System for Producing and Delivering Targeted Antibiotics

Background

Antibiotic resistance is generally regarded as a serious threat to global health, both presently, but also as a threat that will increase in the future. In fact, the U.S. Centers for Disease Control and Prevention indicates antibiotic resistance as one of the principal public health challenges we face. Traditional antibiotic pipelines are not yielding new compounds, as evidenced by only two new classes of antibiotics emerging in the last 30 years. The projected statistics are startling, a recent UN report estimates as many as 10 million deaths globally could be attributed to antibiotic resistance by 2050. Additionally, infections that were once routine to treat are becoming more troublesome to treat and the burden on the healthcare system is growing. It is apparent that alternatives to traditional antibiotics are necessary to combat increasing antibiotic resistance. One such alternative is through repurposing of CRISPR/Cas systems as programmable antimicrobials. A primary challenge that has prevented this concept from reaching the market, is the delivery of CRISPR molecular machines into the bacterial of interest.

Technology Overview

Researchers from the NC State University Department of Food, Bioprocessing, and Nutrition Sciences have developed bacteriophage-mediated delivery of repurposed CRISPR molecular machinery, by engineering probiotic bacteria to encode a phasmid, which contains both plasmid and bacteriophage properties, carrying the CRISPR array embedded in the bacteriophage genome. This specific system is designed for the probiotic Lactobacillus reuteri, which have been engineered to release bacteriophages directly in the human gastrointestinal (GI) tract and through phage-mediated targeting, eliminate a bacteria of interest (e.g. Clostridium difficile). The CRISPR array will be then be delivered to the bacteria of interest, resulting in targeted, strain-specific cell killing, when the native Cas proteins are activated. Targeted killing through this approach reduces the amount of toxins release by the bacteria into the host, since bacteria lysis does not occur. Lactobacillus reuteri are an attractive delivery vehicle since it is a naturally occurring probiotic that can survive passage through and colonize the GI tract, without harming the natural bacteria, and importantly has received Generally Recognized As Safe (GRAS) designation from the FDA.

A paper describing the probiotic delivery system of CRISPR‑mediated antibiotics can be found here.

Benefits

This technology has the potential to revolutionize the advancement of future antibiotics. Lactobacillus reuteri are used as the delivery vehicle, which has received a GRAS designation from the FDA. The delivery vehicle can be taken orally, eliminate bacteria of interest in a strain selective manner, and is efficacious against difficult to treat strains of bacteria. Additionally, the engineered probiotic delivery system is amenable for any CRISPR cassette. This system is not susceptible to antibiotic resistance because the repurposed CRISPR machinery can be used to induce plasmid curing to eliminate plasmids with genes of antibiotic resistance in bacterial cells.

Applications

This invention can be used to design strain specific CRISPR systems for novel antibiotics. This technology realizes the concept using CRISPR molecular machinery for antibiotics and solves the challenge of the CRISPR guide surviving oral ingestion and effectively reaching its desired target. It could also be synergistically used with traditional antibiotics to induce plasmid curing, where the CRISPR machinery can effectively destroy plasmids in bacterial cells that contain antibiotic resistance. Another potential application is in agricultural biotechnology, where the technology could be applied to develop alternatives to traditional antibiotics used in livestock.

Opportunity

NC State University is currently seeking an industry partner or an ambitious entrepreneur to commercialize this technology. There is a strong potential for commercialization of this technology to result in a significant advancement in the field of antibiotics.