ABSTRACT
Foot-and-mouth disease (FMD) vaccines are currently the most powerful protective and preventive measures used to control FMD. In this study, the chimeric vaccine strain containing antigenic epitopes from the FMD virus serotype A, which belongs to the ASIA topotype, was produced and evaluated. The chimeric vaccine strains contain sea-97/G1 (VP4, VP2, VP3) and A22 Iraq (VP1) or G-VII (VP1) for use in FMD vaccines in Asia. The 50% protective dose was determined in mice. Vaccinated mice were challenged with three different type A viruses (Sea-97/G1, Sea-97/G2, G-VII clade) seven days post-vaccination (dpv), and mice that received the vaccine candidates were protected against the three viruses. The protective capability of one of the vaccine candidates was evaluated in pigs. Vaccinated pigs were challenged with three different type A viruses (Sea-97/G1, Sea-97/G2, G-VII clade) at 28 dpv, and pigs that received the vaccine candidate were protected against the three viruses. The results showed that this vaccine candidate, which was designed to provide protection against FMD in Asia, efficiently protected pigs against virus challenge and thus has potential as a broad-spectrum vaccine for various epidemic FMD viruses.
ABSTRACT
Bacillus subtilis DB104, an extracellular protease-deficient derivative of B. subtilis 168, is widely used for recombinant protein expression. An understanding of the changes in gene expression during growth is essential for the commercial use of bacterial strains. Transcriptome and proteome analyses are ideal methods to study the genomic response of microorganisms. In this study, transcriptome analysis was performed to monitor changes in the gene expression level of B. subtilis DB104 while growing on a complete medium. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, K-mean cluster analysis, gene ontology (GO) enrichment analysis, and the function of sigma factors were used to divide 2122 differentially expressed genes (DEGs) into 10 clusters and identified gene functions according to expression patterns. The results of KEGG pathway analysis indicated that ABC transporter is down-regulated during exponential growth and metabolic changes occur at the transition point where sporulation starts. At this point, several stress response genes were also turned on. The genes involved in the lipid catabolic process were up-regulated briefly at 15 h as an outcome of the programmed cell death that postpones sporulation. The results suggest that changes in the gene expression of B. subtilis DB104 were dependent on the initiation of sporulation. However, the expression timing of the spore coat gene was only affected by the relevant sigma factor. This study can help to understand gene expression and regulatory mechanisms in B. subtilis species by providing an overall view of transcriptional changes during the growth of B. subtilis DB104.
ABSTRACT
This study investigated the effect of synthesis time and composition on magnetic properties of FeCo nanoparticles. Fe75Co25, Fe66Co34, Fe52Co48 nanoparticles were synthesized by the polyol method. The saturation magnetization of Fe75 Co25, Fe66Co34, Fe52Co48 nanoparticles was 178 emu/g, 191 emu/g and 197 emu/g, respectively. The coercivity of Fe75 Co25, Fe66Co34, Fe52Co48 was 113 Oe, 131 Oe and 89.2 Oe respectively. The synthesis time of Fe52Co48 nanoparticles was also varied (2 h and 3 h) to determine the optimal synthesis time. The saturation magnetization of Fe52Co48 synthesized for 2 h, 3 h was 243 emu/g, 202 emu/g, respectively. The coercivity of Fe52Co48 synthesized for 2 h and 3 h was 46 Oe and 111 Oe, respectively. The highest saturation magnetization and lowest coercivity was obtained using a synthesis time of 2 h. Based on these results, it was confirmed that Fe52Co48 had the highest saturation magnetization and lowest coercivity among all of the compositions tested, and optimal synthesis time was 2 h.
