Targetable plasmid removal method

Unmet Need

Bacterial pathogens represent a major challenge in the healthcare system. Hospitals harbor complex microbial communities where different bacterial pathogens can transfer undesirable plasmids that encode virulence and antibiotic resistance. This results in more than 2.8 million antibiotic-resistant infections in the United States every year. This results in a greater risk of therapeutic failure, longer hospitalizations, and deaths. To remove these undesirable plasmids, existing chemical-based solutions rely on harsh carcinogenic chemicals that indiscriminately remove bacteria and have a high off-target activity. There is a need for an approach to efficiently remove undesirable plasmids without the off-target effects common to other plasmid removal agents.

Technology

Duke inventors have developed an approach that would outcompete and eliminate undesirable plasmids in bacteria. This technology is intended to be a tool used in antimicrobial control. Specifically, the inventors have developed a synthetic “denial-of-spread” (DoS) plasmid that eliminates its target plasmid through transfer competition and plasmid incompatibility. As a safety mechanism, the DoS plasmid removes itself via induced plasmid suicide. Consequently, the cell will end up with neither the targeted nor the DoS plasmid. The DoS plasmid can be designed specifically for its designed target, eliminating toxic off-target effects common to other plasmid removal agents. The DoS plasmid is scalable and modular, enabling the incorporation of other curing strategies. The inventors have shown that DoS can remove its target plasmids in a mixture containing both target and non-target plasmids. Studies are underway to evaluate the effectiveness of this method in the complex microbial community of a hospital setting.

Other Applications

This technology can also be used as a prophylactic and therapeutic tool to combat drug resistant bacteria in human health, veterinary applications, agriculture, and aquaculture. Additionally, the DoS plasmid can be used as a research tool to study plasmid-encoded phenotypes or to genetically engineer bacteria.

Advantages

• Specifically removes targeted plasmids without off-target effects
• Increased safety through self-eliminating mechanism
• Scalable and modular design compatible with other curing strategies