Profile of Pathogenic Yersinia (e.g., Yersinia enterocolitica) 

General Information and Origin

Yersinia enterocolitica is one of the most common causes of foodborne gastrointestinal infections in Germany and the EU.
These bacteria are often found in pigs, particularly in the tonsils, lymph nodes, and intestines of pigs, but also in pets and our environment (soil, surface water).

Significance

The presence of Yersinia enterocolitica (or pathogenic Yersinia) in ready-to-eat foods is critical as they can potentially cause illnesses. In addition to typical symptoms of food infections such as diarrhea, abdominal pain, vomiting, and fever, chronic joint inflammations can also result from a yersiniosis in rare cases.
This disease is most commonly associated in Germany with the consumption of raw pork products (e.g., minced pork).
It should also be considered that some pathogenic Yersinia strains can still multiply at refrigeration temperatures of +4 °C.

Main Causes of Contaminations

• Poor slaughter hygiene
• Cross-contamination between raw and processed foods due to hygiene errors (e.g., personnel, work tools)
• Hygienic quality of raw materials
• Insufficient heating of food

Growth Conditions

• Temperature: Growth at -1.3 – 43 °C
• pH: Growth at 4.2 - 9.6
• aw-value: Growth up to min. 0.97
• Salt tolerance: max. 5%
• Oxygen requirement: Growth under aerobic and anaerobic conditions

At what temperatures do these microorganisms die?

Generally, it can be assumed that these bacteria are killed when heated to +72 °C for at least two minutes or by an equally effective process. In foods, it's important to note that this temperature-time combination must be reached in the core of the product to safely kill the bacteria.

Further Information and Literature

• www.rki.de: under "Infectious Diseases A-Z"
• www.bfr.bund.de: under "Food Safety"
• www.lgl.bayern.de: under "Food" and then "Hygiene"
• Pathogenic Microorganisms: Zoonoses, W. Heeschen (Behr's Verlag), 2nd edition 2012
• Food Microbiology, J. Krämer and A. Prange, 7th edition 2017
• Microorganisms in Food, H. Keweloh, 2nd edition 2008
• Manual of Food Hygiene, K. Fehlhaber/J. Kleer/F. Kley (Behrs Verlag), 1st edition 2007
• Leaflet "Safely Catered – Especially Vulnerable Groups in Community Facilities," Federal Institute for Risk Assessment, Berlin 2017

```html

Profile of Thermotolerant Campylobacter (especially Campylobacter jejuni)

General and Origin

Thermotolerant Campylobacter or Campylobacter jejuni are the most common causes of bacterial foodborne infections in Europe.

These bacteria are particularly widespread in poultry or poultry meat. But Campylobacter spp. also occurs regularly in other animal species such as cattle, sheep, and pigs.

Significance

Thermotolerant Campylobacter or Campylobacter jejuni is a frequent cause of foodborne infections. The main causes are the consumption of insufficiently heated poultry meat, the consumption of raw milk, and cross-contamination between raw and ready-to-eat foods.

The symptoms of campylobacteriosis include severe abdominal pain, watery-bloody diarrhea, vomiting, headaches, and fever.
Compared to other foodborne illnesses, such as salmonellosis, the course of campylobacteriosis is more prolonged and severe. In rare cases, complications can occur, especially diseases of the nervous system (Guillain-Barré syndrome).

Since the minimal infectious dose of Campylobacter jejuni is relatively low, even small numbers of germs can cause campylobacteriosis. It is not necessary for these germs to multiply in the food. Generally, they do not reproduce in the food, but they survive well at refrigerator temperatures and under protective atmospheres.

Main causes of contamination or illness

• insufficient heating of raw meat
• consumption of raw milk
• poor slaughter hygiene and contamination of animal raw materials (especially poultry meat)
• hygiene errors during production
• cross-contamination

Growth conditions

• Temperature: growth at 25 – 47 °C
• pH value: growth at 4.9 – 9.0
• aw value: growth down to min. 0.98
• Salt tolerance: 0.16 – 1.55%, but strongly influenced by temperature and pH value
• Oxygen requirement: microaerophilic, growth only under a reduced oxygen atmosphere

At what temperatures do these microorganisms die?

In general, it can be assumed that these bacteria are killed by heating to +72 °C for at least two minutes or by an equally effective process. In foods, it is important to ensure that this temperature-time combination is reached at the core of the product to safely kill the bacteria.

Further information

• www.rki.de: under "Infectious Diseases A-Z"
• www.bfr.bund.de: under "Food Safety"
• www.lgl.bayern.de: under "Food" and then "Hygiene"
• Pathogenic Microorganisms: Campylobacter Volume II, G. /F. Reich Behr's Verlag), 1st edition 2013
• Food Microbiology, J. Krämer and A. Prange, 7th edition 2017
• Microorganisms in Foods, H. Keweloh, 2nd edition 2008
• Handbook of Food Hygiene, K. Fehlhaber/J. Kleer/F. Kley (Behrs Verlag), 1st edition 2007
• Information Leaflet "Safely Catered - Particularly Vulnerable Groups in Community Facilities", Federal Institute for Risk Assessment, Berlin 2017

```

Profile of "sulfite-reducing Clostridia" and "Clostridium perfringens"

General Information

Clostridia are capable of forming heat-resistant forms, known as spores. These are very heat stable and can survive heating steps. Furthermore, these bacteria can multiply under the exclusion of oxygen (strict anaerobes) and some strains can produce very dangerous toxins.

Origin

These bacteria and their spores are primarily found in soil, water, and also in the intestinal tract of humans and animals. Due to their widespread distribution, both plant and animal foods can be contaminated with these bacteria.

Importance

Many representatives of the group of sulfite-reducing Clostridia play a role as spoilage agents in foods. Also, pathogens like Clostridium perfringens and Clostridium botulinum are found in this group of bacteria.

Clostridium perfringens is significant as a cause of group illnesses in the restaurant and communal catering industries. Surviving spores germinate in the food after the cooking process and subsequently multiply if insufficiently cooled. Their toxins are triggers of food poisoning.

To prevent excessive bacterial counts, it is important to ensure that the critical temperature range between 10 °C – 65 °C is passed through as quickly as possible (max. 3 hours). Frequently affected foods include, for example, larger pieces of meat, soups or sauces in larger containers, vacuum-packed fish products and other vacuum-packed foods, cooked sausages, and improperly sterilized canned goods. Similar applies for Clostridium botulinum, which can form very dangerous toxins (neurotoxins) that cause correspondingly severe to fatal diseases.

Important Causes of Elevated Clostridia Counts

• insufficient heating or sterilization of food, or temperatures that are too low when keeping warm (warming temperatures of, for example, at least +60 °C)
• inadequate curing or smoking, e.g., of ham or fish products
• insufficient cooling or too long storage duration
• use of contaminated raw materials
• too long of a cooling phase. The critical temperature range between 10 °C and 65 °C must be passed through as quickly as possible (usually max. 3 hours)

Growth Conditions

• Temperature: Growth at 12 – 50 °C
• pH Value: Growth at 5.0 – 8.0
• aw Value: Growth up to min. 0.94
• Oxygen Requirement: strictly anaerobic

At What Temperatures Do These Microorganisms Die?

In general, it can be assumed that these bacteria are killed by heating to +72 °C for at least two minutes or by an equally effective process. In foods, it is important to ensure that this temperature-time combination is achieved at the core of the product to safely kill the bacteria.

The C. perfringens enterotoxin is relatively heat-sensitive, with its biological activity destroyed at 60 °C within 5 minutes.

Further Information and Literature

• www.bfr.bund.de: under "Food Safety"
• www.lgl.bayern.de: under "Food" and then "Hygiene"
• Food Microbiology, J. Krämer and A. Prange, 7th Edition 2017
• Microorganisms in Foods, H. Keweloh, 2nd Edition 2008
• Handbook of Food Hygiene, K. Fehlhaber/J. Kleer/F. Kley (Behrs Verlag), 1st Edition 2007
• Pathogenic Microorganisms: Clostridium perfringens, U. Messelhäußer (Behrs Verlag), 1st Edition 2013
• Leaflet "Safely catered - Particularly vulnerable groups in community facilities", Federal Institute for Risk Assessment, Berlin 2017

Profile on “STEC / VTEC / EHEC”

General Information and Origin

Some strains of Escherichia coli, such as STEC (Shiga toxin-producing Escherichia coli), VTEC (Verotoxin-producing Escherichia coli), or EHEC (Enterohaemorrhagic Escherichia coli), can cause severe foodborne illnesses. In addition to the classic gastrointestinal symptoms of food infections and intoxications (vomiting, diarrhea, fever, …), diseases caused by EHEC strains can lead to HUS syndrome (hemolytic-uremic syndrome) resulting in kidney failure and death.

These dangerous bacteria often occur in the intestines of ruminants (especially cattle, but also, for example, sheep and goats). They can be transmitted to humans through food, as well as through direct contact, for example, in petting zoos.

Significance

The presence of these pathogenic Escherichia coli strains in ready-to-eat foods is undesirable and considered a potential health hazard. Since these infections can sometimes have severe, life-threatening consequences, including death, these pathogens are feared in food. Appropriate measures must be taken when viable STEC/VTEC is detected in ready-to-eat foods. Often, the cause of contamination with these microorganisms is fecal contamination, but due to their longer survival rate in the environment (e.g., in soil), different contamination causes must be considered situationally (see the paragraph below). In addition to raw animal products, these bacteria are also regularly detectable in raw plant foods. Affected foods include raw milk, raw beef, and raw milk cheese, as well as ready-to-eat sprouts and various mixed and leafy salads, and freshly squeezed fruit juices.

Important Causes for Elevated Bacterial Counts

• Fecal or cross-contamination during the slaughtering process
• Contamination of raw animal products, e.g., raw milk and plant-based foods
• Use of contaminated raw materials, e.g., in the production of raw milk soft cheese or mixed, ready-to-eat salads
• Hygiene errors: insufficient separation between raw and processed foods
• Lack of personal hygiene in carriers

Growth Conditions

• Temperature: Growth at 8 - 48 °C
• pH value: Growth to min. 4.0
• aw value: Growth to min. 0.95
• Oxygen requirement: facultatively anaerobic

At what temperatures do these microorganisms die?

In general, it can be assumed that these bacteria are killed at a heating temperature of +72 °C for at least two minutes or in an equally effective process. In food, it must be ensured that this temperature-time combination is reached in the core of the product to safely kill the bacteria.

Further Information and Literature

• www.rki.de: under “Infectious Diseases A-Z”
• www.lgl.bayern.de: under „Food“ and then “Hygiene”
• Food Microbiology, J. Krämer and A. Prange, 7th Edition 2017
• Microorganisms in Food, H. Keweloh, 2nd Edition 2008
• Leaflet “Safely Catered – Particularly Sensitive Groups in Community Facilities”, Federal Institute for Risk Assessment, Berlin 2017

Profile of "Salmonella"

General Information and Origin

As a cause of gastrointestinal diseases, Salmonella plays a significant role worldwide. Common carriers of Salmonella are primarily poultry and pigs, but also reptiles.

These bacteria are usually transmitted through raw animal products, especially poultry, eggs, and pork. However, spices like paprika and pepper as well as herbs can also be contaminated with Salmonella. In most other foods, Salmonella is rarely found.

Humans excrete Salmonella during illness, but possibly also long afterward through stool. These so-called "Salmonella shedders" must not be involved in the production and distribution of perishable foods, as inadequate personal hygiene can lead to transmission to food.

Significance

Despite a significant decline in reported cases for over 20 years, Salmonella remains one of the most common causes of foodborne illnesses. In foods, Salmonella is undesirable. Ready-to-eat foods contaminated with Salmonella are considered health-threatening as these pathogens are capable of causing severe gastrointestinal infections, which can have serious consequences, especially for young children, pregnant women, the elderly, or ill individuals.

Key Causes of Contamination

• Use of contaminated raw materials (e.g., eggs, meat, spices, ...)
• insufficient heating of food
• cross-contamination between raw and processed foods due to inadequate separation between clean and unclean areas or work steps (transmission through contaminated work items, tools, hands, ...)
• poor personal hygiene of Salmonella shedders

Growth Conditions

• Temperature: Growth at 7 - 50 °C
• pH value: Growth at 4.0 – 9.0
• aw value: Growth at min. 0.94
• Oxygen requirement: facultative anaerobic

At what temperatures do these microorganisms die?

Generally, it can be assumed that these bacteria are killed when heated to +72 °C for at least two minutes or by an equally effective process. In food, it must be noted that this temperature-time combination must be reached at the core of the product to safely kill the bacteria.

Further Information and Literature

• www.rki.de: under "Infectious Diseases A-Z"
• www.bfr.bund.de: under "Food Safety"
• www.lgl.bayern.de: under "Food" and then "Hygiene"
• Food Microbiology, J. Krämer and A. Prange, 7th edition 2017
• Microorganisms in Food, H. Keweloh, 2nd edition 2008
• Pathogenic Microorganisms: Zoonoses, W. Heeschen, 2nd edition 2012
• Handbook of Food Hygiene, K. Fehlhaber/J. Kleer/F. Kley (Behrs Verlag), 1st edition 2007
• Information sheet "Safely provided – Particularly sensitive groups in communal facilities", Federal Institute for Risk Assessment, Berlin 2017

Profile on “Staphylococcus aureus”

General Information and Origin

These bacteria are found in many healthy people on the mucous membranes of the nose and throat (e.g. also in nasal secretions, cough aerosols, and saliva), on the skin (especially the scalp and hair), and in stool.

However, these germs are also important food poisoning agents and, in addition to gastrointestinal diseases, cause skin and wound infections, abscesses, and urinary tract infections. Often, humans are the source of food contamination, but raw animal foods (e.g. raw milk) can also be contaminated with this pathogen.

Significance

Staphylococcus aureus can produce toxins in food, which cause severe intoxications (poisonings) in humans. Elevated bacterial counts of Staphylococcus aureus in food are therefore regarded as very critical and indicate poor sanitary conditions during production (especially personal hygiene).

An important characteristic of certain Staphylococcus aureus toxins is that they can be heat-stable and survive heating steps. Therefore, in addition to hygiene, attention must also be paid to adequate cooling temperatures to prevent the growth of the bacteria and their toxin production.

Important Causes of Elevated Bacterial Counts

• Hygiene errors during production (e.g. poor personal hygiene, contaminated work items, surfaces, and equipment, ...)
• Cross-contaminations between raw and processed foods
• Insufficient cooling
• Processing contaminated raw materials
• Inadequate heating of foods

Growth Conditions

• Temperature: Growth at 6.5 - 48 °C, Toxin formation at 10 - 45 °C
• pH value: Growth at 4.0 - 9.3, Toxin formation at min. 4.8
• aw value: Growth up to 0.86
• Salt tolerance: max. 20%
• Oxygen requirement: facultatively anaerobic; toxin production is significantly higher under aerobic growth than under anaerobic growth

At what temperatures do these microorganisms die?

In general, it can be assumed that these bacteria are killed when heated to +72 °C for at least two minutes or by an equally effective process. It should be noted that this temperature-time combination must be achieved in the core of the product to reliably kill the bacteria.

The toxins are very heat-stable and can only be inactivated at 100 °C after half to a full hour so that they no longer cause illness.

Further Information and Literature

• www.bfr.bund.de: under “Food Safety”
• www.lgl.bayern.de: under “Food” and then “Hygiene”
• Pathogenic microorganisms: Staphylococcus aureus, S. Johler/R. Stephan Behr’s Verlag, 1st edition 2010
• Food Microbiology, J. Krämer and A. Prange, 7th edition 2017
• Microorganisms in Food, H. Keweloh, 2nd edition 2008
• Handbook of Food Hygiene, K. Fehlhaber/J. Kleer/F. Kley (Behrs Verlag), 1st edition 2007
• Information leaflet “Safely Fed – Particularly Sensitive Groups in Community Facilities”, Federal Institute for Risk Assessment, Berlin 2017

Growth Conditions

• Temperature: Growth at 6.5 - 48 °C, Toxin formation at 10 - 45 °C
• pH value: Growth at 4.0 - 9.3, Toxin formation at min. 4.8
• aw value: Growth up to 0.86
• Salt tolerance: max. 20%
• Oxygen requirement: facultatively anaerobic; toxin production is significantly higher under aerobic growth than under anaerobic growth

At what temperatures do these microorganisms die?

In general, it can be assumed that these bacteria are killed when heated to +72 °C for at least two minutes or by an equally effective process. It should be noted that this temperature-time combination must be achieved in the core of the product to reliably kill the bacteria.

The toxins are very heat-stable and can only be inactivated at 100 °C after half to a full hour so that they no longer cause illness.

Further Information and Literature

• www.bfr.bund.de: under “Food Safety”
• www.lgl.bayern.de: under “Food” and then “Hygiene”
• Pathogenic microorganisms: Staphylococcus aureus, S. Johler/R. Stephan Behr’s Verlag, 1st edition 2010
• Food Microbiology, J. Krämer and A. Prange, 7th edition 2017
• Microorganisms in Food, H. Keweloh, 2nd edition 2008
• Handbook of Food Hygiene, K. Fehlhaber/J. Kleer/F. Kley (Behrs Verlag), 1st edition 2007
• Information leaflet “Safely Fed – Particularly Sensitive Groups in Community Facilities”, Federal Institute for Risk Assessment, Berlin 2017

Profile on "Mold"

General Information and Origin

Molds are widespread in our environment (soil, plants, air, water, humans...) and are therefore found in many foods.

In plant-based foods such as cereal products, nuts, herbs, spices, vegetables, and fruits, molds also regularly occur in excessive amounts. Dried animal-based foods such as raw cured products can also be affected by spoilage caused by molds.

Significance

Depending on the food group, a certain number of molds is tolerated in most foods. However, if these values are exceeded, it indicates potential spoilage of the food. Unlike most bacteria, many molds have the special ability to grow even at low moisture contents and/or low pH values.

Certain molds can also pose a health risk to consumers, as they can produce highly toxic mycotoxins (e.g., aflatoxins, ochratoxins, fusarium toxins, patulin, ...). Moldy raw and intermediate products should no longer be processed since the toxins are partially very resistant (e.g., heat-resistant) and can withstand processing.

Important Causes for an Excessive Number

• Processing of contaminated raw materials
• Improper storage (excessive humidity or temperatures, too long storage duration…)
• High number of molds in the ambient air (storage, production site)
• Inadequate production hygiene

Growth Conditions

• Temperature: Growth at 0 – 60 °C
• pH Value: Growth at 3.0 – 7.0
• aw Value: Growth up to min. 0.62 – 0.85
• Oxygen Requirement: Aerobic; under anaerobic conditions, some molds can ferment, but growth is generally inhibited after a short time

At What Temperatures Do These Microorganisms Die?

Generally, it can be assumed that most molds are killed when heated to +72 °C for at least two minutes or during an equally effective process. In foods, it is important to ensure that this temperature-time combination is reached at the product's core to safely kill the bacteria.

However, it should be noted that there are also highly heat-resistant strains among molds that can survive the aforementioned temperature-time combination.

Further Information and Literature

• www.lgl.bayern.de: under "Food" and then "Hygiene"
• Food Microbiology, J. Krämer and A. Prange, 7th Edition 2017
• Information Sheet "Safely Catered – Particularly Vulnerable Groups in Community Facilities", Federal Institute for Risk Assessment, Berlin 2017
• Microorganisms in Food, H. Keweloh, 2nd Edition 2008

Profile on "Pseudomonads"

General Information and Origin

Pseudomonads are widespread in our environment (soil, water, and on plants and animals). Therefore, they are also found in many food products such as fresh meat, fish, raw milk, as well as fruits and vegetables.

Importance

In foods with high water content such as fresh meat, fish, cream, chopped vegetables... Pseudomonads play an especially important role as potential spoilage organisms. Elevated counts of pseudomonads can have various causes (see below), but often errors in hygiene and/or storage are of crucial importance.

In dry and/or vacuum-packed foods, their significance as spoilage organisms is much less relevant because they require a lot of water and usually also oxygen to grow.

In water hygiene, Pseudomonas aeruginosa plays an important role as an indicator organism. The presence of Pseudomonas aeruginosa in drinking and mineral water, as well as in bathing water, is undesirable, as it indicates further contamination and biofilms on one hand, and on the other hand is a feared pathogen for, e.g., wound and urinary tract infections in medical facilities and hospitals.

Important Causes for Elevated Numbers

• Hygiene errors during production (e.g. contaminated work items, surfaces, and equipment, insufficient personal hygiene...)
• Processing of contaminated raw materials
• Cross-contamination between raw and processed foods
• Errors in storage (elevated temperatures, too long storage duration...)
• Insufficient heating of food

Growth Conditions

• Temperature: Growth at 0 - 41 °C
• pH-value: Growth at min. 5.0
• Water activity (aw-value): Growth down to min. 0.95
• Oxygen requirement: obligate aerobic

At what temperatures do these microorganisms die?

Generally, it can be assumed that these bacteria are killed when heated to +72 °C for at least two minutes or through any equally effective process. It should be noted in foods that this temperature-time combination must be reached at the core of the product to safely kill the bacteria.

Further Information and Literature

• www.lgl.bayern.de: under "Food" and then "Hygiene"
• Food Microbiology, J. Krämer and A. Prange, 7th edition 2017
• Microorganisms in Food, H. Keweloh, 2nd edition 2008
• Handbook of Food Hygiene, K. Fehlhaber/J. Kleer/F. Kley (Behrs Verlag), 1st edition 2007
• Information Leaflet "Safely Catered – Especially Vulnerable Groups in Community Institutions," Federal Institute for Risk Assessment, Berlin 2017