Staphylococci: Can bacteria affect the skin barrier in neurodermatitis?
It has long been known that certain bacteria are particularly common on the skin of people with neurodermatitis. It is also known that the skin's barrier function suffers from the disease. Scientists have now researched how this could be connected.
Certain bacteria are particularly common in people with eczema
According to health experts, around 3.5 to 5 million people in Germany live with neurodermatitis (atopic dermatitis, atopic eczema). It has long been known that certain bacteria are particularly common on the skin of people with neurodermatitis. Likewise that the skin's barrier function suffers from the chronic inflammatory skin disease. Researchers from the Helmholtz Zentrum München and the Technical University of Munich (TUM) have now determined how this could be connected.
Bacterial composition affects the degree of inflammation
According to the Robert Koch Institute (RKI), neurodermatitis is "one of the most common diseases in childhood and adolescence".
The disease is usually accompanied by severe itching, dry, scaly and reddened skin.
It is also seen as the gateway to the 'allergy career'. Because the skin's barrier disorder often causes sensitization and manifest allergy, according to a statement from the Helmholtz Zentrum München.
"Current studies have shown, for example, that the bacterial composition of the skin influences the degree of inflammation in neurodermatitis," said study co-author Dr. Matthias Reiger.
"In addition, research into the cell system of the skin barrier was able to provide new insights into the function of special genes for maintaining healthy skin."
Correlations between bacteria and skin barrier genes
In the next step, the researchers now wanted to find out whether there are possible correlations between bacteria and genes in the skin barrier. To do this, they collected skin samples from healthy volunteers and from people with neurodermatitis.
In the latter, they differentiated the samples depending on whether the area of the skin was inflamed or not.
"From the patient and control samples, we determined both the composition of the skin bacteria and the genes that were particularly active in the affected skin," explained bioinformatician Prof. Dr. Avidan Neumann, who was also involved in the work.
During the analysis it was noticed that especially staphylococci on the skin dominated by neurodermatitis.
Staphylococci are the cause of many infectious diseases
The Federal Institute for Risk Assessment (BfR) describes on its website how dangerous these bacteria are: “Staphylococci are the cause of many infectious diseases in humans and animals. They can lead to foodborne poisoning as well as infectious diseases. "
It also says: "They often cause purulent wound infections and other purulent infections in humans". For example, the bacteria are often responsible for inflammation in the nose.
Staphylococci can also lead to the so-called toxic shock syndrome.
Health professionals are particularly concerned about multidrug-resistant strains, such as methicillin-resistant Staphylococcus aureus (MRSA), which are often resistant to antibiotics.
Other staphylococci are displaced
As the Helmholtz Zentrum München's communication states, the species Staphylococcus aureus was particularly common on the skin of neurodermatitis patients, regardless of whether the affected skin was inflamed or not.
"For certain inflamed samples, S. aureus even took up to 99 percent of the total microbial composition," said Matthias Reiger.
"In addition, S. aureus seems to be replacing the other staphylococci," the microbiologist continues. "The more often we find S. aureus, the less likely other species are present."
The scientists got help from Switzerland for the analysis of gene activity: The cooperation partners at the Swiss Institute for Allergy and Asthma Research (SIAF) at the University of Zurich analyzed the entire transcriptome of the skin samples.
They noticed that some genes changed significantly, depending on which bacterial inhabitants lived on the skin.
"This effect was particularly pronounced for four genes that are involved in maintaining an intact and stable skin barrier," explained Avidan Neumann.
The results of the researchers were published in the journal "Journal of Allergy and Clinical Immunology". (ad)