A Signature Peptide Strategy for Concurrent Detection of Multiple Pathogens and Toxins in Infant Formula

Area of Science:

• Food safety
• Analytical chemistry
• Microbiology

Background:

• Zero-tolerance regulations for Salmonella and Cronobacter sakazakii in infant formula necessitate rapid detection.
• Existing methods may lack the speed or reliability required for complex dairy matrices.

Purpose of the Study:

• To develop a multiplex targeted-proteomics strategy for simultaneous detection of Salmonella and Cronobacter sakazakii in infant formula.
• To establish a sensitive and reliable method for ensuring infant formula safety.

Main Methods:

• Developed a multiplex targeted-proteomics strategy using species-specific signature peptides.
• Employed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) multiple reaction monitoring (MRM) workflow.
• Utilized a dual identification strategy with retention-time matching and transition-ion ratios for enhanced reliability.

Main Results:

• Achieved simultaneous detection of Salmonella and Cronobacter sakazakii in infant formula within 10 hours of enrichment.
• Demonstrated a sensitivity of 10 CFU/mL for both pathogens.
• Confirmed stable performance in mixed cultures, including the presence of Staphylococcus aureus.

Conclusions:

• The developed peptide-centric MRM approach provides rapid and reliable detection of target pathogens in infant formula.
• This method serves as a valuable complement to conventional culture-based and nucleic-acid-based detection techniques.
• Enhances the safety of infant formula through improved pathogen surveillance.