Isolation and Pathotyping of Infectious Bursal Disease Virus (IBDV) from Field Outbreaks among Chickens in Egypt

Abstract

Infectious bursal disease (IBD) is a main health problem causing considerable economic losses in poultry flocks in Egypt. Throughout 2018-2019, bursae samples were assembled from different chicken's farms localized in four Egyptian governorates (Giza, Bani-Suif, Fayoum and Qalubia). The samples collected from farms recorded history of Infectious Bursal Disease (IBD) signs such as: sudden mortalities; depression; diarrhea; and hemorrhages on bursal tissues, leg and breast muscles. For virus isolation, the collected samples were cultivated in Specific Pathogen Free Embryonated Chickens Eggs (SPF-ECEs) via Chorio-Allantoic-Membrane (CAM).To confirm obtained data of virus isolation, both Agar gel precipitation test (AGPT) and the Reverse Transcription-Polymerase Chain Reaction (RT-PCR) were applied. In AGPT results, the four IBDV isolates gave positive reaction by reference IBDV antisera. RT-PCR was done for amplification of VP2 gene of IBDV isolates. The four viral isolates introduced specific band at size of 620 bp. Pathogenicity test for isolates of IBDV represented that the IBDV isolate no. 1, 2, 4 belong to classical virulent IBDV (cvIBDV) serotype, while IBDV isolate no. 3 belong to very virulent IBDV (vvIBDV) serotype that caused high mortality rates than cvIBDV isolates. The presented results emphasize the determined screened of the IBD field state, as well as apply of supplementary studies to found successful policies to obstruct the viral infection in chicken flocks in Egypt.

Characterization of Newcastle Disease Virus Circulating in Vaccinated Poultry Farms in Egypt During 2020

“…Regarding ICPI, the result showed that isolate from Giza was velogenic with ICPI of 1.652 and isolates from Cairo and Menoufiya governorates were velogenic with ICPI of 1.601 and 1.601 respectively. This result agreed with that obtained by Nabila et al (2014).…”

“…In Egypt, outbreaks of NDV are still frequently occurring in vaccinated poultry flocks, despite the intensive vaccination programs (Mohamed et al, 2011 andNabila et al, 2014). The main objective of the present work was identification of circulating NDV in Egyptian chicken and development of control methods for infection.…”

“…Egypt has been designated as an NDV endemic nation. Despite continued vaccination campaigns, outbreaks continue to occur in vaccinated chicken flocks, posing a danger to the national poultry sector (Nabila et al, 2014). Many NDV outbreaks may be caused by the haphazard use of intense vaccinations, frequent mutations, and the emergence of novel pathotypes of NDV.NDV genotypes II and VII has been reported in Egypt (Naguib et al, 2021).…”

First Detection and Molecular Characterization of Novel Variant Infectious Bursal Disease Virus (Genotype A2dB1b) in Egypt

“…Aside from characterizing field strains from a molecular perspective, it is essential to understand their pathogenic features and ensure that the currently enacted control measures are effective. A wealth of data has been produced in the Egyptian context on the pathogenicity of locally circulating very virulent IBDVs, which consistently cause typical IBD signs and lesions with high mortality rates [59][60][61], and on the protection induced by different live [61], vector [62,63] and immune complex [64] vaccines, which appears adequate. Novel variant IBDVs, on the other hand, are associated with subclinical infections with severe bursal atrophy and lymphocyte depletion [16,46,65,66].…”

Pathological and Epidemiological Study on Newcastle Disease in Broiler Chicken Farms in Egypt between 2021-2022.

“…NDV was initially identified in Egypt in 1948 (Daubney & Mansy, 1948). Since then, Egypt has been regarded as an endemic country for ND (Nabila et al, 2014). NDV has three strains: velogenic (viscerotropic and neurotropic), mesogenic, and lentogenic.…”