Bacterial and viral skin diseases

Research Progress of Dihydroquercetin in the Treatment of Skin Diseases

Skin is a barrier to maintaining the stability of the human environment and preventing the invasion of pathogens. When skin tissue is exposed to the external environment, it will inevitably develop defects due to trauma, injury, burns, ulcers, surgery, and chronic diseases. Rapid skin repair is the key to reducing infection, relieving pain, and improving quality of life. Dihydroquercetin is a kind of flavonoid that has a wide range of pharmacological activities and can improve skin repair, skin inflammation, skin cancer, and so on. In this paper, the application of dihydroquercetin in medical dressings and the research progress in the treatment of skin-related diseases are reviewed, so as to provide reference for further developing dihydroquercetin as a drug for the treatment of skin diseases.

Differences in the skin microbial community between patients with active and stable vitiligo based on 16S rRNA gene sequencing

BACKGROUND/OBJECTIVE

Recent studies have described an association between altered skin microbial community and epidemiology of skin diseases, such as vitiligo, atopic dermatitis and psoriasis. In this study, we conducted microbiological analysis on patients at different stages of vitiligo to determine whether the dysbiosis is associated with disease progression.

METHODS

To characterise the skin microbes in vitiligo patients, we profiled samples collected from 40 patients with active and stable vitiligo using the Novaseq sequencer. Alpha diversity was used to measure richness and uniformity, while Beta diversity (Non-Metric Multi-Dimensional Scaling) analysis was used to show the differences. Moreover, the species differences were evaluated by LEfSe analysis and the flora gene function was predicted using Statistical Analysis of Metagenomic Profiles (STAMP).

RESULTS

The alpha diversity results showed no significant differences between active vitiligo and stable vitiligo, while beta diversity and LEfSe analysis results showed the differences in community composition. Streptomyces and Streptococcus were enriched in active vitiligo compared to stable vitiligo. In addition, the flora gene function of mixed acid fermentation was more pronounced in active vitiligo, while the function of lipid IVA biosynthesis was more significant in stable vitiligo.

CONCLUSION

This study has shown the differences in epidermal microbes between active vitiligo and stable vitiligo. Our results suggest that maintaining the flora balance might be a potential therapeutic target for vitiligo.

Seasonal variations in cardiac implantable electronic device infections

Infections of cardiac implantable electronic devices (CIEDs) have increased over the past decade. However, the impact of the climate on CIED infections is unknown. To determine whether there is a seasonal variation in CIED infections. In this single-center observational study, retrospective analysis of prospectively collected data was performed. Timone Hospital in Marseille (south-east France) is a tertiary care institution and the regional reference center for management of CIED infections. All consecutive patients with CIED extractions for infectious reasons were included over a 12-year period. We noted the mean temperature (°C), precipitation (mm) and the incidence of CIED infections over this period. Among 612 patients [mean (standard deviation) age, 72.4 (13.0) years; 74.0% male], 238 had endocarditis alone (38.9%), 249 had pocket infection alone (40.7%), and 125 had both (20.4%). We found bacterial documentation in 428 patients (70.0%), commensal in 245 (40.0%). The incidence of CIED infections was positively associated with high temperature (regression coefficient = 0.075; P = 0.01) and precipitation (regression coefficient = 0.022; P < 0.01). Seasonal variation was specific of pocket infections, whether they were associated with endocarditis or not. Subgroups with infection seasonality were: women, elderly people (> 75 years), late CIED infection and skin commensal bacterial infections. We found a seasonal variation in pocket infections, whether associated with endocarditis or not. Infections were associated with elevated temperatures and precipitation. Therefore, specific prevention strategy should be discussed in high-risk patients.

Production of cell-cell signalling molecules by bacteria isolated from human chronic wounds

AIM

To (i) identify chronic wound bacteria and to test their ability to produce acyl-homoserine-lactones (AHLs) and autoinducer-2 (AI-2) cell-cell signalling molecules and (ii) determine whether chronic wound debridement samples might contain these molecules.

METHODS AND RESULTS

Partial 16S rRNA gene sequencing revealed the identity of 46 chronic wound strains belonging to nine genera. Using bio-reporter assays, 69.6% of the chronic wound strains were inferred to produce AI-2, while 19.6% were inferred to produce AHL molecules. At least one strain from every genus, except those belonging to the genera Acinetobacter and Pseudomonas, were indicated to produce AI-2. Production of AI-2 in batch cultures was growth-phase dependent. Cross-feeding assays demonstrated that AHLs were produced by Acinetobacter spp., Pseudomonas aeruginosa and Serratia marcescens. Independent from studies of the bacterial species isolated from wounds, AHL and/or AI-2 signalling molecules were detected in 21 of 30 debridement samples of unknown microbial composition.

CONCLUSION

Chronic wound bacteria produce cell-cell signalling molecules. Based on our findings, we hypothesize that resident species generally produce AI-2 molecules, and aggressive transient species associated with chronic wounds typically produce AHLs. Both these classes of cell-cell signals are indicated to be present in human chronic wounds.

SIGNIFICANCE AND IMPACT OF THE STUDY

Interbacterial cell-cell signalling may be an important factor influencing wound development and if this is the case, the presence of AHLs and AI-2 could be used as a predictor of wound severity. Manipulation of cell-cell signalling may provide a novel strategy for improving wound healing.