Background:
The Group B Streptococcus (GBS) Surface Immunogenic Protein (SIP) is a widely conserved protein among the different serotypes, and it’s has been formulated as a vaccine against GBS. We reported that L. lactis that carry out a DNA plasmid which encode the SIP protein gene as a good oral vaccine in animal model. The generation a Genetically Modified Organism (GMO) based in L. lactis is the next step.
Methods:
We used the homologated recombination strategy for generate a L. lactis (GMO) strain that express the sip gene of GBS, for that we exchange the upp gene for the sip gene. The upp gene encodes for uracil phosphoribosyl transferase, which in the presence of 5-fluorouracil generates a toxic metabolite. In addition, the plasmid used for recombination is pMBsacB, which has the sacB gene that codes for levan-sucrose-synthase, which in the presence of sucrose can synthesize a toxic polymer to L. lactis. Finally, the microbiological properties were testing
Results:
We obtained L. lactis GMO, able to grow in the presence of 5-fluorouracil and sucrose, so the absence of the upp gene and the cure of the pMBsacB plasmid indicating the success of recombination. We follow up conventional PCR and DNA sequencing. Also, we not observed difference in bacterial properties between L. lactis and L lactis GMO strain.
Conclusion:
We generated a L. lactis GMO, that express the SIP protein of GBS and it has a potential used as oral vaccine against GBS infection in an animal model.