Rapid and Specific Detection of Bacillus cereus Using Phage Protein-Based Lateral Flow Assays

Area of Science:

• * Food Safety and Microbiology
• * Nanotechnology and Biosensing
• * Molecular Biology and Biotechnology

Background:

• * Traditional Bacillus cereus detection methods are slow and costly.
• * Current lateral flow assays (LFAs) often rely on antibodies, which have production and variability challenges.
• * There is a need for rapid, precise, and alternative diagnostic tools for foodborne pathogens.

Purpose of the Study:

• * To develop and validate bacteriophage-derived proteins as bioreceptors for Bacillus cereus detection in LFAs.
• * To characterize the binding properties of these phage proteins at the biointerface.
• * To create a rapid, cost-effective, and ethical diagnostic assay for Bacillus cereus.

Main Methods:

• * Engineered endolysin cell-wall-binding domains (CBD) and distal tail proteins (Dit) from bacteriophages targeting Bacillus cereus.
• * Characterization of protein-binding properties and biointerface formation on nitrocellulose membranes and gold nanoparticles (AuNPs).
• * Utilization of machine-learning models to predict optimal protein orientation and quantification of AuNP-bacterium binding.

Main Results:

• * Demonstrated specific binding of up to 100 gold nanoparticles (AuNPs) per Bacillus cereus bacterium.
• * Developed a prototype LFA using a combination of two phage proteins.
• * Achieved rapid colorimetric detection of 10^5 Bacillus cereus cells within 15 minutes.

Conclusions:

• * Bacteriophage proteins are effective bioreceptors for rapid Bacillus cereus detection in LFAs.
• * This approach offers a cost-effective, ethical, and customizable alternative to antibody-based diagnostics.
• * The findings pave the way for advanced phage protein-based biosensors for point-of-care diagnostics and public health.