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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Biosciences & Biotechnology Laboratory » Research » Publications at this Location » Publication #275251

Title: Triple-acting lytic enzyme treatment of drug-resistant and intracellular Staphylococcus aureus

item BECKER, STEPHEN - US Department Of Agriculture (USDA)
item Roach, Dwayne
item CHAUHAN, VINITA - University Of North Carolina
item SHEN, YANG - University Of Maryland
item Foster Frey, Juli
item Powell, Anne
item BUCHANNAN, GARY - US Department Of Agriculture (USDA)
item LEASE, RICHARD - US Department Of Agriculture (USDA)
item Mohammadi, Homan
item Harty, William
item Simmons, Chad
item Schmelcher, Mathias
item Camp, Mary
item SHIELDS, KELLY - Brigham & Women'S Hospital
item DOWD, MEGAN - Harvard Medical School
item DONG, SHENGLI - University Of Alabama
item BAKER, JOHN - University Of Alabama
item SHEEN, TAMSIN - San Diego State University
item DORAN, KELLY - San Diego State University
item PRITCHARD, DAVID - University Of Alabama
item ALMEIDA, RAUL - University Of Tennessee
item NELSON, DANIEL - University Of Maryland
item MARRIOTT, IAN - University Of North Carolina
item LEE, JEAN - Brigham & Women'S Hospital
item Donovan, David

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/11/2016
Publication Date: 4/28/2016
Citation: Becker, S.C., Roach, D.R., Chauhan, V., Shen, Y., Foster Frey, J.A., Powell, A.M., Buchannan, G., Lease, R., Mohammadi, H., Harty, W.J., Simmons, C.B., Schmelcher, M., Camp, M.J., Shields, K., Dowd, M., Dong, S., Baker, J.R., Sheen, T.R., Doran, K.S., Pritchard, D.G., Almeida, R., Nelson, D.C., Marriott, I., Lee, J.C., Donovan, D.M. 2016. Triple-acting lytic enzyme treatment of drug-resistant and intracellular Staphylococcus aureus. Scientific Reports. 6:25063.

Interpretive Summary: Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-drug resistant strains highly prevalent. This pathogen has also evolved another way to evade antibiotic treatment by invading and residing intracellularly within animal cells. New treatments that reduce resistance development and tackle intracellular pathogens are sorely needed. We have identified three enzyme activities that cut the cell wall structural element (peptidoglycan) of S. aureus in three unique regions. Any one of the three enzymatic activities can kill the cells when exposed externally. When fused these three enzyme domains maintain each of their activities in the final triple-acting fusion. We have shown that these triple-acting enzyme constructs greatly reduce resistance development compared to the parental enzymes alone and are effective at reducing S. aureus nasal colonization 97%. We also show that when these enzymes (single, double or triple domain harboring) are fused to protein transduction domains, they can enter animal cells and reduce the intracellular load of the pathogen up to 97% in three different cell types from three different species. The effect is maintained in two different animal models (osteomyelitis and mastitis of mice) as well as staphylococcal biofilms. The findings of this work identify the necessary components and methodology for generating multiple domain fusions with elements to address intracellular and multi-drug resistant pathogens. These findings will aid scientists in the development of these and similar molecules as commercializable antimicrobials for use in animal production, animal and human health and food safety.

Technical Abstract: 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 Staphylococcus 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 S. aureus as demonstrated in cultured cells and in mouse models of staphylococcal mastitis and osteomyelitis. Bacterial cell wall degrading enzyme antimicrobials can be engineered to enhance their value as potent therapeutics.