الفهرس 
Cover Page Title in EnglishOnly 14 pages are availabe for public view
 |  | from | 91 |  |  |
| | | from | 91 | | |
Abstract
Newcastle disease (ND) is one of the oldest infectious diseases of affecting many domestic and wild avian species but it is most notable in domestic poultry due to their high susceptibility and the potential for sever impacts of an endemic on poultry industries. The caused virus of ND was categorized on the bases of its pathogenicity and virulence into lentogenic, mesogenic and velogenic. The disease is defined as an infection of birds caused by a virus of avian paramyxovirus serotype 1 (APMV-1) When investigations of ND are the result of severe dis¬ease and high mortality in poultry flocks, it is usual to attempt virus isolation from recently dead birds or mor¬ibund birds that have been killed humanely. ND virus can be confirmed by the use of specific anti¬serum in a haemagglutination inhibition (HI) test. Usu¬ally chicken antiserum that has been prepared against one of the strains of ND virus is used. It is well known that successful control and eradication of infectious diseases depend mainly on accurate diagnosis that depends on application of sensitive, accurate and rapid serological tests. These tests often need specific anti-sera either in necked form (for agar gel precipitation test and virus neutralization test) or in conjugated forms with flourescine isothiocyanate (for fluorescent antibody technique) or with horse radish peroxidase (for enzyme linked immune sorbent assay). The present thesis was designed to prepare and evaluate NDV antiserum in different hosts and conjugation of such serum with flourescin isothiocyanate aiming to provide specific antiserum able to detect and identify NDV in accurate; sensitive and rapid manner with law cost as local a preparation. The obtained experimental results revealed that: 1- Estimation of serum proteins in the prepared anti-ND sera showed that rabbit serum had the levels of 5.45±0.11; 1.85±0.22 and 3.60±0.12g/dl for total serum; albumin and globulin respectively; goat serum had the values of 5.82±0.21; 1.79±0.32 and 4.03±0.10g/dl for total serum; albumin and globulin respectively while Guinea pig serum had the levels of 5.10±0.13; 1.80±15 and 3.2±10g/dl for total serum; albumin and globulin respectively. 2-Rabbit; Guinea pigs and goat anti-NDV hyper immune sera were found to be free from foreign contaminants (aerobic and anaerobic bacteria; fungi and mycoplasma). These sera were titrated using HI test which revealed gradual increasing in ND antibodies recorded their peaks by the 5th week post animal immunization as 8; 7 and 8.5log2/ml in rabbit; Guinea pig and goat’s sera respectively showing that goat serum had the highest levels of ND antibodies. 3-Experimentally infected chickens showed disease signs by the 3rd day post infection. All experimentally infected chickens showed signs of restlessness, increased respiration, and weakness, green diarrhea, muscular tremors, paralysis of legs and wings ending by death. 4-Post mortem findings of died chickens showed dark red purplish hemorrhagic and necrotic lesions in the digestive tract, catarrhal exudates in nasal passages and hemorrhage in trachea. Also ND virus was determined in brain, tracheal and intestinal samples from died chickens through application of HI test and direct FAT. 5-Application of direct fluorescent antibody technique on brain; tracheal and intestinal impression smears of NDV infected chickens using 10 fold dilutions of the prepared conjugated antisera with FITC; revealed that rabbit; Guinea pig and goat sera showed clear very strong positive reactions (++++) as apple green dots up to dilution of 1:100; 1:100 and 1:1000 respectively. Strong positive reactions (+++) were noticed on using serum dilutions 1:1000 of rabbit and Guinea pig sera and 1: 10000 of goat serum. Serum dilution of 1:10000 showed moderate positive FAT (++) using rabbit serum while such degree was obtained with a dilution of 1:100000 using goat serum. Weak reaction (+) was noticed with a dilution of 1:100000 of rabbit serum and 1:10000 of Guinea pig serum and 1:1000000 of goat serum. Further dilutions revealed negative reactions.