The present invention relates to an improved approach for the treatment of
microbial infections in mammals. Specifically, the invention provides
methods and reagents for expressing in mammalian cells proteins that have
anti-microbial activity. The invention provides both genes which have
been modified to allow expression and preferably secretion of active
protein in desired mammalian cells or tissues, and methods of introducing
such modified genes into desired mammalian cells and/or tissues. Most
specifically, genes encode anti-staphylococcal proteins are delivered to
mammalian cells and/or tissues by methods of gene delivery, including
gene therapy and the production of transgenic animals, for the treatment
of mastitis in ruminant animals.