CHALLENGES IN MICROBIOLOGICAL SAFETY
Burkholderia cepacia and Pluralibacter gergoviae are microorganisms that present a significant challengeto the cosmetics industry, particularly in ensuring quality control in production facilities and maintaining
product safety.
Burkholderia cepacia is a gram-negative bacterium that belongs to the so-called Burkholderia cepacia
complex (BCC). This group comprises several closely related species that are characterised by high environmental resistance and adaptability. B. cepacia is particularly feared in the cosmetics industry as it
can form biofilms in water-based products and production facilities. This makes decontamination more
difficult and increases the risk of cross-contamination. The bacterial resistance to many preservatives and
biocides makes it particularly difficult to control in cosmetic products. In addition, this bacterial strain is
known for the so-called phoenix effect: microorganisms which are initially undetectable due to dormancy
or stress later recover and proliferate under favourable conditions, leading to unexpected contamination.
Pluralibacter gergoviae, formerly known as Enterobacter gergoviae, is an opportunistic pathogen that is
also frequently found in cosmetic products. It shows a powerful resistance to certain preservatives, such as
parabens, which are commonly used in the cosmetics industry. P. gergoviae is often isolated in the context of
moisture-rich cosmetics such as creams and lotions and poses a major challenge to product safety.
Monitoring for B. cepacia and P. gergoviae is crucial for quality assurance in production facilities, as contamination can be potentially harmful to health and infested end products can affect consumer confidence. In order to contain these microorganisms, manufacturers of cosmetic products rely on optimised
hygiene measures and the testing of production water. However, adapting the preservation system of the
cosmetics produced can also be considered as a measure.
STUDY ON PRESERVATIVE EFFECTIVENESS
As a manufacturer of natural antimicrobial multifunctionals and preservatives, our aim is to provide safe
and effective solutions to control microbiological contamination in cosmetic products for our customers who have approached us many times in the past with problems of this nature. Given the resistance of
Burkholderia cepacia and Pluralibacter gergoviae to many conventional preservatives, we conducted a
comprehensive study to evaluate the efficacy of various antimicrobial multifunctionals from our portfolio
against these strains.
Several preservatives were tested for their efficacy against five B. cepacia and P. gergoviae strains each
in modified preservative challenge tests. Among these were one ATCC strain and four strains isolated
from industrial samples. The antimicrobial multifunctionals were incorporated into an O/W emulsion with
pH 5.5 at a suitable application concentration and inoculated with the bacterial strains on day 0 of the
test, analogous to a challenge test according to ISO standard 11930. Bacterial growth was examined after
7, 14 and 28 days. The following table shows the results of the modified challenge tests.
Effectiveness of preservatives against the bacterial strains B. cepacia and P. gergoviae according to challenge test method ISO 11930.
The results of our study show that all tested antimicrobials are able to significantly inhibit or entirely eliminate the growth of B. cepacia and P. gergoviae strains in an emulsion. This result confirms that optimised
antimicrobial ingredient combinations make effective preservation possible even against these challenging strains.
Nonetheless, we are aware that the results of this test do not allow a generalised statement to be made
about the effect against these mutation-prone bacteria. Each contamination is an individual case with a
potentially preservation-resistant strain that, accordingly, must be treated individually. However, improving the preservation system in combination with, for example, chemical sanitisation of the production
equipment can be a sensible measure in the fight against these troublesome bacteria.
PREVENTIVE MEASURES AND CONTROL STRATEGIES
The control of Burkholderia cepacia and Pluralibacter gergoviae requires a comprehensive approach,
ranging from precise testing methods to the optimisation of production conditions and improved product
formulation. We are happy to support you in selecting suitable preservatives and multifunctionals from our
portfolio should you have problems with Burkholderia cepacia or Pluralibacter gergoviae contamination
in your production facility and would also like to benefit from our multifunctionals’ other advantages for
your formulations. For further information or a detailed study report, please do not hesitate to contact us.