The skin microbiota is an ecosystem inhabited by a community of more than a million microorganisms (bacteria, viruses, fungi) per square centimeter of skin.
Bacterial composition of skin (cutaneous microbiota) is mostly dominated by the following genera: Propionibacteria (23%), Corynebacteria (22.8%) and staphylococci (16.8%).
Most of the bacteria in epidermis are “commensal” and live in a symbiotic manner with the host that they colonize.
Interactions between the host immune system and its microbiota contribute to the control of the skin bacterial composition as well as to the education of the adaptive immune system of the host.
Imbalance in the microbiota composition can cause cutaneous disorders (dry skin, oily skin, dandruff, etc.) and even pathologies (psoriasis, atopic dermatitis, acne, etc.).
The skin microbiota: models and in vitro assays
Thanks to its expertise in cellular and tissue engineering, Bioalternatives has developed in vitro or ex vivo study models that are suitable for analyzing the interactions between microbiota and skin:
- Isolated bacterial culture (Staphylococcus aureus, Staphylococcus epidermidis, Cutibacterium acnes, Corynebacterium xerosis …)
- Co-culture:
- bacteria on 2D skin models (keratinocytes, fibroblasts, sebocytes, etc.)
- bacteria on 3D skin models (reconstructed epidermis, etc.)
- infection experiments with the HSV-1 virus ( Herpes simplex virus type I)
Both the impact of compounds or formulations on the development of bacteria and the influence of bacteria on cutaneous response can be assessed by these models.
Bioalternatives offers a panel of solutions for the evaluation of:
- Bacterial viability
- Quantification of bacterial colony (CFU)
- Determination of bacterial load (qPCR (Taqman))
- Bacterial adhesion on 3D models (reconstucted epidermis) – quantification of colony, qPCR, radioactivity, SEM
- Biological response of 2D or 3D models (differentiation, inflammation and immune response)
Bioalternatives offers a wide range of microorganisms tested by our laboratory and available for in vitro testing:
BACTERIA
GRAM (+) :
- Staphylococcus aureus
- Staphylococcus epidermidis
- Cutibacterium acnes
- Corynebacterium xerosis
- Streptococcus pyogenes
- Mix of several strains (upon request)
- Other strains upon request
GRAM (-) :
- Pseudomonas aeruginosa
- Other strains upon request
VIRUSES
- Herpes simplex virus type 1 (HSV-1)
- Human Rhinovirus 16 (HRV-16)
YEASTS
Coming soon
Here are a few examples among all standard assays proposed by Bioalternatives in the field of skin microbiota:
The Relationship Between Microbiology Testing and the Skin Microbiota
/in Cosmetics, Skin microbiome /by VanessaMicrobiology testing is essential for substantiating microbiome-friendly and anti-microbial claims. Read on to find out how cosmetic microbiology testing is connected to the skin microbiome.
Microbiota vs. Microbiome: What’s the Difference?
/in Skin microbiome /by VanessaWhat is the difference between microbiota vs. microbiome? Why are they important to human skin? What is the Skin Microbiota test? Learn more here.
Using Reconstructed Human Epidermis model in Skin Microbiome Research
/in Skin microbiome, Skin microbiome /by VanessaSkin microbiome research is developing rapidly. Are you up to date? Find out why 3D skin models are an important development in skin microbiome research.
Profiling TLR agonist activity in keratinocytes and link to bacteria-induced innate immunity activation
/in Cosmetics, Microbiome cutané, Skin microbiome /by VanessaIn this study, our goal was first to functionally profile and characterize the response of normal human keratinocytes (NHEK) to microbial patterns (TLR agonists) and IL-1α in parallel. To do so, the effects of multiple TLR agonists and IL-1α were evaluated on the gene expression profile, on signal transduction (NF-ƘB translocation) and also on IL-8 and IL-6 release. Secondly, we also tried to link these responses to those of pathogens of interest in skin microbiota (namely, C. acnes, S. aureus and P. aeruginosa), by evaluating the effect on IL-8 release by NHEK infected with living bacteria from these 3 strains…