Culturable bacterial flora of juveniles of Pelophylax ridibundus (Pallas, 1771) and influence of abiotic factors on diversity

This study aims to determine the bacterial flora on the skin surface of the juvenile forms of Pelophylax ridibundus inhabiting three different altitudes and examine potential correlations between bacterial diversity, ecological location, and factors. It was attempted to characterize thirty-two bacteria isolated from the Melet River, Sülük Lake, and Çambaşı Pond through combined biochemical and molecular methods. Canonical correspondence analysis showed that the most important ecological factors for microorganisms to settle on frog skin were determined as water conductivity and dissolved oxygen amount. The most frequently isolated bacteria belonged to the genera Erwinia and Pseudomonas. Altitude positively affected Exiguobacterium. This first report of skin cultivable bacteria from P. ridibundus juvenile forms natural population improves our knowledge of amphibian skin bacterial flora. This study contributes to a better understanding of their ecology and how this species has survived in an environment modulated by altitude.

Sodium alginate/poly(vinyl alcohol)/taxifolin nanofiber mat promoting diabetic wound healing by modulating the inflammatory response, angiogenesis, and skin flora

Diabetes-related ulcers are still a therapeutic problem because of their susceptibility to infection, ongoing inflammation, and diminished vascularization. The design and development of novel dressings are clinically urgent for the treatment of chronic wounds due to diabetic ulcers. In this study, we made taxifolin (TAX) loaded sodium alginate (SA)/poly(vinyl alcohol) (PVA) nanofibers for the treatment of chronic wounds. The SA/PVA/TAX nanofibers that have been created are smooth and bead-free, with good thermal stability, hydrophilicity, and mechanical properties. The release profile indicated a sustained drug release, with a cumulative release rate of 64.6 ± 3.7 % at 24 h. In vitro experiments have shown that SA/PVA/TAX has good antibacterial activity, antioxidant activity, and biocompatibility. In vivo experiments have shown that SA/PVA/TAX exhibits desirable biochemical properties and is involved in the diabetic wound healing process by promoting cell proliferation (Ki67), angiogenesis (CD31, VEGFA), and alleviating inflammation (CD68). Western blotting experiments suggest that SA/PVA/TAX may promote diabetic wound healing by inhibiting the TLR4/NF-κB/NLRP3 signaling pathway and upregulating the expression of VEGFA and PDGFA. The 16S rRNA sequencing results showed that SA/PVA/TAX increased the wound surface flora's diversity and reversed the skin microbiota's structural imbalance. Therefore, SA/PVA/TAX can promote diabetic wound healing by modulating the inflammatory response, angiogenesis, and skin flora and has the potential to be an excellent wound dressing.

Borneol-modified chitosan: Antimicrobial adhesion properties and application in skin flora protection

Antimicrobial modifications of chitosan usually endow the products with strong bactericidal activities. However, if the products come into direct contact with human skin, the skin flora, which is beneficial to human health, may be damaged. To address this issue, we developed a stereochemical antimicrobial strategy by grafting borneol 4-formylbenzoate to chitosan using a stable Schiff base bond; this process yielded borneol-modified chitosan (BMC) as a novel antimicrobial material. This material was challenged with gram-negative Escherichia coli, gram-positive Bacillus subtilis, and Aspergillus niger. All tests showed excellent antimicrobial adhesive properties. Guinea pig skin experiments further demonstrated that BMC did not damage the skin flora. Owing to the antimicrobial mechanism of borneol stereochemistry, BMC successfully defended against pathogens and protected the skin flora. Thus, this material may have excellent potential applications in multifunctional textiles, healthcare, and flexible skin electronics.

Culture characterization of the skin microbiome in Type 2 diabetes mellitus: A focus on the role of innate immunity

AIMS

The current study aimed at determining the differences between the cutaneous microbial flora of patients with Type 2 diabetes mellitus (T2DM) and those without, and thus evaluate for cutaneous microbiome dysbiosis in diabetes.

METHODS

We employed a case-control study design with 41 participants in each group. The skin over the toe-web space was swabbed and cultured aerobically. Data was analyzed for differences in microbial prevalences and growths between the two groups. Predictors for heavy colonization by microbes were analysed using logistic regression.

RESULTS

We found significantly higher prevalences of Staphylococcus epidermidis among patients with T2DM (77.5% vs. 53.7%, p=0.02). Further, when prevalent, these bacteria showed a significantly greater degree of skin colonization i.e. CFUs/cm² among these patients, p=0.03. Highly pathogenic bacteria such as S. aureus were more prevalent among patients with T2DM. The regression model determined a significant association between T2DM status and heavy colonization by S. epidermidis (OR - 5.40, p=0.02). Also, agricultural workers were significantly more likely to have heavy colonization by S. epidermidis (OR - 3.75, p=0.02). Other predictor variables did not show significant association with heavy colonization by any of the isolated microbes.

CONCLUSIONS

Our findings support the existence of cutaneous microbiome dysbiosis among patients with T2DM. Literature suggests that microbiome dybiosis in T2DM could stem from the same activated innate immune response that is thought to be central to the development of T2DM. This dysbiosis could increase the risk of developing skin infections.