Profile on "Campylobacter" ("Thermotolerant Campylobacter")

General Information and Origin

Bacteria of the genus Campylobacter are heat-sensitive germs, some of which cause intestinal infections, usually with abdominal pain, vomiting, and diarrhea. Further complications are rare but can occur (e.g., infection of other organs and joint inflammation).

The most important pathogenic species for humans are C. jejuni and C. coli, with the minimum infectious dose ranging from 100 to 1,000 germs. These species belong to the thermotolerant Campylobacter. Transmission to humans mainly occurs through raw or undercooked poultry meat, poultry offal, and raw milk, but also through cross-contamination. The bacteria are found in the intestinal tract of numerous animals (warm-blooded wild, farm, and domestic animals).

Importance

Due to the heat sensitivity of these bacteria, effective killing is assured by heating steps of at least +72 °C for a minimum of 2 minutes. They can survive in vacuum packs or under a protective atmosphere and at chilling temperatures for several weeks. In food, reproduction typically does not occur. However, this is not a condition to pose a health hazard, as even low germ counts can cause illness.

Campylobacter gastroenteritis has been the most common cause of bacterial food infections in Germany and many other European countries for years.

Important Causes of Elevated Germ Counts

• Insufficient heating of food
• Cross-contamination between raw and processed foods
• Hygiene errors during manufacture (e.g., contaminated work tools, surfaces, and equipment,...)
• Processing of contaminated raw materials (particularly poultry meat is relatively frequently contaminated)
• Contamination of vegetables and other plant-based foods through fertilizers or contaminated water

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?

Generally, 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 food, it should 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.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 Publishing, 1st Edition 2013
• 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 Publishing), 1st Edition 2007
• Information Sheet "Safely Catered - Particularly Sensitive Population Groups in Community Facilities", Federal Institute for Risk Assessment, Berlin 2017

Profile on "Enterobacteria"

General Information

Most enterobacteria (Enterobacteriaceae) are widespread in our environment and are considered general hygiene indicator organisms in many foods. Furthermore, their presence in large numbers can lead to spoilage in food. However, within this family of bacteria, there are also important pathogens such as Salmonella, Yersinia enterocolitica, Shigella, and pathogenic Escherichia coli strains. Therefore, this family of bacteria plays a very important role in food hygiene.

Origin

Many representatives of enterobacteria are regularly detected in soil, water, and on plants. Moreover, these bacteria are found in the intestines of humans and animals. Overall, enterobacteria are widely distributed in our environment.

Significance

Due to the wide distribution of this family of bacteria in our environment, a certain number of enterobacteria is tolerated depending on the food. However, certain values should not be exceeded, as elevated levels of enterobacteria indicate manufacturing errors. Such cases are usually referred to as hygiene errors, but the causes can be diverse depending on the food (see following paragraph).

Elevated numbers can lead to sensory deviations and, in the case of official samples, to objections. Although there are pathogens such as Salmonella among the Enterobacteriaceae, in most foods elevated levels of enterobacteria do not indicate a health risk for the consumer.

Important Causes of Elevated Numbers

• Hygiene errors during production (e.g., contaminated work items, surfaces, and equipment, inadequate personal hygiene,...)
• Microbially contaminated raw materials
• Cross-contamination between raw and processed foods
• Insufficient refrigeration and/or prolonged storage of foods (exceeding the shelf life)
• Inadequate heating of the food

Growth Conditions

• Temperature: Growth at min. 0 °C
• pH value: Growth at min. 4.4
• aw value: Growth up 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 when heated to +72 °C for at least two minutes or through an equivalent process. In foods, it is important to ensure that this temperature-time combination is reached in the core of the product to effectively kill the bacteria.

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
• Information sheet "Safely Catered - Particularly Vulnerable Groups in Community Facilities", Federal Institute for Risk Assessment, Berlin 2017

Profile "Listeria monocytogenes"

General Information and Origin

Listeria monocytogenes is increasingly playing an important role as a pathogen because the reported number of cases is continuously rising.

Although Listeria are primarily soil dwellers, these bacteria are widespread in the environment. Listeria can be found on plants, in sewage, and in the feces of healthy and diseased animals. Due to their widespread nature, Listeria are regularly found in raw animal and plant-based foods (e.g., meat, poultry, milk, vegetables, fish, and seafood). However, they also play a significant role in processed foods (e.g., meat and sausage products, smoked fish products, mixed salads).

Despite comprehensive hygiene measures in food operations, they can establish themselves in certain ecological niches and persist there. They are often found in moist areas in slimy coatings or biofilms.

Significance

These bacteria can cause very severe illnesses, especially in pregnant women, infants, elderly, and sick individuals. The proportion of deaths that occur in these individuals is relatively high.

Such cases can be avoided by sufficient heating of food and comprehensive hygiene during production. However, it should be noted that Listeria monocytogenes can still multiply at refrigerator temperatures. Short storage times and low temperatures < +2 °C are necessary to prevent the growth of these bacteria.

Important Causes of Elevated Germ Counts

• Hygiene errors during production (e.g., contaminated work tools, surfaces, and equipment) and biofilm formation in hard-to-reach areas
• Cross-contamination between raw and processed foods
• Processing of contaminated raw materials
• Insufficient cooling and/or overstocking of foods
• Inadequate heating of food

Growth Conditions

• Temperature: Growth at 0 - 45 °C
• pH: Growth at 4.5 - 9.0
• aw-value: Growth down to min. 0.93
• Salt tolerance: max. 10%
• Oxygen requirement: facultative anaerobic, reproduction in vacuum packaging and modified atmosphere packaging possible

At what temperatures do these microorganisms die?

Generally, 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 should be noted that this temperature-time combination must be reached in the core of the product to reliably 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
• Handbook of Food Hygiene, K. Fehlhaber/J. Kleer/F. Kley (Behrs Verlag), 1st edition 2007

Gluten is a naturally occurring protein mixture found in many cereals. For people with gluten intolerance, consumption can have harmful health effects. Information about the absence or reduced presence of gluten in food is regulated by Implementing Regulation (EU) No 828/2014. Gluten and cereals containing gluten are also mandatory declaration substances according to Annex II of Regulation (EC) No 1169/2011 (allergen labeling).

Profile of “aerobic mesophilic colony count”

General Information

The aerobic mesophilic colony count is often referred to as the "total colony count." It provides information about the number of microorganisms (bacteria, yeasts, and molds) that optimally multiply under aerobic conditions in a temperature range between 30 °C and 40 °C.

Origin

Since the aerobic mesophilic colony count includes a large number of microorganisms (such as Enterobacteriaceae, Pseudomonads, Bacillus, Staphylococci, Listeria, yeasts, and molds…), this parameter cannot be attributed to a specific origin. They can be found virtually everywhere: e.g., raw materials, humans, animals, plants, soil, water, air, as well as work surfaces and equipment.

Significance

Aerobic mesophilic microorganisms are found in or on almost all foods (an exception is sterilized foods like canned goods). Depending on the product, a certain number of aerobic mesophilic microorganisms is normal and unavoidable. However, if these values are exceeded, it indicates errors.

An elevated aerobic mesophilic colony count is often regarded as an indicator of hygiene and/or spoilage. Depending on the food and colony count, elevated counts can lead to sensory deviations and objections.

Important causes for elevated counts

• Hygiene errors during production (e.g., contaminated work items, surfaces, and equipment, inadequate personal hygiene…)
• Cross-contamination between raw and processed foods
• Microbially contaminated raw materials
• Insufficient cooling and/or prolonged storage of foods (exceeding the shelf life)
• Insufficient heating of foods or too low and prolonged holding temperatures

At what temperatures do these microorganisms die?

In general, it can be assumed that most bacteria are killed when heated 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.

However, bacterial spores are particularly heat-resistant and can survive these temperatures. Relevant bacteria in foods that form spores include Bacillus cereus, Clostridium perfringens, and Clostridium botulinum.

Further Information and Literature

• www.lgl.bayern.de: under "Food" and then "Hygiene"
• Leaflet “Safely catered – Particularly sensitive groups of people in communal facilities”, Federal Institute for Risk Assessment, Berlin 2017
• Food Microbiology, J. Krämer and A. Prange, 7th Edition 2017
• Microorganisms in Foods, H. Keweloh, 2nd Edition 2008

Fact sheet on "Yeasts"

General Information and Origin

Yeasts are widespread in our environment (plants, humans, soil, air...) and therefore are part of the "normal" microflora in many foods. Plant-based foods such as fruits, as well as other foods with low water content and/or low pH, are particularly at risk of spoilage by yeasts.

Yeasts are also intentionally used in the production of several foodstuffs. These include, for example, alcoholic beverages and baked goods.

Significance

A certain number of yeasts is tolerated in most food groups. However, if these levels are exceeded, it indicates hygiene deficiencies as well as possible premature spoilage of the food (exceptions are foods in which culture yeasts are deliberately used during production).

Yeasts can grow even in the absence of oxygen, producing ethanol. Unlike most bacteria, yeasts have the special ability to grow at low water contents and/or low pH-values.

Particularly in foods with a lowered pH, such as delicatessen products, cheeses and cheese products, and fruit juices, as well as foods with low water content such as fruit concentrates, yeasts are feared spoilage agents as they can lead to sensory changes.

Key Causes for Excessive Numbers

• Hygiene errors during production (e.g., contaminated work tools, surfaces, and equipment, inadequate personal hygiene,...)
• Processing of contaminated raw materials
• Cross-contamination between raw and processed foods
• Errors in storage (excessive temperatures, too long storage duration...)
• High number of yeasts in ambient air
• Insufficient heating of food

Growth Conditions

• Temperature: Growth at 0 - 40°C
• pH: Growth at 1.5 – 8.5
• aw-value: Growth down to min. 0.80
• Oxygen Requirement: Facultatively anaerobic

At what temperatures do these microorganisms die?

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

Further Information and Literature

• www.lgl.bayern.de: under "Food" and then "Hygiene"
• Pathogenic Microorganisms: Yeasts, B. Fiedler (Behr’s Verlag), 2nd edition 2014
• Food Microbiology, J. Krämer and A. Prange, 7th edition 2017
• Microorganisms in Foods, H. Keweloh, 1st edition 2009
• Leaflet "Safely Catered – Particularly Sensitive Population Groups in Community Facilities", German Federal Institute for Risk Assessment, Berlin 2017

Profile on “Hepatitis A”

General Information and Origin

An infection with the worldwide prevalent Hepatitis A virus (HAV) is associated with abdominal, joint, and limb pain, flu-like symptoms, vomiting, nausea, and acute liver inflammation (jaundice). In countries with low hygiene standards, the infection rate is already very high in childhood. In Europe and North America, Hepatitis A infections are now mainly travel-associated, which has led to a continuous decline in the frequency of infections in recent decades.

Importance

Humans are the main host and probably the only reservoir of Hepatitis A viruses. These are excreted with the stool 1 to 2 weeks before the onset of illness and are transmitted through direct contact or smear infections.

The viruses can also be transmitted through the consumption of contaminated food (e.g., shellfish, but also vegetables, salads, or fruits due to fertilization with feces or irrigation with fecally contaminated water) or contaminated (bathing) water. A characteristic of the virus is its high resistance to disinfectants, environmental influences, and heat. However, the number of foodborne Hepatitis A infections in Germany is very low and predominantly travel-associated.

Important Causes of Elevated Germ Counts

• Contamination of food by carriers
• Contamination of vegetables and other plant-based foods by fertilizers or irrigation with fecally contaminated water
• Processing of contaminated raw materials
• Contamination through contaminated drinking water

Growth Conditions

• Viruses can only multiply in living host cells
• Viruses can survive for several days in food and drinking water, but cannot multiply
• Viruses can remain infectious for extended periods at refrigerator and freezing temperatures (-18 °C)
• Susceptible to low pH values, drying, and heating

At What Temperatures Do These Microorganisms Die?

Heating to over 80 °C appears to be sufficient to inactivate even higher concentrations of the viruses within one minute. However, the information in the literature is not consistent, and further research is needed.

Further Information and Literature

• www.rki.de: under “Infectious Diseases A-Z”
• www.bfr.bund.de: under “Food Safety”
• Food Microbiology, J. Krämer and A. Prange, 7th Edition 2017
• Microorganisms in Food, H. Keweloh, 2nd Edition 2008

Fact Sheet on Legionella in Drinking Water

General Information and Origin

Legionella are environmental germs found worldwide. Naturally, they occur in small quantities in surface water and groundwater.

Especially in artificial water systems (e.g., water pipes in buildings), the pathogens find favorable growth conditions at certain temperatures. The multiplication of Legionella mainly occurs in sediments and deposits of the pipe system (biofilms). The presence of Legionella in artificial water systems is primarily influenced by the water temperature and the water's residence time. Especially poorly designed and inadequately maintained water systems are regularly affected by Legionella infestation.

Significance

Legionella cause various diseases in humans, such as flu-like symptoms or severe pneumonia, which can be fatal.

Legionellosis is primarily caused by inhaling atomized or aerosolized water. The pathogens spread through water droplets in the air and can thus be inhaled. Infection usually occurs through showers, whirlpools, humidifiers, faucets, or air conditioning systems. Human-to-human transmission is not possible.

Legal Regulations for Drinking Water

The Drinking Water Ordinance (TrinkwV 2001) prescribes regular testing for Legionella. This affects entrepreneurs and owners of drinking water installations with large systems for drinking water heating, if the water is commercially and/or publicly dispensed and there is also atomization of the water.

A large system refers to a storage drinking water heater or a central flow-through drinking water heater with a content of more than 400 liters or a content of more than three liters in at least one pipeline between the outlet of the drinking water heater and the withdrawal point.

The public dispensing concerns, for example, hospitals, schools, kindergartens, hotels, and nursing homes. These facilities are required to test for Legionella once a year. Likewise, owners/landlords of multi-family houses, housing associations, and property management companies are affected. For these, the required testing interval is three years.

The Drinking Water Ordinance stipulates a technical measure value of 100 colony-forming units (CFU) per 100 ml for Legionella. If this value is exceeded, it must be reported to the responsible health department.

If a company is not legally required to test for Legionella, an examination is still recommended as part of due diligence, especially if showers are present or there is contact with atomized or aerosolized water in other ways.

Important Causes for Elevated Germ Numbers

• Irregular use of water pipes
• Dead ends in the pipe system
• Insufficient regulator temperature on the drinking water heater
• Insufficient water temperatures in the pipe system

Growth Conditions

The optimal growth temperature for Legionella is between 25 - 45 °C.

At what temperatures do these microorganisms die?

At water temperatures above 55 °C, Legionella growth is inhibited. Above 60 °C, Legionella are generally killed.

To protect against Legionella infestation, the water should leave the hot water storage tank at a minimum of 60 °C and return to the storage tank at a minimum of 55 °C. The maximum temperature drop in the pipe system should not exceed five degrees. Water should also not stagnate in the pipes for more than 72 hours.

Further Information and Literature

• www.rki.de: under "Infectious Diseases A-Z"
• UBA recommendation "Systematic Testing of Drinking Water Installations for Legionella According to Drinking Water Ordinance - Sampling, Investigation Procedure, and Indication of Results" from December 18, 2018
• Drinking Water Ordinance - TrinkwV 2001
• www.umweltbundesamt.de under Topics: Drinking Water

Fact Sheet on "Norovirus"

General Information and Origin

Noroviruses are widespread worldwide. They belong to the group of caliciviruses, which are responsible for a large portion of non-bacterial infectious gastrointestinal inflammations. The disease characteristically manifests with projectile vomiting, nausea, diarrhea, and occasionally stomach cramps and predominantly outbreaks seasonally in the winter months.

Significance

The source of infection for noroviruses is often human feces or vomit. Transmission often occurs through contact, smear, or droplet infection, but also through the air via aerosols. Consumption of contaminated food (e.g., shellfish, but also vegetables, salad, or fruit due to fertilization with feces or irrigation with fecal-contaminated water) can also be a cause of illnesses. Due to the high virus concentration in feces or vomit and the very low minimum infectious dose, outbreaks result in a high infection rate.

Noroviruses, alongside rotaviruses, are considered the most common cause of viral gastroenteritis. They are often the cause of outbreaks of illness in communal facilities such as nursing homes, hospitals, and cruise ships, due to their high resistance to disinfectants, environmental influences, and heat. The consequence of an illness can be a significant disruption of the electrolyte and water balance, which can cause complications particularly in young children or older patients.

Important Causes for Increased Bacteria Counts

• Contamination by carriers
• Contamination of vegetables and other plant-based foods by fertilizers or contaminated water
• Processing of contaminated raw materials
• Contamination by polluted drinking water
• Contaminated surfaces

Growth Conditions

• Viruses can only reproduce in living host cells
• Viruses can survive for several days in food and drinking water, but cannot reproduce
• Viruses can remain infectious at refrigerator and freezing temperatures (-18 °C) for a longer period of time
• Susceptible to low pH values, drying out, and heating

At What Temperatures Do These Microorganisms Die?

Heating to over 80 °C apparently is sufficient to inactivate higher concentrations of the viruses within one minute. However, the literature does not uniformly agree on this and further research is needed.

Further Information and Literature

• www.rki.de: under "Infectious Diseases A-Z"
• www.bfr.bund.de: under "Food Safety"
• Pathogenic Microorganisms: Food-Associated Viruses – Norovirus, B. Becker/J. Pfannebecker (Behr's Verlag), 1st edition 2016
• Food Microbiology, J. Krämer and A. Prange, 7th edition 2017
• Microorganisms in Food, H. Keweloh, 2nd edition 2008

Profile of "Presumptive Bacillus cereus"

General Information

Presumptive Bacillus cereus are capable of forming heat-resistant forms, known as spores. These are very heat-stable and can withstand heating processes. Furthermore, these bacteria are sometimes able to produce heat-stable toxins that are very resistant and can cause poisoning with vomiting and/or diarrhea.

Origin

These bacteria or their spores are widespread in our environment. They are found in soil, dust, water, animals, and humans. Therefore, practically all raw plant and animal foods can be contaminated with this germ.

Significance

Spores often germinate in food after the cooking process and multiply there if cooling is inadequate. To prevent excessive germ counts, it is therefore important that the critical temperature range between 10°C - 65°C is passed through as quickly as possible.

Particular caution is advised when cooling large portions! Foods that play an especially important role in this disease are cooked rice, pasta, sauces, spices, dairy products, salads/vegetables, herbs, and desserts.

A special significance is attributed to these bacteria as the cause of group diseases in communal catering. Therefore, these bacteria play a significant role as food poisoners in communal catering and gastronomy.

Important Causes of Excessive Germ Counts

• too low temperatures when keeping warm (generally, warming temperatures of > +60°C are required)
• cooling phase too long. The critical temperature range between 10°C and 65°C must be passed through as quickly as possible (generally max. 3 h)
• insufficient cooling and/or overstocking of foods (exceeding the shelf life)
• microbially contaminated raw materials e.g., herbs, spices,…

Growth Conditions

• Temperature: Growth at 4 - 50°C, toxin production at 37 - 42°C
• pH-value: Growth at 4.3 – 10.5, toxin production up to max. 10.0
• aw-value: Growth up to min. 0.92 – 0.95
• Salt tolerance: 0.5 – 9 %
• Oxygen requirement: facultative anaerobic, preferably aerobic

At What Temperatures Do These Microorganisms Die?

In general, it can be assumed that the vegetative 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 in the core of the product to safely kill the bacteria.

However, foods often also contain spores of these bacteria. These are usually very heat-resistant and even survive cooking processes.

Further Information and Literature

• www.bfr.bund.de: under "Food Safety"
• www.lgl.bayern.de: under "Food" and then "Hygiene"
• Pathogenic Microorganisms: Bacillus cereus, B. Becker (Behr’s Verlag), 1st Edition 2005
• 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 Sheet "Safely Catered - Particularly Vulnerable Groups in Community Facilities", Federal Institute for Risk Assessment, Berlin 2017

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

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 "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 “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 “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 "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

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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

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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