الفهرس 
coverOnly 14 pages are availabe for public view
 |  | from | 99 |  |  |
| | | from | 99 | | |
Abstract
Rabbit hemorrhagic disease is a highly contagious and fatal viral disease. Outbreaks of the disease are generally associated with very high morbidity and mortality rates. Several outbreaks of the disease were recorded along subsequent years until now despite of the availability of RHDV vaccine. Because of high economic losses which affect negatively on rabbit industry in Egypt, the present study was performed to high light the continuous circulation of RHD and to compare between the recent isolates and vaccinal strain on molecular level .A total of 31 liver samples from freshly dead rabbits were collected from Qalyubia ,Kafr-Elsheikh and Beheira provinces and subjected to haemagglutination test using human red blood cells type O. Samples were inoculated into seronegative rabbits then clinical sigs, post mortem and mortality rate were observed, afterwards haemagglutination test were applied on those samples .RT-PCR was performed on all samples using specific primers targeting VP60 gene. Hemagglutination analysis applied on original samples revealed that 15 were found positive for HA with titer values of 5 to 13 log2 while result of inoculation in rabbits revealed presence of 16 samples showed the same clinical picture of natural RHD infection with mortality rate ranging from 20-80% .Also 16 samples were positive for direct detection of virus genome (RT PCR). Sequence and phylogenetic analysis for C-terminal VP60 gene revealed presence of original RHDV Genotype 5 (Vet-Alex-Q2, Vet-Alex-Q7, Vet-Alex-K11) and newly emerged RHDV2 in Egypt (Vet-Abotaleb, Vet-Alex-K15, Vet-Alex-B18, Vet-Alex-B26). Moreover, there is high genetic diversity between present study isolates and vaccinal strain (RHDV-Giza 2006).