Rapid, phenotypic, instruemnt-free detection of bacterial growth

Overview

This technology offers a novel approach to bacterial detection by targeting metabolic activity rather than the presence of bacterial DNA or replication of whole cells. The core insight is that actively growing bacteria continuously synthesize new cell envelope material, and this synthesis can be chemically labeled. When combined with a lateral flow assay readout, the platform allows detection of bacterial growth in a variety of settings and use cases, including antibiotic susceptibility testing in clinic or at home as well as testing for bacterial contaminants in food items or biomanufacturing.

Key advantages include:

• Speed: Produces a signal above negative controls within approximately 90 minutes, additional improvement underway
• Viability discrimination: Signal drops to background levels when bacteria are treated with effective antibiotics, meaning the assay specifically reports on live, metabolically active cells rather than dead cells or residual DNA.
• Broad species compatibility: Robust signal has been observed across every bacterial species tested to date, including E. coli, S. aureus, Klebsiella spp., Pseudomonas aeruginosa, Proteus mirabilis, Mycobacterium abssessus, Mycobacterium abscessus and more.

The platform is designed to be modular, allowing the probe chemistry and readout method to be swapped or tuned depending on the requirements of a given application.

Technical specifications

The assay works by metabolically incorporating a labeled precursor into the bacterial cell surface during active growth. The label is then detected through a lateral flow antibody-based readout system.

• Testing alternative readout methods beyond colorimetric detection
• Adjusting reagent concentrations for maximum signal-to-noise ratio
• Leveraging the modular design to combine the best-performing probe and readout components

The target limit of detection is 100 CFU/mL, representing a 100-fold improvement over current performance.

Technology readiness level

This technology is currently at an early-to-mid stage of development. Proof-of-concept experiments have been completed in E. coli and S. aureus, demonstrating both the speed of detection and the ability to discriminate viable from nonviable bacteria. The assay has been validated through time-course studies and serial dilution experiments.

The next phase of work focuses on pushing the limit of detection from the current 10^4 CFU/mL down to a target of 100 CFU/mL. Because the platform is modular and the team has the capability to modify the probe chemistry, multiple optimization strategies can be pursued in parallel. Additional validation across a broader range of bacterial species and in more complex sample matrices is anticipated as the technology matures toward clinical or commercial deployment.