Abstract: Objective    To construct PG0352 mutant strain and identify it by PCR，RT-PCR and spot assay. Methods       This study was carried out at Center Laboratory of China Medical University Affiliated Stomatology Hospital from July to December 2011. We construct the transformation cassette including PG0352 upstream gene，erm gene and PG0352 downstream gene，transformed this cassette to P. gingivalis W83 by electroporation and screened in TSB agar plate including erythromycin and identified these strains by PCR，RT-PCR and spot assay. Results    There were colonies in TSB agar plate，PG0352 gene was placed by erm gene，and the enzymic activity was abrogated. Conclusion    PG0352 mutant strain can be obtained，which is necessary to clarify the function of PG0352.

Key words: Porphyromonas gingivalis W83, PG0352, mutant strain, PCR, spot assay

摘要： 目的    探讨牙龈卟啉单胞菌W83 PG0352基因突变株的构建和鉴定。方法    本实验于2011年7—12月在中国医科大学口腔医学院中心实验室完成。建立PG0352突变质粒，在T载体上插入PG0352上游基因、红霉素抗性基因和PG0352下游基因，用电转化的方法将质粒转入牙龈卟啉单胞菌菌细胞中，用含有红霉素的TSB培养基筛选PG0352突变株，并通过PCR、RT-PCR和酶活性检测方法对突变株进行鉴定。结果    在含有红霉素的TSB培养基中可见牙龈卟啉单胞菌的菌落，用PCR方法证实在这些菌落中PG0352基因被红霉素抗性基因所替代，且唾液酸酶活性丧失。结论    通过电转化的方法可成功获得PG0352基因突变株，为研究PG0352基因的功能奠定基础。

关键词: 牙龈卟啉单胞菌W83, PG0352, 突变株, PCR, 酶活性检测