Salmonella, antibiotics and climate change
What is changing in food safety regulations

Many food manufacturers treat antibiotic-resistant Salmonella strains as a future threat, failing to recognise that the situation is already changing today. EFSA is issuing scientific opinions, and national food safety authorities are beginning to incorporate these aspects into their recommendations. It is worth understanding what is happening and how it affects the obligations of manufacturers.

Why Salmonella is becoming resistant, and why climate matters

Salmonella antibiotic resistance is the result of natural selection. Bacteria that survive antibiotic exposure reproduce and pass resistance genes to subsequent generations. The problem is that biological processes occur more rapidly at higher temperatures, and climate change means more heat, more moisture, and more pathogen replication cycles throughout the food supply chain.

Consider a grain storage facility or poultry farm where temperatures rise by several degrees Celsius. Any Salmonella present will multiply more rapidly. If antibiotic residues are simultaneously present in that environment (e.g. from the use of veterinary medicines), resistant strains will emerge more quickly. This is not a hypothetical threat – EFSA has drawn attention to this in its most recent scientific opinions.

• Higher temperatures accelerate Salmonella replication
• Changes in precipitation affect humidity levels in storage facilities and production premises
• Longer growing seasons may increase plant exposure to pathogens
• Changes in livestock ecosystems may alter populations of natural Salmonella reservoirs

The current EU regulatory framework – what is already changing

Regulation (EC) No 852/2004 on the hygiene of foodstuffs requires you to implement procedures based on HACCP principles. These procedures must account for microbiological hazards, including Salmonella. The question is: does your hazard analysis include the scenario of increasing pathogen resistance to antibiotics?

Regulation (EC) No 1441/2007 amending Regulation 2073/2005 sets out microbiological criteria for foodstuffs. For Salmonella, the standard is absolute – presence in 25 grams of a sample is unacceptable for most product categories. However, a problem arises here: if strains become antibiotic-resistant, they may be more difficult to inactivate using traditional thermal methods, particularly where those methods were designed on the basis of older data.

• Regulation 852/2004 – obligation to implement HACCP procedures that account for contemporary hazards
• Regulation 1441/2007 – microbiological criteria for Salmonella (zero tolerance for most categories)
• Regulation 1169/2011 – obligation to provide information on allergens and hazards (indirectly relevant to risk communication)
• EFSA scientific opinions from 2023 – increasing emphasis on monitoring resistance throughout the food chain

Expert Tip: Inspections by the Polish Chief Sanitary Inspectorate (GIS) are increasingly including questions not only about the presence of Salmonella, but also about whether the manufacturer monitors pathogen resistance trends within their sector. This is not yet a formal requirement, but it is the direction in which regulations are heading.

How climate change affects your obligations as a manufacturer

First and foremost: climate change means a change in the environmental conditions in which your production operates. If your storage facility or production line previously maintained stable temperature and humidity, and those parameters are now changing, your control procedures must change accordingly.

Regulation 852/2004 requires that production premises be maintained in appropriate hygiene and sanitary conditions. If temperatures are rising, your expenditure on cooling, ventilation and monitoring must rise too. This is not optional – it is a legal requirement.

• Review of air conditioning and refrigeration systems – are they adequate for the new conditions?
• Increased frequency of microbiological testing at critical control points
• Update of hazard analyses in HACCP – inclusion of climate-related scenarios
• Review of disinfection procedures – are they effective against potentially more resistant strains?
• Revision or strengthening of product traceability and withdrawal procedures

Practical steps: what to do now to remain compliant

You do not need to wait for new regulations. The law already requires this of you. Here is a concrete action plan:

• Step 1: HACCP review – add the scenario of "rising temperature and humidity in storage facilities" to your hazard analysis. Check whether your current critical control points are sufficient.
• Step 2: Infrastructure audit – are your cooling, ventilation and temperature monitoring systems up to date? Can they handle higher ambient temperatures?
• Step 3: Review of cleaning and disinfection procedures – are they based on current industry guidelines? Do they account for the possible emergence of more resistant strains?
• Step 4: Increase the frequency of microbiological testing – particularly for high-risk products (poultry, meat, dairy)
• Step 5: Staff training – employees must understand why procedures are changing and how to implement them correctly

Expert Tip: Implementing changes to HACCP is a process that must be documented and verified. Every change should be justified by data – storage temperatures, microbiological test results, industry data. This will serve as the manufacturer's defence if the Polish Chief Sanitary Inspectorate (GIS) asks about the basis for procedural changes.

The most common pitfalls

• Treating this as a future problem – Salmonella resistance already exists. Climate change is an accelerator, not the origin of the problem. Act now.
• Relying solely on microbiological testing – testing is expensive and time-consuming. It must be complemented by preventive procedures (HACCP).
• Ignoring data from your sector – if you are a poultry producer, check which Salmonella strains are being observed in your region. RASFF (Rapid Alert System for Food and Feed) regularly publishes such information.
• Failing to document changes – if you change a procedure, it must be described, justified and approved. Otherwise it is not a change, it is chaos.
• Treating refrigeration as a cost rather than an investment – better cooling systems are not a luxury; they are a food safety requirement.

Monitoring and indicators you should be tracking

The law does not require you to monitor Salmonella antibiotic resistance, but it does require you to monitor microbiological hazards. These two issues are interconnected. Here is what you should be tracking:

• Temperature and humidity in storage facilities – daily or weekly reports
• Microbiological test results – trends in the number of positive Salmonella results
• Data from the national resistance monitoring system (e.g. EFSA EARS-Net) – is the number of resistant strains increasing in your sector?
• Effectiveness of cleaning procedures – surface test results following disinfection
• Number of complaints and withdrawals – an indicator that something is changing in your process

Expert Tip: A simple spreadsheet tracking indicators on a monthly basis is sufficient to detect trends. An increase in positive Salmonella results or rising storage temperatures is a signal to act. This does not require an advanced IT system – discipline and consistency are enough.