Propionibacterium acnes: an update on its role in the pathogenesis of acne

Commensal microbe regulation of skin cells in disease

Human skin is the host to various commensal microbes that constitute a substantial microbial community. The reciprocal communication between these microbial inhabitants and host cells upholds both the morphological and functional attributes of the skin layers, contributing indispensably to microenvironmental and tissue homeostasis. Thus, disruption of the skin barrier or imbalances in the microbial communities can exert profound effects on the behavior of host cells. This influence, mediated by the microbes themselves or their metabolites, manifests in diverse outcomes. In this review, we examine existing knowledge to provide insight into the nuanced behavior exhibited by the microbiota on skin cells in health and disease states. These interactions provide insight into potential cellular targets for future microbiota-based therapies to prevent and treat skin disease.

Anti-CAMP1 IgG promotes macrophage phagocytosis of Cutibacterium acnes type II

Among 5 types of the Christie-Atkins-Munch-Petersen factor (CAMP) of Cutibacterium acnes, CAMP1 is highly expressed in phylotype II as well as IB, and thought to be a virulence factor of opportunistic but fatal blood, soft tissue, and implant-related infections. The target of a human single-chain variable antibody fragment (scFv), recently isolated from a phage display library, has been identified as CAMP1 of phylotype II, using immunoprecipitation followed by mass spectrometry, phage display peptide biopanning, 3D-modelling, and ELISA. The IgG1 format of the antibody could enhance phagocytosis of C. acnes DMST 14916 by THP-1 human monocytes. Our results suggest that the antibody-dependent phagocytosis process is mediated by the caveolae membrane system and involves the induction of IL-1β. This is the first report on the study of a human antibody against CAMP1 of C. acnes phylotype II, of which a potential use as therapeutic antibody against virulence C. acnes infection is postulated.

Exploring Acne Treatments: From Pathophysiological Mechanisms to Emerging Therapies

Acne vulgaris is a common dermatological condition that can present across different ages but predominantly affects adolescents and young adults. Characterized by various lesion types, the pathogenesis of acne is complex, involving genetic, hormonal, microbial, and inflammatory factors. This review comprehensively addresses current and emerging acne management strategies, emphasizing both topical and systemic treatments, procedural therapies, and dietary modifications. Key topical agents include retinoids, benzoyl peroxide, antibiotics, and other specialized compounds. Systemic options like antibiotics, hormonal therapies, and retinoids offer significant therapeutic benefits, particularly for moderate to severe cases. Procedural treatments such as laser devices, photodynamic therapy, chemical peels, and intralesional injections present viable alternatives for reducing acne symptoms and scarring. Emerging therapies focus on novel biologics, bacteriophages, probiotics, and peptides, providing promising future options. This review underscores the importance of personalized approaches to treatment due to the multifaceted nature of acne, highlighting the potential of innovative therapies for improving patient outcomes.

Dissolving Hyaluronic Acid-Based Microneedles to Transdermally Deliver Eugenol Combined with Photothermal Therapy for Acne Vulgaris Treatment

A microneedle transdermal drug delivery system simultaneously avoids systemic toxicity of oral administration and low efficiency of traditional transdermal administration, which is of great significance for acne vulgaris therapy. Herein, eugenol-loaded hyaluronic acid-based dissolving microneedles (E@P-EO-HA MNs) with antibacterial and anti-inflammatory activities are developed for acne vulgaris therapy via eugenol transdermal delivery integrated with photothermal therapy. E@P-EO-HA MNs are pyramid-shaped with a sharp tip and a hollow cavity structure, which possess sufficient mechanical strength to penetrate the stratum corneum of the skin and achieve transdermal delivery, in addition to excellent in vivo biocompatibility. Significantly, E@P-EO-HA MNs show effective photothermal therapy to destroy sebaceous glands and achieve antibacterial activity against deep-seated Propionibacterium acnes (P. acnes) under near-infrared-light irradiation. Moreover, cavity-loaded eugenol is released from rapidly dissolved microneedle bodies to play a sustained antibacterial and anti-inflammatory therapy on the P. acnes infectious wound. E@P-EO-HA MNs based on a synergistic therapeutic strategy combining photothermal therapy and eugenol transdermal administration can significantly alleviate inflammatory response and ultimately facilitate the repair of acne vulgaris. Overall, E@P-EO-HA MNs are expected to be clinically applied as a functional minimally invasive transdermal delivery strategy for superficial skin diseases therapy in skin tissue engineering.

Exploring the association between rosacea and acne by integrated bioinformatics analysis

Clinically, rosacea occurs frequently in acne patients, which hints the existence of shared signals. However, the connection between the pathophysiology of rosacea and acne are not yet fully understood. This study aims to unveil molecular mechanism in the pathogenesis of rosacea and acne. We identified differentially expressed genes (DEGs) by limma and weighted gene co-expression network analysis and screened hub genes by constructing a protein-protein interaction network. The hub genes were verified in different datasets. Then, we performed a correlation analysis between the hub genes and the pathways. Finally, we predicted and verified transcription factors of hub genes, performed the immune cell infiltration analysis using CIBERSORT, and calculated the correlation between hub genes and immune cells. A total of 169 common DEGs were identified, which were mainly enriched in immune-related pathways. Finally, hub genes were identified as IL1B, PTPRC, CXCL8, MMP9, CCL4, CXCL10, CD163, CCR5, CXCR4, and TLR8. 9 transcription factors that regulated the expression of hub genes were identified. The infiltration of γδT cells was significantly increased in rosacea and acne lesions and positively linked with almost all hub genes. These identified hub genes and immune cells may play a crucial role in the development of rosacea and acne.

The antibacterial activity of berberine against Cutibacterium acnes: its therapeutic potential in inflammatory acne

Cutibacterium acnes (C. acnes) is a major pathogen implicated in the evolution of acne inflammation. Inhibition of C. acnes-induced inflammation is a prospective acne therapy strategy. Berberine (BBR), a safe and effective natural ingredient, has been proven to exhibit powerful antimicrobial and anti-inflammatory properties. However, the antimicrobial effect of BBR against C. acnes and its role in C. acnes-mediated inflammatory acne have not been explored. The objective of this investigation was to assess the antibacterial activity of BBR against C. acnes and its inhibitory effect on the inflammatory response. The results of in vitro experiments showed that BBR exhibited significant inhibition zones against four C. acnes strains, with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in the range of 6.25-12.5 μg/mL and 12.5-25 μg/mL, respectively. On the bacterial growth curve, the BBR-treated C. acnes exhibited obvious growth inhibition. Transmission electron microscopy (TEM) images indicated that BBR treatment resulted in significant morphological changes in C. acnes. High-content imaging analysis further confirmed that BBR could effectively inhibit the proliferation of C. acnes. The disruption of cell wall and cell membrane structure by BBR treatment was preliminary confirmed according to the leakage of cellular contents such as potassium (K+), magnesium (Mg2+), and alkaline phosphatase (AKP). Furthermore, we found that BBR could reduce the transcript levels of genes associated with peptidoglycan synthesis (murC, murD, mraY, and murG). Meanwhile, we investigated the modulatory ability of BBR on C. acnes-induced skin inflammation in mice. The results showed that BBR effectively reduced the number of C. acnes colonized in mice's ears, thereby alleviating ear swelling and erythema and significantly decreasing ear thickness and weight. In addition, BBR significantly decreased the levels of pro-inflammatory cytokines IL-6, IL-1β, and TNF-α in auricular tissues. These results suggest that BBR has the potential to treat inflammatory acne induced by C. acnes.

New Molecules of Importance in the Prevention and Treatment of Acne: A Systematic Patent Review (2016-2020)

BACKGROUND

Acne is a highly prevalent disease that mainly affects the pilosebaceous units associated with sebaceous glands, causing inflammatory skin lesions and affecting the self-esteem, mental health, and quality of life of those who suffer from this disease. Different treatments exist today to prevent, reduce, and improve symptoms; however, over the years, there have been problems with bacterial resistance and slight effectiveness with prolonged use.

OBJECTIVE

The purpose of this article is based on the review of patents of new products of principal topical administration for the treatment of acne in recent years 2016-2020, to evaluate and analyze novel synthetic molecules and semi-synthetics with potential therapeutic and preventive in the acne treatment.

METHODS

A systematic review of patents was conducted through the official database of the European Patent Office - Espacenet, where the search focused on the keywords: "acne and bacteria" in the title or abstract. Only patents granted between the years 2016-2020 were included, with products having molecules with a synthetic and semi-synthetic origin, without considering natural, biological products or those used as diagnostic means.

RESULTS

A total of 19 patents were selected, most with principally antimicrobial and antiinflammatory action, where the reduction in the appearance of resistance by C. acnes is verified, and its action is complemented by inhibiting the different pathophysiological mechanisms that lead to the worsening of the disease.

CONCLUSION

Novel approaches in the treatment and prevention of acne, mainly topically, are focused on the reduction of bacterial resistance and irritation compared to current treatments. The use of combined formulations provides better results with additional benefits, improving treatment times and patient adherence.

Immunomodulatory functions of microorganisms in tissue regenerative healing

External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a crucial regulatory role in this process. This review summarises our current understanding of microorganism-immune system interactions, with a focus on how these interactions impact the renewal and repair ability of tissues, including skin, bone, gut, liver, and nerves. This review concludes with a discussion of the mechanisms by which microbes act on various types of immune cells to affect tissue regeneration, offers potential strategies for using microbial therapies to enhance the regenerative repair function of tissues, and suggest novel therapeutic approaches for regenerative medicine. STATEMENT OF SIGNIFICANCE: Microbiological communities have crucial impacts on human health and illness by participating in energy collection and storage and performing various metabolic processes. External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a critical regulatory role in this process. This study reviews the important correlation between microorganisms and the immune system and investigates the mechanism of various microorganism that participate in the regeneration and repair of tissues and organs by modulating immune system.

Modulatory role of vitamins A, B3, C, D, and E on skin health, immunity, microbiome, and diseases

Disruption of the skin barrier and immunity has been associated with several skin diseases, namely atopic dermatitis (AD), psoriasis, and acne. Resident and non-resident immune cells and the barrier system of the skin are integral to innate immunity. Recent advances in understanding skin microbiota have opened the scope of further understanding the various communications between these microbiota and skin immune cells. Vitamins, being one of the important micronutrients, have been reported to exert antioxidant, anti-inflammatory, and anti-microbial effects. The immunomodulatory action of vitamins can halt the progression of skin diseases, and thus, understanding the immuno-pharmacology of these vitamins, especially for skin diseases can pave the way for their therapeutic potential. At the same time, molecular and cellular markers modulated with these vitamins and their derivatives need to be explored. The present review is focused on significant vitamins (vitamins A, B3, C, D, and E) consumed as nutritional supplements to discuss the outcomes and scope of studies related to skin immunity, health, and diseases.

Beneficial Effects of Plant-Based Diets on Skin Health and Inflammatory Skin Diseases

The human skin is a crucial organ that protects the organism from the outer environment. Skin integrity and health depend on both extrinsic and intrinsic factors. Intrinsic factors such as aging and genetic background contribute to weakened skin and disease susceptibility. Meanwhile, extrinsic factors including UV radiation, pollution, smoking, humidity, and poor diet also affect skin health and disease. On the other hand, healthy dietary patterns such as plant-based diets have gained popularity as a complementary therapy for skin health. A plant-based diet is defined as all diets based on plant foods, including an abundance of vegetables, fruits, beans, lentils, legumes, nuts, seeds, fungi, and whole grains, with limited or no animal products or processed foods. However, some authors also exclude or limit processed foods in the definition. Recent research has shown that these diets have beneficial effects on inflammatory skin diseases. This review explored the beneficial effects of plant-based diets on inflammatory skin diseases and plant-based functional foods on healthy skin. In conclusion, plant-based diets and plant-based functional foods may have beneficial effects on skin health through the gut microbiome.

The updates and implications of cutaneous microbiota in acne

Acne is a chronic inflammatory skin disorder that profoundly impacts the quality of life of patients worldwide. While it is predominantly observed in adolescents, it can affect individuals across all age groups. Acne pathogenesis is believed to be a result of various endogenous and exogenous factors, but the precise mechanisms remain elusive. Recent studies suggest that dysbiosis of the skin microbiota significantly contributes to acne development. Specifically, Cutibacterium acnes, the dominant resident bacterial species implicated in acne, plays a critical role in disease progression. Various treatments, including topical benzoyl peroxide, systemic antibiotics, and photodynamic therapy, have demonstrated beneficial effects on the skin microbiota composition in acne patients. Of particular interest is the therapeutic potential of probiotics in acne, given its direct influence on the skin microbiota. This review summarizes the alterations in skin microbiota associated with acne, provides insight into its pathogenic role in acne, and emphasizes the potential of therapeutic interventions aimed at restoring microbial homeostasis for acne management.

Oxidative stress and metabolic syndrome in acne vulgaris: Pathogenetic connections and potential role of dietary supplements and phytochemicals

Acne vulgaris is a highly prevalent skin condition caused by androgen-induced elevated sebum secretion, abnormal keratinization, bacterial colonization, and inflammation. Current research indicates a link between acne vulgaris and the metabolic syndrome, a group of disorders that includes obesity, insulin resistance, hypertension, and dyslipidemia. This link is thought to be modulated by excessive concentrations of oxidative stress markers and chronic inflammation, which are included in the pathophysiological mechanisms shared by both conditions. Excessive generation of reactive oxygen species damages cellular components and initiates an inflammatory response, hence promoting the development of both disorders. The current narrative review focuses on the molecular implications of inflammatory, hormonal, and environmental factors in the acne-metabolic syndrome correlation. Furthermore, it outlines the current state of knowledge related to the phyto-therapeutic approach to these conditions as an adjuvant strategy to allopathic treatment, but future multicenter and larger-scale research studies are needed establish new algorithms to be included in the future management of patients with these conditions.

Cutibacterium acnes KCTC 3314 Growth Reduction with the Combined Use of Bacteriophage PAP 1-1 and Nisin

Severe acne has high psychological impacts recorded worldwide, from depression to suicide. To control acne infection, bacteriophage could be used in synergy or combination with antibiotics/antimicrobials. Bacteriophages are specific to their hosts without interfering with the normal skin microbes and have the ability to lyse bacterial cells. In this current study, the bacteriophage PAP 1-1 was isolated, characterized, and tested against the pathogenic acne-causing bacterium Cutibacterium acnes. Examination under transmission electron microscopy (TEM) revealed that the newly isolated phage has a morphology typical of siphoviruses. Phylogenetic analysis, utilizing the maximum likelihood (ML) algorithm based on complete genome sequences, revealed that PAP 1-1 clustered together with bacteriophages active to Propionibacterium acnes (now known as C. acnes), forming a distinct evolutionary lineage. The genomic analysis further identified the presence of an endolysin gene in PAP 1-1, suggesting its potential to regulate the growth of C. acnes. Subsequent experiments conducted in RCM broth confirmed the ability of PAP 1-1 to effectively control the proliferation of C. acnes. In combination with bacteriocin from Lactococcus lactis CJNU 3001 and nisin, PAP 1-1 greatly decreased the viable cell counts of C. acnes in the broth.

A cross-sectional study examining the prevalence of antibiotic-resistant Cutibacterium acnes isolated from patients with acne in Bangkok, Thailand

Cutibacterium acnes is associated with the pathogenesis of acne vulgaris (AV). The relationship between antibiotic-resistant C. acnes and AV remains unclear. The authors aimed to determine the prevalence of antibiotic-resistant C. acnes and investigate the association of acne severity with topical and systemic treatments in patients with acne. Samples were collected of inflammatory and noninflammatory acne, including closed and open comedones and erythematous papules/pustules from the face of patients with mild to severe acne. The samples were cultured under anaerobic conditions for the isolation of C. acnes. Antibiotic susceptibility tests for erythromycin, tetracycline, doxycycline, clindamycin, and trimethoprim/sulfamethoxazole were performed using the agar dilution method. From 153 patients, 143 viable C. acnes samples were isolated (93.5%). They were found resistant to trimethoprim/sulfamethoxazole (143/143, 100%), clindamycin (108/143, 75.5%), erythromycin (105/143, 73.4%), tetracycline (74/143, 51.7%), and doxycycline (73/143, 51.1%). There was no significant correlation between the prevalence of antibiotic resistance and acne severity. High-level resistant C. acnes correlated with higher clinical severity of acne in patients taking doxycycline (τ_b  = 0.3). The present prevalence of antibiotic-resistant C. acnes was high in Thailand. Antibiotic stewardship in AV treatment should be encouraged to prevent further antibiotic resistance crises.

Lutein attenuates Propionibacterium acnes-induced inflammation by inhibiting pyroptosis of human keratinocyte cells via TLR4/NLRP3/Caspase-1 pathway

BACKGROUND

Previous studies found Propionibacterium acnes (P. acnes) has a strong association with acne inflammation and cell pyroptosis. Because of the various side effects of current acne medicines, it is important to explore alternative drugs with anti-inflammatory activity against P. acnes. we explored the effect of Lutein on P. acnes-induced cell pyroptosis and accelerated the recovery of acne inflammation in vitro and vivo.

METHODS

Lutein was utilized to expose HaCaT keratinocytes, then we reassessed the effect of Lutein on the cell apoptosis, pyroptotic-associated inflammatory factors and catabolic enzymes in heat-killed P. acnes-treated HaCaT cells. Next, living P. acnes was intradermally injected into the right ears of ICR mice to induce mice with acne inflammation, and the effect of Lutein on living P. acnes-induced inflammation was investigated. Moreover, we explored the mechanism of Lutein on TLR4/NLRP3/Caspase-1 pathways by ELISA, immunofluorescence microscopy, and western blot assay.

RESULTS

Heat-killed P. acnes triggered remarkable cell pyroptosis, pyroptotic inflammatory factors and catabolic enzymes in HaCaT cells, including up-regulating interleukin (IL)-1β, IL-18, TNF-α, MMP3, MMP13, ADAMTS4, and ADAMTS5, TLR4, NLRP3, caspase-1, and the ratio of gasdermin D to cleaved gasdermin D, whereas these effects were suppressed by Lutein. In addition, Lutein effectively improved ear redness, swelling, and the expression of TLR4, IL-1β and TNF-α in vivo. Finally, NLRP3 activator (nigericin) increased caspase-1, IL-1β and IL-18 level, while TLR4 inhibitor (TAK-242) significantly blocked this effect in heat-killed P. acnes-treated cells.

CONCLUSIONS

Lutein attenuated P. acnes-caused pyroptosis of HaCaTs and the subsequent acne inflammation via the TLR4/NLRP3/Caspase-1 pathway.

Role of Oral Retinoids in Treatment of Acne Vulgaris With a Bioinformatics-Based Perspective of Personalized Medicine

Acne vulgaris is a skin condition characterized by the inflammation or hyperactivity of sebaceous glands on the skin, which results in the creation of comedones, lesions, nodules, and perifollicular hyperkeratinization. Increased sebum production, follicular blockage, and bacterial colonization may contribute to the disease etiology. Environmental factors, hormonal imbalance, and genetic predisposition can alter the severity of the disease. Its mental and monetary effects can be problematic for the society. In this study, we examined the role of isotretinoin in the treatment of acne vulgaris based on evidence from prior research. This review literature study compiled publications on the treatment of acne vulgaris from 1985 to 2022 based on PubMed and Google Scholar publications. Additional bioinformatics analyses were accompanied by GeneCards, STRING model, and DrugBank databases. These complementary analyses were designed to obtain a better perspective of personalized medicine which is highly required for dose-precise administrations of acne vulgaris treatment. Isotretinoin has been recognized as an effective treatment for acne vulgaris, particularly in cases that have been resistant to previous medications or have resulted in scarring, according to gathered data. Oral isotretinoin inhibits the proliferation of Propionibacterium acne, a critical factor in the development of acne lesions; also, it has been shown to be effective in reducing the number of Propionibacterium-resistant patients and regulating sebum production and reducing sebaceous gland size more effectively than other treatment options resulting in general improvements in skin clarity and acne severity and reduce inflammatory in 90% of patients. In addition to its efficacy, the majority of patients have shown that oral isotretinoin is well tolerated. This review highlights the use of oral retinoids, particularly isotretinoin, as an effective and well-tolerated treatment option for acne vulgaris. It has been proven that oral isotretinoin is useful for achieving long-lasting remission in patients with severe or resistant instances. Despite the fact that oral isotretinoin is related to a number of potential harmful effects, skin dryness was the most common side effect reported by patients that can be managed with the aid of suitable monitoring and drug administration against specific genes identified by genotyping of the susceptible variants of genes involved in TGFβ signaling pathway.

Recent advances in understanding inflammatory acne: Deciphering the relationship between Cutibacterium acnes and Th17 inflammatory pathway

Acne vulgaris is a common chronic inflammatory skin disease of the pilosebaceous units. Four factors contribute to acne: hyperseborrhea and dysseborrhea, follicular hyperkeratinisation, skin microbiome dysbiosis and local immuno-inflammation. Recent key studies have highlighted a better understanding of the important role of Cutibacterium acnes (C. acnes) in the development of acne. Three major findings in the last decade include: (1) the ability of C. acnes to self-organize in a biofilm associated with a more virulent activity, (2) the loss of the C. acnes phylotype diversity and (3) the central role of the Th17 pathway in acne inflammation. Indeed, there is a close link between C. acnes and the activation of the Th17 immuno-inflammatory pathway at the initiation of acne development. These mechanisms are directly linked to the loss of C. acnes phylotype diversity during acne, with a predominance of the pro-pathogenic phylotype IA1. This specifically contributes to the induction of the Th17-mediated immuno-inflammatory response involving skin cells, such as keratinocytes, monocytes and sebocytes. These advancements have led to new insights into the underlying mechanisms which can be harnessed to develop novel treatments and diagnostic biomarkers. A major disadvantage of traditional treatment with topical antibiotics is that they induce cutaneous dysbiosis and antimicrobial resistance. Thus, future treatments would no longer aim to 'kill' C. acnes, but to maintain the skin microbiota balance allowing for tissue homeostasis, specifically, the restoration of C. acnes phylotype diversity. Here, we provide an overview of some of the key processes involved in the pathogenesis of acne, with a focus on the prominent role of C. acnes and the Th17-inflammatory pathways involved.

Change in Cutibacterium acnes phylotype abundance and improvement of clinical parameters using a new dermocosmetic product containing Myrtus communis and Celastrol enriched plant cell culture extracts in patients with acne vulgaris

BACKGROUND

Acne is a multifactorial chronic inflammatory disease of the pilosebaceous unit, where Cutibacterium acnes plays a main role. Recent papers demonstrated that specific C. acnes phylotypes were correlated with the severity of inflammatory acne and reported a specific loss of C. acnes phylotype diversity in this context.

OBJECTIVES

The aim of this exploratory study was to evaluate the efficacy of a new dermocosmetic product containing Myrtus communis and Celastrol-enriched plant cell culture extracts on C. acnes phylotype abundance and clinical parameters in subjects with mild to moderate acne vulgaris.

METHODS

Cutibacterium acnes phylotype diversity was evaluated by single-locus sequence typing sequencing on the nonlesional areas of the forehead, that is, areas excluding inflammatory lesions (papules and pustules) on day 1 (D1) and after 56 days (D57) of twice daily application of the dermocosmetic product on the whole face. Clinical efficacy on acne was also assessed by acne lesion counting and Global Evaluation Acne (GEA) score on D1 and D57.

RESULTS

Our study confirmed the link between the presence of some C. acnes phylotypes and acne severity. The dermocosmetic cream was linked to a positive impact on C. acnes phylotypes: a significant decrease in pro-pathogen phylotype IC and increase in nonpathogen phylotype IB were observed in the nonlesional areas of acne on D57 compared to D1. In parallel, the clinical results showed a significant decrease in inflammatory and comedonal acne lesions and a significant improvement in the acne severity according to the GEA score.

CONCLUSIONS

This study showed that the application of a new dermocosmetic product containing M. communis and Celastrol-enriched plant cell culture extracts was linked to a change in the C. acnes phylotype abundance and an improvement in acne severity.

Myrtus communis and Celastrol enriched plant cell culture extracts control together the pivotal role of Cutibacterium acnes and inflammatory pathways in acne

INTRODUCTION

Acne is a multifactorial inflammatory disease of the pilosebaceous unit in which Cutibacterium acnes is one of the main triggers. A strong predominance of C. acnes phylotype IA1 is present in acne skin with higher biofilm organization and virulence, promoting local immuno-inflammation, especially the Th17 pathway.

OBJECTIVES

We evaluated the single and combined pharmacological properties of the plant extracts, Myrtus communis (Myrtacine®) and Celastrol enriched plant cell culture (CEE) extracts on the C. acnes/Th17 pathway.

METHODS

The effect of Myrtacine® on the virulence of C. acnes phylotype IA1 was quantified according to the expression of several related genes. The activity of Myrtacine® and CEE on the inflammatory cascade was assessed using monocytes-derived dendritic cells (Mo-DC) stimulated with membranes or biofilms of the C. acnes phylotype IA1. Finally, the effect of CEE on the Th17 pathway was studied using C. acnes stimulated sebocyte 2D cultures and 3D skin tissue models containing preactivated Th17 cells.

RESULTS

Myrtacine® had an anti-virulence effect, evident as a significant and strong inhibition of the expression of several virulence factor genes by 60%-95% compared to untreated controls. Myrtacine® and CEE significantly inhibited proinflammatory cytokine (IL-6, IL-8, IL-12p40 and TNF-α) production by Mo-DC in response to C. acnes phylotype IA1. Interestingly, these two ingredients resulted in synergistic inhibition of most cytokines when used in combination. Finally, we demonstrated an inhibitory effect of CEE, in solution or formulated at 0.3%, specifically on IL-17 release by Th17 lymphocytes in a C. acnes-stimulated sebocyte 2D cultures and by Th17-lymphocytes integrated in a 3D skin models.

CONCLUSIONS

2D and 3D models were developed to represent relevant and specific pathways involved in acne. Myrtacine® and CEE were shown to alter one or more of these pathways, indicating their potential beneficial effects on this disease.

Preoperative topical benzoyl peroxide treatment is effective in reducing Cutibacterium acnes in shoulder surgery: a systematic review

BACKGROUND

Cutibacterium acnes (C acnes) colonization can have a significant impact on patients undergoing both arthroscopic and open shoulder surgery with regard to postoperative infection. Its resistance to standard preoperative skin preparations and prophylactic antibiotics has led to a need for a more targeted therapy. Topical benzoyl peroxide (BPO) has been used by dermatologists in the treatment for acnes due to its bactericidal and penetrative effects through the dermal layer. The aim of this systematic review is to review the effectiveness of topical BPO preoperatively in shoulder surgery in reducing C acnes colonization and postoperative infection.

METHODS

A review of the online databases Medline and Embase was conducted on December 15, 2021, according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The review was registered prospectively in the PROSPERO database. Clinical studies reporting superficial and deep sample microbiology and postoperative complications were included. The studies were appraised using the revised Cochrane Risk of Bias 2 (ROB 2) tool for randomized studies and the Methodological Index for Non-Randomized Studies (MINORS) tool.

RESULTS

The search strategy identified 10 studies for inclusion (6 randomized control trials, 2 prospective cohort studies, and 2 case series), including a total of 482 patients. Seven studies were comparable, testing BPO against alternative standard skin preparations. Of the 10 studies, 7 showed a decrease in the load of C acnes on the skin and/or deep tissues, of which 6 demonstrated statistical significance. Men were shown to have a statistically significant increase in the colonization rate of C acnes. Scheer et al (2021) demonstrated 4500 colony-forming units/mL in males and 900 colony-forming units/mL in females. In studies where the number of BPO applications was higher, BPO appeared more effective. Dizay et al demonstrated C acnes elimination in 78.9% with more than 1 application compared with 66.7% if only applied once. Three studies looked at the effectiveness of BPO during the operative timeline with 1 demonstrating its statistically significant effectiveness at reducing colonization 2 hours into the operation (P = .048).

CONCLUSION

BPO is effective as a topical treatment at reducing C acnes colonization before shoulder surgery. However, the relationship between duration of treatment, frequency of application, and gender requires further research.

Zinc and Zinc Transporters in Dermatology

Zinc is an important trace mineral in the human body and a daily intake of zinc is required to maintain a healthy status. Over the past decades, zinc has been used in formulating topical and systemic therapies for various skin disorders owing to its wound healing and antimicrobial properties. Zinc transporters play a major role in maintaining the integrity of the integumentary system by controlling zinc homeostasis within dermal layers. Mutations and abnormal function of zinc-transporting proteins can lead to disease development, such as spondylocheirodysplastic Ehlers-Danlos syndrome (SCD-EDS) and acrodermatitis enteropathica (AE) which can be fatal if left untreated. This review discusses the layers of the skin, the importance of zinc and zinc transporters in each layer, and the various skin disorders caused by zinc deficiency, in addition to zinc-containing compounds used for treating different skin disorders and skin protection.

Sulforaphene Attenuates Cutibacterium acnes-Induced Inflammation

Acne is a chronic inflammatory disease of the sebaceous gland attached to the hair follicles. Cutibacterium acnes is a major cause of inflammation caused by acne. It is well known that C. acnes secretes a lipolytic enzyme to break down lipids in sebum, and free fatty acids produced at this time accelerate the inflammatory reaction. There are several drugs used to treat acne; however, each one has various side effects. According to previous studies, sulforaphene (SFEN) has several functions associated with lipid metabolism, brain function, and antibacterial and anti-inflammatory activities. In this study, we examined the effects of SFEN on bacterial growth and inflammatory cytokine production induced by C. acnes. The results revealed that SFEN reduced the growth of C. acnes and inhibited proinflammatory cytokines in C. acnes-treated HaCaT keratinocytes through inhibiting NF-κB-related pathways. In addition, SFEN regulated the expression level of IL-1α, a representative pro-inflammatory cytokine expressed in co-cultured HaCaT keratinocytes and THP-1 monocytes induced by C. acnes. In conclusion, SFEN showed antibacterial activity against C. acnes and controlled the inflammatory response on keratinocytes and monocytes. This finding means that SFEN has potential as both a cosmetic material for acne prevention and a pharmaceutical material for acne treatment.

Acne Vulgaris, Atopic Dermatitis and Rosacea: The Role of the Skin Microbiota-A Review

The skin harbors a huge number of different microorganisms such as bacteria, fungi and viruses, and it acts as a protective shield to prevent the invasion of pathogens and to maintain the health of the commensal microbiota. Several studies, in fact, have shown the importance of the skin microbiota for healthy skin. However, this balance can be altered by intrinsic and extrinsic factors, leading to the development of skin disease, such as acne vulgaris (AV), atopic dermatitis (AD) and rosacea(RS). Although these diseases are widespread and affect both adolescents and adults, the scientific correlation between these disorders and the skin microbiota and physiological parameters (TEWL, hydration and lipid composition) is still unclear. This review aims to investigate the current literature regarding the correlation between the skin microbiota and its imbalance underlying microbiological aspects, how the skin microbiota changes over the course of the disease and the current possible treatments. The following reported studies show a general imbalance of the bacterial flora. For this reason, more in-depth studies are necessary to explore the different subspecies and strains involved in all three diseases.

Development of skin sebum medium and inhibition of lipase activity in Cutibacterium acnes by oleic acid

Cutibacterium acnes is associated with the exacerbated inflammation of acne vulgaris, which occurs through the immune induction and pathogenicity factor production. Sebum, which is not present in the growth medium currently used to study acne, is present in acne pustules in differing concentrations among the pathological stages, such as the initial formation and inflammatory phase. To evaluate the effect of C. acnes on inflammation exacerbation in acne pustules in vitro, we developed an skin sebum medium containing artificial sebum and studied the growth and pathogenicity factor production of C. acnes in the skin sebum medium.

The growth and lipase activity of C. acnes ATCC11828 were tested using skin sebum medium containing different sebum concentrations. Only lipase activity decreased in the skin sebum medium culture containing 0.5 % sebum when compared with that without sebum, while both growth and lipase activity decreased in cultures with 1.0 % sebum. Therefore, the growth and lipase activity of C. acnes changed in the presence of sebum. Furthermore, when the growth and lipase activity of C. acnes were tested in skin sebum medium containing sebum components, unsaturated fatty acids, such as oleic acid and triolein, led to a decrease in lipase activity without inducing a change in growth. In the presence of oleic acid, C. acnes lipase activity decreased noncompetitively in a concentration-dependent manner.

Our data showed that C. acnes growth and lipase activity changed upon sebum addition to the skin sebum medium, and acne inflammation caused by C. acnes needs to be studied under conditions similar to those in acne pustules.

Cannabidiol Inhibits Inflammation Induced by Cutibacterium acnes-Derived Extracellular Vesicles via Activation of CB2 Receptor in Keratinocytes

Background

Acne is a common inflammatory skin disease, while cannabidiol (CBD) is a representative non-psychoactive phytocannabinoid which has been proved to exert universal anti-inflammatory properties. This study aimed to explore the effect of CBD on acne inflammation induced by Cutibacterium acnes-derived extracellular vesicles (CEVs) in keratinocytes and reveal the underlying mechanisms.

Methods

Normal human epidermal keratinocytes (NHEKs) were stimulated by CEVs in the presence of CBD or vehicle. Interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α levels were examined by RT-PCR and ELISA. The expression of cannabinoid type-2 (CB2) receptor and transient receptor potential vanilloid type-1 (TRPV1) was detected by Western blotting. TNF-α levels in the presence of CB2 receptor antagonist (AM630) or TRPV1 antagonist (Capsazepine) were detected by RT-PCR. The activation of MAPK and NF-κB signaling pathways and the nuclear translocation of NF-κB p65 upon CBD treatment were analyzed by Western blotting and immunofluorescence assay, respectively.

Results

The expression of inflammatory cytokines (IL-6, IL-8 and TNF-α) in CEVs-stimulated NHEKs was suppressed by CBD. CB2 receptor expression was upregulated by CBD, whereas CEVs-promoted TRPV1 expression was downregulated by CBD. AM630 reversed TNF-α levels inhibited by CBD. Capsazepine exerted an inhibitory effect on CEVs-induced inflammation and had synergistic effect with CBD. The phosphorylation of ERK1/2 and NF-κB p65 and nuclear translocation of NF-κB p65 were induced by CEVs but reduced by CBD.

Conclusion

The results indicated that CBD could inhibit inflammation induced by CEVs in NHEKs, which was mediated by activation of CB2 receptor and enhanced by the TRPV1 antagonist, through inactivation of the MAPK and NF-κB signaling pathways. CBD might be a potential novel strategy for acne treatment in the future.

The immunomodulatory potential of phage therapy to treat acne: a review on bacterial lysis and immunomodulation

Background

Characterized by an inflammatory pathogenesis, acne is the most common skin disorder worldwide. Altered sebum production, abnormal proliferation of keratinocytes, and microbiota dysbiosis represented by disbalance in Cutibacterium acnes population structure, have a synergic effect on inflammation of acne-compromised skin. Although the role of C. acnes as a single factor in acne development is still under debate, it is known that skin and skin-resident immune cells recognize this bacterium and produce inflammatory markers as a result. Control of the inflammatory response is frequently the target for acne treatment, using diverse chemical or physical agents including antibiotics. However, some of these treatments have side effects that compromise patient adherence and drug safety and in the case of antibiotics, it has been reported C. acnes resistance to these molecules. Phage therapy is an alternative to treat antibiotic-resistant bacterial strains and have been recently proposed as an immunomodulatory therapy. Here, we explore this perspective about phage therapy for acne, considering the potential immunomodulatory role of phages.

Methodology

Literature review was performed using four different databases (Europe PubMed Central-ePMC, Google Scholar, PubMed, and ScienceDirect). Articles were ordered and selected according to their year of publication, number of citations, and quartile of the publishing journal.

Results

The use of lytic bacteriophages to control bacterial infections has proven its promising results, and anti-inflammatory effects have been found for some bacteriophages and phage therapy. These effects can be related to bacterial elimination or direct interaction with immune cells that result in the regulation of pro-inflammatory cytokines. Studies on C. acnes bacteriophages have investigated their lytic activity, genomic structure, and stability on different matrices. However, studies exploring the potential of immunomodulation of these bacteriophages are still scarce.

Conclusions

C. acnes bacteriophages, as well as other phages, may have direct immunomodulatory effects that are yet to be fully elucidated. To our knowledge, to the date that this review was written, there are only two studies that investigate anti-inflammatory properties for C. acnes bacteriophages. In those studies, it has been evidenced reduction of pro-inflammatory response to C. acnes inoculation in mice after bacteriophage application. Nevertheless, these studies were conducted in mice, and the interaction with the immune response was not described. Phage therapy to treat acne can be a suitable therapeutic alternative to C. acnes control, which in turn can aid to restore the skin's balance of microbiota. By controlling C. acnes colonization, C. acnes bacteriophages can reduce inflammatory reactions triggered by this bacterium.

T Cell Extracellular Traps: Tipping the Balance Between Skin Health and Disease

The role of extracellular traps (ETs) in the innate immune response against pathogens is well established. ETs were first identified in neutrophils and have since been identified in several other immune cells. Although the mechanistic details are not yet fully understood, recent reports have described antigen-specific T cells producing T cell extracellular traps (TETs). Depending on their location within the cutaneous environment, TETs may be beneficial to the host by their ability to limit the spread of pathogens and provide protection against damage to body tissues, and promote early wound healing and degradation of inflammatory mediators, leading to the resolution of inflammatory responses within the skin. However, ETs have also been associated with worse disease outcomes. Here, we consider host-microbe ET interactions by highlighting how cutaneous T cell-derived ETs aid in orchestrating host immune responses against Cutibacterium acnes (C. acnes), a commensal skin bacterium that contributes to skin health, but is also associated with acne vulgaris and surgical infections following joint-replacement procedures. Insights on the role of the skin microbes in regulating T cell ET formation have broad implications not only in novel probiotic design for acne treatment, but also in the treatment for other chronic inflammatory skin disorders and autoimmune diseases.

The Role of Herbal Medicine in the Treatment of Acne Vulgaris: A Systematic Review of Clinical Trials

Over the past few decades, interest in medicinal plants and phytochemicals for the treatment of skin disorders, including acne vulgaris, has progressively increased. Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit, which mainly occurs in adolescents and young adults. The treatment focuses on the four main factors involved in its pathogenesis: increased sebum production, hyperkeratinization, overgrowth of Cutibacterium acnes, and inflammation. The treatment includes topical retinoids, benzoyl peroxide, antibiotics, and oral isotretinoin. In this regard, the use of herbal medicine as a complementary and alternative medicine is a promising strategy. The main objective of this study was to systematically evaluate the efficacy and safety of medicinal plants and phytochemicals in the treatment of acne vulgaris. Three scientific databases (PubMed, Web of Science, and Scopus) were searched from inception to January 2021. Clinical trials comparing herbal therapies with placebo or other medicines for the treatment of acne vulgaris were included and analyzed. Outcome measures of interest comprised acne lesions (inflammatory and noninflammatory), sebum production, acne severity, and quality of life. The risk of bias in the included randomized controlled trials (RCTs) was assessed using the Cochrane risk-of-bias tool. A total of 34 clinical trials involving 1753 participants met the inclusion criteria for this systematic review. Most trials showed that herbal medicine significantly reduces inflammatory and noninflammatory acne lesions and has a relevant effect on acne severity. Some medicinal plants revealed equal or higher efficacy to standard treatments. No significant difference between groups in sebum production and quality of life was observed and no severe adverse events were reported. This systematic review provides evidence that medicinal plants and phytochemicals are promising treatments for mild to moderate acne vulgaris. However, more quality of evidence and standardized methodologies are needed to support their effectiveness and safety claims.

Genomic Island-Mediated Horizontal Transfer of the Erythromycin Resistance Gene erm(X) among Bifidobacteria

Antibiotic resistance is a serious medical issue driven by antibiotic misuse. Bifidobacteria may serve as a reservoir for antibiotic resistance genes (ARGs) that have the potential risk of transfer to pathogens. The erythromycin resistance gene erm(X) is an ARG with high abundance in bifidobacteria, especially in Bifidobacterium longum species. However, the characteristics of the spread and integration of the gene erm(X) into the bifidobacteria genome are poorly understood. In this study, 10 tetW-positive bifidobacterial strains and 1 erm(X)-positive bifidobacterial strain were used to investigate the transfer of ARGs. Conjugation assays found that the erm(X) gene could transfer to five other bifidobacterial strains. Dimethyl sulfoxide (DMSO) and vorinostat significantly promoted the transfer of the erm(X) from strain Bifidobacterium catenulatum subsp. kashiwanohense DSM 21854 to Bifidobacterium longum subsp. suis DSM 20211. Whole-genome sequencing and comparative genomic analysis revealed that the erm(X) gene was located on the genomic island BKGI1 and that BKGI1 was conjugally mobile and transferable. To our knowledge, this is the first report that a genomic island-mediated gene erm(X) transfer in bifidobacteria. Additionally, BKGI1 is very unstable in B. catenulatum subsp. kashiwanohense DSM 21854 and transconjugant D2TC and is highly excisable and has an intermediate circular formation. In silico analysis showed that the BKGI1 homologs were also present in other bifidobacterial strains and were especially abundant in B. longum strains. Thus, our results confirmed that genomic island BKGI1 was one of the vehicles for erm(X) spread. These findings suggest that genomic islands play an important role in the dissemination of the gene erm(X) among Bifidobacterium species. IMPORTANCE Bifidobacteria are a very important group of gut microbiota, and the presence of these bacteria has many beneficial effects for the host. Thus, bifidobacteria have attracted growing interest owing to their potential probiotic properties. Bifidobacteria have been widely exploited by the food industry as probiotic microorganisms, and some species have a long history of safe use in food and feed production. However, the presence of antibiotic resistance raises the risk of its application. In this study, we analyzed the transfer of the erythromycin resistance gene erm(X) and revealed that the molecular mechanism behind the spread of the gene erm(X) was mediated by genomic island BKGI1. To the best of our knowledge this is the first report to describe the transfer of the gene erm(X) via genomic islands among bifidobacteria. This may be an important way to disseminate the gene erm(X) among bifidobacteria.

Suppression of Cutibacterium acnes-Mediated Inflammatory Reactions by Fibroblast Growth Factor 21 in Skin

Cutibacterium acnes (C. acnes) is a common commensal bacterium that is closely associated with the pathogenesis of acne. Fibroblast growth factor 21 (FGF21), as a favorable regulator of glucose and lipid metabolism and insulin sensitivity, was recently shown to exert anti-inflammatory effects. The role and mechanism of FGF21 in the inflammatory reactions induced by C. acnes, however, have not been determined. The present study shows that FGF21 in the dermis inhibits epidermal C. acnes-induced inflammation in a paracrine manner while it functions on the epidermal layer through a receptor complex consisting of FGF receptor 1 (FGFR1) and β-Klotho (KLB). The effects of FGF21 in heat-killed C. acnes-induced HaCaT cells and living C. acnes-injected mouse ears were examined. In the presence of C. acnes, FGF21 largely counteracted the activation of Toll-like receptor 2 (TLR2), the downstream nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways induced by C. acnes. FGF21 also significantly reduced the expression of proinflammatory cytokines, including interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α. Taken together, these findings indicate that FGF21 suppresses C. acnes-induced inflammation and might be used clinically in the management and treatment of acne.

Where environmental microbiome meets its host: subway and passenger microbiome relationships

Subways are urban transport systems with high capacity. Every day around the world, there are more than 150 million subway passengers. Since 2013, thousands of microbiome samples from various subways worldwide have been sequenced. Skin bacteria and environmental organisms dominate the subway microbiomes. The literature has revealed common bacterial groups in subway systems; even so, it is possible to identify cities by their microbiome. Low-frequency bacteria are responsible for specific bacterial fingerprints of each subway system. Furthermore, daily subway commuters leave their microbial clouds and interact with other passengers. Microbial exchange is quite fast; the hand microbiome changes within minutes, and after cleaning the handrails, the bacteria are re-established within minutes. To investigate new taxa and metabolic pathways of subway microbial communities, several high-quality metagenomic-assembled genomes (MAG) have been described. Subways are harsh environments unfavorable for microorganism growth. However, recent studies have observed a wide diversity of viable and metabolically active bacteria. Understanding which bacteria are living, dormant, or dead allows us to propose realistic ecological interactions. Questions regarding the relationship between humans and the subway microbiome, particularly the microbiome effects on personal and public health, remain unanswered. This review summarizes our knowledge of subway microbiomes and their relationship with passenger microbiomes.

Microbiome and Probiotics in Acne Vulgaris—A Narrative Review

Acne vulgaris is a chronic disease characterised by the appearance of eruptions such as whiteheads, blackheads, pustules, papules, and cysts. Among factors that cause acne vulgaris are the abnormal keratinisation of the sebaceous canal, bacterial colonisation (Cutibacterium acnes), increased sebum production, genotypic factors, and hormonal disorders. Treatment is often long and tedious, and can lead to a reduction in quality of life and social isolation. The intestinal microbiota is greatly important in the formation of acne lesions. It is also responsible for the proper immunity of the organism. Acne is a disease that can be related to the condition of the digestive tract and its microbiome. Research shows that the use of probiotics may reduce skin eruptions. The probiotic supplementation and cosmetics markets are very dynamically developing. The use of internal supplementation and probiotic-containing cosmetics gives hope for the improvement of the skin condition of people with acne.

Red Seaweed-Derived Compounds as a Potential New Approach for Acne Vulgaris Care

Acne vulgaris (AV) is a chronic skin disease of the pilosebaceous unit affecting both adolescents and adults. Its pathophysiology includes processes of inflammation, increased keratinization, sebum production, hormonal dysregulation, and bacterial Cutibacterium acnes proliferation. Common AV has been treated with antibiotics since the 1960s, but strain resistance has emerged and is of paramount concern. Macroalgae are known producers of substances with bioactive properties, including anti-viral, antibacterial, antioxidant, and anti-inflammatory properties, among several others. In particular, red algae are rich in bioactive compounds such as polysaccharides, phenolic compounds, lipids, sterols, alkaloids, and terpenoids, conferring them antioxidant, antimicrobial, and anti-inflammatory activities, among others. Thus, the exploration of compounds from marine resources can be an appealing approach to discover new treatment options against AV. The aim of this work is to provide an overview of the current knowledge of the potentialities of red macroalgae in the treatment of AV by reviewing the main therapeutic targets of this disease, and then the existence of compounds or extracts with bioactive properties against them.

Propanediol (and) Caprylic Acid (and) Xylitol as a New Single Topical Active Ingredient against Acne: In Vitro and In Vivo Efficacy Assays

In addition to dermatological complications, acne can affect the quality of life of individuals in numerous ways, such as employment, social habits and body dissatisfaction. According to our expertise, caprylic acid and propanediol would not have a direct action on Cutibacterium acnes. Despite this, we investigated the existence of a synergistic effect among xylitol, caprylic acid and propanediol as a mixture of compounds representing a single topical active ingredient that could benefit the treatment against acne. In vitro and in vivo assays were performed to challenge and to prove the efficacy of propanediol, xylitol and caprylic acid (PXCA) against acne. PXCA had its MIC challenged against C. acnes (formerly Propionibacterium acnes) and Staphylococcus aureus, resulting in concentrations of 0.125% and 0.25%, respectively, and it also developed antimicrobial activity against C. acnes (time-kill test). PXCA was able to reduce the 5-alpha reductase expression in 24% (p < 0.01) in comparison with the testosterone group. By the end of 28 days of treatment, the compound reduced the skin oiliness, porphyrin amount and the quantity of inflammatory lesions in participants. According to the dermatologist evaluation, PXCA improved the skin's general appearance, acne presence and size.

Secretory Proteases of the Human Skin Microbiome

The human skin is our outermost layer and serves as a protective barrier against external insults. Advances in next generation sequencing have enabled the discoveries of a rich and diverse community of microbes - bacteria, fungi and viruses that are residents of this surface. The genomes of these microbes also revealed the presence of many secretory enzymes. In particular, proteases which are hydrolytic enzymes capable of protein cleavage and degradation are of special interest in the skin environment which is enriched in proteins and lipids. In this minireview, we will focus on the roles of these skin-relevant microbial secreted proteases, both in terms of their widely studied roles as pathogenic agents in tissue invasion and host immune inactivation, and their recently discovered roles in inter-microbial interactions and modulation of virulence factors. From these studies, it has become apparent that while microbial proteases are capable of a wide range of functions, their expression is tightly regulated and highly responsive to the environments the microbes are in. With the introduction of new biochemical and bioinformatics tools to study protease functions, it will be important to understand the roles played by skin microbial secretory proteases in cutaneous health, especially the less studied commensal microbes with an emphasis on contextual relevance.

Effects of Ulva sp. Extracts on the Growth, Biofilm Production, and Virulence of Skin Bacteria Microbiota: Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes Strains

Ulva sp. is known to be a source of bioactive compounds such as ulvans, but to date, their biological activity on skin commensal and/or opportunistic pathogen bacteria has not been reported. In this study, the effects of poly- and oligosaccharide fractions produced by enzyme-assisted extraction and depolymerization were investigated, for the first time in vitro, on cutaneous bacteria: Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes. At 1000 μg/mL, poly- and oligosaccharide fractions did not affect the growth of the bacteria regarding their generation time. Polysaccharide Ulva sp. fractions at 1000 μg/mL did not alter the bacterial biofilm formation, while oligosaccharide fractions modified S. epidermidis and C. acnes biofilm structures. None of the fractions at 1000 μg/mL significantly modified the cytotoxic potential of S. epidermidis and S. aureus towards keratinocytes. However, poly- and oligosaccharide fractions at 1000 μg/mL induced a decrease in the inflammatory potential of both acneic and non-acneic C. acnes strains on keratinocytes of up to 39.8%; the strongest and most significant effect occurred when the bacteria were grown in the presence of polysaccharide fractions. Our research shows that poly- and oligosaccharide Ulva sp. fractions present notable biological activities on cutaneous bacteria, especially towards C. acnes acneic and non-acneic strains, which supports their potential use for dermo-cosmetic applications.

Altered Skin and Gut Microbiome in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by the formation of nodules, abscesses, and fistula at intertriginous sites. The skin-gut axis is an area of emerging research in inflammatory skin disease and is a potential contributory factor to the pathogenesis of HS. 59 patients with HS provided fecal samples, nasal and skin swabs of affected sites for analysis. 30 healthy controls provided fecal samples and 20 healthy controls provided nasal and skin swabs. We performed bacterial 16S rRNA gene amplicon sequencing on total DNA derived from the samples. Microbiome alpha diversity was significantly lower in the fecal, skin and nasal samples of individuals with HS which may be secondary to disease biology or related to antibiotic usage. Ruminococcus gnavus was more abundant in the fecal microbiome of individuals with HS, which is also reported in Crohn's disease (CD), suggesting comorbidity due to shared gut microbiota alterations. Finegoldia magna was over-abundant in HS skin samples relative to healthy controls. It is possible local inflammation is driven by F. magna through promoting the formation of neutrophil extracellular traps (NET). These alterations in both the gut and skin microbiome in HS warrant further exploration, and therapeutic strategies including fecal microbiota transplant (FMT) or bacteriotherapy could be of benefit.

The 10-Point Plan 2021: Updated Concepts for Improved Procedural Safety During Facial Filler Treatments

Dermal filler treatments require constant reassessment for improving and safeguarding the rapidly evolving aesthetic field. Suboptimal injection technique, patient selection and product knowledge have touted a concerning increase in filler complications, with new challenges such as the COVID-19 pandemic leading to new paradigms in the understanding, prevention, diagnosis and treatment of complications. The updated 10-point plan has been developed to curtail complications through consideration of causative factors, categorized as patient, product, and procedure-related. Patient-related factors include a preprocedural consultation with careful elucidation of skin conditions (acne, rosacea, dermatitis), systemic disease (allergies, autoimmune disease, underlying bacterial and viral disease (herpes simplex virus, COVID-19 infection), medications (antineoplastic drugs, recreational drugs) and previous cosmetic procedures (including fillers and energy-based devices). Patient assessment should include standardized photography and also evaluate the role of social media, ethnicity, gender, generational, and LGBTQ+ needs. Specified informed consent for both adverse events and their treatment is essential due to the increase in vascular complications, including the risk of blindness. Product-related factors include the powerful advantage of reversibility when using hyaluronic acid (HA) products. Product characteristics such as molecular weight and filler degradation should be understood. Product layering over late or minimally degradable fillers is still inadvisable due to the initial filler being teased into reactivity. Procedural factors such as consistent photographic documentation, procedural planning, aseptic non-touch technique (ANTT), knowledge of topographical anatomy and angiosomes, and technical dexterity including pinch anatomy and needle skills are of pivotal importance. The final section is dedicated to algorithms and checklists for managing and treating complications such as allergic hypersensitivity reactions, vascular events, infection, edema and late-onset adverse events (LOAEs). The updated 10-point plan is a methodical strategy aimed at further minimising the risk of dermal filler complications.

Antibacterial Susceptibility Testing of Cutibacterium acnes in Acne Vulgaris Patients

Introduction

Combination therapy is widely used for the treatment of acne vulgaris (AV), including local anti-inflammatory drugs containing antimicrobials, such as clindamycin or erythromycin, to inhibit Cutibacterium acnes (C. acnes) growth and at the same time reduce the production of inflammatory mediators. The aim of the study is to compare the antibacterial susceptibility of C. acnes to clindamycin and erythromycin in AV patients compared with healthy patients in the control group (CG).

Methods

The prospective study included 56 patients with clinically diagnosed AV symptoms and 12 patients were included in the CG who did not have AV. In the AV group, patient specimen was contents of pustules obtained by squeezing pustules, but in the CG, the specimen was content of sebaceous glands. All specimens were cultivated on a combined Mueller-Hinton solid medium. Identification was done by VITEK2 and followed by determination of antibacterial susceptibility of the isolated C. acnes strains by E-test.

Results

C. acnes was isolated from samples of 28 (50%) in the AV group, whereas in the CG, C. acnes was isolated from 10 samples (80%). Resistance to clindamycin in both groups was similar, in 6 (21.4%) samples from patients in the AV group and in 2 (20.0%) samples in the CG, but resistance to erythromycin in the AV patients was higher compared to the CG, in 8 (28.6%) and 1 (10%) accordingly.

Conclusion

Patients with AV have higher rates of resistance to erythromycin than the CG, while resistance to clindamycin is comparable. Resistance data showed no statistically significant association between use of erythromycin and clindamycin and the development of resistance. More C. acnes were identified in the CG than in the AV group.

Updated Treatment for Acne: Targeted Therapy Based on Pathogenesis

Previous approaches to acne management have focused on the four main factors implicated in acne, namely, androgen-mediated sebogenesis (considered integral to acne), hyperkeratinization, colonization with Cutibacterium acnes, and inflammation related to both innate and adaptive mechanisms. Recent advances have facilitated potential novel approaches to acne management, as the pathophysiology and the immunological aspects related to acne and wound healing have evolved. Particular targets that have been shown to be closely involved in acne pathophysiology and wound healing include interleukin (IL)-1β, IL-17, IL-23, and tumor necrosis factor alpha (TNFα). Biological antibodies targeting IL-1β, IL-17, IL-23, and TNFα could provide novel approaches for treating severe acne and related disorders. Acne is primarily a disease associated with sebogenesis. Monosaturated free acids are important components. Insulin growth factor 1 (IGF-1) promotes the proliferation and differentiation of sebocytes and IL-1β. Research into the microbiome may also provide insights into potential future therapeutic options for acne. Scars, both atrophic and hypertrophic, are common sequelae to acne. Risk factors associated with the development of acne scars include genetic, systemic, local, and lifestyle factors. Pro-inflammatory cytokines have been shown to play a crucial role in the development of acne-induced hypertrophic scars. Treatment for extensive inflammatory keloid scarring is limited. Surgery and postoperative radiotherapy are two possible options. Transforming growth factor-β (TGFβ), IL-6, matrix metalloproteinase (MMP), IGF-1, and B cells are found in keloid or hypertrophic scar tissues. Biological antibodies targeting these cytokines may be a potential strategy for the prevention and treatment of this type of scar in the future. Future treatment for acne should embrace approaches that target the main etiological factors of acne. In particular, specific emphasis on aggressive treatment in the acute inflammatory phase to reduce the likelihood of scarring and other clinical sequelae, such as pigmentary changes would be highly desirable. Treatment for established acne-induced sequelae should also be considered.

Porphyrins produced by acneic Cutibacterium acnes strains activate the inflammasome by inducing K+ leakage

Some Cutibacterium acnes subgroups dominate on healthy skin, whereas others are frequently acne associated. Here we provide mechanistic insights into this difference, using an anaerobic keratinocyte-sebocyte-C. acnes co-culture model. An acneic C. acnes strain as well as its porphyrins activates NRLP3 inflammasome assembly, whereas this was not observed with a non-acneic strain. Low levels of intracellular K⁺ in keratinocytes stimulated with extracted porphyrins or infected with the acneic strain were observed, identifying porphyrin-induced K⁺ leakage as trigger for inflammasome activation. Using a panel of C. acnes strains, we found that porphyrin production and IL-1β release are correlated and are higher in acneic strains. This demonstrates that the latter produce more porphyrins, which interact with the keratinocyte cell membrane, leading to K⁺ leakage, NLRP3 inflammasome activation, and IL-1β release and provides an explanation for the observation that some C. acnes strains are associated with healthy skin, whereas others dominate in acneic skin.

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We developed an anaerobic keratinocyte-sebocyte-C. acnes co-culture model

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Acneic C. acnes strains and their porphyrins activate NRLP3 inflammasome assembly

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Activation of the NRLP3 inflammasome is not observed in non-acneic strains

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Porphyrins from acneic C. acnes activate the inflammasome by inducing K⁺ leakage

Cutibacterium Acnes Tetracycline Resistance Profile in Patients with Acne Vulgaris, in a Colombian Dermatologic Center

INTRODUCTION

Acne is a chronic inflammatory disease, in which different events intervene in its pathogenesis, one of which is Cutibacterium acnes (C. acnes). Resistance of this bacteria to different antimicrobials used in treatment has been described in different regions of the world. The purpose of the study is to estimate the resistance of C. acnes to cyclins in patients with moderate and severe acne over 18 years of age.

MATERIALS AND METHODS

An analytical cross-sectional study was carried out. Samples were taken from inflammatory lesions with a comedone extractor. The content of the samples was incubated in an anaerobic atmosphere to grow C. acnes. Finally, the susceptibility of C. acnes to tetracycline, minocycline and doxycycline was determined.

RESULTS

Samples were taken from 147 patients, of which 129 showed growth of C. acnes, finding that 5.43% of the strains were resistant to tetracycline, 5.43% to doxycycline, 0.78% to minocycline and cross resistance between doxycycline and tetracycline in all the cases. An association was found between resistance and being 25 years of age or older. No association was found with the prior use of antibiotics, a history of misuse of oral or topical antibiotics, and other demographic and clinical characteristics evaluated.

CONCLUSIONS

The resistance found of C. acnes to cyclines was lower than that reported in other studies. Although no relationship was found with the previous use of antibiotics, it is a factor described in previous studies, which is why the proper use of antibiotics is imperative to avoid the appearance of resistance.

Spermidine-induced recovery of human dermal structure and barrier function by skin microbiome

An unbalanced microbial ecosystem on the human skin is closely related to skin diseases and has been associated with inflammation and immune responses. However, little is known about the role of the skin microbiome on skin aging. Here, we report that the Streptococcus species improved the skin structure and barrier function, thereby contributing to anti-aging. Metagenomic analyses showed the abundance of Streptococcus in younger individuals or those having more elastic skin. Particularly, we isolated Streptococcus pneumoniae, Streptococcus infantis, and Streptococcus thermophilus from face of young individuals. Treatment with secretions of S. pneumoniae and S. infantis induced the expression of genes associated with the formation of skin structure and the skin barrier function in human skin cells. The application of culture supernatant including Streptococcal secretions on human skin showed marked improvements on skin phenotypes such as elasticity, hydration, and desquamation. Gene Ontology analysis revealed overlaps in spermidine biosynthetic and glycogen biosynthetic processes. Streptococcus-secreted spermidine contributed to the recovery of skin structure and barrier function through the upregulation of collagen and lipid synthesis in aged cells. Overall, our data suggest the role of skin microbiome into anti-aging and clinical applications.

Development and characterization of a 3D in vitro model mimicking acneic skin

Acne is an inflammatory skin disease of the pilosebaceous unit, involving four essential factors: hyperseborrhoea combined to a modification of sebum composition, colonization by Cutibacterium (C.) acnes, hyperkeratinization and secreted inflammation. Understanding and mimicking compromised skin is essential to further develop appropriate therapeutic solutions. This study aimed to develop new in vitro 3D models mimicking acneic skin, by combining two main factors involved in the physiopathology, namely, altered sebum composition and C. acnes invasion. Normal human keratinocytes were first used to generate reconstructed human epidermis (RHE) that were then left untreated (control) or treated topically with a combination of both peroxidized squalene and C. acnes cultures. Once validated, this model considered relevant to mimic acneic skin, was further improved by using different phylotypes of C. acnes strains specifically isolated from healthy and acneic patients. While both phylotypes IB and II did not significantly alter RHE, C. acnes IA1 strains induce major acneic skin hallmarks such as hyperkeratinization, secreted inflammation and altered barrier function. Interestingly, these results are obtained independently of the origin of IA1 phylotypes (acneic vs. healthy patient), thus suggesting a role of the ecosystem in controlling C. acnes virulence in healthy skin. In conclusion, by combining two major factors involved in the physiopathology of acne, we (1) succeeded to design in vitro 3D models mimicking this skin disorder and (2) highlighted how C. acnes phylotypes can have an impact on epidermal physiology. These relevant models will be suitable for the substantiation of therapeutic molecules dedicated to acne treatment.

Improving aseptic injection standards in aesthetic clinical practice

The rise in popularity and demand for nonsurgical injectable aesthetic procedures is inherently accompanied by an increase in reported complications, particularly those related to infection. Aseptic technique is under the control of aesthetic practitioners and can be modified to minimize the potential for cross-contamination and infection. This should be a key consideration during all clinical procedures, particularly those involving breach of the skin's natural defenses and the use of soft tissue filler. A consensus group of five UK expert aesthetic clinicians were convened to discuss current best practice for aseptic techniques in medical aesthetics. The aim of the consensus group was to recommend a step-by-step procedure to achieve optimal aseptic practice in private clinics, and define important considerations for reducing infection risk during the whole patient journey: pre-, during- and postaesthetic procedure. Recommendations were based on current evidence and extensive clinical experience. Various procedure recommendations were made to achieve and maintain a high standard of asepsis and infection control. Guidance was divided into three phases for patients and health care professionals, covering preprocedure (including patient selection), during-procedure, and postprocedure considerations. Although adherence to standard hospital guidance on handwashing and cleanliness measures is a cornerstone of controlling cross-contamination, aesthetic clinics carry a high potential risk of infection-particularly as popular treatments with dermal fillers primarily involve the face. This expert consensus guidance recommends procedures to mitigate the potential risks of asepsis.