Propagation of lentogenic Newcastle disease virus V4 strain in specific-pathogen-free embryonated chicken eggs of different ages

Har, Jing Wei (2023) Propagation of lentogenic Newcastle disease virus V4 strain in specific-pathogen-free embryonated chicken eggs of different ages. [Project Paper] (Submitted)

Text lp FPV 2023 104.pdf Download (1MB)

Abstract

Newcastle Disease (ND) is highly contagious viral disease of birds caused by Newcastle disease virus (NDV). NDV is a single serotype virus which recently been grouped under the genus Avian Orthoavulavirus type 1 (AOAV-1) under the family Paramyxoviridae. The virus can be further classified as velogenic, mesogenic and lentogenic based on the virus pathotypes, where the development of live attenuated vaccine is based on lentogenic NDV strains. NDV isolation and propagation in specific-pathogen-free (SPF) embryonated chicken eggs (ECE) are common practices used in diagnosing ND and in producing vaccine using ECE aged 8-10 days. However, younger ECE may be able to support the growth of the virus due to the incomplete development of innate immunity as compared to older ECE. Furthermore, younger ECE as early as one day old has been used to rescue novel reverse genetic viruses including NDV for the development of live attenuated vaccine. This study is part of a bigger study in evaluating the ECE age and immune status in supporting the propagation of NDV vaccine strains. Therefore, this study aimed to study the differences in lentogenic NDV V4 strain titers following inoculation of 3-day-old, 5-day-old and 10-day-old SPF ECE via the allantoic cavity with different inoculation doses at 10³, 10⁴, 10⁵ of the virus. Sterile saline inoculated ECE of different ages was used as negative controls. The ECE was checked for viability daily for embryonic death. The ECE was incubated at 37C for 3 days. ECE showing embryonic death was chilled at 4C. Allantoic fluid of ECE was harvested to detect NDV based on a hemagglutinin (HA) spot test and HA titration test. Results from the HA titration test showed that the HA titer of allantoic fluid harvested from 10-day-old ECE was significantly higher than 5-day-old ECE (P<0.05). However, propagation of the virus using 3-day-old ECE was not successful as none of the allantoic fluid of the inoculated ECE showed positive HA results. There was a positive correlation with virus yield when viruses of different doses were inoculated into 5 and 10-day-old ECE. Inoculation of V4 virus with the dose of 10⁵ into 5 and 10-day-old ECE showed the highest mean HA titers of 10⁵ and 1010, respectively (P<0.05). In conclusion, 5-day-old and 10-day-old ECE can support the growth and propagation of NDV V4 strain xv but 10-day-old ECE produces higher virus titer, this may indicate that usage of 10-day-old ECE is most suitable for isolation, and propagation of lentogenic NDV V4 strain.

Item Type:	Project Paper
Faculty:	Faculty of Veterinary Medicine
Depositing User:	Ms. Nordeena Abdul Aziz
Date Deposited:	18 Nov 2024 08:12
Last Modified:	18 Nov 2024 08:12
URI:	http://psaspb.upm.edu.my/id/eprint/2145

Actions (login required)

View Item