Bovine myeloid antimicrobial peptide-27(BMAP-27) belongs to the cathelicidin family of peptides which displays rapid bactericidal activity against Staphylococcus aureus, Streptococcus uberis, and Escherichia coli1. Cathelicidins belong to the large group of cationic peptides with amphipathic properties and have critical role in mammalian innate immune system. BMAP-27 is cytotoxic to human erythrocytes and neutrophils, although at higher than microbicidal concentrations1-2. It has a potential for the treatment of bacterial infections in individuals with cystic fibrosis-associated lung infections.