Construction and identification of cag1 gene mutant of Helicobacter pylori
LING Feng1,2， WANG Xia-chun1， CHEN Cheng1， YU Min1， ZHU Hong1， LUO Cai-feng3， SHAO Shi-he1
（1.School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang Jiangsu 212013; 2.Department of Clinical Laboratory, Kunshan Hospital of Traditional Chinese Medicine, Suzhou Jiangsu 215300; 3.School of Clinical Medicine, Jiangsu University, Zhenjiang Jiangsu 212013, China）
Abstract：[Abstract]Objective: To establish cag1 gene mutant of Helicobacter pylori(H.pylori) NCTC11637 for exploring the influence of cag1 gene on cytotoxin associated gene pathogenicity island(cag PAI). Methods: The cag1 gene deletion fragment(upstream and downstream of the open reading frames) was amplified by two pairs of primers designed according to the sequence of cag1 and its upper and down streams. Then electroporation was used to transfect the suicide plasmid into H.pylori. Positive clones were screened out on the basis of kanamycin resistance and confirmed by PCR and DNA sequencing. GES-1 cells were infected with either the obtained cag1 gene mutant or the wild-type strain for 8 h. Morphological changes of infected cells were observed under microscope. Results: We generated and identified a cag1 gene mutant of H.pylori. The cag1 gene mutant caused much less scattering and elongation of GES-1 cells than the H.pylori wild-type strain. Conclusion: The cag 1 gene mutant of H.pylori was successfully obtained, which proved that the absence of cag1 strongly affected the virulence of H.pylori.
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2013, Vol. 23 
