Antimicrobial Enzyme Fusions Reduce Resistance and Kill Intracellular Staphylococcus aureus

摘要

Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Here we describe engineered triple-acting staphylolytic peptidoglycan hydrolases wherein three unique antimicrobial activities from two parental proteins are combined into a single fusion protein, effectively reducing the incidence of resistant strain development. The fusion protein reduced colonization by S. aureus in a rat nasal colonization model, surpassing the efficacy of either parental protein. Modification of the triple-acting lytic construct with a protein transduction domain significantly enhanced both biofilm eradication and the ability to kill intracellular Staphylococcus aureus as demonstrated in cultured cells, and mouse models of staphylococcal mastitis and osteomyelitis. Bacterial cell wall degrading enzyme antimicrobials can be engineered to enhance their value as potent therapeutics.

主权项

1. A recombinant fusion nucleic acid encoding an antimicrobial Staphylococcus-specific triple fusion protein, wherein said encoded fusion protein comprises (1) a LysK endolysin CHAP endopeptidase domain, (2) a LysK endolysin amidase domain, and (3) a lysostaphin glycyl-glycine endopeptidase domain and a cell wall binding domain, wherein when in the K-L configuration, comprises: (1) a LysK endolysin CHAP endopeptidase domain, (2) a LysK endolysin amidase domain, (3) a lysostaphin glycyl-glycine endopeptidase domain, and cell wall binding domain, or when in the L-K configuration, comprises: (1) a lysostaphin glycyl-glycine endopeptidase domain, (2) a LysK endolysin-derived CHAP endopeptidase domain, (3) a LysK endolysin-derived amidase domain and a cell wall binding domain, said protein capable of cutting the peptidoglycan at three unique covalent bonds of the peptidoglycan simultaneously, with each domain being active independent of the others and each independent domain being capable of lysing the bacteria.