MRSA and VRE strains kill C. elegans using traits that contribute to the pathogenesis of infection in mammals, and this model system can be used to study host-pathogen interactions involving staphylococcal and enterococcal virulence factors. Importantly, Staphylococcus aureus virulence determinants involved in mammalian pathogenesis, including the quorum-sensing global virulence regulatory system agr, the global virulence regulator sarA, and the alternative sigma factor sigma(B) are required for full pathogenicity in nematodes. Based on these observations, we developed a C. elegans-S. aureus screening assay that is performed using the 384-well plate format. This whole animal assay can be used to screen compound libraries, allowing the identification of compounds that prevent host killing that would not be detected in traditional in vitro screens. Our objective is to implement this C. elegans-based assay and utilize automated, high-throughput, whole animal screens to identify compounds with efficacy against MRSA, VRE and VRSA. Identified compounds will be evaluated by carrying out dose-response and time-course studies, determining in vitro MICs, determining toxicity, and by prioritizing the compounds for testing in mammals. We also propose to characterize the compounds previously identified in a C. elegans - E. faecalis screen, and synergize with other Subprojects in order to study compounds identified through the C. elegans assays and characterize compounds from other Subrojects. The C. elegans-based assays are particularly appealing in that they allow concurrent evaluation of toxicity and antimicrobial activity, as well as study of bacterial cells that are in a non-planktonic form. Thus false leads can be eliminated from further consideration early, and new leads will be clearly identified. In addition to compounds that have direct antibacterial activity, the C. elegans-based assays will identify compounds that affect bacterial virulence factors and host function, providing new leads, but also new chemical biology tools for exploring host/pathogen interaction.

Public Health Relevance

There is an imperative need to identify new classes of antibacterials. MRSA and VRE infection, and the recent spread of vancomycin resistance to MRSA resulting in VRSA infection, are leading healthcare concerns. However, the rate of new antibiotic discovery is unlikely to meet the expected need for the foreseeable future. This project takes new approaches for antimicrobial drug discovery.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Program Projects (P01)
Project #
5P01AI083214-05
Application #
8376871
Study Section
Special Emphasis Panel (ZAI1-LG-M)
Project Start
2012-09-01
Project End
2016-08-31
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
5
Fiscal Year
2012
Total Cost
$665,993
Indirect Cost
$36,727
Name
Massachusetts Eye and Ear Infirmary
Department
Type
DUNS #
073825945
City
Boston
State
MA
Country
United States
Zip Code
02114
Truong-Bolduc, Q C; Wang, Y; Chen, C et al. (2017) Transcriptional Regulator TetR21 Controls the Expression of the Staphylococcus aureus LmrS Efflux Pump. Antimicrob Agents Chemother 61:
Gwisai, Tinotenda; Hollingsworth, Nisha Rosita; Cowles, Sarah et al. (2017) Repurposing niclosamide as a versatile antimicrobial surface coating against device-associated, hospital-acquired bacterial infections. Biomed Mater 12:045010
Truong-Bolduc, Q C; Khan, N S; Vyas, J M et al. (2017) Tet38 Efflux Pump Affects Staphylococcus aureus Internalization by Epithelial Cells through Interaction with CD36 and Contributes to Bacterial Escape from Acidic and Nonacidic Phagolysosomes. Infect Immun 85:
Ibberson, Carolyn B; Stacy, Apollo; Fleming, Derek et al. (2017) Co-infecting microorganisms dramatically alter pathogen gene essentiality during polymicrobial infection. Nat Microbiol 2:17079
Zheng, Zhaojun; Tharmalingam, Nagendran; Liu, Qingzhong et al. (2017) Synergistic Efficacy of Aedes aegypti Antimicrobial Peptide Cecropin A2 and Tetracycline against Pseudomonas aeruginosa. Antimicrob Agents Chemother 61:
Saavedra, José T; Schwartzman, Julia A; Gilmore, Michael S (2017) Mapping Transposon Insertions in Bacterial Genomes by Arbitrarily Primed PCR. Curr Protoc Mol Biol 118:15.15.1-15.15.15
Rajagopal, Mithila; Walker, Suzanne (2017) Envelope Structures of Gram-Positive Bacteria. Curr Top Microbiol Immunol 404:1-44
Matano, Leigh M; Morris, Heidi G; Hesser, Anthony R et al. (2017) Antibiotic That Inhibits the ATPase Activity of an ATP-Binding Cassette Transporter by Binding to a Remote Extracellular Site. J Am Chem Soc 139:10597-10600
Lebreton, François; Manson, Abigail L; Saavedra, Jose T et al. (2017) Tracing the Enterococci from Paleozoic Origins to the Hospital. Cell 169:849-861.e13
Nakaminami, Hidemasa; Chen, Chunhui; Truong-Bolduc, Que Chi et al. (2017) Efflux Transporter of Siderophore Staphyloferrin A in Staphylococcus aureus Contributes to Bacterial Fitness in Abscesses and Epithelial Cells. Infect Immun 85:

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