are under vaccine-induced immune pressures. In line with the clinical outcomes, all isolates showed the 112RRQKR|F117 cleavage motif and phylogenetic analysis revealed grouping of isolates into the genotype VII, and specifically sub-genotype VIId. Further analysis of the putative fusion protein sequence showed a number of substitutions (n=10) in functionally important domains and based on these differences, the studied isolates could be categorized into four distinct groups (A-D). Importantly, two residues (N30 and K71) were conserved in the commercial live vaccine and Egyptian field strains that are present in class II, genotype II. Collectively, these data enhance our knowledge of the evolution of genotype VIId NDV under the vaccine-induced immune pressures. In addition, our findings suggest that the use of genotype II-type vaccines in Egypt may be implicated in the emergence of new variants rather than providing benefits against NDV infections.

Genetic Characterization of Egyptian Field Isolates of Infectious Bursal Disease Virus

Detection and characterization of field infectious bursal disease virus (IBDV) isolates circulating among different broiler breeds representing three Egyptian governorates with a history of vaccination against IBDV, was done during 2013- 2015. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to amplify and produce clear band of 620 Base pair (bp) product within the hypervariable region of the IBDV viral protein (VP2) gene. The IBDV was prevalent in thirty out one hundred flocks (30%). Subsequently, chosen PCR products were subjected to further analysis by sequencing and phylogenetic studies. Amino acid substitution in VP2 region used to establish a clear framework on the epidemiology of isolated IBDV . Genetic analysis showed that all examined IBDV isolates characterized as vvIBDV had amino acids residues(222A, 242I, 256I, 294I, 299S) which showed to be unique for all vvIBDV strains and clustered phylogenetically with the previously Egyptian IBDVs ( 99.3-100% ) identity. While, vaccinal IBDV strains (BURSA-VAC and UNIVAX) were clustered in another group with (91.1–91.9%), (91.9–92.6%) identity respectively which might leads to vaccination failure and reemergence of disease. Consequently, we recorded wide range of genetic similarities (94.8-95.6) with the recombinant vaccines (VP2 of Faragher 52/70) seed virus, which showed superior protective efficacy against recent Egyptian vvIBDV isolates. IBDV is still a threat against poultry industry. It is important to keep track on appearance and evolution of antigenically different IBDV circulating strains followed by regular updating of the vaccination strategy.