Objective: To construct a recombinant Lactobacillus acidophilus that expresses high levels of Helicobacter pylori (Hp) adhesin Hp0410.
Methods: The gene fragment encoding Hp0410 was amplified by PCR from the DNA of H. pylori NCTC11639 strain and cloned into the shuttle plasmid pMG36e to construct pMG36e-Hp0410, which was transformed into Lactobacillus acidophilus by electroporation. The target protein was confirmed with SDS-PAGE and silver nitrate staining and analyzed by Western blotting. The stability of the recombinant plasmid was assessed by drawing the growth curve of the recombinant Lactobacillus acidophilus.
Results: A 750-bp fragment was inserted into the pMG36e plasmid and transformed into Lactobacillus lactis. The transformed bacterium expressed the target protein with a relative molecular mass of about 34 kD. Western blotting confirmed that the expressed proteins could be recognized by the serum of patients with Hp infection. The recombinant plasmid pMG36e-Hp0410 exhibited good stability in the presence or absence of erythromycin.
Conclusions: The recombinant Lactobacillus acidophilus with high constitutive expression of Hp0410 has been constructed successfully.