Salmonella remains one of the most consequential foodborne pathogens, responsible for significant global illness, costly recalls, and reputational damage across the food industry. With more than 2,500 serovars and the ability to persist across diverse environments and foods, Salmonella demands robust, validated testing strategies that are both sensitive and operationally efficient. 

While poultry and eggs are well-known sources of Salmonella contamination, recent outbreaks have implicated tomatoes, peanut butter, sprouts, dairy products, chocolate, cake mixes, powdered infant formula, pet food, and animal feed. Salmonella is versatile, resilient, and widespread; hence, the need for vigilant testing from primary production and the processing environment to finished product.

Choosing the right testing strategy is a crucial link in ensuring public health and protecting brand integrity. Producers and manufacturers face a real and ever-present risk of serious brand damage and loss of consumer confidence if Salmonella is not effectively managed.

Considerations for Method Selection

Laboratories must balance resource limitations, cost restrictions, industry demands, and compliance with relevant regulations when designing their testing programs. 

To mitigate the risks of Salmonella to the public, the regulatory environment and testing requirements are constantly evolving to combat the risk and accommodate innovation and new products introduced to the market. Many markets and customers require methods adopted by the lab to be aligned to ISO 6579-1, the Food and Drug Administration's (FDA's) Bacteriological Analytical Manual (BAM), the U.S. Department of Agriculture Food Safety and Inspection Service's (USDA-FSIS') Microbiology Laboratory Guidebook (MLG), or validated alternatives (e.g., AOAC International, Afnor NF Validation, MicroVal). With import and export business, the regulatory requirements double as many laboratories end up adhering to several sets of regulatory requirements. 

In addition to external factors like regulations, operational decisions (within the company or laboratory) also play a significant role in determining the appropriate testing methodology to adopt. High-throughput labs, for example, may prioritize single-enrichment workflows and automation to reduce handling steps and turnaround time, while smaller labs may prefer simple culture methods with minimal instrumentation.

When selecting a method for your lab, consider if it is fit for purpose from all relevant angles:

• Regulatory and customer requirements 
• Matrices and sample sizes
• Throughput and turnaround
• People and equipment
• Data needs.

Salmonella testing is at once a public health necessity, a regulatory requirement, and a business imperative. Whether your lab has decided to adopt a reference method or utilize the speed and scalability of validated alternative methods, this guide provides a clear, practical roadmap. By matching method to matrix, compliance context, and operational constraints, and by utilizing automation and smart media choices where appropriate, labs can have confidence in their results. 

Download this free guide to Salmonella test methods for food laboratories for a simple outline of relevant reference methods—e.g., ISO 6579-1:2017 (Horizontal Method for the Detection of Salmonella Species) and USDA-FSIS MLG 4.13 (Isolation and Identification of Salmonella, Rapid Screening Salmonella Test Procedure)—as well as information about Thermo Fisher Scientific products that can be used according to the methods.

By Thermo Fisher Scientific