The gram-negative peptidoglycan, which lies subjacent to the outer membrane, is relatively thin and undecorated by surface proteins or carbohydrates. The cell wall binding domain (CBD) epitopes are usually carbohydrates or teichoic acids that are unique to a species, much like a bacterial fingerprint. The most extensively studied lysins in animal models are Cpl-1, an N-acetylmuramidase, and PAL, an N-acetylmuramoyl-Lalanine amidase, both of which are from phages that infect Streptococcus pneumoniae. PlyG demonstrates lytic activity on a variety of Bacillus anthracis strains as well as one Bacillus cereus strain. Importantly, the enzyme was shown to be effective in killing and detecting germinating spores in addition to vegetative cells. The spore coat that normally forms an impenetrable surface for lytic enzymes undergoes an increase in porosity following germination, allowing lysins access to the peptidoglycan. Phage therapy has additional advantages of being self-replicating, has over 100 years of historical use, has obtained some regulatory approval, and can target either gram-positive or gram-negative organisms. Lysin therapy, in contrast, is not self-replicating and at the moment requires additional techniques to show efficacy on gram-negative bacteria. Clearly, both phage therapy and lysin therapy represent reasonable alternatives for management of food-borne pathogens.