Alterations of human skin microbiome and expansion of antimicrobial resistance after systemic antibiotics

The Role of the Skin Microbiome in Acne: Challenges and Future Therapeutic Opportunities

Acne vulgaris is a widespread dermatological condition that significantly affects the quality of life of adolescents and adults. Traditionally, acne pathogenesis has been linked to factors such as excess sebum production, follicular hyperkeratinization, and the presence of Cutibacterium acnes (C. acnes). However, recent studies have highlighted the role of the skin microbiome, shifting focus from individual pathogens to microbial community dynamics. This review critically evaluates existing research on the skin microbiome and its relationship to acne, focusing on microbial diversity, C. acnes strain variability, and emerging therapies targeting the microbiome. While certain studies associate C. acnes with acne severity, others show this bacterium's presence in healthy skin, suggesting that strain-specific differences and overall microbial balance play crucial roles. Emerging therapeutic approaches, such as probiotics and bacteriophage therapy, aim to restore microbial equilibrium or selectively target pathogenic strains without disturbing the broader microbiome. However, the lack of standardized methodologies, limited longitudinal studies, and the narrow focus on bacterial communities are major limitations in current research. Future research should explore the broader skin microbiome, including fungi and viruses, use consistent methodologies, and focus on longitudinal studies to better understand microbial fluctuations over time. Addressing these gaps will enable the development of more effective microbiome-based treatments for acne. In conclusion, while microbiome-targeted therapies hold promise, further investigation is needed to validate their efficacy and safety, paving the way for innovative, personalized acne management strategies.

Oral Microbial Translocation Genes in Gastrointestinal Cancers: Insights from Metagenomic Analysis

Along with affecting oral health, oral microbial communities may also be endogenously translocated to the gut, thereby mediating the development of a range of malignancies in that habitat. While species-level studies have proven the capability of oral pathogens to migrate to the intestine, genetic evidence supporting this mechanism remains insufficient. In this study, we identified over 55,000 oral translocation genes (OTGs) associated with colorectal cancer (CRC) and inflammatory bowel disease (IBD). These genes are primarily involved in signal transduction and cell wall biosynthesis and show consistency in their functions between IBD and CRC. Furthermore, we found that Leclercia adecarboxylata, a newly discovered opportunistic pathogen, has a significantly high abundance in the gut microbiota of colorectal cancer patients. OTGs of this pathogen were enriched in 15 metabolic pathways, including those associated with amino acid and cofactor metabolism. These findings, for the first time, provide evidence at the genetic level of the transfer of oral pathogens to the intestine and offer new insights into the understanding of the roles of oral pathogens in the development of gastrointestinal cancers.

Impact of doxycycline post-exposure prophylaxis for sexually transmitted infections on the gut microbiome and antimicrobial resistome

Doxycycline post-exposure prophylaxis (doxy-PEP) reduces bacterial sexually transmitted infections among men who have sex with men and transgender women. Although poised for widespread clinical implementation, the impact of doxy-PEP on antimicrobial resistance remains a primary concern as its effects on the gut microbiome and resistome, or the antimicrobial resistance genes (ARGs) present in the gut microbiome, are unknown. To investigate these effects, we studied participants from the DoxyPEP trial, a randomized clinical trial comparing doxy-PEP use, a one-time doxycycline 200-mg dose taken after condomless sex (DP arm, n = 100), to standard of care (SOC arm, n = 50) among men who have sex with men and transgender women. From self-collected rectal swabs at enrollment (day-0) and after 6 months (month-6), we performed metagenomic DNA sequencing (DNA-seq) or metatranscriptomic RNA sequencing (RNA-seq). DNA-seq data were analyzable from 127 samples derived from 89 participants, and RNA-seq data were analyzable from 86 samples derived from 70 participants. We compared the bacterial microbiome and resistome between the two study arms and over time. The median number of doxycycline doses taken since enrollment by participants with DNA-seq data was zero (interquartile range (IQR): 0-7 doses) for the SOC arm and 42 (IQR: 27-64 doses) for the DP arm. Tetracycline ARGs were detected in all day-0 DNA-seq samples and in 85% of day-0 RNA-seq samples. The proportional mass of tetracycline ARGs in the resistome increased between day-0 and month-6 in DP participants from 46% to 51% in the metagenome (P = 2.3 × 10-2) and from 4% to 15% in the metatranscriptome (P = 4.5 × 10-6), but no statistically significant increases in other ARG classes were observed. Exposure to a higher number of doxycycline doses correlated with proportional enrichment of tetracycline ARGs in the metagenome (Spearman's ρ = 0.23, P = 9.0 × 10-3) and metatranscriptome (Spearman's ρ = 0.55, P = 3.7 × 10-8). Bacterial microbiome alpha diversity, beta diversity and total bacterial mass did not differ between day-0 and month-6 samples from DP participants when assessed by either DNA-seq or RNA-seq. In an abundance-based correlation analysis, we observed an increase over time in the strength of the correlation between tetracycline ARGs and specific bacterial taxa, including some common human pathogens. In sum, doxy-PEP use over a 6-month period was associated with an increase in the proportion of tetracycline ARGs comprising the gut resistome and an increase in the expression of tetracycline ARGs. At 6 months of doxy-PEP use, no residual differences were observed in alpha and beta diversity or taxonomic composition of the gut microbiome. As doxy-PEP is implemented as a public health strategy, further studies and population-level surveillance of doxycycline-resistant pathogens are needed to understand the implications of these findings. ClinicalTrials.gov registration number: NCT03980223 .

Calcium‐dependent antimicrobials: Nature‐inspired materials and designs

Bacterial infection remains a major complication answering for the failures of various implantable medical devices. Tremendous extraordinary advances have been published in the design and synthesis of antimicrobial materials addressing this issue; however, the clinical translation has largely been blocked due to the challenge of balancing the efficacy and safety of these materials. Here, calcium's biochemical features, natural roles in pathogens and the immune systems, and advanced uses in infection medications are illuminated, showing calcium is a promising target for developing implantable devices with less infection tendency. The paper gives a historical overview of biomedical uses of calcium and summarizes calcium's merits in coordination, hydration, ionization, and stereochemistry for acting as a structural former or trigger in biological systems. It focuses on the involvement of calcium in pathogens' integrity, motility, and metabolism maintenance, outlining the potential antimicrobial targets for calcium. It addresses calcium's uses in the immune systems that the authors can learn from for antimicrobial synthesis. Additionally, the advances in calcium's uses in infection medications are highlighted to sketch the future directions for developing implantable antimicrobial materials. In conclusion, calcium is at the nexus of antimicrobial defense, and future works on taking advantage of calcium in antimicrobial developments are promising in clinical translation.

Microbiome contributions to pain: a review of the preclinical literature

ABSTRACT

Over the past 2 decades, the microbiome has received increasing attention for the role that it plays in health and disease. Historically, the gut microbiome was of particular interest to pain scientists studying nociplastic visceral pain conditions given the anatomical juxtaposition of these microorganisms and the neuroimmune networks that drive pain in such diseases. More recently, microbiomes both inside and across the surface of the body have been recognized for driving sensory symptoms in a broader set of diseases. Microbiomes have never been a more popular topic in pain research, but to date, there has not been a systematic review of the preclinical microbiome pain literature. In this article, we identified all animal studies in which both the microbiome was manipulated and pain behaviors were measured. Our analysis included 303 unique experiments across 97 articles. Microbiome manipulation methods and behavioral outcomes were recorded for each experiment so that field-wide trends could be quantified and reported. This review specifically details the animal species, injury models, behavior measures, and microbiome manipulations used in preclinical pain research. From this analysis, we were also able to conclude how manipulations of the microbiome alter pain thresholds in naïve animals and persistent pain intensity and duration in cutaneous and visceral pain models. This review summarizes by identifying existing gaps in the literature and providing recommendations for how to best plan, implement, and interpret data collected in preclinical microbiome pain experiments.

Bacteriocin diversity, function, discovery and application as antimicrobials

Bacteriocins are potent antimicrobial peptides that are produced by bacteria. Since their discovery almost a century ago, diverse peptides have been discovered and described, and some are currently used as commercial food preservatives. Many bacteriocins exhibit extensively post-translationally modified structures encoded on complex gene clusters, whereas others have simple linear structures. The molecular structures, mechanisms of action and resistance have been determined for a number of bacteriocins, but most remain incompletely characterized. These gene-encoded peptides are amenable to bioengineering strategies and heterologous expression, enabling metagenomic mining and modification of novel antimicrobials. The ongoing global antimicrobial resistance crisis demands that novel therapeutics be developed to combat infectious pathogens. New compounds that are target-specific and compatible with the resident microbiota would be valuable alternatives to current antimicrobials. As bacteriocins can be broad or narrow spectrum in nature, they are promising tools for this purpose. However, few bacteriocins have gone beyond preclinical trials and none is currently used therapeutically in humans. In this Review, we explore the broad diversity in bacteriocin structure and function, describe identification and optimization methods and discuss the reasons behind the lack of translation beyond the laboratory of these potentially valuable antimicrobials.

Staphylococcus aureus Tetracycline Resistance and Co-resistance in a Doxy-PEP-Eligible Population

In Staphylococcus aureus infections in men eligible for doxycycline post-exposure prophylaxis (doxy-PEP), tetracycline non-susceptibility is more prevalent than in the overall population and is associated with resistance to trimethoprim-sulfamethoxazole and clindamycin. Doxy-PEP may select for S. aureus multi-drug resistance, underscoring the importance of surveillance.

Biomaterials for non-invasive trans-tympanic drug delivery: requirements, recent advances and perspectives

Various non-invasive delivery systems have recently been developed as an alternative to conventional injections. Local transdermal administration represents the most attractive method due to the low systemic side effects, excellent ease of administration, and persistent drug release. The tympanic membrane (TM), a major barrier between the outer and middle ear, has a similar structure of the stratum corneum compared to the surface of the skin. After several attempts, non-invasive trans-tympanic drug delivery has been regarded as a promising option in the treatment of middle and inner ear diseases. The round window membrane (RWM) was a possible non-invasive delivery approach from the middle to inner ear. The improved permeability of nanocarriers crossing the RWM is a current hotspot in therapeutics for inner ear diseases. In this review, we include the latest studies exploring non-invasive trans-tympanic delivery to treat middle and inner ear diseases. Both passive and active delivery systems are described. A summary of the benefits and disadvantages of various delivery systems in clinical practice and production procedures is introduced. Finally, future possible approaches for its effective application as a non-invasive middle and inner ear drug delivery system are characterised.

Effectiveness of combined local therapy with antibiotics and fibrin vs. vacuum-assisted wound therapy in soft tissue infections: a retrospective study

PURPOSE

Soft tissue infections can be severe and life-threatening. Their treatment consists currently in radical surgical wound debridement and combined systemic antimicrobial therapy. Different side effects are possible. Local antibiotic therapy represents a new approach to reduce side effects and improve healing. The aim of this study is to assess the effectiveness of the local sprayed use of antibiotics with fibrin sealing compared with negative pressure wound therapy as an established treatment of soft-tissue infections.

METHODS

In this retrospective study, patients with soft tissue infections who underwent surgical treatment were analysed. One group consists of patients, who received local fibrin-antibiotic spray (FAS) (n = 62). Patients treated by vacuum-assisted wound therapy (VAWT) as the established treatment were the control group (n = 57). Main outcomes were differences in the success of healing, the duration until healing and the number of needed operations.

RESULTS

Clinical healing could be achieved for 55 patients (98.21%) in the FAS group vs. 47 patients (92.16%) in the VAWT group (p = 0.19). Time to require this was 10.65 ± 10.38 days in the FAS group and 22.85 ± 14.02 days in the VAWT group (p < 0.001). In the FAS group, patients underwent an average of 1.44 ± 0.72 vs.3.46 ± 1.66 operations in the VAWT group (p < 0.001).

CONCLUSION

Compared to vacuum-assisted wound therapy in soft tissue infections, local fibrin-antibiotic spray shows faster clinical healing and less needed operations. Leading to shorter hospital stays and more satisfied patients. The combination of sprayed fibrin and antibiotics can be seen as a promising and effective method.

The effect of combining antibiotics on resistance: A systematic review and meta-analysis

When and under which conditions antibiotic combination therapy decelerates rather than accelerates resistance evolution is not well understood. We examined the effect of combining antibiotics on within-patient resistance development across various bacterial pathogens and antibiotics. We searched CENTRAL, EMBASE and PubMed for (quasi)-randomised controlled trials (RCTs) published from database inception to November 24th, 2022. Trials comparing antibiotic treatments with different numbers of antibiotics were included. A patient was considered to have acquired resistance if, at the follow-up culture, a resistant bacterium (as defined by the study authors) was detected that had not been present in the baseline culture. We combined results using a random effects model and performed meta-regression and stratified analyses. The trials' risk of bias was assessed with the Cochrane tool. 42 trials were eligible and 29, including 5054 patients, were qualified for statistical analysis. In most trials, resistance development was not the primary outcome and studies lacked power. The combined odds ratio (OR) for the acquisition of resistance comparing the group with the higher number of antibiotics with the comparison group was 1.23 (95% CI 0.68-2.25), with substantial between-study heterogeneity (I 2 =77%). We identified tentative evidence for potential beneficial or detrimental effects of antibiotic combination therapy for specific pathogens or medical conditions. The evidence for combining a higher number of antibiotics compared to fewer from RCTs is scarce and overall, is compatible with both benefit or harm. Trials powered to detect differences in resistance development or well-designed observational studies are required to clarify the impact of combination therapy on resistance.

In utero or early-in-life exposure to antibiotics and the risk of childhood atopic dermatitis, a population-based cohort study

BACKGROUND

Atopic dermatitis (AD) is a common inflammatory disease of the skin that begins early in life and can be lifelong. The purpose of our study was to evaluate whether fetal exposure and/or early-life exposure of a child to antibiotics increases the risk of early-onset AD.

OBJECTIVES

We hypothesize that antibiotic exposure in utero or early in life (e.g. first 90 days) increases the likelihood that children develop AD.

METHODS

Utilizing a large, prospectively collected electronic medical records database, we studied the association of antibiotic exposure received in utero or very early in life and the relative risk of onset of AD in a population-based cohort study. Associations were estimated using proportional hazards models as hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

The risk of AD in childhood was increased after in utero or early-life antibiotic exposure. For any in utero antibiotic exposure the HR (CI) was 1.38 (1.36-1.39). However, penicillin demonstrated the strongest association with AD for both in utero exposure [1.43 (1.41-1.44)] and for childhood exposure [1.81 (1.79-1.82)]. HRs were higher in children born to mothers without AD than in those with AD pointing to effect modification by maternal AD status.

CONCLUSIONS

Children born to mothers exposed to antibiotics while in utero had, depending on the mother's history of AD, approximately a 20-40% increased risk of developing AD. Depending on the antibiotic, children who received antibiotics early in life had a 40-80% increased risk of developing AD. Our study supports and refines the association between incident AD and antibiotic administration. It also adds population-based support to therapeutic attempts to treat AD by modifying the skin microbiome.

The skin microbiome in pediatric atopic dermatitis and food allergy

The skin microbiome is an extensive community of bacteria, fungi, mites, viruses and archaea colonizing the skin. Fluctuations in the composition of the skin microbiome have been observed in atopic dermatitis (AD) and food allergy (FA), particularly in early life, established disease, and associated with therapeutics. However, AD is a multifactorial disease characterized by skin barrier aberrations modulated by genetics, immunology, and environmental influences, thus the skin microbiome is not the sole feature of this disease. Future research should focus on mechanistic understanding of how early-life skin microbial shifts may influence AD and FA onset, to guide potential early intervention strategies or as microbial biomarkers to identify high-risk infants who may benefit from possible microbiome-based biotherapeutic strategies. Harnessing skin microbes as AD biotherapeutics is an emerging field, but more work is needed to investigate whether this approach can lead to sustained clinical responses.

Combination of Neovestitol and Vestitol Modifies the Profile of Periodontitis-Related Subgingival Multispecies Biofilm

The aim of this study was to evaluate the effect of the combination of neovestitol-vestitol (CNV) compounds obtained from Brazilian red propolis on the microbiological profile of a mature multispecies subgingival biofilm. The biofilm with 32 bacterial species associated with periodontitis was formed for seven days using a Calgary device. Treatment with CNV (1600, 800, 400, and 200 μg/mL), amoxicillin (54 μg/mL), and vehicle control was performed for 24 h on the last day of biofilm formation. Biofilm metabolic activity and DNA-DNA hybridization (checkerboard) assays were performed. The groups treated with CNV 1600 and amoxicillin reduced 25 and 13 species, respectively, compared to the control vehicle treatment (p ≤ 0.05); both reduced P. gingivalis, while only CNV reduced T. forsythia. When the data from the two treatments (CNV and AMOXI) were compared, a statistically significant difference was observed in 13 species, particularly members of Socransky's orange complex. Our results showed that CNV at 1600 μg/mL showed the best results regarding the metabolic activity of mature biofilms and obtained a reduction in species associated with the disease, such as T. forsythia, showing a better reduction than amoxicillin. Therefore, CNV seems to be a promising alternative to eradicate biofilms and reduce their pathogenicity.

Barriers and Facilitators Affecting Long-Term Antibiotic Prescriptions for Acne Treatment

Importance

Dermatologists prescribe more oral antibiotics per clinician than clinicians in any other specialty. Despite clinical guidelines that recommend limitation of long-term oral antibiotic treatments for acne to less than 3 months, there is little evidence to guide the design and implementation of an antibiotic stewardship program in clinical practice.

Objective

To identify salient barriers and facilitators to long-term antibiotic prescriptions for acne treatment.

Design, Setting, and Participants

This qualitative study assessed data collected from stakeholders (including dermatologists, infectious disease physicians, dermatology resident physicians, and nonphysician clinicians) via an online survey and semistructured video interviews between March and August 2021. Data analyses were performed from August 12, 2021, to January 20, 2024.

Main Outcomes and Measures

Online survey and qualitative video interviews developed with the Theoretical Domains Framework. Thematic analyses were used to identify salient themes on barriers and facilitators to long-term antibiotic prescriptions for acne treatment.

Results

Among 30 participants (14 [47%] males and 16 [53%] females) who completed the study requirements and were included in the analysis, knowledge of antibiotic guideline recommendations was high and antibiotic stewardship was believed to be a professional responsibility. Five salient themes were to be affecting long-term antibiotic prescriptions: perceived lack of evidence to justify change in dermatologic practice, difficulty navigating patient demands and satisfaction, discomfort with discussing contraception, iPLEDGE-related barriers, and the absence of an effective system to measure progress on antibiotic stewardship.

Conclusions and Relevance

The findings of this qualitative study indicate that multiple salient factors affect long-term antibiotic prescribing practices for acne treatment. These factors should be considered in the design and implementation of any future outpatient antibiotic stewardship program for clinical dermatology.

Doxycycline post-exposure prophylaxis for sexually transmitted infections impacts the gut antimicrobial resistome

Doxycycline post-exposure prophylaxis (doxy-PEP) reduces bacterial sexually transmitted infections (STIs) among men who have sex with men and transgender women. While poised for widespread clinical implementation, the impact of doxy-PEP on antimicrobial resistance remains a primary concern as its effects on the gut microbiome and resistome, or the antimicrobial resistance genes (ARGs) present in the gut microbiome, are unknown. To investigate these effects, we studied participants from a randomized clinical trial who either received doxy-PEP as a one-time doxycycline 200 mg taken after condomless sex (DP arm, n = 100) or standard of care treatment (SOC arm, n = 50). From self-collected rectal swabs at enrollment (day-0) and after 6 months (month-6), we performed metagenomic DNA sequencing (DNA-seq) or metatranscriptomic RNA sequencing (RNA-seq). DNA-seq data was analyzable from 127 samples derived from 89 participants, and RNA-seq data from 86 samples derived from 70 participants. We compared the bacterial microbiome and resistome between the two study arms and over time. Tetracycline ARGs were detected in all day-0 DNA-seq samples and 85% of day-0 RNA-seq samples. The proportional mass of tetracycline ARGs in the resistome increased between day-0 and month-6 in DP participants from 46-51% in the metagenome (p = 0.02) and 4-15% in the metatranscriptome (p < 0.01), but no changes in other ARG classes were observed. Exposure to a higher number of doxycycline doses correlated with proportional enrichment of tetracycline ARGs in the metagenome (Spearman's ρ = 0.23, p < 0.01) and metatranscriptome (Spearman's ρ = 0.55, p < 0.01). Bacterial microbiome alpha diversity, beta diversity, and total bacterial mass did not differ between day-0 and month-6 samples from DP participants when assessed by either DNA-seq or RNA-seq. In an abundance-based correlation analysis, we observed an increase over time in the strength of the correlation between tetracycline ARGs and specific bacterial taxa, including some common human pathogens. In sum, doxy-PEP use over a 6-month period was associated with an increase in the proportion of tetracycline ARGs comprising the gut resistome, and an increase in the expression of tetracycline ARGs. Notably, doxy-PEP did not significantly alter alpha diversity or taxonomic composition of the gut microbiome, and did not demonstrate significant increases in non-tetracycline ARG classes. Further studies and population level surveillance are needed to understand the implications of these findings as doxy-PEP is implemented as a public health strategy.

Abundance and diversity of methicillin-resistant bacteria from bathroom surfaces at workplaces using CHROMagar media, 16S, and dnaJ gene sequence typing

University campus communities consist of dynamic and diverse human populations originated from different regions of the country or the world. Their national/global movement to and from campus may contribute to the spread and buildup of methicillin-resistant (MR) bacteria, including MR Staphylococci (MRS) on high-touch surfaces, sinks, and toilets. However, studies on MR bacteria contamination of surfaces, sinks, and toilets are scarce in workplaces outside of healthcare settings. Hence, little is known whether university communities contaminate campus bathrooms by MR bacteria. This study evaluated the abundance, identity, and phylogenetics of MR bacteria grown on CHROMagar MRSA media from bathrooms at workplaces. We collected 21 sink and 21 toilet swab samples from 10 buildings on campus and cultured them on CHROMagar MRSA media, extracted DNA from MR bacteria colonies, sequenced PCR products of 16S and dnaJ primers, determined the sequence identities by BLAST search, and constructed a phylogenetic tree. Of 42 samples, 57.1% (24/42) harbored MR bacteria. MR bacteria were more prevalent on the sink (61.9%) than in the toilet (52.2%) and in male bathrooms (54.2%) than in female bathrooms (41.7%). The colony count on the bathroom surfaces of 42 samples varied in that 42.9% (18/42), 33.3, 14.3, and 9.5% of samples harbored 0, 100, and > 1000 MR bacteria colonies, respectively. Of MR bacteria sequenced, BLAST search and phylogenetic analysis showed that Staphylococcus accounted for 60% of the MR bacteria and the rest were non-Staphylococci. Of Staphylococcus carrying MR (n = 15), 53.3% were S. hemolyticus followed by S. lugdunensis (26.7%), S. epidermidis (8%), and a newly discovered S. borealis in 2020 (4%). Of non-Staphylococci MR bacteria, 20% accounted for Sphingomonas koreensis. Campus bathrooms serve as a reservoir for diverse bacteria carrying MR, which pose a direct risk of infection and a potential source of horizontal gene transfer. To reduce the health risk posed by MR bacteria in high traffic areas such as bathrooms additional environmental monitoring and improved decontamination practices are needed.

Contribution of the patient microbiome to surgical site infection and antibiotic prophylaxis failure in spine surgery

Despite modern antiseptic techniques, surgical site infection (SSI) remains a leading complication of surgery. However, the origins of SSI and the high rates of antimicrobial resistance observed in these infections are poorly understood. Using instrumented spine surgery as a model of clean (class I) skin incision, we prospectively sampled preoperative microbiomes and postoperative SSI isolates in a cohort of 204 patients. Combining multiple forms of genomic analysis, we correlated the identity, anatomic distribution, and antimicrobial resistance profiles of SSI pathogens with those of preoperative strains obtained from the patient skin microbiome. We found that 86% of SSIs, comprising a broad range of bacterial species, originated endogenously from preoperative strains, with no evidence of common source infection among a superset of 1610 patients. Most SSI isolates (59%) were resistant to the prophylactic antibiotic administered during surgery, and their resistance phenotypes correlated with the patient's preoperative resistome (P = 0.0002). These findings indicate the need for SSI prevention strategies tailored to the preoperative microbiome and resistome present in individual patients.

N-acyl homoserine lactones lactonase est816 suppresses biofilm formation and periodontitis in rats mediated by Aggregatibacter actinomycetemcomitans

Aims

The current study aimed to explore the adjuvant therapeutic effect of N-acyl homoserine lactones (AHLs)-lactonase est816 on Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) biological behaviors and periodontitis progression.

Methods

The inhibitory properties of est816 were detected by live/dead bacterial staining, scanning electron microscope (SEM), crystal-violet staining and reverse-transcription quantitative PCR (RT-qPCR). Biocompatibility of est816 on human gingival fibroblasts (HGFs) and human gingival epithelial cells (HGEs) was evaluated by CCK8 and ELISA. The ligature-induced periodontitis model was established in rats. Micro computed tomography and immunohistochemical and histological staining served to evaluate the effect of est816 on the prevention of periodontitis in vivo.

Results

est816 significantly attenuated biofilm formation, reduced the mRNA expression of cytolethal distending toxin, leukotoxin and poly-N-acetyl glucosamine (PNAG) and downregulated expressions of interleukin-6 and tumor necrosis factor-α with low cell toxicity. In vivo investigations revealed est816 decreased alveolar bone resorption, suppressed matrix metalloproteinase-9 expression and increased osteoprotegerin expression.

Conclusion

est816 inhibited A. actinomycetemcomitans biofilm formation and virulence release, resulting in anti-inflammation and soothing of periodontitis in rats, indicating that est816 could be investigated in further research on periodontal diseases.

Stable closure of acute and chronic wounds and pressure ulcers and control of draining fistulas from osteomyelitis in persons with spinal cord injuries: non-interventional study of MPPT passive immunotherapy delivered via telemedicine in community care

Background

Micropore particle technology (MPPT) is a topical wound treatment. It is a passive immunotherapy, acting via the skin and wound microbiome without the use of antimicrobial action. In a general patient population, it removed wound infections 60% and initiated tissue regeneration 50% quicker than antibiotics and antiseptics. As MPPT supports the immune system, the aim was to confirm that MPPT is also effective in immunocompromised individuals. People with spinal cord injury (SCI) are immunodeficient due to their injury and not an underlying disease and recruit 50% fewer immune cells to an injury. The study, therefore, determined the efficacy, safety, health economics, and sustainability of MPPT in acute and chronic wounds and pressure ulcers in this patient population.

Methods

Pressure ulcers in SCI persons are an orphan indication, patient variability is high, and ICH E10 excludes comparators due to ethical concerns. The study design was, therefore, a single-arm, non-interventional, observational, post-market surveillance study of MPPT for treating wounds and pressure ulcers and removing soft tissue infection in connection with draining fistulas in SCI persons. The study was based on telemedicine in community care.

Results

The study included 44 wounds. All acute and chronic grade 1-4 wounds and pressure ulcers reached stable closure. In wounds acting as fistulas draining from an underlying, primary focus of infection, e.g., osteomyelitis, MPPT removed the soft tissue infection in approx. 2.5 months and supported regeneration, considerably reducing fistula sizes. Compared to standard care, per-wound cost savings were 51 to 94% depending on wound grade and age, and substantial nursing resources were freed up. The telemedicine approach was well received by participants and supported independence and self-care. The use of antimicrobials, plastics, and synthetic polymers was essentially eliminated. MPPT did not require bed rest.

Conclusion

The study confirmed that MPPT is safe and effective in treating acute and chronic wounds in immunocompetent and immunocompromised individuals, including wounds with antimicrobial-resistant infections. MPPT also removes soft tissue infections caused by an underlying primary focus of infection, such as osteomyelitis. Non-healing wounds currently represent an unmet clinical need. The findings suggest that a therapy acting via the microbiome without antimicrobial actions is effective.

Value of inflammatory response and oxidative damage in the diagnosis of infections in severe alcoholic hepatitis

Severe alcoholic hepatitis is the most lethal complication in alcohol dependent patients. The concurrence of infections in these patients is very frequent. Both produce a systemic inflammatory response syndrome (SIRS), secondary to intense release of inflammatory cytokines, which can complicate the diagnosis. In our study, Interleukin (IL)-6 and IL-10 levels are higher in patients with SIRS (p<0.001 and p = 0.033, respectively). IL-4, IL-6, Interferon-gamma (IFNγ), Tumor necrosis factor alpha (TNFα) and IL-17 levels correlate with liver function, as estimated by MELD-Na (p = 0.018, p = 0.008, p = 0.009, p = 0.016 and p = 0.006, respectively). Malondialdehyde (MDA), a product of lipid peroxidation and marker of cell damage, also correlates with liver function (p = 0.002), but not with SIRS or infections. Only elevated IL-6 correlates independently with the presence of infections (RR=1.023 IC 95% 1.000-1.047), so it may be useful for the correct diagnosis in these patients. Values greater than 30 pg/mL have a sensitivity: 86.7% and specificity: 94.7% for the diagnosis of infections.

Investigation of the potential roles of adipose stem cells and substances of natural origin in the healing process of E. coli infected wound model in Rats

Skin infections by pathogenic microorganisms are a serious problem due to the potential of dissemination through the bloodstream to various organs causing toxic effects that may be up to mortality. Escherichia coli (E. coli) is one of the most predominant Gram-negative bacterial species present globally with great attention for investigation. The current study is designed to investigate the possible role of adipose tissue-derived stem cells (ADSCs), as well as natural products such as Trichoderma viride (T. viride) extract, Saccharomyces boulardii (S. boulardii) solution in the enhancement of wound healing process in the infected skin with E. coli. Ninety-six female rats were divided into 8 groups (12 animal/group): normal skin, wounded skin, wounded skin infected with E. coli, infected-wounded skin treated by ADSCs, infected-wounded skin treated by T. viride extract, infected-wounded skin treated by S. boulardii solution, infected-wounded skin treated a combination of treatments, infected-wounded skin treated by gentamicin. At day 21 animal weights and bacterial count were detected and compared. Animals were sacrificed and skin from various groups was investigated using a light microscope for sections stained by (hematoxylin eosin, Masson trichrome, and PCNA) as well as transmission electron microscopy. Pro-inflammatory (IL-1β, TNF- α, and IL-13), anti-inflammatory cytokine (IL-4), and antioxidant enzymes (Superoxide dismutase, glutathione, and catalase) were assessed in various groups revealing that ADSCs lightly shift levels of these parameters in various rat groups to regular levels, while administration of T. viride extract, S. boulardii solution, their combination with ADSCs and gentamicin treatment drive the tested cytokines and enzymes to significant levels similar to a normal level where combination therapy gave the best result. The current findings revealed the possibility of using certain natural products as possible substitutes to regularly applied antibiotics with successive protective results in the wound infection model.

Utility of Routine Preoperative Urinalysis in the Prevention of Surgical Site Infections

OBJECTIVE

Preoperative assessment is important for neurosurgical risk stratification, but the level of evidence for individual screening tests is low. In preoperative urinalysis (UA), testing may significantly increase costs and lead to inappropriate antibiotic treatment. We prospectively evaluated whether eliminating preoperative UA was noninferior to routine preoperative UA as measured by 30-day readmission for surgical site infection in adult elective neurosurgical procedures.

METHODS

A single-institution prospective, pragmatic study of patients receiving elective neurosurgical procedures from 2018 to 2020 was conducted. Patients were allocated based on same-day versus preoperative admission status. Rates of preoperative UA and subsequent wound infection were measured along with detailed demographic, surgical, and laboratory data.

RESULTS

The study included 879 patients. The most common types of surgery were cranial (54.7%), spine (17.4%), and stereotactic/functional (19.5%). No preoperative UA was performed in 315 patients, while 564 underwent UA. Of tested patients, 103 (18.3%) met criteria for suspected urinary tract infection, and 69 (12.2%) received subsequent antibiotic treatment. There were 14 patients readmitted within 30 days (7 without UA [2.2%] vs. 7 with UA [1.2%]) for subsequent wound infection with a risk difference of 0.98% (95% confidence interval -0.89% to 2.85%). The upper limit of the confidence interval exceeded the preselected noninferiority margin of 1%.

CONCLUSIONS

In this prospective study of preoperative UA for elective neurosurgical procedures using a pragmatic, real-world design, risk of readmission due to surgical site infection was very low across the study cohort, suggesting a limited role of preoperative UA for elective neurosurgical procedures.

Antimicrobial-loaded biodegradable nanoemulsions for efficient clearance of intracellular pathogens in bacterial peritonitis

Intracellular pathogenic bacteria use immune cells as hosts for bacterial replication and reinfection, leading to challenging systemic infections including peritonitis. The spread of multidrug-resistant (MDR) bacteria and the added barrier presented by host cell internalization limit the efficacy of standard antibiotic therapies for treating intracellular infections. We present a non-antibiotic strategy to treat intracellular infections. Antimicrobial phytochemicals were stabilized and delivered by polymer-stabilized biodegradable nanoemulsions (BNEs). BNEs were fabricated using different phytochemicals, with eugenol-loaded BNEs (E-BNEs) affording the best combination of antimicrobial efficacy, macrophage accumulation, and biocompatibility. The positively-charged polymer groups of the E-BNEs bind to the cell surface of macrophages, facilitating the entry of eugenol that then kills the intracellular bacteria without harming the host cells. Confocal imaging and flow cytometry confirmed that this entry occurred mainly via cholesterol-dependent membrane fusion. As eugenol co-localized and interacted with intracellular bacteria, antibacterial efficacy was maintained. E-BNEs reversed the immunosuppressive effects of MRSA on macrophages. Notably, E-BNEs did not elicit resistance selection after multiple exposures of MRSA to sub-therapeutic doses. The E-BNEs were highly effective against a murine model of MRSA-induced peritonitis with better bacterial clearance (99 % bacteria reduction) compared to clinically-employed treatment with vancomycin. Overall, these findings demonstrate the potential of E-BNEs in treating peritonitis and other refractory intracellular infections.

Expanded microbiome niches of RAG-deficient patients

The complex interplay between microbiota and immunity is important to human health. To explore how altered adaptive immunity influences the microbiome, we characterize skin, nares, and gut microbiota of patients with recombination-activating gene (RAG) deficiency-a rare genetically defined inborn error of immunity (IEI) that results in a broad spectrum of clinical phenotypes. Integrating de novo assembly of metagenomes from RAG-deficient patients with reference genome catalogs provides an expansive multi-kingdom view of microbial diversity. RAG-deficient patient microbiomes exhibit inter-individual variation, including expansion of opportunistic pathogens (e.g., Corynebacterium bovis, Haemophilus influenzae), and a relative loss of body site specificity. We identify 35 and 27 bacterial species derived from skin/nares and gut microbiomes, respectively, which are distinct to RAG-deficient patients compared to healthy individuals. Underscoring IEI patients as potential reservoirs for viral persistence and evolution, we further characterize the colonization of eukaryotic RNA viruses (e.g., Coronavirus 229E, Norovirus GII) in this patient population.

A Pipeline for Constructing Reference Genomes for Large Cohort-Specific Metagenome Compression

Metagenomic data compression is very important as metagenomic projects are facing the challenges of larger data volumes per sample and more samples nowadays. Reference-based compression is a promising method to obtain a high compression ratio. However, existing microbial reference genome databases are not suitable to be directly used as references for compression due to their large size and redundancy, and different metagenomic cohorts often have various microbial compositions. We present a novel pipeline that generated simplified and tailored reference genomes for large metagenomic cohorts, enabling the reference-based compression of metagenomic data. We constructed customized reference genomes, ranging from 2.4 to 3.9 GB, for 29 real metagenomic datasets and evaluated their compression performance. Reference-based compression achieved an impressive compression ratio of over 20 for human whole-genome data and up to 33.8 for all samples, demonstrating a remarkable 4.5 times improvement than the standard Gzip compression. Our method provides new insights into reference-based metagenomic data compression and has a broad application potential for faster and cheaper data transfer, storage, and analysis.

Bioprospecting the Skin Microbiome: Advances in Therapeutics and Personal Care Products

Bioprospecting is the discovery and exploration of biological diversity found within organisms, genetic elements or produced compounds with prospective commercial or therapeutic applications. The human skin is an ecological niche which harbours a rich and compositional diversity microbiome stemming from the multifactorial interactions between the host and microbiota facilitated by exploitable effector compounds. Advances in the understanding of microbial colonisation mechanisms alongside species and strain interactions have revealed a novel chemical and biological understanding which displays applicative potential. Studies elucidating the organismal interfaces and concomitant understanding of the central processes of skin biology have begun to unravel a potential wealth of molecules which can exploited for their proposed functions. A variety of skin-microbiome-derived compounds display prospective therapeutic applications, ranging from antioncogenic agents relevant in skin cancer therapy to treatment strategies for antimicrobial-resistant bacterial and fungal infections. Considerable opportunities have emerged for the translation to personal care products, such as topical agents to mitigate various skin conditions such as acne and eczema. Adjacent compound developments have focused on cosmetic applications such as reducing skin ageing and its associated changes to skin properties and the microbiome. The skin microbiome contains a wealth of prospective compounds with therapeutic and commercial applications; however, considerable work is required for the translation of in vitro findings to relevant in vivo models to ensure translatability.

Oral and Topical Probiotics and Postbiotics in Skincare and Dermatological Therapy: A Concise Review

The skin microbiota is a pivotal contributor to the maintenance of skin homeostasis by protecting it from harmful pathogens and regulating the immune system. An imbalance in the skin microbiota can lead to pathological conditions such as eczema, psoriasis, and acne. The balance of the skin microbiota components can be disrupted by different elements and dynamics such as changes in pH levels, exposure to environmental toxins, and the use of certain skincare products. Some research suggests that certain probiotic strains and their metabolites (postbiotics) may provide benefits such as improving the skin barrier function, reducing inflammation, and improving the appearance of acne-prone or eczema-prone skin. Consequently, in recent years probiotics and postbiotics have become a popular ingredient in skincare products. Moreover, it was demonstrated that skin health can be influenced by the skin-gut axis, and imbalances in the gut microbiome caused by poor diet, stress, or the use of antibiotics can lead to skin conditions. In this way, products that improve gut microbiota balance have been gaining attention from cosmetic and pharmaceutical companies. The present review will focus on the crosstalk between the SM and the host, and its effects on health and diseases.

One population, multiple lifestyles: Commensalism and pathogenesis in the human mycobiome

Candida auris and Candida albicans can result in invasive fungal diseases. And yet, these species can stably and asymptomatically colonize human skin and gastrointestinal tracts. To consider these disparate microbial lifestyles, we first review factors shown to influence the underlying microbiome. Structured by the damage response framework, we then consider the molecular mechanisms deployed by C. albicans to switch between commensal and pathogenic lifestyles. Next, we explore this framework with C. auris to highlight how host physiology, immunity, and/or antibiotic receipt are associated with progression from colonization to infection. While treatment with antibiotics increases the risk that an individual will succumb to invasive candidiasis, the underlying mechanisms remain unclear. Here, we describe several hypotheses that may explain this phenomenon. We conclude by highlighting future directions integrating genomics with immunology to advance our understanding of invasive candidiasis and human fungal disease.

Staphylococcal diversity in atopic dermatitis from an individual to a global scale

Atopic dermatitis (AD) is a multifactorial, chronic relapsing disease associated with genetic and environmental factors. Among skin microbes, Staphylococcus aureus and Staphylococcus epidermidis are associated with AD, but how genetic variability and staphylococcal strains shape the disease remains unclear. We investigated the skin microbiome of an AD cohort (n = 54) as part of a prospective natural history study using shotgun metagenomic and whole genome sequencing, which we analyzed alongside publicly available data (n = 473). AD status and global geographical regions exhibited associations with strains and genomic loci of S. aureus and S. epidermidis. In addition, antibiotic prescribing patterns and within-household transmission between siblings shaped colonizing strains. Comparative genomics determined that S. aureus AD strains were enriched in virulence factors, whereas S. epidermidis AD strains varied in genes involved in interspecies interactions and metabolism. In both species, staphylococcal interspecies genetic transfer shaped gene content. These findings reflect the staphylococcal genomic diversity and dynamics associated with AD.

Hybrid microneedle arrays for antibiotic and near-IR photothermal synergistic antimicrobial effect against Methicillin-Resistant Staphylococcus aureus

The rise of antibiotic-resistant skin and soft tissue infections (SSTIs) necessitates the development of novel treatments to improve the efficiency and delivery of antibiotics. The incorporation of photothermal agents such as plasmonic nanoparticles (NPs) improves the antibacterial efficiency of antibiotics through synergism with elevated temperatures. Hybrid microneedle (MN) arrays are promising local delivery platforms that enable co-therapy with therapeutic and photothermal agents. However, to-date, the majority of hybrid MNs have focused on the potential treatment of skin cancers, while suffering from the shortcoming of the intradermal release of photothermal agents. Here, we developed hybrid, two-layered MN arrays consisting of an outer water-soluble layer loaded with vancomycin (VAN) and an inner water-insoluble near-IR photothermal core. The photothermal core consists of flame-made plasmonic Au/SiO2 nanoaggregates and polymethylmethacrylate (PMMA). We analyzed the effect of the outer layer polymer, polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), on MN morphology and performance. Hybrid MNs produced with 30 wt% PVA contain a highly drug-loaded outer shell allowing for the incorporation of VAN concentrations up to 100 mg g-1 and temperature increases up to 60 °C under near-IR irradiation while showing sufficient mechanical strength for skin insertion. Furthermore, we studied the combinatorial effect of VAN and heat on the growth inhibition of methicillin-resistant Staphylococcus aureus (MRSA) showing synergistic inhibition between VAN and heat above 55 °C for 10 min. Finally, we show that treatment with hybrid MN arrays can inhibit the growth of MRSA due to the synergistic interaction of heat with VAN reducing the bacterial survival by up to 80%. This proof-of-concept study demonstrates the potential of hybrid, two-layered MN arrays as a novel treatment option for MRSA-associated skin infections.

Reservoirs of antimicrobial resistance in the context of One Health

The emergence and spread of antimicrobial resistance (AMR) and resistant bacteria, are a global public health challenge. Through horizontal gene transfer, potential pathogens can acquire antimicrobial resistance genes (ARGs) that can subsequently be spread between human, animal, and environmental reservoirs. To understand the dissemination of ARGs and linked microbial taxa, it is necessary to map the resistome within different microbial reservoirs. By integrating knowledge on ARGs in the different reservoirs, the One Health approach is crucial to our understanding of the complex mechanisms and epidemiology of AMR. Here, we highlight the latest insights into the emergence and spread of AMR from the One Health perspective, providing a baseline of understanding for future scientific investigations into this constantly growing global health threat.

Temporal shifts of the microbiome associated with antibiotic treatment of purpuric drug eruptions related to epidermal growth factor receptor inhibitors

BACKGROUND

Epidermal growth factor receptor (EGFR) inhibitors are selective and effective treatments for cancers with relevant mutations. Purpuric drug eruptions are an uncommon but clinically significant dermatological side effect related to EGFR inhibitor use that are associated with positive bacterial cultures and responsive to antibiotic treatment. However, the longitudinal temporal shifts in the skin microbiome that occur before and after antibiotic treatment of purpuric drug eruptions remain largely unknown.

OBJECTIVES

To characterize temporal changes in the skin and mucosal microbiomes before and after antibiotic treatment of EGFR inhibitor-related purpuric drug eruptions.

METHODS

Twelve patients who experienced EGFR inhibitor-related purpuric drug eruptions were recruited from a dermato-oncology clinic in Taiwan from May 2017 to April 2018. Swabs were obtained from skin lesions and the nasal mucosa before and after antibiotic treatment of purpuric drug eruptions. After the amplification and sequencing of bacterial 16S rRNA genes, the diversity and compositions of microbiomes sampled at different time points were compared.

RESULTS

The alpha diversity (represented by the Shannon index) of the skin microbiome increased significantly in the recovered phase of purpuric drug eruptions compared with that of the active phase. By contrast, the nasal microbiome showed no significant change in alpha diversity. The relative abundance of Staphylococcus significantly decreased in samples from skin of the recovered phase, which was confirmed by analysis of compositions of microbiomes (ANCOM) and the ALDEx2 analysis packages in R.

CONCLUSIONS

The cutaneous microbiome of purpuric drug eruptions showed a significant increase in alpha diversity and a decrease in the relative abundance of Staphylococcus following antibiotic treatment. These findings may help guide antimicrobial therapy of this EGFR inhibitor-related condition.

Antibiotics and Antimicrobial Resistance in Acne: Epidemiological Trends and Clinical Practice Considerations

Antimicrobial resistance is an increasing public health problem worldwide. The interest of a focus on antimicrobial resistance in acne lies on the facts that acne vulgaris (acne) is the most common skin disease worldwide, that the bacterium Cutibacterium acnes (C. acnes, formerly Propionibacterium acnes) plays a key role in the pathogenesis of acne, while at the same time being part of the skin flora, and that antibiotics are commonly recommended for acne treatment. The overuse of topical and/or systemic antibiotics, the long treatment courses used for acne, and the availability of over-the-counter antibiotic preparations, have led to the worldwide emergence of resistant strains in acne patients. In this review, we discuss the epidemiological trends of antimicrobial resistance in acne, the need to avoid the perturbation of the skin microbiome caused by anti-acne antibiotics, and the clinical practice considerations related to the emergence of resistant strains in acne patients. In light of the increasing risk of antimicrobial resistance, raising concerns over the misuse of antibiotics, prescribing patterns can be a critical target for antibiotic stewardship efforts. Also, the selection of non-antibiotic therapies for acne, whenever possible, may offer significant advantages.

Strains to go: interactions of the skin microbiome beyond its species

An extraordinary biodiversity of bacteria, fungi, viruses, and even small multicellular eukaryota inhabit the human skin. Genomic innovations have accelerated characterization of this biodiversity both at a species as well as the subspecies, or strain level, which further imparts a tremendous genetic diversity to an individual's skin microbiome. In turn, these advances portend significant species- and strain-specificity in the skin microbiome's functional impact on cutaneous immunity, barrier integrity, aging, and other skin physiologic processes. Future advances in defining strain diversity, spatial distribution, and metabolic diversity for major skin species will be foundational for understanding the microbiome's essentiality to the skin ecosystem and for designing topical therapeutics that leverage or target the skin microbiome.

Exploring strain diversity of dominant human skin bacterial species using single-cell genome sequencing

To understand the role of the skin commensal bacterial community in skin health and the spread of pathogens, it is crucial to identify genetic differences in the bacterial strains corresponding to human individuals. A culture-independent genomics approach is an effective tool for obtaining massive high-quality bacterial genomes. Here we present a single-cell genome sequencing to obtain comprehensive whole-genome sequences of uncultured skin bacteria from skin swabs. We recovered 281 high-quality (HQ) and 244 medium-quality single-amplified genomes (SAGs) of multiple skin bacterial species from eight individuals, including cohabiting group. Single-cell sequencing outperformed in the genome recovery from the same skin swabs, showing 10-fold non-redundant strain genomes compared to the shotgun metagenomic sequencing and binning approach. We then focused on the abundant skin bacteria and identified intra-species diversity, especially in 47 Moraxella osloensis derived HQ SAGs, characterizing the strain-level heterogeneity at mobile genetic element profiles, including plasmids and prophages. Even between the cohabiting individual hosts, they have unique skin bacterial strains in the same species, which shows microdiversity in each host. Genetic and functional differences between skin bacterial strains are predictive of in vivo competition to adapt bacterial genome to utilize the sparse nutrients available on the skin or produce molecules that inhibit the colonization of other microbes or alter their behavior. Thus, single-cell sequencing provides a large number of genomes of higher resolution and quality than conventional metagenomic analysis and helps explore the skin commensal bacteria at the strain level, linking taxonomic and functional information.

Spinal muscular atrophy

Spinal muscular atrophy (SMA) is a neurodegenerative disorder caused by mutations in SMN1 (encoding survival motor neuron protein (SMN)). Reduced expression of SMN leads to loss of α-motor neurons, severe muscle weakness and often early death. Standard-of-care recommendations for multidisciplinary supportive care of SMA were established in the past few decades. However, improved understanding of the pathogenetic mechanisms of SMA has led to the development of different therapeutic approaches. Three treatments that increase SMN expression by distinct molecular mechanisms, administration routes and tissue biodistributions have received regulatory approval with others in clinical development. The advent of the new therapies is redefining standards of care as in many countries most patients are treated with one of the new therapies, leading to the identification of emerging new phenotypes of SMA and a renewed characterization of demographics owing to improved patient survival.

Skin Microbiome and Treatment-Related Skin Toxicities in Patients With Cancer: A Mini-Review

The human skin hosts millions of bacteria, fungi, archaea, and viruses. These skin microbes play a crucial role in human immunological and physiological functions, as well as the development of skin diseases, including cancer when the balance between skin commensals and pathogens is interrupted. Due to the linkages between inflammation processes and skin microbes, and viral links to skin cancer, new theories have supported the role a dysbiotic skin microbiome plays in the development of cancer and cancer treatment-related skin toxicities. This review focuses on the skin microbiome and its role in cancer treatment-related skin toxicities, particularly from chemotherapy, radiation therapy, and immunotherapy. The current literature found changes in the diversity and abundance of the skin microbiome during cancer treatments such as radiation therapy, including lower diversity of the skin microbiome, an increased Proteobacteria/Firmicutes ratio, and a higher abundance of pathogenic Staphylococcus aureus. These changes may be associated with the development and severity of treatment-related skin toxicities, such as acute radiation dermatitis, hand-foot syndrome in chemotherapy, and immunotherapy-induced rash. Several clinical guidelines have issued potential interventions (e.g., use of topical corticosteroids, phototherapy, and non-pharmaceutical skin care products) to prevent and treat skin toxicities. The effectiveness of these promising interventions in alleviating treatment-related skin toxicities should be further tested among cancer patients.

The Role of the Skin Microbiome in Health and Disease

Human skin acts as a barrier between the body and the outside environment, preventing disease-causing organisms and foreign substances from getting into our body. The skin also serves as an ecosystem for billions of microorganisms, collectively called the skin microbiome. Some of these microorganisms are merely bystanders, while others work together with the skin to fight invaders or promote immunity. While knowledge of the skin microbiome lags behind that of the gut microbiome, there is growing evidence that microbial imbalances on the skin are associated with skin disorders and chronic wounds.

The expression and the tumor suppressor role of CLDN6 in colon cancer

As a member of the tight junction family, CLDN6 is a tumor suppressor in breast cancer, but its role in colon cancer is unknown. In this research, we aimed at revealing the function of CLDN6 in colon cancer. We found that colon cancer tissues lowly expressed CLDN6, and the expression of CLDN6 was negatively correlated with lymph node metastasis. Similarly, CLDN6 was lowly expressed in the colon cancer cell line SW1116, and overexpression of CLDN6 inhibited cell proliferation in vitro and in vivo. Consistently, the migration and invasion abilities of cells were significantly inhibited after CLDN6 overexpression. In addition, we demonstrated that CLDN6 may inhibit the migration and invasion abilities by activating the TYK2/STAT3 pathway. Therefore, our data indicated that CLDN6 acted as a tumor suppressor and had the potential to be regarded as a biomarker for the progression of colon cancer.

Microbiota and maintenance of skin barrier function

Human skin forms a protective barrier against the external environment and is our first line of defense against toxic, solar, and pathogenic insults. Our skin also defines our outward appearance, protects our internal tissues and organs, acts as a sensory interface, and prevents dehydration. Crucial to the skin's barrier function is the colonizing microbiota, which provides protection against pathogens, tunes immune responses, and fortifies the epithelium. Here we highlight recent advances in our understanding of how the microbiota mediates multiple facets of skin barrier function. We discuss recent insights into pathological host-microbiota interactions and implications for disorders of the skin and distant organs. Finally, we examine how microbiota-based mechanisms can be targeted to prevent or manage skin disorders and impaired wound healing.

Therapy development for spinal muscular atrophy: perspectives for muscular dystrophies and neurodegenerative disorders

BACKGROUND

Major efforts have been made in the last decade to develop and improve therapies for proximal spinal muscular atrophy (SMA). The introduction of Nusinersen/Spinraza™ as an antisense oligonucleotide therapy, Onasemnogene abeparvovec/Zolgensma™ as an AAV9-based gene therapy and Risdiplam/Evrysdi™ as a small molecule modifier of pre-mRNA splicing have set new standards for interference with neurodegeneration.

MAIN BODY

Therapies for SMA are designed to interfere with the cellular basis of the disease by modifying pre-mRNA splicing and enhancing expression of the Survival Motor Neuron (SMN) protein, which is only expressed at low levels in this disorder. The corresponding strategies also can be applied to other disease mechanisms caused by loss of function or toxic gain of function mutations. The development of therapies for SMA was based on the use of cell culture systems and mouse models, as well as innovative clinical trials that included readouts that had originally been introduced and optimized in preclinical studies. This is summarized in the first part of this review. The second part discusses current developments and perspectives for amyotrophic lateral sclerosis, muscular dystrophies, Parkinson's and Alzheimer's disease, as well as the obstacles that need to be overcome to introduce RNA-based therapies and gene therapies for these disorders.

CONCLUSION

RNA-based therapies offer chances for therapy development of complex neurodegenerative disorders such as amyotrophic lateral sclerosis, muscular dystrophies, Parkinson's and Alzheimer's disease. The experiences made with these new drugs for SMA, and also the experiences in AAV gene therapies could help to broaden the spectrum of current approaches to interfere with pathophysiological mechanisms in neurodegeneration.