Propionibacterium acnes in the pathogenesis and immunotherapy of acne vulgaris

Glycyrrhizin functionalized CuS Nanoprobes for NIR Light-based therapeutic mitigation of acne vulgaris

Acne Vulgaris or Acne is a multifactorial bacterial infection caused by Propionibacterium acne, leading to inflammation and decreased quality of life, especially in adolescence. Currently, antibiotics and retinoids are preferred for treating acne. However, their continuous usage may lead to anti-microbial resistance and other side effects. Therefore, research on developing effective strategies to reduce antimicrobial resistance and improve acne healing is ongoing. The current work reports the synthesis and evaluation of near-infrared light-absorbing copper sulfide (CuS) nanoparticles loaded with a biomolecule, Glycyrrhizin (Ga). The photothermal efficacy studies, and in-vitro and in-vivo experiments indicated that the Ga-CuS NPs generated localized hyperthermia in acne-causing bacteria, leading to their complete growth inhibition. The results indicated that the Ga-Cus NPs possess excellent antibacterial and anti-inflammatory properties in the acne and inflammatory models. This could be from the synergistic effect of CuS NPs mediated mild Photothermal effect and inherent pharmacological properties of Ga. Further detailed studies of the formulations can pave the way for application in cosmetic clinics for the effective and minimally invasive management of Acne-like conditions.

Anti-Bacterial Activity of Green Synthesised Silver and Zinc Oxide Nanoparticles against Propionibacterium acnes

Propionibacterium acnes plays a critical role in the development of acne vulgaris. There has been a rise in the number of patients carrying P. acnes strains that are resistant to antibiotics. Thus, alternative anti-microbial agents are required. Zinc oxide (ZnO-NPs) and silver (Ag-NPs) nanoparticles can be used against several antibiotic-resistant bacteria. The impact of Ag-NPs and ZnO-NPs against two clinical strains of P. acnes, P1 and P2, and a reference strain, NCTC747, were investigated in this research. A chemical approach for the green synthesis of Ag-NPs and ZnO-NPs from Peganum harmala was employed. The microtiter plate method was used to examine the effects of NPs on bacterial growth, biofilm development, and biofilm eradication. A broth microdilution process was performed in order to determine minimal inhibitory (MIC) concentrations. Ag-NPs and ZnO-NPs had a spherical shape and average dimensions of 10 and 50 nm, respectively. MIC values for all P. acnes strains for Ag-NPs and ZnO-NPs were 125 µg/mL and 250 µg/mL, respectively. Ag-NP and ZnO-NP concentrations of 3.9- 62.5 µg/mL and 15-62.5 µg/mL significantly inhibited the growth and biofilm formation of all P. acnes strains, respectively. ZnO-NP concentrations of 15-62.5 μg/mL significantly inhibited the growth of NCTC747 and P2 strains. The growth of P1 was impacted by concentrations of 31.25 μg/mL and 62.5 μg/mL. Biofilm formation in the NCTC747 strain was diminished by a ZnO-NP concentration of 15 μg/mL. The clinical strains of P. acnes were only affected by ZnO-NP titres of more than 31.25 μg/mL. Established P. acne biofilm biomass was significantly reduced in all strains at a Ag-NP and ZnO-NP concentration of 62.5 µg/mL. The findings demonstrated that Ag-NPs and ZnO-NPs exert an anti-bacterial effect against P. acnes. Further research is required to determine their potential utility as a treatment option for acne.

Application of bacteriophage φPaP11-13 attenuates rat Cutibacterium acnes infection lesions by promoting keratinocytes apoptosis via inhibiting PI3K/Akt pathway

Acne vulgaris caused by antibiotic-resistant Cutibacterium acnes (C. acnes) infection is difficult to treat conventionally. Phages have been suggested as a potential solution, but research on the mechanism of phage treatment is inadequate. This research investigates the underlying molecular mechanisms of phage φPaP11-13 attenuating C. acnes-induced inflammation in rat models. We found that rats infected with C. acnes had higher average ear thickness, greater enrichment of inflammatory cells as shown by hematoxylin-eosin (HE) staining, and fewer TUNEL (TdT-mediated dUTP Nick-End Labeling)-positive keratinocytes visualized by IF staining. Moreover, an increase of IGF-1 and IGF-1 receptor (IGF-1r) was detected using the immunohistochemical (IHC) staining method, Western blot (WB), and quantitative real-time PCR (qRT-PCR) when infected with C. acnes, which was decreased after the application of phage φPaP11-13. By applying the IGF-1 antibody, it was demonstrated that the severity of C. acnes-induced inflammation was relevant to the expression of IGF-1. Through WB and qRT-PCR, activation of the PI3K/Akt pathway and a down-regulation of the BAD-mediated apoptosis pathway were discovered after C. acnes infection. Subsequently, it was shown that the activation of the PI3K/Akt pathway against BAD-mediated apoptosis pathway was alleviated after applying phage φPaP11-13. Furthermore, applying the IGF-1r inhibitor, Pan-PI3K inhibitor, and Akt inhibitor reversed the changing trends of BAD induced by C. acnes and phage φPaP11-13. This study demonstrates that one of the critical mechanisms underlying the attenuation of acne vulgaris by phage φPaP11-13 is lysing C. acnes and regulating keratinocyte apoptosis via the PI3K/Akt signaling pathway.IMPORTANCECutibacterium acnes infection-induced acne vulgaris may cause severe physical and psychological prognosis. However, the overuse of antibiotics develops drug resistance, bringing challenges in treating Cutibacterium acnes. Bacteriophages are currently proven effective in MDR (multiple drug-resistant) Cutibacterium acnes, but there is a significant lack of understanding of phage therapy. This study demonstrated a novel way of curing acne vulgaris by using phages through promoting cell death of excessive keratinocytes in acne lesions by lysing Cutibacterium acnes. However, the regulation of this cell cycle has not been proven to be directly mediated by phages. The hint of ternary relation among "phage-bacteria-host" inspires huge interest in future phage therapy studies.

Discovery and Characterization of a Novel Bacteriocin HA2-5 that Strongly Inhibits Propionibacterium acnes

Increased drug resistance has significantly reduced the effectiveness of antibiotics used in the treatment of Propionibacterium acnes. Therefore, there has been a trend toward the development of new antimicrobial agents to circumvent drug resistance. In this study, we isolated and purified a novel bacteriocin, HA2-5, from Bacillus haynesii HA2, which effectively killed P. acnes through membrane disruption at a minimum inhibitory concentration (MIC) of 8 μg/mL. HA2-5 with 2× MIC was able to kill 99.9% of P. acnes within 24 h. HA2-5 shows excellent stability and tolerance to temperature, pH, proteases, chemical reagents, UV radiation, and metal ions, with almost no loss of inhibitory activity after treatment. In addition, the very low hemolytic activity and cytotoxicity suggest that HA2-5 is biosafe. Notably, HA2-5 exhibits preferred antibacterial activity against gram-positive pathogens with an MIC of 16-32 μg/mL. In conclusion, this study shows that bacteriocin HA2-5 has the potential to be used as an alternative to antibiotics for acne treatment.

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.

Skin dysbiosis and Cutibacterium acnes biofilm in inflammatory acne lesions of adolescents

Acne vulgaris is a common inflammatory disorder affecting more than 80% of young adolescents. Cutibacterium acnes plays a role in the pathogenesis of acne lesions, although the mechanisms are poorly understood. The study aimed to explore the microbiome at different skin sites in adolescent acne and the role of biofilm production in promoting the growth and persistence of C. acnes isolates. Microbiota analysis showed a significantly lower alpha diversity in inflammatory lesions (LA) than in non-inflammatory (NI) lesions of acne patients and healthy subjects (HS). Differences at the species level were driven by the overabundance of C. acnes on LA than NI and HS. The phylotype IA1 was more represented in the skin of acne patients than in HS. Genes involved in lipids transport and metabolism, as well as potential virulence factors associated with host-tissue colonization, were detected in all IA1 strains independently from the site of isolation. Additionally, the IA1 isolates were more efficient in early adhesion and biomass production than other phylotypes showing a significant increase in antibiotic tolerance. Overall, our data indicate that the site-specific dysbiosis in LA and colonization by virulent and highly tolerant C. acnes phylotypes may contribute to acne development in a part of the population, despite the universal carriage of the microorganism. Moreover, new antimicrobial agents, specifically targeting biofilm-forming C. acnes, may represent potential treatments to modulate the skin microbiota in acne.

Efficacy of the combination of P5 peptide and photodynamic therapy mediated by bixin and chlorin-e6 against Cutibacterium acnes biofilm

In this study, the action of antimicrobial peptide (AMP) P5 and antimicrobial photodynamic therapy (aPDT) mediated by bixin and chlorin-e6 (Ce6) on Cutibacterium acnes (C. acnes) in planktonic phase and biofilm were evaluated both as monotherapies and combined therapies. Microbial viability after treatments were quantified by colony-forming units per milliliter of the sample (CFU/mL) and have demonstrated that all treatments employed exerted bactericidal activity, reducing the microbial load by more than 3 log₁₀ CFU/mL, also demonstrating for the first time in the literature the antimicrobial photodynamic effect of bixin that occurs mostly through type I mechanism which was proved by the quantification of superoxide anion production. Bacterial biofilm was completely eliminated only after its exposure to aPDT mediated by this PS, however, Ce6 proved to be a more efficient PS, considering that most of the photodynamic effect of bixin- aPDT was exerted by excitation of the endogenous C porphyrins of C. acnes with blue light. The combination of P5 with Ce6-aPDT showed a synergistic effect on the bacterial biofilm with a reduction in microbial load by more than 10 log₁₀ CFU/mL, in which the ability of P5 to permeabilize the polymeric extracellular matrix of the biofilm explains the obtained results, with greater internalization of the PS as shown by the Confocal Laser Scanning Microscopy. One-way ANOVA (Analysis of Variance) with Tukey's post-test and two-way ANOVA with Bonferroni's post-test were used to compare the values of continuous variables between the control group and the treatment groups.

Effect of combining Zingiber officinale and Juglans regia extracts on Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis: antibiofilm action and low toxicity

Objective was evaluated the therapeutic effect of Juglans regia (J) and Zingiber officinale (Z) extracts, alone or associated (Z75% + J25%, Z50% + J50% and Z25% + J75%) applied on planktonic cultures and biofilms of Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus, as well as analyzing the cytotoxic effects of plant extracts on mouse macrophages (Raw 264-7). Broth microdilution assay was performed (M7-A6 - CLSI). Anti-biofilm activities and cytotoxicity on Raw 264-7 were studied using MTT assay and scanning electron microscopy. ANOVA with post-hoc Tukey HSD applied for parametric data and Kruskal-Wallis with Conover-Iman test, for non-parametric (p<0.05). On P. acnes biofilm, Z50% + J50% reduced 46.9% in 5 min and Z25% + J75% reduced 74.1% in 24hs. On S. aureus, Z75% + J25% reduced 23.1% in 5 min Z25% +J75% reduced 79.4% in 24hs. On S. epidermidis, Z75% + J25% reduced 74.6% in 5 min and 82.05% in 24 h. The treatments on macrophages for 24 h promoted a maximum reduction by 14,5% for groups of extracts associations. On multispecies biofilm, Z75%+J25% reduced 84.3% in 24 h. In conclusion association of glycolic extracts provided therapeutic effect, demonstrated antimicrobial activity and low cytotoxicity.

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.

Anti-Inflammatory and Anti-Acne Effects of Hamamelis virginiana Bark in Human Keratinocytes

Cutibacterium acnes (C. acnes) is recognized as one of the main triggers of the cutaneous inflammatory response in acne vulgaris, a chronic skin disorder with a multifactorial origin. Witch hazel (Hamamelis virginiana L.) is a plant widely used for skin inflammatory conditions, with some preliminary anti-inflammatory evidence on the skin, but lacking data on acne conditions. This study aimed to evaluate the effect of a glycolic extract from Hamamelis virginiana bark (HVE) versus C. acnes-induced inflammation in human keratinocytes (HaCaT). Phytochemical investigations of HVE identified hamamelitannin (HT) and proanthocyanidins as the most abundant compounds (respectively, 0.29% and 0.30% w/w_extract). HVE inhibited C. acnes-induced IL-6 release (IC₅₀: 136.90 μg/mL), by partially impairing NF-κB activation; however, no antibacterial or antibiofilm activities were found. In addition, HVE showed greater anti-inflammatory activity when TNF-α was used as a proinflammatory stimulus (IC₅₀ of 38.93 μg/mL for IL-8 release), partially acting by antioxidant mechanisms, as shown for VEGF inhibition. The effects of HVE are primarily based on the proanthocyanidin content, as HT was found inactive on all the parameters tested. These results suggest further investigations of HVE in other inflammatory-based skin diseases.

The role of Propionibacterium acnes in and Modic type 1 changes : A literature review

Propionibacterium acnes (P. acnes) is part of the normal flora of human skin, oral cavity, intestinal tract and external ear canal. However, breach in the mucosa as well as ruptured annulus fibrosus provide favorable pathway for P. acnes to nucleus pulposus where it can proliferate under anaerobic condition. In past two decades many authors have identified P. acnes in routine culture of discs. There studies showed that almost 50% of discs cultured were positive for various organism, and in vast majority of culture positive disc, P. acnes was the primary organism isolated. However, there are few studies that refute the hypothesis that P. acnes has a role in pathogenesis of Modic type 1 changes. Identification of P. acnes in culture indicates the infective patho-mechanism in the pathogenesis of Modic type 1 changes, which may be ameable to antibiotic treatment. However, it is still difficult to identify which subset of these patients (patients with low back pain with type 1 Modic change) are infective in nature. Further investigation and more clinical trails will be required for clear identification of the infective subgroup among low back patient in general. J. Med. Invest. 67 : 21-26, February, 2020.

Modification of Anti-acne Bawang Dayak (Eleutherine bulbosa (Mill.)Urb.) Cream to Propionibacterium acnes

Bawang dayak is one of the traditional medicines in Central Kalimantan, used to treat acne vulgaris. Previous research reported that a cream made with bawang dayak extract's active ingredient could inhibit Propionibacterium acnes' growth. However, bawang dayak has a pungent odor that causes discomfort, where the cream separates after 3 days of storage, which decreases its potency. This study aims to improve the quality of the anti-acne cream formulation of bawang dayak extract from previous studies with the addition of cinnamon, honey, and peppermint. The modified formula of bawang dayak extract cream was evaluated and tested for its antibacterial activity in vitro. The results showed an increase in the organoleptic test, especially the smell, which gave a more comfortable fragrance than the previous formula. The pH measurement of the cream shows the results suitable for topical applications. However, the homogeneity observations show that all the formulas are homogeneous, seen from uniform colors but contain coarse grains. The antibacterial activity test of all cream formulations against P. acnes showed inhibition zone diameter between 14.85 and 17.10 mm, all of which were moderate and larger than previous studies. It can be concluded that the modification of the cream formula with the active ingredient of bawang dayak extract showed an increase in the inhibition zone against P. acnes and improved organoleptic properties.

Evaluation of tea tree oil physicochemical features and its antimicrobial activity against Cutibacterium acnes (Propionibacterium acnes) ATCC 6919

Introducción.

El aceite del árbol de té es un aceite esencial reconocido por sus propiedades antimicrobianas.

Objetivos.

Evaluar la composición, características y efecto antimicrobiano del aceite al 2 % del árbol de té y su concentración inhibitoria mínima (CIM) contra Cutibacterium acnes (Propionibacterium acnes).

Materiales y métodos.

Se evaluó el quimiotipo en tres lotes diferentes de este aceite mediante cromatografía de gases, así como su actividad antimicrobiana en concentración al 2 % v/v y la CIM contra C. acnes mediante ensayo de difusión en agar (guía M11-A8 CLSI).

Resultados.

Los lotes evaluados presentaron los quimiotipos ajustados a la norma ISO 4730, lo que indicó la alta calidad del producto. Los lotes contenían de 30 a 40 % de terpinen-4-ol, compuesto que favorece la actividad antimicrobiana, la cual presentó en todos los lotes un efecto dependiente de la concentración contra C. acnes, con una inhibición del crecimiento microbiano en concentración al 2 % v/v en todas las pruebas. La concentración inhibitoria mínima fue de 0,25 % v/v. La actividad antimicrobiana del aceite del árbol de té contra este microorganismo ya ha sido reportada con una concentración inhibitoria mínima entre 0,05 y 1,25 % v/v, rango que cobija la obtenida en este estudio.

Conclusiones.

Los resultados evidenciaron la gran calidad de este producto y su capacidad como agente antibacteriano contra C. acnes. Se deben hacer estudios con otros aislamientos del microorganismo provenientes de pacientes con acné vulgar para confirmar su actividad general y la de cada uno de sus componentes.

Comparative Efficacy of Pharmacological and Nonpharmacological Interventions for Acne Vulgaris: A Network Meta-Analysis

Acne has several effects on physical symptoms, but the main impacts are on the quality of life, which can be improved by treatment. There are several acne treatments but less evidence comparing their relative efficacy. Thus, we assessed the comparative efficacy of pharmacological and nonpharmacological interventions for acne. We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from inception to April 2019, to include randomized controlled trials for acne that compared topical antibiotics (TA), benzoyl peroxide (BPO), topical retinoids (TR), oral antibiotics (OA), lasers, light devices including LED device (LED), photodynamic therapy (PDT), and intense pulsed light, chemical peels (CP), miscellaneous therapies or complementary and alternative medicine (MTCAM), or their combinations. We performed Bayesian network meta-analysis with random effects for all treatments compared with placebo and each other. Mean differences (MDs) of lesions count and risk ratios of adverse events with their 95% credible intervals (CrIs) were calculated, and all interventions were ranked by the Surface Under the Cumulative Ranking (SUCRA) values. Additional frequentist additive network meta-analysis was performed to detect the robustness of results and potential interaction effects. Sensitivity analyses were carried out with different priors, and metaregression was to adjust for nine potential effect modifiers. In the result, seventy-three randomized controlled trials (27,745 patients with mild to moderate acne), comparing 30 grouped intervention categories, were included with low to moderate risk of bias. For adverse effects, OA had more risk in combination treatment with others. For noninflammatory lesions reduction, seventeen interventions had significant differences comparing with placebo and three interventions (TR+BPO: MD = −21.89, 95%CrI [−28.97, −14.76]; TR+BPO+MTCAM: −22.48 [−34.13, −10.70]; TA+BPO+CP: −20.63 [−33.97, −7.13]) were superior to others with 94, 94, and 91% SUCRA values, respectively. For inflammatory lesions reduction, nineteen interventions were significantly better than placebo, and three interventions (TR+BPO: MD = −12.13, 95%CrI [−18.41, −5.80]; TR+BPO+MTCAM: −13.21 [−.39, −3.04]; LED: −11.30 [−18.34, −4.42]) were superior to others (SUCRA: 81, 81, and 77%, respectively). In summary of noninflammatory and inflammatory lesions results, TR+BPO and TA+BPO were the best options compared to others. The frequentist model showed similar results as above. In summary, current evidence supports the suggestion that TR+BPO and TA+BPO are the best options for mild to moderate acne. LED is another option for inflammatory lesions when drug resistance occurs. All the combinations involved with OA showed more risk of adverse events than others. However, the evidence of this study should be cautiously used due to the limitations.

Protecting the outside: biological tools to manipulate the skin microbiota

Interest surrounding the role that skin microbes play in various aspects of human health has recently experienced a timely surge, particularly among researchers, clinicians and consumer-focused industries. The world is now approaching a post-antibiotic era where conventional antibacterial therapeutics have shown a loss in effectiveness due to overuse, leading to the looming antibiotic resistance crisis. The increasing threat posed by antibiotic resistance is compounded by an inadequate discovery rate of new antibiotics and has, in turn, resulted in global interest for alternative solutions. Recent studies have demonstrated that imbalances in skin microbiota are associated with assorted skin diseases and infections. Specifically, restoration of this ecosystem imbalance results in an alleviation of symptoms, achieved simply by applying bacteria normally found in abundance on healthy skin to the skin of those deficient in beneficial bacteria. The aim of this review is to discuss the currently available literature on biological tools that have the potential to manipulate the skin microbiota, with particular focus on bacteriocins, phage therapy, antibiotics, probiotics and targets of the gut-skin axis. This review will also address how the skin microbiota protects humans from invading pathogens in the external environment while discussing novel strategies to manipulate the skin microbiota to avoid and/or treat various disease states.

Post-Rhinoplasty Acne, Frequency and Role Players

Introduction

Acne is a common complain among post rhinoplasty patients. While rhinoplasty is done for aesthetic reasons and acne expressively affects the individual’s appearance, we aimed to study its incidence and role players.

Materials and Methods:

A descriptive cross-sectional study was performed on 152 (143 females and 9 males) patients admitted for rhinoplasty during January 2016 to March 2017. Patients were examined by a dermatologist prior to surgery and 7, 30 and 90 days after rhinoplasty using the Global Acne Grading System and responded to a list of questions on the probable risk factors of acne. Psychological status was examined by the perceived stress scale-14 and the Hospital Anxiety and Depression Scale.

Results:

The patients' mean age was 28.9±3.82 yrs. Mild and moderate acne were observed in 21.7% (n=33) of the cases in the preoperative visit. The incidence of mild and moderate acne was 36.1%, 42.8% and 23% after 7, 30 and 90 days of surgery, respectively. One week after rhinoplasty, acne manifested in 14.9% of cases with no history of acne. Mean age significantly differed between those with and without post-surgical acne at all post-surgical visits (P> 0.001 and P=0.001 and P=0.015, respectively). Hospital anxiety and depression and perceived stress levels were significantly higher in patients who presented with acne on the first post-surgical visit compared to those with no acne presentations (P=0.04 and P=0.02, respectively).

Conclusion:

External psychological stress may be the main role player in post-rhinoplasty acne. Consultation or referral of patients to an experienced psychologist is highly recommended for a better outcome and fewer complications.

Antibiotics Drive Microbial Imbalance and Vitiligo Development in Mice

Vitiligo is impacted by environmental triggers. We studied the contribution of the microbiome in FH mice, in which depigmentation is mediated by tyrosinase-reactive T cells. The mice received oral antibiotics and were monitored for depigmentation. The microbiome was studied in fecal and skin samples using 16S rRNA analysis. The resulting T-cell distributions were evaluated. In untreated mice, pigment loss did not expand to the pelage, whereas mice in the ampicillin group were approximately 1/3 depigmented at 30 weeks. In contrast to models of autoimmunity that are less dependent on IFN-γ, ampicillin but not neomycin treatment correlated with accelerated disease and reduced bacteria in the fecal pellets. Modified cytokine patterns in the tissue and serum suggest a response that transcends the gut. Ampicillin-induced depigmentation was accompanied by gut but not skin dysbiosis, and reduced T cell numbers in both sites. Neomycin induced a redistribution of gut T cells and an accumulation of skin regulatory T cells. This treatment spurred a Bacteroides-dominated population of fecal bacteria. Reduced diversity is prominent particularly after ampicillin treatment, when the gut is dominated by Pseudomonas species. In line with current concepts relating the microbiome and the immune system, we predict that dietary measures might promote skin health and delay vitiligo onset.

Corynebacterium tuberculostearicum, a human skin colonizer, induces the canonical nuclear factor-κB inflammatory signaling pathway in human skin cells

INTRODUCTION

Corynebacterium tuberculostearicum (C. t.) is a ubiquitous bacterium that colonizes human skin. In contrast to other members of the genus Corynebacterium, such as toxigenic Corynebacterium diphtheriae or the opportunistic pathogen Corynebacterium jeikeium, several studies suggest that C. t. may play a role in skin health and disease. However, the mechanisms underlying these effects remain poorly understood.

METHODS

To investigate whether C. t. induces inflammatory pathways in primary human epidermal keratinocytes (HEKs) and human cutaneous squamous carcinoma cells (SCCs), cell culture, reverse transcription-polymerase chain reaction (PCR), enzyme-linked immunosorbent assay, immunofluorescence microscopy, Western blot, chromatin immunoprecipitation-PCR, small interfering RNA knockdown and luciferase reporter expression system were used.

RESULTS

Herein, we demonstrate that C. t. upregulates the messenger RNA (mRNA) and protein levels of inflammatory mediators in two human skin cell lines, HEKs and SCCs. We further show activation of the canonical nuclear factor-κB (NF-κB) pathway in response to C. t. infection, including phosphorylation of the inhibitor of κB (IκB), the nuclear translocation of NF-κB subunit (NF-κB-P₆₅ ) and the recruitment of NF-κB-P₆₅ and RNA polymerase to the NF-κB response elements at the promoter region of the inflammatory genes. Lastly, the data confirm that C. t.-induced tumor necrosis factor mRNA expression in HEKs is toll-like receptor 2 (TLR₂ ) dependent.

CONCLUSION

Our results offer a mechanistic model for C. t.-induced inflammation in human keratinocytes via TLR₂ and activation of IκB kinase and downstream signaling through the canonical NF-κB pathway. Relevance to chronic inflammatory diseases of the skin and cutaneous oncology is discussed.

Target Proteins of Phloretin for Its Anti-Inflammatory and Antibacterial Activities Against Propionibacterium acnes-Induced Skin Infection

Phloretin is a natural chalcone with antibacterial and anti-inflammatory effects. This study investigated the anti-acne activity of phloretin against Propionibacterium acnes-induced skin infection and the potential target proteins of its anti-inflammatory and antibacterial effects. Phloretin potently inhibited the growth of P. acnes and P. acnes-induced Toll-like receptor (TLR) 2-mediated inflammatory signaling in human keratinocytes. Secreted embryonic alkaline phosphatase assay confirmed that the anti-inflammatory activity of phloretin is associated with the P. acnes-stimulated TLR2-mediated NF-κB signaling pathway. Phloretin significantly decreased the level of phosphorylated c-Jun N-terminal kinase (JNK), showing a binding affinity of 1.184 × 10⁻⁵ M⁻¹. We also found that phloretin binds with micromolar affinity to P. acnes β-ketoacyl acyl carrier protein (ACP) synthase III (KAS III), an enzyme involved in fatty acid synthesis. Conformation-sensitive native polyacrylamide gel electrophoresis showed that phloretin reduced KAS III-mediated 3-ketoacyl ACP production by over 66%. A docking study revealed that phloretin interacts with the active sites of JNK1 and KAS III, suggesting their involvement in P. acnes-induced inflammation and their potential as targets for the antibacterial activity of phloretin. These results demonstrate that phloretin may be useful in the prevention or treatment of P. acnes infection.

Propionibacterium (Cutibacterium) acnes Bacteriophage Therapy in Acne: Current Evidence and Future Perspectives

Acne vulgaris is the most common dermatological disorder worldwide. It is a multifactorial disease that involves increased sebum production, hyperkeratinization of the pilosebaceous unit, Propionibacterium acnes (Cutibacterium acnes) colonization, and inflammation. The human skin microbiome hosts a wide variety of microorganisms, including bacteria, viruses, and fungi. A delicate balance of these microorganisms is essential for the barrier function of the skin. Propionibacterium acnes represents nearly 90% of the human skin microbiome of healthy adults. Acne is a chronic recurrent disease that requires long-lasting treatment, which has led to the emergence of antibiotic resistance. New alternatives to traditional therapy are emerging, including antimicrobial peptides, natural engineered antibodies, and bacteriophages. Bacteriophages have been shown to play a role in human skin health and disease. There is evidence supporting phage therapy in many types of skin infections. P. acnes bacteriophages have been isolated and characterized. However, only a few in vitro studies have tested the ability of bacteriophages to kill P. acnes. Furthermore, there is no evidence on bacteriophage therapy in the treatment of acne in humans. In this review, we summarize the most recent evidence regarding P. acnes bacteriophages and the potential role of these bacteriophages in the treatment of acne. Further research on this field will provide the evidence to use phage therapy to decrease rates of antibiotic resistance and restore antibiotic susceptibility of P. acnes.

Antibiotics and specialized metabolites from the human microbiota

Human microbiota associated with each body site produce specialized molecules to kill human pathogens. Advanced bioinformatics tools will help to discover unique microbiome chemistry.

Prevalence of Propionibacterium acnes in Intervertebral Discs of Patients Undergoing Lumbar Microdiscectomy: A Prospective Cross-Sectional Study

Background

The relationship between intervertebral disc degeneration and chronic infection by Propionibacterium acnes is controversial with contradictory evidence available in the literature. Previous studies investigating these relationships were under-powered and fraught with methodical differences; moreover, they have not taken into consideration P. acnes’ ability to form biofilms or attempted to quantitate the bioburden with regard to determining bacterial counts/genome equivalents as criteria to differentiate true infection from contamination. The aim of this prospective cross-sectional study was to determine the prevalence of P. acnes in patients undergoing lumbar disc microdiscectomy.

Methods and Findings

The sample consisted of 290 adult patients undergoing lumbar microdiscectomy for symptomatic lumbar disc herniation. An intraoperative biopsy and pre-operative clinical data were taken in all cases. One biopsy fragment was homogenized and used for quantitative anaerobic culture and a second was frozen and used for real-time PCR-based quantification of P. acnes genomes. P. acnes was identified in 115 cases (40%), coagulase-negative staphylococci in 31 cases (11%) and alpha-hemolytic streptococci in 8 cases (3%). P. acnes counts ranged from 100 to 9000 CFU/ml with a median of 400 CFU/ml. The prevalence of intervertebral discs with abundant P. acnes (≥ 1x10³ CFU/ml) was 11% (39 cases). There was significant correlation between the bacterial counts obtained by culture and the number of P. acnes genomes detected by real-time PCR (r = 0.4363, p<0.0001).

Conclusions

In a large series of patients, the prevalence of discs with abundant P. acnes was 11%. We believe, disc tissue homogenization releases P. acnes from the biofilm so that they can then potentially be cultured, reducing the rate of false-negative cultures. Further, quantification study revealing significant bioburden based on both culture and real-time PCR minimize the likelihood that observed findings are due to contamination and supports the hypothesis P. acnes acts as a pathogen in these cases of degenerative disc disease.

Ethosomes Loaded with Cryptotanshinone for Acne Treatment through Topical Gel Formulation

The aim of this study was to develop ethosomes loaded with cryptotanshinone (CPT) and formulate them as a topical gel for the treatment of acne. Ethosomes were prepared and evaluated for vesicle size, CPT loading and encapsulation efficiency. Optimized ethosomes were formulated as Carbomer 974 gels and compared with conventional hydroethanolic gels for transdermal permeation and skin deposition in vitro. The anti-acne activity and skin irritation of the gel was investigated in rabbits. Optimized ethosomes had an average vesicle size of 69.1 ± 1.9 nm with CPT loading and encapsulation efficiency of 0.445 ± 0.007 mg/mL and 40.31 ± 0.67%, respectively. The transdermal flux and skin deposition of the optimized ethosomal gel were 2.5- and 2.1-times those of conventional gels. The ethosomal gel revealed better anti-acne effect with only slight skin irritation. This study demonstrates that ethosomal formulation is an effective dermal delivery system for CPT, and that CPT ethosomal gels are promising future acne treatments.