EFSA Scientific opinion - Microbiological hazards in food and feed production environments - What to remember?
In January 2024, the EFSA has released a scientific opinion about persistence of microbiological hazards in food and feed production and processing environments. In this article bioMérieux helps you to extract the highlights from this publication.
1. What are the relevant bacterial hazards persistent in the environment?
The persistence of microbiological hazards in food and feed production and processing environments is a significant concern for public health, with important associated health risks for consumers and economic losses for producers.
Foodborne outbreaks have been linked to strains persistently colonizing the food environment or equipment, often caused by closely-related genotypes. Sites that are difficult to clean and disinfect, along with the special abilities of certain microbial strains to withstand stress, desiccation, disinfection, and form biofilms, are the most relevant determinants of persistence.
In the meat sector, Listeria monocytogenes and Salmonella enterica are prevalent, while L. monocytogenes is a concern for fish and seafood, dairy, fruits and vegetables.
The feed and eggs sectors are primarily affected by S. enterica and Cronobacter poses a threat in infant formula.
Pathogens able to persist across various sectors include specific subtypes of L. monocytogenes, Salmonella, and Cronobacter. Implementing enhanced environmental monitoring measures can help reduce the time and cost typically associated with classical environmental monitoring activities, thereby mitigating the risks posed by these persistent microbiological hazards.
Factors increasing persistence in environment cited in the document are:
Poor hygienic design of equipment; inadequate cleaning and disinfection of facilities; inadequate zoning or hygienic barriers; raw material contamination and, for some bacteria, intense humidity (e.g. Listeria monocytogenes) or aireation, ventilation or dust (e.g. Salmonella, Cronobacter). Also genotypic and phenotypic features from the microorganisms may increase the capacity to persist.
2. Measures for monitoring hazards in environment
a. Measure 1: Sampling and testing
Designing an effective environmental sampling and testing program involves several critical steps.
Firstly, identifying sample locations is essential; these locations are selected based on areas that are most susceptible to contamination, such as equipment surfaces, drains, and high-traffic zones. The target organisms typically include pathogens like Listeria monocytogenes, which is prevalent in dairy environments. The frequency, timing, and number of samples must be meticulously planned to ensure regular monitoring and detection of potential hazards. A robust sampling protocol and precise test methods are crucial for obtaining accurate and reliable results. Recording and evaluating these results against defined limits allow for the early detection of contamination. Finally, establishing clear follow-up actions ensures that any identified issues are promptly addressed to mitigate risks, thereby maintaining food safety and protecting public health.
For dairy food production, Bulletin of the International Dairy Federation (IDF) 525/2023 is providing practical considerations of sampling for environmental monitoring.
b. Measure 2: Hygienic measures
Implementing comprehensive hygienic measures is critical to ensuring food safety. These measures include:
- Water Quality: Ensuring the use of clean, potable water in all aspects of food production and processing. Regular testing and monitoring of water sources are essential to prevent contamination.
- Food Safety Culture: Cultivating a strong food safety culture within the organization. This involves training employees on best practices, promoting awareness, and fostering a commitment to maintaining high standards of hygiene and safety.
- Cleaning Infrastructure: Investing in effective cleaning infrastructure. This includes having the appropriate equipment and cleaning agents for thorough sanitation of all surfaces and equipment. Special attention should be given to hard-to-reach areas to prevent microbial persistence.
- Technical Maintenance: Regular maintenance of equipment to ensure it is functioning correctly and not contributing to contamination. This involves routine inspections, timely repairs, and updates to equipment as necessary to meet hygiene standards.
- Personnel Hygiene: Implementing strict personal hygiene protocols for all employees. This includes proper handwashing, the use of protective clothing, and ensuring that staff understand and follow hygiene practices to prevent cross-contamination.
By focusing on these key areas, it can significantly reduce the risk of contamination, ensuring a safer production environment and enhancing the overall quality and safety of finished products.
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c. Measure 3: Source tracking of a contamination
Conducting a thorough root cause analysis is essential for identifying and mitigating the factors contributing to persistent microbiological hazards in the food and feed production environment. The approach includes the following steps:
- Identify the Most Probable Factors/Sites: Determine the specific locations and conditions within the production environment that are most likely to harbor contamination. This involves detailed inspections and reviewing historical data to pinpoint areas with recurrent issues.
- Define the Most Appropriate Interventions: Based on the identified factors and sites, develop targeted interventions to address the root causes. This might include changes in cleaning protocols, modifications to equipment design, or enhanced training for personnel.
Effective source tracking and evaluation of persistence are facilitated by methods capable of subtyping isolates. These methods provide the discriminatory power to determine if isolates from different environments or sampling times are the same or closely related, which is crucial for tracking the spread and origin of contaminants. Additionally, novel approaches of environmental testing based on the untargeted analysis of the microbiome through metagenomics offer significant potential benefits for source tracking and investigation of persistence.
Metagenomics allows for comprehensive analysis of all genetic material in a sample, providing a deeper understanding of the microbial community and identifying otherwise undetectable pathogens.
Regular microbiological testing is widely recognized as essential. A well-designed environmental sampling and testing program is the most effective strategy for identifying contamination sources and detecting potentially persistent hazards. Trend analysis of test results can serve as an early warning system, highlighting emerging issues before they escalate.
Sampling and testing activities should go beyond the enumeration of hygiene indicators to target specific pathogenic microorganisms. Detailed characterization of isolates is necessary for effective investigations. Typing several isolates from each sample or enrichment helps capture the full diversity of the sample, providing a comprehensive understanding of the contamination and its sources.
In addition EFSA consider important that all information collected is gathered in risk assessment models.
By incorporating metagenomics and following these steps, producers can implement more effective control measures, reducing the risk of contamination and enhancing the overall safety of their products.
