Identification Of Virulence Related Gene In Brucella Abortus And Functional Study Of LsrB Protein

Accoding to our previous study, in this study, we have further indentified necessary genes for Brucella abortus to establish chronic infection in mouse model using PCR-based signature tagged mutagenesis. To study of these virulence-related genes, a series of plasmids were constructed to clone and express exogenous genes in Brucella. In further study, we have elucidated the function of a LysR family transcriptional regulator LsrB protein, which gives an insight into Brucella pathogenesis.Solutions presented in this thesis can be summarized as follows:-Fifty-six mutants were identified as attenuated strains,53 genes were confirmed as virulence-related genes, of these,39 genes were novel identified in this study.-Fifty-three genes were annotated in this study, and were further discussed between roles of these genes and virulence based on functional classification.-A series of pTM plasmids were constructed to clone the exogenous gene in Brucella, containing pTM1-Cm?pTM2-Amp and pTM3-Km plasmids.-pGH-6× His and pZT-6× His plasmids were constructed to express and inducible express the exogenous gene in Brucella, respectively.-A LysR family transcriptional regulator LsrB protein was identified as virulence related gene, which is involed in Brucella intracellular survival and establishing chronic infection.-LsrB protein is involved in Brucella resistance to oxidative and nitrisotative stress, natutal serum and escaping host immune surveilance.-It was elucidated that LsrB protein have a conserved regulatory mechanism in bacteria of Rhizobiales.