Fact sheet on thermotolerant Campylobacter, especially Campylobacter jejuni

General information
Thermotolerant Campylobacter, particularly the bacterium Campylobacter jejuni, are the most frequent causes of bacterial foodborne infections in Europe. Ingestion of even low numbers of organisms can lead to a foodborne gastrointestinal infection.

Campylobacter jejuni originally occurs in the intestinal tract of wild birds and poultry but also infects other farm and companion animals. Animals usually show no clinical symptoms.

Characteristics

• Rod-shaped bacteria
• Gram-negative
• Oxidase-positive
• Catalase-positive

Sources / Occurrence

• Naturally present in the intestinal tract of various animal species
• The bacterium is widespread especially in poultry and wild birds but also in mammals (e.g., cattle, sheep, pigs)
• In the environment the bacterium can be found in soil and in surface waters or wastewater

Significance

• Thermotolerant Campylobacter are common pathogens. They are transmitted to humans via food; therefore their presence in ready-to-eat foods is fundamentally undesirable (foodborne zoonotic pathogens)
• Even low numbers of Campylobacter jejuni can trigger a foodborne gastrointestinal illness (campylobacteriosis). These organisms generally do not multiply in the food and multiplication is not a prerequisite for infection
• At room temperature and in the presence of oxygen the organisms die off relatively quickly. In vacuum-packed or modified atmosphere-packaged products combined with refrigeration, they can survive for several weeks

Clinical features

• Minimal infectious dose: generally low organism numbers between 10^2 to 10^3 CFU/g
• Incubation period: 1 to 7 days
• Duration of illness: a few days up to about one week
• Symptoms: diarrhea (sometimes bloody), vomiting, abdominal pain, high fever, headache. Relatively severe course of enteritis (inflammatory intestinal infection)
• Further complications are rare but may occur (infections of other organs, joint inflammations, as well as Guillain-Barré syndrome)
• Compared with other foodborne infections such as salmonellosis, the course of disease is usually longer and more severe

Examples of affected foods

• Poultry meat and offal
• Meat from warm-blooded wild and farm animals
• Raw milk
• Surface water
• When operational and personnel hygiene are inadequate, contamination of ready-to-eat foods can occur

Conditions for growth

• Temperature:
  • Optimum: +42 °C
  • Minimum: +25 °C
  • Generally no growth above +50 °C
• pH: growth at pH 5.0 to 9.0
• a_w value: growth at a water activity of at least 0.98
• Salt tolerance: 0.16 to 1.55 %, but strongly affected by temperature and pH
• Oxygen requirement: microaerophilic (up to max. 5 % oxygen)

Inactivation by heating

• Exposure at +72 °C for at least 2 minutes will inactivate the bacteria (Attention: check core temperature)

1. Review workplace organization in the facility
   1. Separate work areas, equipment and utensils for raw and processed foods
   2. Separation of "clean" and "unclean" areas and activities
2. Train employees regarding potential errors and improvement measures
3. Verification by visual on-site inspections and follow-up testing

1. Review the execution of cleaning and disinfection:
   1. Hygiene plan
   2. Execution of cleaning and disinfection e.g. dosing of the disinfectant, contact time, use of suitable and clean materials and cleaning cloths
2. Avoid residual moisture and biofilms. Ensure good drying of equipment, devices and surfaces
3. Train employees regarding potential errors and improvement measures
4. Repeat cleaning and disinfection
5. Verification by visual on-site inspections, environmental testing and follow-up testing

1. Review processes, production protocols and documentation
2. Most bacteria are inactivated at a core temperature of +72 °C for at least 2 minutes. Exceptions include heat-stable spores and toxins. In these cases considerably higher temperatures and exposure times are required. Further information can be found, for example, in the respective information sheets (fact sheets)
3. Check the correctness of processes and temperatures
   1. In general, holding temperatures above +60 °C are required
   2. Rapid cooling: after 3 hours a core temperature of at least +7 °C must be reached (special caution is required for large quantities)
4. Verification by follow-up testing

Deficiencies in infection control:
There is a risk of transmission of pathogenic microorganisms from humans to product-contact surfaces or directly to food

Examples:

Salmonella from carriers or ill employees

Staphylococcus aureus from employees with inflamed or purulent wounds or with colonization of the nasopharynx

1. Employees who are ill with or suspected of infections such as Salmonella, EHEC/STEC, Shigella, Vibrio cholerae, hepatitis A or E viruses or other infectious gastrointestinal diseases, or who excrete the aforementioned bacterial pathogens, are not allowed to work in food establishments handling highly perishable foods and kitchens under the Infection Protection Act (IfSG) (see IfSG § 42)
2. The same applies to employees with inflamed or purulent wounds. Non-infected wounds must be hygienically covered
3. Regular training/instruction of employees regarding required infection control measures
4. Verification by visual on-site inspections, checks of training records and follow-up testing

1. Train employees regarding potential errors and improvements
2. Regular hand cleaning and disinfection and/or regular glove changes
3. Regular changing of work clothing. Ensure work clothing is kept clean
4. Train employees on infection control requirements
5. Verification by visual on-site inspections and follow-up testing

1. Check products at goods receipt for e.g. incoming or transport temperature, shelf life, packaging, deviations or abnormalities
2. The same applies to goods before use in production. When in doubt do not use the food and consult a supervisor
3. Review microbiological specifications. If necessary, arrange laboratory testing of suspicious products or request results from the supplier
4. Verification by follow-up testing

1. Review processes, environmental conditions, production protocols and documentation
2. Verification by follow-up testing

1. Maintain distance from fields with livestock; keep wildlife away from fields using e.g. fences or nets
2. Water hygiene: contaminated water must not be used for irrigation. Irrigation and drainage systems must be suitable. Regular monitoring of microbiological water quality
3. No microbiologically contaminated fertilizers should be used in crop production
4. Personnel and work hygiene during harvest and downstream steps
5. Remove soil and contaminants by washing
6. Verification by follow-up testing