Combinatorial genetic technology for the development of new anti-infectives

Context.—We previously developed a novel technology known as instant evolution for high-throughput analysis of mutations in Escherichia coli ribosomal RNA.Objective.—To develop a genetic platform for the isolation of new classes of antiinfectives that are not susceptible to drug resistance based on the instant evolution system.Design.—Mutation libraries were constructed in the 16S rRNA gene of E coli and analyzed. In addition, the rRNA genes from a number of pathogenic bacteria were cloned and expressed in E coli. The 16S rRNA genes were incorporated into the instant-evolution system in E coli.Setting.—The Department of Biological Sciences, Wayne State University, Detroit, Mich.Main Outcome Measures.—Ribosome function was assayed by measuring the amount of green fluorescent protein produced by ribosomes containing mutant or foreign RNA in vivo.Results.—We have developed a new combinatorial genetic technology (CGT) platform that allows high-throughput in vivo isolation and analysis of rRNA mutations that might lead to drug resistance. This information is being used to develop anti-infectives that recognize the wild type and all viable mutants of the drug target. CGT also provides a novel mechanism for identifying new drug targets.Conclusions.—Antimicrobials produced using CGT will provide new therapies for the treatment of infections caused by human pathogens that are resistant to current antibiotics. The new therapeutics will be less susceptible to de novo resistance because CGT identifies all mutations of the target that might lead to resistance during the earliest stages of the drug discovery process.