Optical Identification of Bacteria and/or Treatment of Bacterial Infections Using Engineered Phages

Background

The rise of antibiotic-resistant bacterial infections is widely recognized as an urgent threat to health, making it increasingly important to find alternative approaches to killing harmful organisms. Detecting harmful bacteria is crucial in combating the spread of antibiotic-resistant strains, but current detection methods are limited due to extensive time and equipment requirements. Additionally, there are limitations on the ability to accurately and successfully target specific strains of bacteria for study. Therefore, there is a critical need for rapid and accurate new methods of detecting specific bacterial species. A versatile and effective detection method would have wide-ranging applications in medicine, food safety, and more.

Bacteriophages (phages) are abundant and ubiquitous, and they represent highly evolved and very efficient systems of bacterial targeting. However, there are difficulties in using phages to combat bacteria including a lack of therapeutic control and a lack of understanding the biology of most phages. Gold nanoparticles represent a potential platform for rapid diagnosis based on the sensitivity of the surface plasmon resonance to aggregation state, which produces a visible color change. They have been demonstrated to detect pathogenic bacteria in multiple systems. However, the isolation and production of antibodies can be costly and non-trivial, and optimization may be required to improve stability and solubility in the relevant chemical context.

Description

Researchers at the University of California, Santa Barbara have created strategies to detect and combat bacterial species. The method of detection is rapid, inexpensive, and simple, and it can be used to identify a variety of bacterial species. This strategy is based on the interaction between bacterial cells and the viruses that infect them, phages. Colorimetric sensing allows for clear detection using a visible spectral shift that is produced around aggregation around cell phage complexes. Thiolation of engineered phages allows binding of gold nanoparticles, which aggregate on the phages, amplifying the interaction and resulting in a visible color change. It can be applied to any bacteria that are targeted from a metagenomic sample. While the standard detection time is four hours, this technology can detect bacteria in twenty minutes, or less. This detection strategy requires minimal lab equipment and minimal training.

Engineered phages can also be used to selectively target and kill and various bacterial cell types. The phages used can be of any type, serotype, or species. The approach involves a topical application, and is not injected into the body, making it easy to initiate. Further, the phage-targeted thermoablation of selected bacterial cells provides a way to selectively kill harmful organisms while sparing the surrounding healthy tissue.

Advantages

• Rapid colorimetric detection of multiple bacterial species for food safety or strategic selection of an antibiotic
• Minimal equipment and training required
• Inexpensive        
• Treatment of infection with selective thermoablation of targeted bacteria while sparing surrounding tissues
• Can be applied widely to many bacterial species
• Accurate, successful, and safe, therapy for antibiotic resistant bacterial infections

Applications

• Medicine
• Food safety

Patent Status

Patent Pending

Related Materials

• PCT: Targeted phage for bacterial detection and destruction