Novel ST-Specific Molecular Target-Based Method for Simultaneous and Quantitative Detection of Staphylococcus aureus...

Area of Science:

• Microbiology
• Food Science
• Molecular Biology

Background:

• Staphylococcus aureus is a critical foodborne pathogen causing various infections.
• Three predominant sequence types (STs)—ST7, ST188, and ST398—are prevalent in food and clinical settings.
• Accurate detection of these specific STs in food is crucial for public health.

Purpose of the Study:

• To screen for and identify novel sequence type (ST)-specific molecular targets for Staphylococcus aureus ST7, ST188, and ST398.
• To develop a rapid and accurate assay for detecting these three predominant S. aureus STs in food matrices.

Main Methods:

• Pan-genome analysis of 505 Staphylococcus strain genomes to identify ST-specific targets.
• Development and validation of multiplex PCR (mPCR) and quantitative PCR (qPCR) assays using identified targets.
• Determination of limits of detection (LODs) in artificially contaminated milk and testing on actual food samples.

Main Results:

• Five novel ST-specific targets were successfully identified for S. aureus ST7, ST188, and ST398.
• Developed mPCR and qPCR assays demonstrated excellent specificity and sensitivity, without non-target bacterial interference.
• The qPCR assay achieved low LODs, ranging from 1.2 × 10^2 to 6.4 × 10^3 CFU/mL, offering high sensitivity for detection.

Conclusions:

• The developed mPCR and qPCR assays provide a rapid, reliable, and accurate alternative to standard MLST analysis for identifying S. aureus STs in food.
• This novel molecular detection technology is valuable for preventing and controlling S. aureus ST contamination in food.
• The assays hold significant potential for application and promotion in food safety surveillance and control strategies.