As disclosed herein methods are provided to identify compounds with antimicrobial activity, and methods for treating subjects by administering the compounds. In particular, the invention provides methods for treating and/or preventing microbial diseases and infections. One aspect of the present invention is directed to the identification of bactericidal compounds that function like chemokines. In one embodiment compounds are identified that bind to the extracellular domains of Bacillus anthracis FtsX. Compounds that bind to FtsX are then screened for bactericidal activity. In one embodiment compounds are screened to identify compounds that bind to the peptide.