Detection and isolation of a recent infectious bursal disease virus from chicken farms in Egypt during 2021

Abstract

Infectious bursal disease virus (IBDV) is considered as an economic challenge to the poultry industry. Monitoring of circulated recent IBDV is very significant in controlling the spreading of disease in Egypt. In this study, we are targeting VP2 gene of IBDV in bursal samples from 15 different infected chicken commercial farms in seven Egyptian governorates. Reverse transcriptase polymerase chain reaction (RT-PCR) was used for virus detection, 7 out of 15 examined farms from four governorates involving Qaluobia, Dakahlia, Sharkia, Gharbiya were IBDV positive. Isolation of IBDV was carried out by inoculation on chorioallantoic membrane of specific pathogen free embryonated chicken eggs (SPF-ECEs). The infectivity titration of the third passage of IBDV strains was 6.4, 5.6, 5.5 and 5.4 Log 10 EID50/0.1ml respectively for Dakahlia, Sharkia, Qaluobia and Gharbiya, then identified by RT-PCR and sequenced. The Neutralization index of Qaluobia isolate was 3. In conclusion, a recent Egyptian very virulent Infectious bursal disease virus (vvIBDV) strains antigenically different serotype 1 was circulated and further molecular characterization is required.

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

“…However, considering that very virulent IBDVs are widespread in the country and that the investigated governorates were in proximity to each other, it might be assumed that very virulent and variant strains are cocirculating in the same areas. It is also worth noting that field IBDVs have already been detected in all the governorates from which no positive samples were retrieved [24,26,[55][56][57][58], suggesting that this finding was due to the small sample size rather than the actual absence of field strains in these settings.…”