title: Biological Pathotyping of Newcastle Disease Viruses in Sudan 2008-2013.
abstract: The biological properties and pathogenicity of seven Newcastle disease virus field isolates were studied. These isolates were recovered from different outbreaks in Sudan (5 from chickens and 2 from pigeons) during 2008-2013. Based on intracerebral pathogenicity index, four NDV isolates were characterized as velogenic (their ICPI ranged 2.0-1.6) and three isolates were characterized as mesogenic (ICPI ranged 1.2-1.3). The mean death time for all isolates ranged from 54 to 76.8 hours. The elution time of the viruses from chicken erythrocytes and the ability to haemagglutinate mammalian red blood cells differed considerably in their reactions.
authors.affiliation: Veterinary Research Institute, P.O. Box 8067, Khartoum, Sudan.
authors.forename: Egbal Sidahmed Abdelrahim
authors.initials: ES
authors.lastname: Bilal
authors.affiliation: Veterinary Research Institute, P.O. Box 8067, Khartoum, Sudan.
authors.forename: Iman Mohammed
authors.initials: IM
authors.lastname: Elnasri
authors.affiliation: Veterinary Research Institute, P.O. Box 8067, Khartoum, Sudan.
authors.forename: Aymen Mohamed
authors.initials: AM
authors.lastname: Alhassan
authors.affiliation: Veterinary Research Institute, P.O. Box 8067, Khartoum, Sudan.
authors.forename: Khalda Abdelaziz
authors.initials: KA
authors.lastname: Khalifa
authors.affiliation: Veterinary Research Institute, P.O. Box 8067, Khartoum, Sudan.
authors.forename: Jedddha Ibrahim
authors.initials: JI
authors.lastname: Elhag
authors.affiliation: Veterinary Research Institute, P.O. Box 8067, Khartoum, Sudan.
authors.forename: Selma Osman
authors.initials: SO
authors.lastname: Ahmed