Isolation, identification and pathotyping of Newcastle disease virus from chickens in Egypt

Abstract

A B S T R A C TEgypt is endemic for Newcastle disease virus (NDV) with continuous long-lasting outbreaks causing significant losses in the poultry industry. This study was designed to isolate and identify NDV from different localities in Egypt (Giza, Gharbiya, Kalyobiya, Sharkia, Menofia, Fayoum and Minia) among chicken flocks and estimate its virulence using Mean death time (MDT) and intra-cerebral pathogenicity index (ICPI). Forty samples were collected from chickens either alive or dead showing clinical findings and post-mortem lesions characteristic for NDV. Virus propagation in embryonated chicken eggs was confirmed by hemagglutination (HA) test and identified by hemagglutination inhibition (HI) test using NDV specific antiserum. The results indicated that 23 (57.5 %) out of 40 samples were NDV positive. The isolate from Giza was velogenic with MDT of 48 hours and ICPI of 1.625. While the isolate from Qualubiya was lentogenic with MDT of 96 hours and ICPI of 0.4375.These findings provide data on biological pathotyping of NDV in chickens in Egypt and emphasize importance of NDV surveillance for improving of strategies for the control of the disease.

Pathogenicity of local identified NDV strain related to genotype VII to 28 day old commercial broiler chickens

“…18,25,28 Mortalities " Table 1" start at the 3 rd dpi with death of 7birds in rate of 46.7%. 18,26,28 At the 4 th dpi same severe signs were detected with death of 2birds (13.3%). In 5 th dpi: greenish diarrhea was obvious with respiratory signs with death of 2birds (13.3%).…”

“…VIId is the predominant pathogen involved currently in ND outbreaks in poultry worldwide. [24][25][26][27] Recent findings suggest that the virulent virus may emerge in poultry as a result of mutations in viruses of low virulence. 24 Mean HI titer was 8.5±1.19 and 1±1.06 at 1 and 28days of age 18.…”

“…while mortalities reach 80% in 5 dpi. 18,26,28 Endemic ND can cause mortality of up to 60% in village chickens. 25 Post mortem examination of dead infected chickens " Figure 2" showed dehydrated, anorexic bird, Catarrhal tracheitis with hemorrhagic mucosa " Figure 2A", Congested enlarged liver with sub capsular hemorrhage " Figure 2B", Enlarged mottled spleen " Figure 2C" hemorrhages on the tips of periventricular glands " Figure 2D", Congested serosal surface of intestine " Figure 2E", liver and muscle congestion, greenish intestinal contents " Figure 2F" , greenish content of proventriculus and gizzard " Figure 2G", Hemorrhagic cecal tonsils serosal view " Figure 2H" Necrosis and ulceration in mucosal of cecal tonsils " Figure 2I".…”

Concurrent Respiratory Disease in Broiler Chickens in Egypt during 2020

“…The most severe respiratory disease is Newcastle Disease (ND) that causing high mortality in poultry flocks (OIE, 2012). In Egypt, the NDV was first recorded in 1948 (Daubney and Mansy, 1948) then spread rapidly in Egypt despite vaccination programs (Abdel-Moneim et al, 2006b;El-Bagoury et al, 2015).…”

Efficacy of an inactivated Vaccine prepared from a new isolate of Newcastle Disease Virus

“…Because NDV is RNA virus which characterized by the high rates of mutation and replication and large population sizes, so RNA viruses evolve rapidly (Domingo and Holland, 1997). The NDV local isolates from Giza 2014 showed a pattern of 112R/K-R-Q-R/K-R↓F117 F protein cleavage site motif characteristic to velogenic NDV strains and the NDV local isolates from Qualubiya 2014 showed a pattern of 112G/E-K/R-Q-G/E-R↓L117 F protein cleavage site motif characteristic to lentogenic NDV strains (El-Bagoury et al, 2015;El-Habbaa et al, 2017).…”