The Detection of Pathogenic Porcine E.coli Virulence Gene (astA,stb)

[ Objective] This paper aimed to find out the relationship between pathogenic procine E. coli virulence gene and pathogenicity, and ex- plore the pathogenic mechanism of E. coil [ Methed] The detection of two E. coil virulence genes was performed. PCR method was taken to test the virulence genes, astA and stb, from 39 strains of typical serotype O porcine E. coli which had been separated and identified. [ Result] It＇s found that of the 39 isolates of porcine E. coli, 22 carried virulence gene astA which represented 56.41%, and 27 carried virulence gene stb which repre- sented 69.23%. [ Conclusion] This study has provided scientific data for future E. coil pathogenicity researches.

中草药对大菱鲆源哈维氏弧菌的体外抑菌效果

为了解中草药对大菱鲆源哈维氏弧菌的体外抑菌效果,采用琼脂扩散法和二倍稀释法测定了哈维氏弧菌菌株对18种中草药的敏感性。结果显示:五倍子、石榴皮、大黄、乌梅和苏木的抑菌作用最强,最小抑菌浓度(MIC)<12.5 mg/m L;黄连、马齿苋、鱼腥草、穿心莲、公丁香和桉树叶的抑菌作用次之,MIC为12.5~25mg/m L;沙棘、黄柏、辣蓼、甘草和薄荷抑菌效果较好,最小抑菌浓度(MIC)为100~500 mg/m L;而陈皮、石菖蒲的抑菌作用不明显,MIC均大于500 mg/m L。结果表明,18种中草药中五倍子、石榴皮、大黄、乌梅和苏木对大菱鲆源哈维氏弧菌有较好的抑菌效果,可为防治大菱鲆哈维氏弧菌病中草药制剂的开发提供参考。