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目的比较O139群霍乱弧菌国际标准株MO45和O1群E l Tor型霍乱弧菌国际标准株N16961基因组中毒力岛区域分子特征。方法从MO45基因组中筛选含有毒力岛上游的VC0815基因及其上游基因片段并克隆到pNEB193中命名为pNEBVC081545,绘制pNEBVC081545的限制性酶切图谱并与N16961同段序列限制性酶切图谱进行比较。在pNEBVC081545中选择VC0815基因上游的一段侧序列进行亚克隆,测序后与N16961同段序列比较。结果pNEBVC081545限制性酶切图谱中VC0815基因上游序列图谱中第1个碱基位置是限制性内切酶位点为KpnⅠ,第732位为SalⅠ,第819位为HpaⅠ,第1578位为BglⅡ,第1600位为H indⅢ,第1943位为XbaⅠ,第3247位为EcoRⅠ,此段序列限制性内切酶图谱与N16961同段序列限制性酶切图谱完全相同。对SalⅠ和EcoRⅠ之间的序列进行亚克隆,并对该段序列测序,测序结果表明该段核酸序列与N16961中同段序列完全相同。结论O139霍乱弧菌可能是E l Tor霍乱弧菌O抗原突变而产生的菌群。
Objective To compare molecular characteristics of virulence island regions in the international genomic library of the V. cholerae O139 genomic group MO45 and O1 group E l Tor V. cholerae. Methods VC0815 gene upstream of virulence island and its upstream gene fragment were screened from MO45 genome and cloned into pNEB193 and named pNEBVC081545. The restriction map of pNEBVC081545 was drawn and compared with the restriction map of N16961. A partial sequence upstream of the VC0815 gene was selected for sub-cloning in pNEBVC081545 and compared with the same sequence of N16961 after sequencing. Results The nucleotide sequence of the first nucleotide in the upstream sequence of VC0815 in pNEBVC081545 was KpnⅠ, the 732th was SalⅠ, the 819th was HpaⅠ, and the 1578th was BglⅡ. 1600 ind Hind III, 1943 for Xba I, 3247 for EcoR I, the restriction endonuclease map of this sequence and N16961 identical sequence of the same restriction endonuclease map. The sequence between SalI and EcoRI was subcloned and the sequence was sequenced. The sequencing results showed that the sequence of the sequence was the same as that of N16961. Conclusion Vibrio cholerae O139 may be caused by mutation of E l Tor Vibrio cholerae O antigen.