Compositions and methods for antibiotic potentiation and drug discovery

A method of identifying an antibiotic potentiator target gene comprising steps of:

• contacting a microbial cell with an antibiotic agent, wherein the microbial cell has a genetic alteration that significantly reduces or eliminates expression of a gene;
• comparing growth or survival of the microbial cell with growth or survival of a microbial cell having higher expression of the gene than the cell having the genetic alteration;
• and
• determining that the gene is an antibiotic potentiator target gene if the growth, survival, or both of the microbial cell having the genetic alteration is lower than the growth, survival, or both of the microbial cell having higher expression of the gene.

A method of identifying an agent that potentiates activity of an antibiotic comprising steps of:

• providing an assay system comprising a test compound, wherein the assay system is suitable for performing an assay to detect expression of an antibiotic potentiator target gene or to detect activity of an expression product of an antibiotic potentiator target gene;
• determining whether the test compound inhibits expression of the antibiotic potentiator target gene or inhibits or interferes with activity of an expression product of the antibiotic potentiator target gene;
• and
• identifying the test compound as a potentiator of the antibiotic if the test compound inhibits expression of the antibiotic potentiator target gene or inhibits or interferes with activity of an expression product of the antibiotic potentiator target gene.

A method of identifying a candidate antibiotic potentiating agent comprising steps of

• contacting a protein comprising a polypeptide encoded by an antibiotic potentiator target gene with a test compound;
• determining whether the test compound binds to the protein;
• and
• identifying the test compound as an antibiotic potentiating agent if it binds to the protein.

A method of identifying a candidate antibiotic potentiating agent comprising steps of

• contacting a first microbial cell with a test compound and an antibiotic agent, wherein the microbial cell overexpresses an antibiotic potentiator target gene;
• comparing growth or survival of the first microbial cell with growth or survival, respectively, of a second microbial cell maintained under substantially equivalent conditions, wherein the second microbial cell does not overexpress the antibiotic potentiator target gene but is otherwise substantially identical to the first microbial cell;
• and
• determining that the test compound potentiates activity of the antibiotic agent if the growth, survival, or both of the first microbial cell is greater than the growth, survival, or both, of the second microbial cell