The present invention provides a Mitrecin A polypeptide useful in prevention and treatment of one or more bacteria. Also provided is a method to kill or prevent growth of one or more bacteria comprising contacting the one or more bacteria with a Mitrecin A polypeptide. The target bacteria can be selected from the group consisting of a Gram-positive bacterium, a Gram-negative bacterium, or both. In one embodiment, the present invention is drawn to a polynucleotide encoding a Mitrecin A polypeptide, a vector comprising the polynucleotide, a host cell comprising the polynucleotide, or a composition comprising the Mitrecin A polypeptide, the polynucleotide, the vector, or the host cell.