肠产志贺样毒素且具侵袭力的大肠埃希氏菌和肠侵袭性大肠埃希氏菌的侵袭基因比较

MOLECULAR COMPARISION OF INVASIVE GENE IN ENTEROSHIGA LIKETOXINPRODUCING AND INVASIVE ESCHERICHIA COLI ENTEROINVASIVE ESCHERICHIA COLI AND SHIGELLA SPECIES

目的比较肠产志贺样毒素且具侵袭力的大肠埃希氏菌（Ｅｎｔｅｒｏ－ＳＬＴｓ－ＰｒｏｄｕｃｉｎｇａｎｄＩｎｖａｓｉｖｅＥｓｃｈｅｒｉｃｈｉａｃｏｌ－ｉ，ＥＳＩＥＣ）和肠侵袭性大肠埃希氏菌的侵袭基因，阐明它们之间的异同。方法使用质粒酶切图谱分析，侵袭性基因ｉｐａＢ、ｉ－ｐａＣ、ｉｐａＤ的ＰＣＲ和Ｓｏｕｔｈｅｒｎｂｌｏｔ杂交实验，以及利用ＥＩＥＣ８４０１菌株的侵袭性大质粒酶切产物作为探针与ＥＳＩＥＣ大质粒进行Ｓｏｕｔｈｅｒｎｂｌｏｔ杂交等方法。结果发现ＥＳＩＥＣ菌株不具有ＥＩＥＣ、志贺氏菌所特有的ｉｐａＢ、ｉｐａＣ、ｉｐａＤ基因；ＥＳＩＥＣ菌株质粒与ＥＩＥＣ、志贺氏菌质粒同源性很小。结论ＥＳＩＥＣ菌株编码侵袭力的基因与ＥＩＥＣ及志贺氏菌的侵袭基因是完全不同的，证明对ＥＳＩＥＣ的分类是正确的。

Aim The plasmid DNA of Enteroshigaliketoxin producing and invasive Escherichia coli (ESIEC)was hybridized with plasmid probe of EIEC and Shigella species.So as to clarify the similarities and differents between them.ZMethods The invasive gene in ESIECEIEC and shigella Species were compared by restriction endonuclease analysis,polymerase chain reaction(PCR) and hybridization of ipaBipaCipaD genes,hybridization of the DIGlabelled enzymedigested plasmid of EIEC 8401 strain with restriction fragments of the plasmid of ESIEC strains. Results It was proved that ESIEC strains were lack of XipaBipaCipaD genes,the key genes encoding invasiveness of EIEC and Shigella species.It was further found that the homology of plasmid DNA between ESIEC and EIEC or ShigellaWTBZ species was low. Conclusion Data suggested that the invasive locus of ESIEC was completely different from that of EIEC and Shigella species.The name of ESIEC as a new category of diarrheagenic E.coli was based on solid.However,some differences of restriction fragments patterns among plasmid DNA of ESIEC F171,R145,89/67 strains also need be noticed and it is possible to further clarify the ESIEC strains.