Ke-Xia Wang1, Xue-Feng Wang. 1. School of Medicine, Anhui University of Science and Technology, Huainan 232001, Anhui Province, China. kexiawang2003@yahoo.com.cn
Abstract
AIM: To clone and sequence the cagA gene fragment of Helicobacter pylori (H pylori) with coccoid form. METHODS: H pylori strain NCTC11637 were transformed to coccoid form by exposure to antibiotics in subinhibitory concentrations. The coccoid H pylori was collected. cagA gene of the coccoid H pylori strain was amplified by PCR. After purified, the target fragment was cloned into plasmid pMD-18T. The recombinant plasmid pMD-18T-cagA was transformed into E.coli JM109. Positive clones were screened and identified by PCR and digestion with restriction endonucleases. The sequence of inserted fragment was then analysed. RESULTS: cagA gene of 3,444 bp was obtained from the coccoid H pylori genome DNA. The recombinant plasmid pMD-18T-cagA was constructed, then it was digested by BamH I+Sac I, and the product of digestion was identical with the predicted one. Sequence analysis showed that the homology of coccoid and the reported original sequence H pylori was 99.7%. CONCLUSION: The recombinant plasmid containing cagA gene from coccoid H pylori has been constructed successfully. The coccoid H pylori contain completed cagA gene, which may be related to pathogenicity of them.
AIM: To clone and sequence the cagA gene fragment of Helicobacter pylori (H pylori) with coccoid form. METHODS: H pylori strain NCTC11637 were transformed to coccoid form by exposure to antibiotics in subinhibitory concentrations. The coccoid H pylori was collected. cagA gene of the coccoid H pylori strain was amplified by PCR. After purified, the target fragment was cloned into plasmid pMD-18T. The recombinant plasmid pMD-18T-cagA was transformed into E.coli JM109. Positive clones were screened and identified by PCR and digestion with restriction endonucleases. The sequence of inserted fragment was then analysed. RESULTS: cagA gene of 3,444 bp was obtained from the coccoid H pylori genome DNA. The recombinant plasmid pMD-18T-cagA was constructed, then it was digested by BamH I+Sac I, and the product of digestion was identical with the predicted one. Sequence analysis showed that the homology of coccoid and the reported original sequence H pylori was 99.7%. CONCLUSION: The recombinant plasmid containing cagA gene from coccoid H pylori has been constructed successfully. The coccoid H pylori contain completed cagA gene, which may be related to pathogenicity of them.
Authors: Yvette J Debets-Ossenkopp; Germán Reyes; Janet Mulder; Birgit M aan de Stegge; José T A M Peters; Paul H M Savelkoul; J Tanca; Amado S Peña; Christina M J E Vandenbroucke-Grauls Journal: J Antimicrob Chemother Date: 2003-01 Impact factor: 5.790
Authors: B Janas; E Czkwianianc; L Bak-Romaniszyn; H Bartel; D Tosik; I Płaneta-Małecka Journal: Am J Gastroenterol Date: 1995-10 Impact factor: 10.864