Recommendations include e.g. mozzarella, brined cheese, raw meat, meat products, casings, fish and fish products, soft and shellfish, instant and dried products, ready meals, prepared dishes, delicatessen products, cereal products, bread, bakery and pastry goods, pasta, dried fruits, oilseeds, nuts, mixed salads, fruit salads, herbs and spices, ice cream and chocolate.

Microbiological criteria are included in several chapters of the Ph.Eur. Chapter 5.1.4 contains the acceptance criteria for non-sterile dosage forms (Table 1) as well as for raw materials used in their production (Table 2). Chapter 5.1.8 contains the acceptance criteria for herbal medicinal products for oral use.

Furthermore, many monographs of individual substances include specific acceptance criteria for microbiological quality.

Frequent detections occur, for example, in raw milk, fresh meat, spreadable raw sausage, soft cheese, leafy vegetables, and sprouts. Meat from ruminants and game is more frequently contaminated than pork.

Commonly contaminated are, for example, raw milk, raw milk cheese, semi-hard cheese, ready-to-eat sausages, pre-sliced cooked sausages, spreadable raw sausages, sliced packaged fruits or salads (ready-to-eat products), raw seafood, or smoked fish.

The detection of germs in a cosmetic product always requires special attention. Contaminated raw materials, deficiencies in manufacturing, or even contamination of packaging materials can be causes.

Regardless of the detected quantity, identification should always be carried out. Only in this way can a risk assessment be conducted based on the number of microorganisms combined with the type of germ (risk group, hazard potential). This allows the question of the product's marketability to be answered.

Additionally, within the framework of a microbiological risk management system, one obtains information about possible sources of entry with the aim of avoiding similar contaminations in the future.

The purpose of the preservation challenge test is to confirm that the cosmetic product, when used as intended, prevents microbial growth and is thus microbiologically stable. However, it should be noted that preservation challenge tests are merely models and do not guarantee 100% safety.
The execution of a preservation challenge test is required by the EU Cosmetics Regulation as part of the safety assessment (see Annex I, Point 3 of the Regulation).
Exempt from the requirement to conduct a preservation challenge test are products that meet one or more of the following conditions.

• pH value: <3
• pH value: >10
• water-free products
• alcohol content: >20%
• filling temperature: >65°C
• water activity: <0.75
• solvent-based products
• oxidizing products
• aluminum chlorohydrate content: >25%

Other low-risk products may be identified as part of an individual risk assessment.

Certain toxin-producing strains of E.coli can cause diarrhea and more severe illnesses in humans, such as hemolytic uremic syndrome (HUS). Kidney failure and even death can result from this condition.

Listeria monocytogenes can easily overcome anatomical barriers in the body and, for example, penetrate the intestines, the blood-brain barrier, or the placenta without any problems.

For those affected by listeriosis, the disease is associated with a comparatively higher damage than with other foodborne infection pathogens (e.g., fever, muscle pain, gastrointestinal diseases, meningitis, sepsis). The mortality rate is about 10-20% for the general population and up to 75% for risk groups (pregnant women, newborns, young children, immunocompromised adults, those taking immunosuppressants or stomach acid inhibitors).

Since no minimum infectious dose can be determined for Salmonella, the absence of Salmonella is required in ready-to-eat foods. As a food safety criterion according to Annex I Chapter 1 of Regulation (EC) No. 2073/2005, the absence of Salmonella in 25g (or 10g) of food is always required. A quantitative determination is therefore not sufficiently informative for the microbiological assessment of foods.

The Regulation (EC) No. 2073/2005 on microbiological criteria for foodstuffs establishes sampling frequencies and microbiological limits (process hygiene and food safety criteria). It is directed at food business operators and sets the legal minimum requirements for the microbiological quality of certain foods. These include, for example, ready-to-eat meals, carcasses, meat preparations, milk and dairy products, egg products, and cut fruit and vegetables.

The requirements for microbially low-risk products are described in the standard ISO 29621 "Guidelines for the risk assessment and identification of microbiologically low-risk products". 

These are products that, due to their physicochemical properties, inhibit the growth of microorganisms or kill them.
These are products that meet one or more of the following requirements.

• pH-value: <3
• pH-value: >10
• anhydrous products
• alcohol content: >20%
• filling temperature: >65°C
• water activity: <0.75
• solvent-based products
• oxidizing products
• aluminum chlorohydrate content: >25%

Other low-risk products can be identified as part of an individual risk assessment.
For microbiologically low-risk products, a preservative efficacy test is not necessary as part of the safety assessment.

Biofilms are communities of bacteria, fungi, protozoa, or algae that attach to surfaces in aqueous systems, grow there, and form a slime layer. This layer usually consists of polysaccharides and protects the underlying microorganisms from influences such as disinfectants or high temperatures.

If you would like to learn more about biofilms, we recommend the following interesting information sources:

Fraunhofer Institute

Biospektrum.de

Wikipedia

The German Society for Hygiene and Microbiology (DGHM e.V.) publishes microbiological reference and warning values, which provide an objective basis for businesses and authorities to assess the microbiological-hygienic status of a food product or a food group. DGHM recommendations exist for selected food groups. They are available for a fee at www.dghm-richt-warnwerte.de.

The two variants of the preservative efficacy test differ in some aspects of the methods and assessment criteria. For implementation according to ISO 11930, the following applies:

• the microbial status of the product must be checked before implementation
• Escherichia coli is required as an additional test organism
• a different nutrient medium (Potato Dextrose Agar) is prescribed for Aspergillus brasiliensis
• the procedures for preparing the microorganism cultures are newly regulated
• there are no requirements for microbial reduction after 2 days
• there are different requirements for the yeast Candida albicans and the mold Aspergillus brasiliensis
• a margin of 0.5 log levels is permissible to account for measurement uncertainty
• Criterion A and B no longer have the same significance

Further information on the two types of challenge tests can be found in the BAV Newsletter Cosmetics Part 3 (available at https://www.bav-institut.de/files/newsletters/Sondernewsletter-Kosmetik-Teil-3-in-2013.pdf ).

The European Pharmacopoeia specifies in the chapters describing the microbiological methods (2.6.12, 2.6.13, and 2.6.31) that the suitability of the test method for detecting microorganisms in the presence of the product must be demonstrated. This proof must be reconfirmed for all changes to the method or the product.

For this purpose, the product is inoculated with suspensions of the organisms mentioned in the aforementioned chapters, treated further as described there, and incubated on the mentioned media under the specified conditions.

In quantitative methods, the number for each reference microorganism may deviate by a maximum factor of 2 from the reference value, which was determined using the same methods in the absence of the product.

In qualitative methods, the growth of the reference microorganisms must be detectable as the result of the test in the absence of the product.

If the suitability of the method cannot be demonstrated using standard procedures, the method must be appropriately adjusted (for example, by higher product dilutions or by using a different diluent or other neutralizing substances).

In the European Pharmacopoeia (Ph. Eur.), the monograph 2153 defines excipient-free pellets for homeopathic preparations as solid preparations made from sucrose, lactose, or other suitable excipients. 

These excipient-free pellets form the basis for the well-known globules. The Ph. Eur. distinguishes between two different types of globules:

• Impregnated homeopathic pellets (Globules – Granula homoeopathica imbuta) Ph. Eur. Monograph 2079
• Coated homeopathic pellets (Globuli velati – Granula homoeopathica velata) Ph. Eur. Monograph 2786

The impregnated homeopathic pellets are the excipient-free variant, which are impregnated with one or more liquid homeopathic preparations.

In contrast, the excipient-free pellets in coated homeopathic globules are coated with a sucrose syrup in which the homeopathic preparations are contained (dissolved). Independently, other triturations (for example, mineral active substances triturated with milk sugar) can also be incorporated.

Both groups are common in that they are intended for sublingual or oral use. Even though the water activity of the two product groups is likely to be very low (low water content, high sugar content), the Ph. Eur. requires a microbiological quality control for globules. The acceptance criteria are identical for the excipient-free pellets and both variants of globules.

The following acceptance criteria are required in the respective monographs:

• Total aerobic microbial count (according to Ph. Eur. 2.6.12): 102 CFU/g
• Total yeast and mold count: (according to Ph. Eur. 2.6.12): 101 CFU/g
• Pseudomonas aeruginosa (according to Ph. Eur. 2.6.13): Absent
• Staphylococcus aureus (according to Ph. Eur. 2.6.13): Absent

In order to comply with the Ph. Eur. requirements, globules also require microbiological testing. As a microbiological laboratory specializing in the testing of pharmaceuticals, the BAV Institute can gladly assist you with this.

In the European Pharmacopoeia (Ph.Eur.), the monograph 2153 defines excipient pellets for homeopathic preparations as solid preparations made from sucrose, lactose, or other suitable excipients.

These excipient pellets form the basis for the well-known globules. The Ph. Eur distinguishes between two different types of globules:

• Impregnated homeopathic pellets (Globuli – Granula homoeopathica imbuta) Ph.Eur. Monograph 2079
• Coated homeopathic pellets (Globuli velati – Granula homoeopathica velata) Ph.Eur. Monograph 2786

Impregnated homeopathic pellets are excipient variants impregnated with one or more liquid homeopathic preparations.

In contrast, the excipient pellets for coated homeopathic pellets are covered with a sucrose syrup in which the homeopathic preparations are contained (dissolved). Independently, other triturations (for example, mineral-effective substances with lactose powdered) can also be incorporated.

Both groups are intended for sublingual or oral use. Even though the water activity of both product groups is likely to be very low (low water content, high sugar content), the Ph.Eur. provides for a microbiological purity test for globules. The acceptance criteria are identical for the excipient pellets as well as for the two variants of globules.

The following acceptance criteria are required in the respective monographs.

• Total aerobic microbial count (according to Ph.Eur. 2.6.12): 102 CFU/g
• Total yeast and mold count (according to Ph.Eur. 2.6.12): 101 CFU/g
• Pseudomonas aeruginosa (according to Ph.Eur. 2.6.13): Absent
• Staphylococcus aureus (according to Ph.Eur. 2.6.13): Absent

Therefore, to comply with the Ph.Eur. requirements, globules also need a microbiological test. As a microbiological laboratory specialized in the testing of pharmaceuticals, the BAV Institute would be pleased to support you.

Annex I Chapter 1 of Regulation (EC) No. 2073/2005 sets criteria for pathogenic microorganisms that must not be exceeded. These criteria apply to products on the market, not at the manufacturing level.

The regulation focuses only on certain food groups.
Criteria exist for the following parameters:

• Listeria monocytogenes
• Salmonella
• Staphylococcal enterotoxin
• Cronobacter spp.
• E.coli
• STEC
• Histamine

Annex I Chapter 2 of Regulation (EC) No 2073/2005 establishes criteria to verify the implementation of good hygiene practices and the application of the principles of the HACCP concept. These criteria do not apply to products already on the market but exclusively at the manufacturer level.

Criteria are set for the following food categories:

• Carcasses
• Minced meat
• Mechanically separated meat
• Meat preparations
• Milk and dairy products
• Egg products
• Fishery products
• Vegetables, fruits, and products made from them

Zoogenic pathogens can cause diseases or infections that can be transmitted from animals to humans through direct or indirect contact as well as through food. These include various bacteria, viruses, fungi, and parasites. In Germany, the following pathogens are relevant, among others:
Salmonella, Campylobacter, verotoxin-producing E. coli (STEC/VTEC/EHEC), Yersinia enterocolitica, Listeria monocytogenes, methicillin-resistant Staphylococcus aureus (MRSA), rabies, Trichinella, toxoplasmosis.

Profile of "Acetic Acid Bacteria"

General Information and Origin

• also called Acetobacteriaceae
• gram-negative rods
• oxidize ethanol to acetic acid
• tolerate low pH values
• found in foods containing sugar
• in plant raw materials (e.g., fruits)

Importance in the Cosmetics and Pharmaceutical Sector

Acetic acid bacteria lead to microbial spoilage of the product through their breakdown of ethanol to acetic acid. This usually results in less health impairment and more sensory changes. The product becomes more acidic due to the formed acetic acid, and the smell changes towards acetic acid. In the food sector, acetic acid bacteria are typical spoilage organisms that are very frequently found.

Important Causes of Contamination

Causes are often the use of raw materials contaminated with acetic acid bacteria. Another possibility is introduction from the environment, as they can be easily transported through the air from contaminated areas. However, acetic acid bacteria can also indicate weaknesses in operational hygiene. For example, they can grow in product residues in pipelines and can be flushed out at various times, contaminating further or later products.

Important Measures

One of the most important measures to prevent contamination of cosmetics with acetic acid bacteria is the appropriate selection and examination of the raw materials used. Since acetic acid bacteria grow particularly well in acidic conditions, reducing pH levels is not a suitable method of control. In contrast, thermal treatment is possible, as the microorganisms are relatively sensitive to temperature. Literature reports a decimal reduction time of 0.09 – 0.14 minutes at 60°C and 1.20 - 1.30 minutes at 54°C [1].

Examination for Acetic Acid Bacteria

To determine acetic acid bacteria, determining the total microbial count using CASO medium is often not sufficient, as they do not grow well on this universal medium. They are often found in routine testing on the medium used for yeast and mold determination, as it has a lower pH value and the incubation time is longer (acetic acid bacteria only form very small colonies that grow very slowly). If acetic acid bacteria are suspected, a targeted examination for this type of microorganism is suggested. For this, orange-fruit juice agar is used as a nutrient medium based on a method derived from the food sector.

Bibliography

[1] G. Rachon, C.J. Rice, K. Pawlowsky, C.P. Raleigh: Challenging the assumptions around the pasteurization requirements of beer spoilage bacteria, J. Inst. Brew. 2018

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

Escherichia coli

General Information and Origin

• belongs to the family of Enterobacteriaceae

• gram-negative, acid-forming, flagellated rods

• part of the natural intestinal flora of humans and animals

• there, producer of vitamins and part of the immune defense

• some species pathogenic toxin producers

Significance in the Cosmetic and Pharmaceutical Industry

Escherichia coli (E. coli) is one of the most well-researched microorganisms and holds significant importance in the food industry, in addition to cosmetics. It is considered a model organism for the entire family of Enterobacteriaceae. Although detection in cosmetic settings is extremely rare, its absence in 1g of product is required by DIN EN ISO 17516 (microbiological limits for cosmetic products). It serves here as an indicator for hygiene-related contamination. In preservation stress tests for cosmetics, E. coli is included as one of a total of five test organisms and as a representative of enterobacteria.

In the pharmaceutical industry, it is a lead germ for all products for oral use, whose exclusion is required in non-plant products. However, even in plant-based products, which usually have quite high microbiological limits, E. coli is relatively strictly regulated.

Important Causes of Contamination

The microorganism is multifaceted, and so are the causes for product contamination. As a natural inhabitant of plants, a possible entry path is the use of non-sterile raw materials. At the same time, as a typical intestinal resident, it can also be an indicator of poor hygiene. In this case, production water or humans are often cited as the cause.

Important Preventive Measures

The occurrence of these bacteria can be significantly reduced by appropriate hygiene measures. Due to the fact that pathogenic E. coli strains exist, which can cause severe poisoning symptoms, reduction and killing are usually indispensable (for oral intake). For cutaneous intake, E. coli plays only a very minor role.

The germ is relatively sensitive to higher temperatures. The so-called D65 value for E. coli is 0.1 minutes (reduction of the germ count by at least 90% in 0.1 minutes). Therefore, thermal treatment of a contaminated product is a suitable measure for germ reduction. Furthermore, a number of well-known disinfectants and preservatives are effective against the growth of E. coli.

The most important measure, however, remains preventing contamination through appropriate operational and personal hygiene.

Literature

www.bav-institut.de

www.bfr.bund.de

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

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

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

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

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

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 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 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

Fact Sheet on "Bacillus spp."

General Information and Origin

• Gram-positive, mostly motile rod-shaped bacteria
• Aerobic or facultatively anaerobic growth
• Widespread in the environment, preferably in soil/dust
• Very resistant to environmental influences
• Characteristic is the formation of endospores

Significance in Cosmetics and Pharmaceuticals

Bacillus spp. are capable of forming resistant forms, known as spores. These are very heat stable and can withstand heating steps. Furthermore, these bacteria can partially produce heat-stable toxins that are very resistant and can cause poisoning with vomiting and/or diarrhea. This can lead to critical situations, especially in the food sector.

In the cosmetic or pharmaceutical sector, Bacillus spp. are generally considered uncritical because the number of vegetative cells in a contaminated product usually remains stable and multiplication throughout the products' lifecycle is rather unlikely.

The spores of Bacillus spp. often survive the production process due to their mentioned heat stability. Since they are neither considered "specified microorganisms," which should not be detectable in 1g of product, nor classic spoilage organisms in cosmetic products, germ counts below the threshold value are generally considered uncritical. The cause of contamination is often found in contaminated raw materials or insufficient equipment hygiene. As Bacillus spp. are spore-formers, equipment cleaning and disinfection are particularly crucial. If cleaning and disinfection, especially regarding the mentioned spores, are inadequate, they can remain in the system and multiply. When favorable growth conditions occur, the transition from spores to the vegetative reproductive form is possible.

Major Causes of Contaminations

• Use of contaminated raw materials (often unevenly distributed in powders)
• Environment (air, packaging, etc.)
• Insufficient cleaning and disinfection, e.g.
  • of manufacturing equipment (plants and devices)

Important Measures

• Selection of reliable raw material suppliers and microbiological examination of raw materials
• Proper cleaning and disinfection of manufacturing equipment (plants and devices)
• Cleansers and disinfectants must also be capable of removing spores
• Good operational hygiene

Interesting link: https://www.bav-institut.de/de/newsletter/Special Issue Pharmaceuticals No. 2: Assessment of Critical Microorganisms in Non-Sterile Pharmaceutical Products Part 2

Profile on "Burkholderia spp."

General Information and Origin

• belong to the family Burkholderiaceae
• gram-negative motile rods
• obligately aerobic
• widely distributed in the environment, preferably in water
• facultatively pathogenic for humans, animals, and plants

Importance in the Cosmetic and Pharmaceutical Sector

Burkholderia species are found in water. They are undemanding, resilient, and survive in purified water and disinfectant solutions containing quaternary ammonium compounds, hexachlorophene, or chlorhexidine. In water-rich cosmetics and pharmaceuticals, Burkholderia can potentially multiply significantly.

A large portion of all recalls of the aforementioned products is due to Burkholderia cepacia. Affected products included baby wipes, nasal sprays, and mouth rinses. In most cases, contaminated water was identified as the main cause.

A critical aspect of this microorganism, in addition to its resilience and ability to survive unfavorable environmental conditions, is that it frequently occurs in biofilms. Detachment of individual parts of the biofilm, which then irregularly disperse into the product, makes it particularly difficult to detect the microorganism during finished product release testing.

Even if Burkholderia is detected only in small amounts, it is important to examine this contamination more closely and monitor further development, as in many cases there may be a delayed increase in germ numbers.

Major Causes of Contamination

• insufficient cleaning and disinfection, e.g.
  • of the water treatment plant
  • of the water piping system
  • of the manufacturing equipment (facilities and devices)
• poor equipment design, e.g.
  • residual water in facilities and pipes
  • dead-ends
  • incomplete cleaning and disinfection

⇒ The consequence of poor equipment design and/or errors in cleaning and disinfection is usually the formation of biofilms in the water system or in parts of the equipment, especially pipelines, seals, valves….

In biofilms, Burkholderia spp. is largely protected from:

• high temperatures
• pH fluctuations
• chemical disinfectants
• UV radiation

Important Measures

• proper design as well as cleaning and disinfection of the water system. In particular, biofilm formation must be avoided, as removing an existing biofilm is usually very difficult
• correct cleaning and disinfection of the manufacturing equipment (facilities and devices)
• good operational and personal hygiene

Interesting link: www.deutsche-apotheker-zeitung.de

Profile of "Pluralibacter gergoviae" (formerly Enterobacter gergoviae)

General Information and Origin

• belong to the family of Enterobacteriaceae
• gram-negative rods
• facultative anaerobes
• widely distributed in the environment, e.g., in the intestines of humans and animals, on plants, and in water
• facultatively pathogenic germs, partially with antibiotic resistances

Importance in the Cosmetics and Pharmaceutical Sector

The number of recall notifications in recent years due to Pluralibacter gergoviae in cosmetics is increasing. Affected products are often baby shampoo, baby cream, shower gel, toothpaste, etc.

In a recent statement from the BfR in 2020, it is required that all cosmetic products must be fundamentally free of P. gergoviae. This must be demonstrated through appropriate investigations.

For example, although shower gel is quickly rinsed off, contact with mucous membranes or open wounds cannot be excluded. There is thus a risk that the microorganisms could enter the bloodstream.

Pluralibacter gergoviae is known for the so-called "Phoenix effect," in which a contamination believed to be gone reappears after some time, usually in very high numbers. Pluralibacter gergoviae can adapt to preservatives, meaning it can acquire but also lose certain properties. The entry into the product usually occurs through water used as a raw material. However, poor system hygiene also plays a major role. The germ frequently occurs in biofilms.

Important Causes of Contaminations

• insufficient cleaning and disinfection, e.g.,
  • of the water treatment plant
  • of the water piping system
  • of the manufacturing equipment (systems and devices)
• poor system design, e.g.,
  • residual water in systems and pipes
  • dead spots
  • incomplete cleaning and disinfection

⇒ The consequence of inadequate system design and/or errors in cleaning and disinfection is usually biofilm formation in the water system or system parts, especially pipes, seals, valves....

In biofilms, Pluralibacter gergoviae is largely protected from:

• high temperatures
• pH value fluctuations
• chemical disinfectants
• UV radiation

Important Measures

• proper design as well as cleaning and disinfection of the water system. In particular, biofilm formation must be avoided, as the removal of an existing biofilm is usually very difficult
• correct cleaning and disinfection of the manufacturing equipment (systems and devices)
• good operational and personal hygiene

The BfR statement titled "Skin creams, make-up, and shampoos should be free of Pluralibacter gergoviae" can be found here:

www.bfr.bund.de

Profile of Pseudomonas aeruginosa

General Information and Origin

• belong to the family of Pseudomonads
• gram-negative, motile rods
• obligate aerobe
• widespread soil and water germ
• pathogenic for humans and animals

Significance in the Cosmetic and Pharmaceutical Field

Due to its pathogenic properties (e.g. causing purulent infections), the guideline for Cosmetic Products – Microbiology – Microbiological Limits (DIN EN ISO 17516) requires that Pseudomonas aeruginosa must not be detectable in 1g of product.

An important characteristic of Pseudomonas aeruginosa is its extreme indifference to external living conditions. Pseudomonas aeruginosa can survive for long periods in both moist and dry environments. In cosmetic and pharmaceutical manufacturing plants, pseudomonads can be found anywhere where sufficient water is present (washrooms, pipelines and equipment with residual moisture, water system, etc.). They can adapt to the environment and thus resist preservation and disinfection.

A particularly critical aspect of this microorganism, besides its resilience and ability to survive under unfavorable environmental conditions, is that it is often found in biofilms. Detachment of individual parts of the biofilm, which then irregularly enter the product, makes it particularly difficult to safely and reliably detect the microorganism during the finished product release inspection.

Even with small quantities of this bacterium in the product, it is important to monitor further development, as in many cases there can be a delayed increase in germ numbers.

Important Causes of Contamination:

• insufficient cleaning and disinfection, e.g.
  • of the water treatment system
  • of the water pipe system
  • of the manufacturing equipment (plants and devices)
• poor plant design, e.g.
  • residual water in plants and pipes
  • dead spots
  • incomplete cleaning and disinfection

⇒ The consequence of poor plant design and/or errors in cleaning and disinfection is usually biofilm formation in the water system or in plant parts, especially in pipelines, seals, valves, etc.

In the form of biofilms, Pseudomonas aeruginosa is largely protected against:

• high temperatures
• pH-value fluctuations
• chemical disinfectants
• UV radiation

Important Preventive Measures

• Proper design and cleaning and disinfection of the water system. In particular, biofilm formation must be avoided, as removing an existing biofilm is usually very difficult.
• Correct cleaning and disinfection of manufacturing equipment (plants and devices)
• Good operational and personnel hygiene

For more interesting information about this microorganism, please refer to the following publications:

www.wissenschaft.de

www.ecv.de

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 “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

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