Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: 6/11/2004
Publication Date: 6/11/2004
Citation: Donovan, D.M., Wall, R.J., Pritchard, D., Talbot, N.C. 2004. Expression of a group b streptococcus bacteriophage lysin in mammalian cells. [abstract]. American Society for Microbiology. No. M-035.
Technical Abstract: Bacteriophage therapy is effective against only those pathogens that the bacteriophage can both infect and replicate within. This dual requirement limits the range of bacterial pathogens that any given bacteriophage can be used to control. Alternatively, bacteriophage endolysins have been shown to digest the cell walls from a much broader range of pathogens than their phage of origin can infect. Taking advantage of this fact, Fischetti and coworkers have shown that bacteriophage endolysins when added exogenously, kill certain pathogens and prevent infection in mouse model systems. It is the goal of this work to express a Group B Streptococcus (GBS) endolysin in mammalian cells with the long term goal to express bacteriophage endolysins in the mammary gland of transgenic dairy cows to control and prevent mastitis, a disease that costs the dairy industry ~$2 billion annually. The initial stage of this work is to demonstrate expression of the GBS endolysin in a mammalian cell line, as a prelude to creating a transgenic model. The endolysin gene was previously modified to include a His tag at the carboxy terminal end of the protein, which assists in its isolation. The expression cassette was constructed by inserting this modified endolysin gene between the 4.2 kb-5' flanking region and 2.1 kb-3' flanking region of the ovine beta-lactoglobulin gene. These eukaryotic sequences have been used successfully to express other antimicrobials in dairy cattle mammary glands. The current phase of the work focuses on expression of the lysin protein in a mammary epithelial cell line.