Simultaneous detection of pathogenic bacteria using agglutination test based on colored silica nanoparticles

Area of Science:

• Nanotechnology
• Microbiology
• Food Science

Background:

• Simultaneous detection of multiple foodborne pathogens remains a challenge.
• Existing methods can be time-consuming and require specialized equipment.
• Rapid, on-site detection is crucial for effective food safety management.

Purpose of the Study:

• To develop a novel agglutination test for simultaneous detection of pathogenic bacteria.
• To utilize colored silica nanoparticles (colored-SiNPs) as carriers for the agglutination test.
• To establish a rapid and easy method for in situ screening of food and feed contaminants.

Main Methods:

• Monodisperse colored-SiNPs (red and blue) were synthesized using reverse microemulsion.
• Antibodies against E. sakazakii (IgG-red-SiNPs) and S. pullorum/S. gallinarum (IgG-blue-SiNPs) were prepared.
• A mixture of antibody-conjugated SiNPs was used for simultaneous agglutination tests.

Main Results:

• The developed agglutination test successfully detected E. sakazakii, S. pullorum, and S. gallinarum simultaneously.
• Obvious agglutination phenomena were observed, indicating the presence of target bacteria.
• The detection range for these pathogens was established from 4×10^3 to 4×10^9 CFU/mL.
• The method was validated by detecting pathogens in spiked food samples.

Conclusions:

• A novel, rapid agglutination test using colored-SiNPs enables simultaneous detection of multiple foodborne pathogens.
• This method is sensitive, specific, and suitable for in situ applications.
• The test offers a valuable tool for rapid screening of pathogenic microorganisms in food and feed, enhancing food safety.