Revealing the secret life of skin - with the microbiome you never walk alone.

The human skin microbiome has recently become a focus for both the dermatological and cosmetic fields. Understanding the skin microbiota, that is the collection of vital microorganisms living on our skin, and how to maintain its delicate balance is an essential step to gain insight into the mechanisms responsible for healthy skin and its appearance. Imbalances in the skin microbiota composition (dysbiosis) are associated with several skin conditions, either pathological such as eczema, acne, allergies or dandruff or non-pathological such as sensitive skin, irritated skin or dry skin. Therefore, the development of approaches which preserve or restore the natural, individual balance of the microbiota represents a novel target not only for dermatologists but also for skincare applications. This review gives an overview on the current knowledge on the skin microbiome, the currently available sampling and analysis techniques as well as a description of current approaches undertaken in the skincare segment to help restoring and balancing the structure and functionality of the skin microbiota.

Le microbiome de la peau humaine est récemment devenu un centre d'intérêt pour les domaines dermatologique et cosmétique. Comprendre le microbiote cutané, à savoir la collection de microorganismes vitaux vivant sur notre peau, et comment maintenir son équilibre délicat est une étape essentielle pour mieux comprendre les mécanismes responsables d'une peau saine et son apparence. Les déséquilibres dans la composition microbiotique de la peau (dysbiose) sont associés à plusieurs affections cutanées, soit pathologiques comme l'eczéma, l'acné, les allergies ou les pellicules, soit non pathologiques comme la peau sensible, irritée ou sèche. Par conséquent, le développement d'approches qui préservent ou restaurent l'équilibre naturel et individuel du microbiote représente une nouvelle cible non seulement pour les dermatologues mais aussi pour les experts en cosmétiques. Cette revue donne un aperçu des connaissances actuelles sur le microbiome cutané, les techniques d'échantillonnage et d'analyse actuellement disponibles ainsi qu'une description des approches actuelles entreprises dans le segment des soins de la peau pour aider à restaurer et équilibrer la structure et la fonctionnalité du microbiote de la peau.

The Association of the Skin Microbiota With Health, Immunity, and Disease.

The human skin is densely colonized by a highly diverse microbiota comprising all three domains of life. Long believed to represent mainly a source of infection, the human skin microbiota is nowadays well accepted as an important driver of human (skin) health and well-being. This microbiota is influenced by many host and environmental factors and interacts closely with the skin immune system. Although cause and effect are usually difficult to discriminate, changes in the skin microbiota clearly play a role in the pathobiology of many types of skin disease and cosmetic disorders. Consequently, treatment and prevention strategies have to respect this role, rendering pre- and probiotic and even transplantation therapies an additional option to the use of antibiotics.

Identification of compounds inhibiting the C-S lyase activity of a cell extract from a Staphylococcus sp. isolated from human skin.

UNLABELLED: The C-S lyase activity of bacteria in the human armpit releases highly malodorous, volatile sulfur compounds from nonvolatile precursor molecules. Such compounds significantly contribute to human body odour. Hence, C-S lyase represents an attractive target for anti-body-odour cosmetic products. Here, aiming at a final use in an ethanol-based deodorant formulation, 267 compounds and compound mixtures were screened for their ability to inhibit the C-S lyase activity of a Stapyhlococcus sp. crude extract. Staphylococcus sp. Isolate 128, closely related to Staphylococcus hominis, was chosen as the test bacterium, as it showed a reproducibly high specific C-S lyase activity on three different culturing media. Using a photometric assay and benzylcysteine as substrate, six rather complex, plant-derived compound mixtures and five well defined chemical compounds or compound mixtures were identified as inhibitors, leading to an inhibition of ≥70% at concentrations of ≤0·5% in the assay. The inhibition data have demonstrated that compounds with two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue are characteristic for the inhibition. The substances identified as C-S lyase inhibitors have the potential to improve the performance of anti-body-odour cosmetic products, for example, ethanol-based deodorants. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacterial C-S lyase represents one of the key enzymes involved in human body odour formation. The aim of this study was to identify compounds inhibiting the C-S lyase activity of a Staphylococcus sp. isolate from the human skin. The compounds identified as the best inhibitors are characterized by the following features: two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue. They might be used to improve the performance of cosmetic products aiming to prevent the formation of microbially caused human body odour, for example, ethanol-based deodorants.

A glimpse under the rim--the composition of microbial biofilm communities in domestic toilets.

AIM: To determine the microbial composition of biofilms in domestic toilets by molecular means. METHODS AND RESULTS: Genomic DNA was extracted from six biofilm samples originating from households around Düsseldorf, Germany. While no archaeal 16S rRNA or fungal ITS genes were detected by PCR, fingerprinting of bacterial 16S rRNA genes revealed a diverse community in all samples. These communities also differed considerably between the six biofilms. Using the Ribosomal Database Project (RDP) classifier tool, 275 cloned 16S rRNA gene sequences were assigned to 11 bacterial phyla and 104 bacterial genera. Only 15 genera (representing 121 sequences affiliated with Acidobacteria, Actinobacteria, Bacteroidetes, Planctomycetes and Proteobacteria) occurred in at least half of the samples or contributed at least 10% of the sequences in a single biofilm. These sequences were defined as 'typical' for toilet biofilms, and they were examined in more detail. On a 97% sequence similarity level, these sequences represented 56 species. Twelve of these were closely related to well-described bacterial species, and only two of them were categorized as belonging to risk group 2. No 16S rRNA genes of typical faecal bacteria were detected in any sample. Virtually all 'typical' clones were found to be closely related to bacteria or to sequences obtained from environmental sources, implicating that the flushing water is the main source of recruitment. CONCLUSION: In view of the great diversity of mostly yet-uncultured bacteria and the considerable differences between individual toilets, very general strategies appear to be most suited for the removal and prevention of toilet biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: For the first time, a molecular fingerprinting and cloning approach was used to monitor the species composition in biofilm samples taken from domestic toilets. Knowledge about the microbial composition of biofilms in domestic toilets is a prerequisite for developing and evaluating strategies for their removal and prevention.

Identification and sequence analysis of the soxB gene essential for sulfur oxidation of Paracoccus denitrificans GB17.

The coding region for lithotrophic sulfur oxidation (Sox) in Paracoccus denitrificans GB17 was identified by isolation of a transposon Tn5-mob mutant with a Sox- phenotype (strain TP19). The corresponding wild-type region was cloned previously (G. Mittenhuber, K. Sonomoto, M. Egert, and C. G. Friedrich, J. Bacteriol. 173:7340-7344, 1991). Sequence analysis of a 2.5-kb subclone that complemented strain TP19 revealed that Tn5-mob was inserted into a coding region for a 553-amino-acid polypeptide named SoxB. This polypeptide had an M(r) of 60.573, including a possible signal peptide. The function of the SoxB protein of P. denitrificans GB17 appeared to be identical to that of enzyme B of the thiosulfate-oxidizing enzyme system of Thiobacillus versutus. The amino acid compositions of the two proteins were identical, and the amino acid sequences of three internal peptides of enzyme B as determined by Edman degradation were identical to corresponding sequences of the deduced SoxB protein of P. denitrificans GB17.

[An unusual constellation of findings in polymyositis--differential diagnosis and clinical course]. / Ungewöhnliche Befundkonstellation bei Polymyositis--Differentialdiagnostik und klinischer Verlauf.

Clinical and biochemical findings are described in a 34-year-old female with atypical polymyositis. Uncommon clinical features in this patient included distally accented decreased muscle strength and myalgias, atypical electromyographic findings, a remarkable discrepancy between clinical findings and laboratory parameters of myolysis, unexplained episodes of somnolism, presence of increased serum lactate levels, and a unilateral mamma aplasia. For this combination of signs a polymyositis or an inclusion body myositis, but also a metabolic or heredodegenerative myopathy was considered. Finally, the idiopathic polymyositis was confirmed histologically and a marked improvement in the clinical and biochemical signs occurred after commencement of high-dose methylprednisolone.

Identification of the DNA region responsible for sulfur-oxidizing ability of Thiosphaera pantotropha.

For the identification of the DNA region responsible for the sulfur-oxidizing ability (Sox) of Thiosphaera pantotropha, we used previously isolated Tn5-mob insertional Sox- mutants. For seven mutants, the Tn5-mob insertion was localized on the chromosome rather than on the megaplasmids pHG41 or pHG42 by using the Tn5-mob-harboring vehicle pSUP5011 as probe. The specific insertion of Tn5-mob into a sox gene was determined for one Sox- mutant, strain TP19. An 18-kb EcoRI fragment was cloned in Escherichia coli by using the mobilizable plasmid pSUP202 as vector and the kanamycin resistance gene of Tn5 as marker. Conjugal transfer of the resulting hybrid plasmid, pKS3-13, to the wild type resulted in two phenotypically different groups of recombinants. Ninety-five percent of the recombinants were Sox+, kanamycin resistant, and tetracycline resistant; 5% were homogenote recombinants exhibiting the Sox-, kanamycin-resistant, tetracycline-sensitive phenotype, and these indicated the specific insertion. To isolate the respective wild-type sox gene, total DNA from a heterogenote recombinant was partially restricted with EcoRI, religated, and transformed in E. coli. Transformants carrying a pSUP202-derived hybrid plasmid with the intact sox gene were identified by screening for a tetracycline-resistant, kanamycin-sensitive, and chloramphenicol-sensitive phenotype and by complementation of the Sox- mutant TP19. A plasmid of this type, pEG12, contained an insert of 13 kb which gave a positive signal in Southern hybridization with the homologous probe of pKS3-13. pEG12 was used to determine the DNA homology of the sulfur-oxidizing enzyme systems of other thiobacteria. Strong hybridization signals were obtained with total DNA of the neutrophilic sulfur-oxidizing bacteria Paracoccus denitrificans, Thiobacillus versutus, and Rhodobacter capsulatus. No hybridization signal was obtained with DNA of other neutrophilic or acidophilic thiobacteria examined.

[Quantitative architectonic variations in the visual cortex of mice following varying light exposure of the visual organ]. / Quantitativ-architektonische Veränderungen der Sehrinde von Maüsen bei unterschiedlichen Lichteinwirkungen auf das Sehorgan

Quantitative - architectural investigations were carried through with two experimental groups of white mice. One group was expsed to a source of light day and night, the other group lived under normal light variations. The animals of both groups were already born under the mentioned conditions and killed in etherization after 51 days. After the determination of the brain-weights, which showed smaller quantities for the group living under light day and night, sections of 10 mum were stained according to the NISSL method and the thickness of the cortex was measured. The layers in the area striata were examined with regard to possible differences. But in this connection no differences between the two groups were to be found. According to the point - method the different coefficients of the cortical layers were determined. The mathematical - statistical analysis with the help of t-test showed significantly bigger coefficients with the latter group (living under light day and night). These coefficients correspond to a smaller part of volume of neurons or their components in a defined volume. This way it was proved that changed light conditions result in changes of the microscopical structure of the area striata. At the same time significant changes occur in the nucleus-plasma-relation of the various layers. These make us recognize the functional adaptations to the changed environmental influences.