Characterization of Variant Strain of Newcastle Disease Virus in Egypt
Journal Title: Journal of Veterinary Medical Research - Year 2006, Vol 16, Issue 1
Abstract
During 2005, velogenic Newcastle disease virus (NDV) caused a major outbreak among commercial broiler chicken in Egypt. The outbreak raised concerns regarding the protective immunity of commercially available vaccines for prevention and control of this virus in poultry. The virus was isolated from broiler farm suffered from more than 95% mortalities. The isolate was confirmed not to be avian influenza virus (AIV) by rapid chromatographic strip test, and characterized as NDV using reverse transcription-polymerase chain reaction (RT-PCR) which amplified a portion of the fusion gene of NDV and haemagglutination inhibition (HI) test. This isolate confirmed to be velogenic viscerotropic NDV by mean death time (MDT) test and pathogenicity to 7-week old chickens. We tried to determine whether the existing commercial live NDV La Sota vaccine could provide protection against the isolated virus or not. Birds received a single dose of live La Sota type vaccine at 3 weeks of age and were challenged 2 weeks postvaccination with a lethal dose of NDV. Results indicated that the live vaccine did not protect against morbidity but reduced mortality in comparison to controls. All unvaccinated control chickens challenged with NDV died within 5 days post-challenge (pc). Protection from disease did not correlate with the presence of antibody titers (determined by HI) at day of challenge. These results underscore the need to develop new NDV vaccines and vaccine strategies for use during outbreak situations to protect birds from both disease and infection and to reduce virus shedding.
Authors and Affiliations
A. S. Abdel-Moneim1; Azza A. El-Sawah2; M. A. Kandil3 1Department of Virology, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt 2Department of Poultry and Rabbit diseases, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt. 3Department of Biochemistry, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt.
Molecular characterization and genotyping of recent isolate of Infectious Bronchitis Virus (IBV) in Egypt
In this study a total number of 22 organ samples (including trachea, lung and kidney) from 22 broiler farms from northern Upper Egypt were collected from Mars 2017 to June 2018 from chickens showing clear clinical and pa...
Radiologic and ultrasonographic studies of kidneys in goat
A study was performed on fifty normal goats for radiographic (only 20 animals), and sonographic (the all 50 animals) investigations. Radiographic results revealed that, both kidneys had bean shaped and smooth contour. T...
Study on the capability of a dual capripox vaccine in protection of cattle against LSD infection
The experiment applied on four groups of calves, each of four calves. Three calves from each group were vaccinated with one of the following attenuated vaccines: Lumpy skin disease vaccine (LSD), Romanian sheep pox (RSP)...
Some virulence factors of Escherichia coli isolated from diarrheic calves
Escherichia coliare the most common cause of diarrhea in calves. Diarrhea in calvesremains one of the most important problems faced by livestock, causing great economic losses. Some strains ofE. coli characterized by the...
The use of different stabilizers for improving integrity of the locally prepared lyophilized Brucella melitensis Rev 1 vaccine
Stability study of biological products especially living bacterial vaccines plays an important role for determination of product changes in maintenance period and ensures safety, efficacy and maintenance of biological pr...