Newcastle disease is one of the main concerns of poultry farmers. Detection of virulent strains of Newcastle disease virus (NDV) has a great impact on control measures against the disease. In this study RT-PCR was optimized in high sensitivity in order to differentiate the virulent from non-virulent NDV isolates directly in tissue homogenates. The vaccinal NDV strain and known field isolates we...

Staphylococcus aureus carrying PVL gene remain major health problem associated with highly virulent infections. Characterization of such gene is important to know the impact and the functional significance of nucleotide variations. PCR and standard sequencing were performed for twelve Sudanese strains from different sources. Protein structures prediction, modeling and physiochemical analysis we...

Classical swine fever (CSF) severity is dependent on the virulence of the CSF virus (CSFV) strain. The earliest event detected following CSFV infection is a decrease in lymphocytes number. With some CSFV strains this leads to lymphopenia, the severity varying according to strain virulence. This lymphocyte depletion is attributed to an induction of apoptosis in non-infected bystander cells. We c...

In vivo infection studies in Japanese flounder (Paralichthys olivaceus) demonstrated that the number of viable cells of the virulent strain (NUF251) of Edwardsiella tarda increased gradually in kidney and hepato-pancreas after intraperitoneal injection, but the low virulent strain (NUF194) did not. To gain insight into the virulence factors of E. tarda, in vitro responses of Japanese flounder (...

bacterial leaf streak (bls) caused by xanthomonas translucens pv. cerealis (xtc) is an important disease of wheat (triticum aestivum l.) worldwide. the management methods presently in practice are insufficient to meet current safety and/or efficacy standards. therefore, use of resistant genotypes is the best approach to manage bls. the present study was undertaken to identify possible sources o...

ND is a highly contagious virus disease affecting poultry, cage and aviary birds, and wild birds. There are a number of strains of the disease, which differ in the severity of their clinical signs, ranging from inapparent to a rapidly fatal condition. In its highly virulent form, ND can rapidly cause up to 100 per cent mortality in bird flocks and poses a devastating threat to the poultry indus...

The virulence potential of 51 Listeria monocytogenes isolates, including strains from cheese, cheese production environments and from human cases of listeriosis, was evaluated in this study. The isolates were used to infect HT-29 cell monolayers in an in vitro test of virulence, based on a plaque-forming assay (PFA). Fifteen selected isolates were used for subcutaneous footpad inoculation in mi...