Development and Validation of Pathogen Environmental Monitoring Programs for Small Cheese Processing Facilities

Area of Science:

• Food safety
• Microbiology
• Environmental monitoring

Background:

• Pathogen environmental monitoring programs (EMPs) are vital for ready-to-eat food producers.
• Small and farmstead cheese processors require tailored monitoring strategies.

Purpose of the Study:

• To develop, implement, and evaluate pathogen EMPs for Listeria spp. and Salmonella in small cheese processing facilities.
• To assess the effectiveness of routine sampling plans through validation sampling.

Main Methods:

• Designed facility-specific EMPs with monthly sampling for nine small cheese facilities.
• Utilized pulsed-field gel electrophoresis for pathogen subtyping.
• Conducted validation sampling with 50-150 samples per facility to assess routine plan efficacy.

Main Results:

• Salmonella was detected in one facility, likely from an adjacent farm.
• Listeria spp. were found in all nine facilities; L. monocytogenes prevalence was 1.35%.
• Molecular data indicated persistent Listeria strains in seven facilities and L. monocytogenes in four.
• Validation sampling revealed discrepancies in detection frequencies compared to routine sampling in four facilities.

Conclusions:

• Developed a science- and statistics-based model for creating and validating pathogen EMPs.
• Highlights the need for tailored and validated monitoring programs in small food processing facilities.
• Demonstrates potential variability in routine sampling plan effectiveness for pathogen detection.