Curing Virulence Plasmids From Bacillus Anthracis And The Analysis Of Comparative Proteomics

Infections with Bacillus anthracis result in acute disease called anthrax, which is lethal most of the time and can affect both humans and other animals. Anthrax is a kind of extremely hazardous infectious diseases. Especially in recent years, terrorists conducted bioterrorism events using spore, which interfered with people's daily life and social and economic circumstance seriously. Therefore, studying about B. anthracis has theoretical value and potential social benefits.In this study, on the basis of the theory of plasmid incompatibility we constructed two mutant strains:A16RPI1 and A16PI2 using the B. anthracis vaccine strain A16R and wild-type strain A16 as experiment strains respectively. The growth curve of the strains A16RPI1, A16RP, A16PI2 and A16R was mensured respectively and their carbohydrate metabolic properties and A16PI2's capacity of forming capsule were investigated. The whole cell proteins extracted from 23 h incubated A16RPI1 and A16RP or extracted from 20 h incubated A16PI2 and A16R were prepared and two-dimensional electrophoresis (2-DE) reference maps in gels of pH 4-7 were constructed. Through the comparison of the 2-DE reference maps, we found out different proteins between them and did mass spectrometry analysis. The main results of experiments were as follows:1) The growth trend of the strain A16RPI1 was similar to that of the strain A16RP, and results of utilizing carbohydrate of them were also compared to each other.2) The growth trend of the strain A16PI2 was similar to that of the strain A16R, and there was a difference between them in utilizing carbohydrate:A16PI2 could utilize fructose but A16R not. Through the identification of the capacity of forming capsule, we found that A16PI2 indeed lost this capacity.3) There were only 5 different proteins between A16RPI1 and A16RP, which mainly were translation elongation factors and enzymes of amino acid transport and metabolism, and all located in cytoplasm.4) There were 22 different proteins between A16PI2 and A16R. Those different proteins mainly located in cytoplasm except for a function unknown protein, which located on membrane. And the analysis of the proteins' function showed majority of them focus on translation, amino acid transport and metabolism, sporulation.