Propionibacterium (Cutibacterium) granulosum Extracellular DNase BmdE Targeting Propionibacterium (Cutibacterium) acnes Biofilm Matrix, a Novel Inter-Species Competition Mechanism

Acne vulgaris is the most common dermatological disorder worldwide affecting more than 80% of adolescents and young adults with a global prevalence of 231 million cases in 2019. The involvement of the skin microbiome disbalance in the pathophysiology of acne is recognized, especially regarding the relative abundance and diversity of Propionibacterium acnes a well-known dominant human skin commensal. Biofilms, where bacteria are embedded into a protective polymeric extracellular matrix, are the most prevalent life style for microorganisms. P. acnes and its biofilm-forming ability is believed to be a contributing factor in the development of acne vulgaris, the persistence of the opportunistic pathogen and antibiotic therapy failures. Degradation of the extracellular matrix is one of the strategies used by bacteria to disperse the biofilm of competitors. In this study, we report the identification of an endogenous extracellular nuclease, BmdE, secreted by Propionibacterium granulosum able to degrade P. acnes biofilm both in vivo and in vitro. This, to our knowledge, may represent a novel competitive mechanism between two closely related species in the skin. Antibiotics targeting P. acnes have been the mainstay in acne treatment. Extensive and long-term use of antibiotics has led to the selection and spread of resistant bacteria. The extracellular DNase BmdE may represent a new bio-therapeutical strategy to combat P. acnes biofilm in acne vulgaris.

Histology of Cardiac Sarcoidosis with Novel Considerations Arranged upon a Pathologic Basis

Sarcoidosis is a rare disease of isolated or diffuse granulomatous inflammation. Although any organs can be affected by sarcoidosis, cardiac sarcoidosis is a fatal disorder, and it is crucial to accurately diagnose it to prevent sudden death due to dysrhythmia. Although endomyocardial biopsy is invasive and has limited sensitivity for identifying granulomas, it is the only modality that yields a definitive diagnosis of cardiac sarcoidosis. It is imperative to develop novel pathological approaches for the precise diagnosis of cardiac sarcoidosis. Here, we aimed to discuss commonly used diagnostic criteria for cardiac sarcoidosis and to summarize useful and novel histopathologic criteria of cardiac sarcoidosis. While classical histologic observations including noncaseating granulomas and multinucleated giant cells (typically Langhans type) are the most important findings, others such as microgranulomas, CD68+ CD163− pro-inflammatory (M1) macrophage accumulation, CD4/CD8 T-cell ratio, Cutibacterium acnes components, lymphangiogenesis, confluent fibrosis, and fatty infiltration may help to improve the sensitivity of endomyocardial biopsy for detecting cardiac sarcoidosis. These novel histologic findings are based on the pathology of cardiac sarcoidosis. We also discussed the principal histologic differential diagnoses of cardiac sarcoidosis, such as tuberculosis myocarditis, fungal myocarditis, giant cell myocarditis, and dilated cardiomyopathy.

Structural stability of Cutibacterium acnes acyl carrier protein studied using CD and NMR spectroscopy

To survive in diverse environments, bacteria adapt by changing the composition of their cell membrane fatty acids. Compared with aerobic bacteria, Cutibacterium acnes has much greater contents of branched-chain fatty acids (BCFAs) in the cell membrane, which helps it survive in anaerobic environments. To synthesize BCFAs, C. acnes acyl carrier protein (CaACP) has to transfer growing branched acyl intermediates from its hydrophobic cavity to fatty acid synthases. CaACP contains an unconserved, distinctive Cys50 in its hydrophobic pocket, which corresponds to Leu in other bacterial acyl carrier proteins (ACPs). Herein, we investigated the substrate specificity of CaACP and the importance of Cys50 in its structural stability. We mutated Cys50 to Leu (C50L mutant) and measured the melting temperatures (Tms) of both CaACP and the C50L mutant by performing circular dichroism experiments. The Tm of CaACP was very low (49.6 °C), whereas that of C50L mutant was 55.5 °C. Hydrogen/deuterium exchange experiments revealed that wild-type CaACP showed extremely fast exchange rates within 50 min, whereas amide peaks of the C50L mutant in the heteronuclear single quantum coherence spectrum remained up to 200 min, thereby implying that Cys50 is the key residue contributing to the structural stability of CaACP. We also monitored chemical shift perturbations upon apo to holo, apo to butyryl, and apo to isobutyryl conversion, confirming that CaACP can accommodate isobutyryl BCFAs. These results provide a preliminary understanding into the substrate specificity of CaACPs for the production of BCFAs necessary to maintain cell membrane fluidity under anaerobic environments.

Efficacy of a Retinoid, Keratolytic, Anti-Inflammatory and Antibacterial Gel and Spray Formulations in Mild Common Acne

Background and Objectives: For the treatment of mild/moderate acne, topical retinoids and antibacterial molecules are used in monotherapy or in combination. An exfoliating and anti-inflammatory action can increase the clinical efficacy of this therapeutic approach. A topical product in Gel and Spray Formulations (GF and SF) with retinoids (hydroxypinacolone retinoate and encapsulated retinol), with anti-inflammatory (niacinamide), antibacterial (biopep15) and keratolytic (glycolic and salicylic acids) activity has recently been developed. Topical retinoids have anti-inflammatory, anti-seborrheic and anticomedone-formation properties. Biopep15 is an oligopeptide with antibacterial action that can interfere with lipoteichoic acid, a component of the wall of Cutibacterium acnes. In addition, Biopep15 can perform also an antagonistic action against the Toll-Like-Receptor 2, involved in the pathogenesis of acne. Niacinamide has a well-known anti-inflammatory action. Salicylic and glycolic explain keratolytic and exfoliating activities. In this study the objective was to determine the efficacy and tolerability of GF and SF in mild/ moderate comedogenic acne. Methods: In a 4-week, open-label, prospective trial, 32 patients between the ages of 15 and 30 have been evaluated. All participants gave their written consent. Treatment with gel (for facial lesions) and spray (for lesions located on thorax, back and shoulder) applied twice daily were used. To assess clinical efficacy, a count of comedogenic lesions (open and closed comedones; non-inflammatory lesions: NIL) and inflammatory lesions (IL; papules, and pustules) was performed and the reduction in the number of lesions after 2 and 4 weeks of treatment was evaluated. An evaluation of Total lesions count (TL; NIL+IL) was also performed.The lesion count data were analysed with a paired Student's t test.We evaluated also the exfoliating/keratolytic activity and the effect on sebum production assessed at baseline, after 2 and 4 weeks of treatment. Finally, to evaluate Cutibacterium acnes (C. acnes) skin colonization, we performed a fluorescence detection of skin porphyrin content at baseline and at day 28, by mean of Visiopor PP 34 camera. Results: All patients completed the trial. At baseline the NIL, IL and TL count were 14.3, 8.7 and23, respectively. After 2 weeks of GF/SF treatment, NIL, IL and TL significantly decreased to 9.7 (-32%), 6.8 (-22%) and 16.5 (-29%), respectively. At the end of the treatment, a significant reduction in comparison with baseline was observed for NIL (-49%) IL (-63%) and TL (-54%). The exfoliating index evaluated in comparison with baseline value improved not significantly by 13% at day 14, and significantly (p=0.05) by 18% at day 24. The Cutibacterium acnes skin colonization area was significantly (p=0.02) reduced by 28% in comparison with baseline. Treatment was well tolerated, and local tolerability was assessed as optimal by all patients. Conclusion: This new anti-acne combination formula based on retinoids, antibacterial oligopeptide, keratolytic and anti-inflammatory agents have shown high clinical efficacy and good tolerability in patients with mild to moderate acne. The treatment shows also a keratolytic effect and a significant reduction of C. acnes skin colonization.

Antimicrobial Formulation of Chrysopogon zizanioides Essential Oil in an Emulsified Lotion for Acne

Acne is a skin condition arising from excess sebum production and microbial overgrowth within the pilosebaceous unit. Several commercial essential oils have shown promising activity against acne-related pathogens. Due to their volatility and thermal instability, the formulation of essential oils into commercial products remains a pharmaceutical challenge. Thus, this study aimed to develop a viable anti-acne topical treatment as an oil-in-water emulsified lotion to overcome these challenges. Chrysopogon zizanioides (vetiver) displayed noteworthy antimicrobial activity with a mean minimum inhibitory concentration of 0.14 mg/mL against Cutibacterium acnes, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes. Emulsified lotions containing C. zizanioides were developed through the hydrophilic-lipophilic balance approach. At tested hydrophilic-lipophilic balance values of 8, 9, and 10, C. zizanioides emulsified lotions displayed maximum stability at hydrophilic-lipophilic balance 9 with a minimum change in mean droplet size and polydispersity index of 20.61 and 33.33%, respectively, over 84 days. The C. zizanioides emulsified lotion at optimum hydrophilic-lipophilic balance 9 completely inhibited the growth of C. acnes and killed S. aureus, S. epidermidis, and S. pyogenes within 24 h. Additionally, the lotion retained antimicrobial activity against these test micro-organisms over the 84-day stability test period. Thus, the C. zizanioides emulsified lotion demonstrated physical stability and antimicrobial efficiency, making it an ideal natural product anti-acne treatment.

Cutibacterium acnes Induces the Expression of Immunosuppressive Genes in Macrophages and is Associated with an Increase of Regulatory T-Cells in Prostate Cancer

In an immune suppressive tumor microenvironment constituted by immunosuppressive cells and immunosuppressive mediators, tumors may improve their ability to give rise to a clinically relevant cancer. In the present study, we found that C. acnes might contribute to an immunosuppressive environment by recruiting regulatory T cells and by increasing the expression of immunosuppressive mediators such as PD-L1, CCL17, and CCL 18.