In order to identify virulence factors of the pathogen, the outer membrane proteins of virulent and avirulent strains of Riemerella anatipestifer were compared by a proteome analysis. Three protein spots differentially expressed between the two strains were observed by 2-DE gels, and were further analyzed using in gel tryptic digestion and peptide mass fingerprinting. Three proteins were identified. W1 was Hsp20, W2 and W3 were transposon. Although the exact role of these proteins has not been characterized, the exclusive expression in virulent strain may indicate that they play an important role in the pathogenesis of Riemerella anatipestifer infection. Although only two virulence factors identified, it opens a path to the further analysis of virulence factors of Riemerella anatipestifer.

Aim To study the apoptosis of human hep-atoma cell line ( HepG2 ) induced by different polar parts of Arnebia euchroma ( Royle ) Johnst ( AE ) and to verify its anti-hepatoma effect by a mouse orthotopic liver cancer model so as to explore the anti-cancer effect of AE extract. Methods Firstly, MTT method and Annexin V-FITC/PI double staining method were used to detect the anti-proliferative and pro-apoptotic effects of each polar part of AE on HepG2 cells, and Western blot was used to detect the expression of Bcl-2 apoptosis family proteins incells. Based on the above experimental results, the effective parts with significant pro-apoptotic effect were screened out for anti-in situ liver cancer experiments in mice, and the organ indexes, liver function indexes and tissue sections of mice with orthotopic liver cancer before and after administration were evaluated. Results With the decrease of the polarity of AE extract,the anti-proliferation and pro-apoptotic effects on HepG2 cells were enhanced, and the anti-proliferation and apoptosis-inducing effects of AE petroleum ether fraction ( AEP) were the most significant. When AEP dose was 1.56 (μg • L