الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Newcastle disease virus (NDV) causes significant economic losses to the poultry industry worldwide, despite the availability of vaccination.
In this study, 50 samples were collected from suspected diseased broilers poultry farms in Kafrelsheikh governorate suffer from respiratory manifestations as coughing, sneezing and gasping with daily mortalities. Firstly, samples prepared and injected in Embryonated Chicken Eggs 9days old at the allantoic cavity, the collected fluid were examined by slide haemagglutination test then examined by conventional RT-PCR by using specific primer target the fusion gene, 35samples were positive out of 50 samples with 70% isolation percent.
- 2 field isolates samples were further sequenced and analyzed among different accession numbers on gene bank These strains were named MW881875 and MW881876, and belong to the genotype VII NDV, with 97% identity to an Israeli strain, and limited similarity to LaSota vaccine (genotype II) (76% ).
- Phylogenetic analysis of the sequences indicated that circulating NDV genotype VII were in homology to NDV isolates previously isolated from Israel, Egypt, and china and distinct from lasota vaccinal strains.
Therefore updated vaccine strains should match those strains circulating in the field and further antigenic studies are also required to illustrate variation among vaccine strains
Nanoparticles are effective against many pathogens, including bacteria, fungi, parasites, and viruses.
- To investigate the antiviral efficacy of propolis and chitosan nanoparticles against NDV using VERO cells.
Summary
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- The cell cytotoxic concentrations (CC50%) of chitosan, propolis, and a mixture of propolis with chitosan against Vero cells were 327.41 ± 12.63 μg/ml, 109.48 ± 8.36 μg/ml, and 231.78 ± 11.46 μg/ml, respectively.
- TCID50 assay showed that nanoparticles exert their antiviral effects post exposure to NDV with chitosan, propolis, and mixture, producing a significant decrease in viral titer. Concentrations of 62 μg/mL chitosan, 13 μg/mL propolis, and 30 μg/mL mixture led to reductions in virus titer of 2, 2.66, and 2.5 log10 TCID50, respectively, when compared to the control value of 4 log10 TCID50.
- Propolis with chitosan had good antiviral activity, since chitosan has no antiviral activity alone .the association of the two components improves the antimicrobial performance of their active principles in comparison with their separate application that can interact to form chelates leading to novel antimicrobial agents, without posing any dangerous to the substrate where in the composite material is applied.