Fact sheet on Enterobacteriaceae

General
Enterobacteriaceae (= enterobacteria) play an important role in cosmetics. This large family of bacteria includes numerous genera with different relevance and characteristics.

→ More specific information on some representatives: see profiles on E. coli and P. gergoviae

Characteristics

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

Origin / Occurrence

• Widespread in our environment (e.g., soil, plants and surface water).
• For some genera (e.g., Escherichia coli) the intestines of animals and humans are the natural reservoir.

Significance

• Hygiene indicator and spoilage organisms (e.g., Serratia spp).
• Part of the normal microbial flora of plants (e.g., Pantoea spp).
• In certain cases an indicator for fecal contamination (e.g., E. coli).
• The presence of certain Enterobacteriaceae, especially Pluralibacter gergoviae, may also indicate weaknesses related to water, such as biofilm formation.

Important note

• For E. coli, absence is required in cosmetic products according to ISO 17516. See profile Escherichia coli.
• Pluralibacter gergoviae is also undesirable in cosmetics and should be assessed critically; see profile Pluralibacter gergoviae.

Growth conditions

• Temperature:
  • Optimum: generally at +30 °C to +37 °C
  • Minimum: mostly +7 °C (depending on the species, exceptions even down to 0 °C)
  • Generally no growth above +50 °C
• pH: Growth at pH 5.5 to 9.0 (depending on the species, exceptions even down to pH 4.4).
• a_w-value: Growth at a water activity of at least 0.95.
• Oxygen requirement: Growth with and without oxygen (facultative anaerobes).

Inactivation by heating

• At +72 °C for a minimum contact time of 2 minutes (Note: monitor core temperature).

1. Verify the execution of cleaning and disinfection:
   1. Hygiene plan specifying how cleaning and disinfection are to be performed, e.g., dosing, contact time, use of suitable and clean materials and cleaning cloths
2. Train staff regarding potential errors and corrective measures
3. Repeat cleaning and disinfection
4. Verify effectiveness through on-site inspections and follow-up tests (e.g., swab and contact plate sampling)

1. Check water systems and piping for correct function and condition. Avoid water stagnation in, e.g., pipes, systems, hoses…
2. Regularly microbiologically and technically inspect water systems and piping (observe maintenance intervals)
3. In case of contamination of water systems, respond immediately and initiate corrective actions. Involve specialist companies if necessary
4. Verify effectiveness through regular follow-up testing

1. Inspect incoming goods for, e.g., shelf life, packaging, deviations or microbiological abnormalities
2. This also applies to goods prior to use in production. Do not use raw materials if contamination is suspected
3. Check microbiological specifications. If necessary, arrange laboratory testing of suspicious products or request results from the supplier
4. Verify effectiveness by follow-up testing

1. Ensure adherence to the formulation
2. If necessary, perform a preservative efficacy test (challenge test)
3. If necessary, adjust the preservation system
4. Verify effectiveness by repeating the preservative efficacy test

1. Review and document production processes
2. Train personnel
3. Verify effectiveness by regular microbiological product testing

1. Review workplace organization
   1. Separate work areas, tools and utensils
   2. Separation of "clean" and "unclean" areas and activities
2. Train staff regarding potential errors and corrective measures
3. Verify effectiveness through on-site inspections and follow-up tests

1. Check airborne microbial counts and ventilation systems via technical inspection and environmental monitoring
2. Avoid high humidity and condensate formation
3. Appropriate cleaning and disinfection (see section "Cleaning and disinfection")
4. Train staff regarding potential errors and corrective measures
5. Verify effectiveness through on-site inspections and follow-up tests

1. Train staff on hand and personnel hygiene, potential errors and behavior in case of certain illnesses
2. Monitor hand hygiene, glove changes and cleanliness of work clothing
3. Verify effectiveness through on-site inspections and follow-up tests (e.g., swab and contact plate sampling)