Using Lactococcus lactis as Surrogate Organism to Study Group A Streptococcus Surface Proteins.

Area of Science:

• Microbiology
• Bacteriology
• Molecular Biology

Background:

• Group A Streptococcus (GAS) possesses numerous virulence factors, complicating the study of individual determinants.
• Redundancy among GAS surface proteins, like adhesins, presents challenges in functional investigations.
• Lactococcus lactis, a related non-pathogenic bacterium, offers a tractable system for studying GAS surface proteins.

Purpose of the Study:

• To describe a method for generating recombinant Lactococcus lactis strains that express specific Group A Streptococcus surface proteins.
• To outline the validation and quantification procedures for confirming surface expression of GAS proteins in L. lactis.

Main Methods:

• Utilizing Lactococcus lactis as a surrogate host for expressing heterologous bacterial surface proteins.
• Employing established molecular cloning techniques and protocols for genetic manipulation.
• Developing workflows for generating recombinant L. lactis strains and assessing protein surface localization.

Main Results:

• Successful generation of recombinant L. lactis strains capable of expressing GAS surface proteins.
• Established protocols for validating and quantifying the surface expression levels of these proteins.

Conclusions:

• Recombinant Lactococcus lactis is a valuable tool for dissecting the roles of individual Group A Streptococcus virulence factors.
• This approach facilitates the functional investigation of GAS surface proteins in a controlled, non-pathogenic system.