Capripoxvirus, a member of the poxviridae family causes three economically important diseases in ruminants namely, lumpy skin disease (LSD) in cattle, sheeppox in sheep, and goatpox in goats. Albeit non-zoonotic in nature, they have the potential to cause high economic loss among the farmers. Capripoxvirus members share common structural proteins and can rise cross-immunity among them. The present study aimed to design a recombinant chimeric vaccine from immunogenic proteins of these three members to protect all the host species by using immunoinformatics analysis and adding approved adjuvants. The palmitoylated EEV (Extracellular Enveloped Virion) membrane glycoprotein of LSD virus, SPPV-ORF 117 of sheeppox virus, B5R (EEV host range protein) of goatpox virus, and a common protein to all the members, P32, were the major immunodominant proteins used in the present chimeric vaccine construction. Several computational programs were employed to define the most immunogenic regions in selected proteins and different possible adjuvants and universal T-helper agonists were linked to the new construct. The designed vaccine construct was examined for physicochemical properties, immunogenicity and the 3D model was designed by using reliable software. Docking analysis and Molecular Dynamics simulation were carried out to determine the interaction between the designed vaccine and TLR molecules. Consequently, the lowest energy value showed the greater ability of the designed vaccine to interact with TLRs to induce an immune response. Besides appropriate physicochemical properties and acceptable stability in different host cells, the final designed vaccine is expected to have potential in stimulating both the humoral and cellular responses.

Salmonella Typhimurium (STM) is a facultative anaerobe of zoonotic importance and one of the causative agents of non-typhoidal salmonellosis (NTS). During infection, STM must adapt to the changes in oxygen concentration encountered in the crucial niches of host like gut lumen and intramacrophage environments. But being a chemo-organoheterotroph, STM is capable of obtaining its energy from organic sources via redox reactions. NarL, a transcription factor and the response regulator of the two-component regulatory system NarX/L, gets activated under nitrate rich anaerobic condition. Upon activation, it upregulates the nitrate reduction during anaerobic respiration. However, in this study, we observed a significant attenuation of virulence in the narL-knockout strain of STM, while the respective morphotypes got rescued upon genetic complementation. Along with motility and biofilm forming ability, the mutant strain displayed reduced intracellular replication in either intestinal epithelial cells or monocyte-derived macrophages of poultry origin. Further, in vivo competitive assay in the murine model showed that wild type STM significantly outcompeted its isogenic narL null mutant.