Development of a Visual Assay for Detection of Viable Cronobacter sakazakii Using RT-PSR and Hydroxynaphthol Blue...

Area of Science:

• Food Microbiology
• Molecular Diagnostics
• Food Safety

Background:

• Cronobacter sakazakii is a dangerous foodborne pathogen found in powdered infant formula.
• Infants and the elderly are particularly vulnerable to C. sakazakii infections.
• Current detection methods can be time-consuming and require specialized equipment.

Purpose of the Study:

• To develop a rapid, visual detection method for viable Cronobacter sakazakii.
• To utilize reverse transcription-polymerase spiral reaction (RPS) and hydroxynaphthol blue (HNB) for detection.
• To provide a low-equipment-dependent assay for on-site food safety monitoring.

Main Methods:

• Optimization of reverse transcription-polymerase spiral reaction (RPS) conditions.
• Integration of hydroxynaphthol blue (HNB) indicator for visual detection.
• Validation of the assay using artificially contaminated powdered infant formula samples.

Main Results:

• The assay provides visual detection of viable C. sakazakii within 55 minutes.
• Optimized conditions yielded high specificity and sensitivity.
• The detection limit was as low as 1.2 × 10^1 CFU/mL.
• The method demonstrated 100% accuracy in artificially contaminated samples.

Conclusions:

• A rapid, visual, and sensitive detection method for viable C. sakazakii has been developed.
• The assay is suitable for resource-limited settings due to low equipment dependence.
• This method enhances food safety protocols for powdered infant formula.