Cutibacterium acnes: Much ado about maybe nothing much

Genome-wide meta-analysis identifies novel loci conferring risk of acne vulgaris

Acne vulgaris is a common chronic skin disorder presenting with comedones, cystic structures forming within the distal hair follicle, and in most cases additionally with inflammatory skin lesions on the face and upper torso. We performed a genome-wide association study and meta-analysis of data from 34,422 individuals with acne and 364,991 controls from three independent European-ancestry cohorts. We replicated 19 previously implicated genome-wide significant risk loci and identified four novel loci [11q12.2 (FADS2), 12q21.1 (LGR5), 17q25.3 (FASN), and 22q12.1 (ZNRF3-KREMEN1)], bringing the total number of reported acne risk loci to 50. Our meta-analysis results explain 9.4% of the phenotypic variance of acne. A polygenic model of acne risk variants showed that individuals in the top 5% of the risk percentiles had a 1.62-fold (95% CI 1.47-1.78) increased acne risk relative to individuals with average risk (20-80% on the polygenic risk score distribution). Our findings highlight the Wnt and MAPK pathways as key factors in the genetic predisposition to acne vulgaris, together with the effects of genetic variation on the structure and maintenance of the hair follicle and pilosebaceous unit. Two novel loci, 11q12.2 and 17q25.3, contain genes encoding key enzymes involved in lipid biosynthesis pathways.

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.

Cutibacterium acnes in spine tissue: characteristics and outcomes of non-hardware-associated vertebral osteomyelitis

Cutibacterium acnes isolation from spine tissue can be challenging because the organism can represent a contaminant. There is a paucity of data regarding the role of C. acnes in non-hardware-associated vertebral osteomyelitis (VO). Herein we evaluate the clinical and microbiological characteristics, treatment, and outcome of patients with C. acnes VO. Data were retrospectively collected from adults with a positive spine culture for C. acnes at Mayo Clinic, Rochester (MN), from 2011 to 2021. Patients with spinal hardware and polymicrobial infections were excluded. Of the subjects, 16 showed radiological and clinical findings of VO: 87.5 % were male, the average age was 58 years (±15 SD), and back pain was the predominant symptom. Of the lesions, 89.5 % involved the thoracic spine. Of the subjects, 69 % had experienced an antecedent event at the site of VO. In five subjects, C. acnes was isolated after 7 d of anaerobic culture incubation. Thirteen subjects were treated with parenteral β-lactams, and three with oral antimicrobials, without any evidence of recurrence. Twenty-one subjects were not treated for VO, as C. acnes was considered a contaminant; at follow-up, none had evidence of progressive disease. C. acnes should be part of microbiological differential diagnosis in patients with suspected VO, especially in the context of a prior spinal procedure. Anaerobic spine cultures should undergo prolonged incubation to enable recovery of C. acnes. C. acnes VO may be managed with oral or parenteral antimicrobial therapy. Without clinical and radiological evidence of VO, a single positive culture of C. acnes from spine tissue frequently represents contaminants.

Hydra and the hair follicle - An unconventional comparative biology approach to exploring the human holobiont

The microbiome of human hair follicles (HFs) has emerged as an important player in different HF and skin pathologies, yet awaits in-depth exploration. This raises questions regarding the tightly linked interactions between host environment, nutrient dependency of host-associated microbes, microbial metabolism, microbe-microbe interactions and host immunity. The use of simple model systems facilitates addressing generally important questions and testing overarching, therapeutically relevant principles that likely transcend obvious interspecies differences. Here, we evaluate the potential of the freshwater polyp Hydra, to dissect fundamental principles of microbiome regulation by the host, that is the human HF. In particular, we focus on therapeutically targetable host-microbiome interactions, such as nutrient dependency, microbial interactions and host defence. Offering a new lens into the study of HF - microbiota interactions, we argue that general principles of how Hydra manages its microbiota can inform the development of novel, microbiome-targeting therapeutic interventions in human skin disease.