人苍白杆菌分离株部分生物学性状的研究

Study on the partial biological characteristics ochrobactrum anthropi isolated

目的对本院分离鉴定的1株人苍白杆菌进行16srRNA基因序列分析以及脂多糖内毒素活性和外膜蛋白免疫性的初步研究。方法采用自行设计的引物对菌株做PCR扩增和16srRNA基因序列测定;用酚水法提取脂多糖作相关生物学活性试验;提取外膜蛋白组分免疫动物,观察其对羊布氏杆菌是否有交叉保护作用。结果本院分离的人苍白杆菌与购自美国苍白杆菌ATCC菌株和购自北京的羊布氏杆菌之间核苷酸序列具有高度同源性((98%);人苍白杆菌脂多糖具有内毒素生物学活性,但较大肠埃希菌脂多糖为弱;以人苍白杆菌外膜蛋白免疫小鼠不能抵御布氏杆菌的攻击。结论我院分离的人苍白杆菌在遗传学上与羊布氏杆菌具有非常密切的亲缘关系,但其外膜蛋白组分对羊布氏杆菌无交叉保护作用。人苍白杆菌脂多糖具有内毒素的活性,可能是一种重要的致病因子,但其毒性低于大肠埃希菌脂多糖。

Objective To determine the sequence of 16s rRNA gene of the O. anthropi strain isolated from our hospital, and study its LPS virulence and OMP immunogenicity. Methods The partial 16s rRNA gene of this strain was amplified by PCR and then sequenced; The biological activities of LPS extracted by phenol-water method were examined. The mice were immunized with O. anthropi OMP, and the cross-protection against the challenge of B. melitensis was observed. Results The DNA homology between our isolated strain and the American ATCC strain of O. anthropi or B. melitensis strain from Beijing were more than 98% respectively. The O. anthropi LPS had a lot of endotoxin activities, but weaker than that of E. coli. The mice vaccinated with O. anthropi OMP could not be protected from the challenge of B. melitensis. Conclusion The O. anthropi strain isolated by us was in a close phylogenetic relationship with B. melitensis, but there was no cross-protection between O. anthropi OMP and B. melitensis OMP. The O. anthropi LPS possessed endotoxic activity and may be an important pathogenic factor, although its virulence was lower than E. coli LPS.