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

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