Construction of an attenuated Salmonella typhimurium vaccine strain carrying helicobacter pylori hpaA gene

Background/Aims: To construct a recombinant live attenuated Salmonella typhimurium vaccine strain carrying Helicobacter pylori (H. pylori) hpaA gene. Methods: By means of molecular biology, hpaA gene was amplified from H. pylori genome DNA and cloned into a procaryotic expression plasmid pTrc99A. After sequence analysis, the identified recombinant plasmid was then used to transform a live attenuated Salmonella typhimurium vaccine strain SL3261, and the positive clones were screened by polymerase chain reaction (PCR) and restriction enzyme digestion. Results: Confirmed by the above methods, a recombinant procaryotic expression plasmid pTrc99A-hpaA harbouring about 560 bp hpaA gene was constructed, and the recombinant plasmid was then introduced into a live attenuated Salmonella typhimurium vaccine strain SL3261 successfully. Conclusions: A recombinant live attenuated Salmonella typhimurium vaccine strain harbouring H. pylori hpaA gene was constructed and identified; this work will help developing and oral recombinant live vaccine against H. pylori infection.