In vitro antimicrobial susceptibility patterns of Propionibacterium acnes isolated from patients with acne vulgaris

Utilizing the photodynamic properties of curcumin to disrupt biofilms in Cutibacterium acnes: A promising approach for treating acne

BACKGROUND

The treatment of acne vulgaris is often challenging due to the antibiotic resistance frequently observed in Cutibacterium acnes (C.acnes), a prevalent bacterium linked to this condition.

OBJECTIVE

The objective of this research was to examine the impact of curcumin photodynamic therapy (PDT) on the survival of C.acnes and activity of biofilms produced by this microorganism.

METHODS

Following the Clinical and Laboratory Standards Institute (CLSI) guidelines, we assessed the drug sensitivity of 25 clinical C.acnes strains to five antibiotics (erythromycin, clindamycin, tetracycline, doxycycline, minocycline) and curcumin by implementing the broth microdilution technique. In addition, we established C.acnes biofilms in a laboratory setting and subjected them to curcumin-PDT(curcumin combined with blue light of 180 J/cm2). Afterwards, we evaluated their viability using the XTT assay and observed them using confocal laser scanning microscopy.

RESULTS

The result revealed varying resistance rates among the tested antibiotics and curcumin, with erythromycin, clindamycin, tetracycline, doxycycline, minocycline, and curcumin exhibiting resistance rates of 72 %, 44 %, 36 %, 28 %, 0 %, and 100 %, respectively. In the curcumin-PDT inhibition tests against four representative antibiotic-resistant strains, it was found that the survival rate of all strains of planktonic C. acnes was reduced, and the higher the concentration of curcumin, the lower the survival rate. Furthermore, in the biofilm inhibition tests, the vitality and three-dimensional structure of the biofilms were disrupted, and the inhibitory effect became more significant with higher concentrations of curcumin.

CONCLUSION

The results emphasize the possibility of using curcumin PDT as an alternative approach for the treatment of C.acnes, especially in instances of antibiotic-resistant variations and infections related to biofilms.

Antimicrobial Properties Related to Anti-Acne and Deodorant Efficacy of Hedychium coronarium J. Koenig Extracts from Pulsed Electric Field Extraction

This study investigated the potential of pulsed electric field (PEF) extraction in enhancing the antimicrobial properties related to anti-acne and deodorant properties of Hedychium coronarium extract. The dried leaf and rhizome of H. coronarium were extracted using 95% v/v ethanol through both conventional solvent extraction and PEF extraction techniques (10, 14, and 20 kV/cm). The chemical composition of the extracts was analyzed. The antimicrobial activities, specifically in relation to acne treatment against Cutibacterium acnes and deodorant properties against Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Pseudomonas aeruginosa, and Escherichia coli, were determined. The irritation profile of was evaluated using the hen's egg chorioallantoic membrane test. The results showed that PEF extraction increased the extract yield, particularly at an electric field strength of 20 kV/cm. Furthermore, PEF extraction significantly enhanced the ellagic acid content, particularly in the leaf extract. Furthermore, the leaf extract demonstrated stronger inhibitory effects against microorganisms associated with body odor and acne compared to the rhizome extract. Notably, all extracts exhibited no signs of irritation, indicating their safety. Overall, the findings suggest that PEF extraction from H. coronarium enhances yield, bioactive compound content, and antimicrobial effects. This indicates the potential of the extract for acne treatment and deodorant use.

A Prospective, Randomized, Comparative Study of Topical Minocycline Gel 4% with Topical Clindamycin Phosphate Gel 1% in Indian Patients with Acne Vulgaris

Acne vulgaris is characterized by inflammatory and non-inflammatory skin lesions with a high prevalence among adolescents in India. Not enough studies are reported on the use of topical antibiotics for the management of acne in the Indian population. The proposed study aims to compare the efficacy and safety of topical minocycline gel 4% with topical clindamycin gel 1% in the Indian population. A randomized, open-label, double-arm study was planned at two centers in India. One hundred patients were enrolled and randomized equally to two treatment arms. The drugs were applied once daily, preferably at the same time each day. The number of inflammatory and non-inflammatory lesions, as well as the investigator's global assessment (IGA), were obtained at the baseline and on weeks 3, 6, 9, and 12. The change in these parameters from baseline to week 12 was compared between the two treatment arms. A tolerability assessment was also performed on selected parameters. The age of patients ranged between 14 and 31 years, with female preponderance in each arm. On week 12, the percent change in inflammatory and non-inflammatory lesions in the minocycline 4% arm was significantly higher than in the clindamycin 1% arm (p < 0.0001). The IGA treatment success was significantly higher in the minocycline arm compared to the clindamycin arm on weeks 9 and 12, with p-values of 0.001 and 0.015, respectively. Tolerability assessment revealed significantly improved parameter performance in the minocycline arm compared to the clindamycin arm. On subgroup analysis, in adolescents, minocycline was found to be more efficacious than clindamycin. The comparative assessment resulted in a significantly improved performance of minocycline gel 4% compared to clindamycin gel 1% in the Indian population, thus making it a preferred choice for the treatment of moderate-to-severe acne in India.

Recurrent Lymphocytic Pleural Effusion as a Complication of Ventriculopleural Shunt Meningitis Caused by Cutibacterium Acnes

Cutibacterium acnes (C. acnes) is part of the normal flora and has been linked to many invasive and pleural infections. Though it is usually considered a contaminant bacterium, full antimicrobial therapy might result in the resolution of foreign body-related infections. In this report, we describe an infection that started as ventriculopleural shunt meningitis but was complicated by a recurrent lymphocytic pleural infection. Ultimately, there was a resolution of pleural effusions after treatment of C. acnes.

Rhodomyrtone as a New Natural Antibiotic Isolated from Rhodomyrtus tomentosa Leaf Extract: A Clinical Application in the Management of Acne Vulgaris

Rhodomyrtone, a plant-derived principal compound isolated from Rhodomyrtus tomentosa (Myrtaceae) leaf extract, was assessed as a potential natural alternative for the treatment of acne vulgaris. The clinical efficacy of a 1% liposomal encapsulated rhodomyrtone serum was compared with a marketed 1% clindamycin gel. In a randomized and double-blind controlled clinical trial, 60 volunteers with mild to moderate acne severity were assigned to two groups: rhodomyrtone serum and clindamycin gel. The volunteers were instructed to apply the samples to acne lesions on their faces twice daily. A significant reduction in the total numbers of acne lesions was demonstrated in both treatment groups between week 2 and 8 (p < 0.05). Significant differences in acne numbers compared with the baseline were evidenced at week 2 onwards (p < 0.05). At the end of the clinical trial, the total inflamed acne counts in the 1% rhodomyrtone serum group were significantly reduced by 36.36%, comparable to 34.70% in the clindamycin-treated group (p < 0.05). Furthermore, a commercial prototype was developed, and a clinical assessment of 45 volunteers was performed. After application of the commercial prototype for 1 week, 68.89% and 28.89% of volunteers demonstrated complete and improved inflammatory acne, respectively. All of the subjects presented no signs of irritation or side effects during the treatment. Most of the volunteers (71.11%) indicated that they were very satisfied. Rhodomyrtone serum was demonstrated to be effective and safe for the treatment of inflammatory acne lesions.

Effect of Blue Light and Photosensitizers on Cutibacterium acnes on Shoulder Periprosthetic Joint Infection Isolates

Introduction:Cutibacterium acnes is gaining recognition as a leading pathogen after orthopaedic shoulder procedures. Photodynamic therapy, a combination of light and a photosensitizer, has demonstrated antimicrobial activity against C. acnes in the treatment of acne vulgaris. We sought to evaluate the effect of photodynamic therapy using blue light and photosensitizers on C. acnes isolates from shoulder prosthetic joint infections.

Methods:C. acnes strains isolated from 19 patients with shoulder PJI were exposed to blue light alone (415 nm) or in combination with photosensitizers (fluorescein, riboflavin and demeclocycline). C. acnes strains were divided into 4 categories: Highly Sensitive (HS), Sensitive (S), Weakly Sensitive (WS), Resistant to blue light.

Results: 13 of 19 C. acnes strains (68%) were S or HS to blue light alone. Of these 19 strains tested, 11 were tested with blue light and fluorescein or blue light plus riboflavin. Fluorescein (1 µg/mL) enhanced the effect of blue light in 6 of 11 strains (55%). Blue light plus riboflavin (10 µg/mL) resulted enhanced killing in 3 of 11 strains (27%), but produced a paradoxical photoprotective effect in 4 of 11 strains (36%), resulting in a net decrease compared to blue light alone. Demeclocycline, however, enhanced the effect of blue light in 16 of 17 strains (94 %).

Conclusions: Blue light with the addition of photosensitizers killed C. acnes from periprosthetic shoulder infections in vitro, with demeclocycline having the most pronounced effect.

Antibiotic resistance in acne: changes, consequences and concerns

Antibiotic resistance in acne was first observed in the 1970s and has been a major concern in dermatology since the 1980s. The resistance rates and types of antimicrobials have subsequently shown great variations in regions and countries. Illustrative of this is the resistance to topical erythromycin and clindamycin which continues to be a problem worldwide, while resistance to systemic treatment with tetracyclines has remained low during the past decade. The resistance for the newer macrolides like azithromycin and clarithromycin has been increasing. The results of antibiotic resistance may include treatment failure of acne, disturbance of skin microbiota, induction of opportunistic pathogens locally and systemically, and dissemination of resistant strains to both healthcare personnel and the general population. The ensuing complications, such as aggravated opportunistic infections caused by Propionibacterium acnes and the emergence of multiresistant superbugs, have not yet been confirmed.

Topical Minocycline Foam 4%: A Review in Acne Vulgaris

Topical minocycline foam 4% (Amzeeq™) is approved in the USA for the treatment of inflammatory lesions of non-nodular, moderate to severe acne vulgaris (acne) in patients aged ≥ 9 years. It was developed to minimize systemic minocycline absorption and toxicity, and its high lipid content allows efficient drug movement through sebum and into affected sites. The favorable in vitro resistance profile of oral minocycline seen in Cutibacterium acnes (C. acnes) isolates was maintained with topical minocycline foam 4%. In 12-week, phase III clinical trials, once-daily topical minocycline foam 4% significantly improved both inflammatory and noninflammatory lesions relative to foam vehicle in patients aged ≥ 9 years with moderate to severe acne and was reported by most patients to be satisfactory or highly satisfactory to use. Extension trial data indicated that topical minocycline foam 4% continued to be effective for up to 52 weeks' therapy. Topical minocycline foam 4% was generally well tolerated in these patients, with most adverse events (AEs) and all serious AEs considered to be unrelated to treatment. Cutaneous AEs were uncommon, and findings from a dermal safety study showed that topical minocycline foam 4% did not have any effects related to phototoxicity, photoallergy, skin sensitization and skin irritation. Topical minocycline foam 4% is thus a useful addition to available treatment options for the management of inflammatory lesions of non-nodular, moderate to severe acne in adult and pediatric patients aged ≥ 9 years.

Evaluating FMX-101 as a promising therapeutic for the treatment of acne

INTRODUCTION

Oral minocycline is a mainstay of therapy for moderate-to-severe acne; however, systemic side effects which include hepatotoxicity, lupus-like syndrome, drug hypersensitivity syndrome, autoimmune hepatitis, polyarteritis nodosa, gastrointestinal side effects and skin hyperpigmentation are of concern. Topical antibiotics commonly used in acne, such as erythromycin and clindamycin, present high P. acnes resistance rates which has opened the market for new topical antibiotics. FMX-101 is a novel topical minocycline foam that has shown promising results in phase I, II and III trials for the treatment of moderate-to-severe acne with a better safety profile than oral minocycline.

AREAS COVERED

The author provides an overview FMX-101 including its clinical efficacy and safety. The author then provides their expert opinion on this treatment and its potential for the treatment option for acne.

EXPERT OPINION

The topical foam formulation of FMX-101 has been shown to reduce both inflammatory and non-inflammatory lesions and to improve IGA scores in patients with moderate-to-severe acne without significant systemic absorption thus limiting associated side effects. Overall, the proven efficacy and safety profile of FMX-101, together with the low systemic absorption, high skin tolerability and cosmetically acceptable foam formulations render this novel therapy an important addition to the acne treatment armamentarium.

Multidrug resistance in anaerobes

Multidrug resistance (MDR) in anaerobes is not a well-known topic. Bacteroides fragilis group isolates have numerous resistance determinants such as multidrug efflux pumps, cfiA and nimB genes and activating insertion sequences, and some isolates exhibited extensive drug-resistant patterns. MDR rates in B. fragilis group were from 1.5 to >18% and up to >71% in cfiA and nimB positive isolates carrying insertion sequences. MDR was present in >1/2 of Clostridioides difficile isolates, most often in epidemic/hypervirulent strains and unusually high metronidazole or vancomycin resistance has been reported in single studies. MDR was found in Prevotella spp. (in ≤10% of isolates), Finegoldia magna, Veillonella spp. and Cutibacterium acnes. Resistance in the anaerobes tends to be less predictable and anaerobic microbiology is required in more laboratories. New hopes may be new antibiotics such as eravacycline, cadazolid, surotomycin, ridinilazol or C. difficile toxoid vaccines; however, more efforts are needed to track the MDR in anaerobes.

Efficacy and safety of a novel topical minocycline foam for the treatment of moderate to severe acne vulgaris: A phase 3 study

BACKGROUND

FMX101 4% topical minocycline foam has been shown to be an effective and safe treatment for acne vulgaris (AV).

OBJECTIVE

To further evaluate the efficacy and safety of FMX101 4% in treating moderate to severe acne vulgaris.

METHODS

A 12-week, multicenter, randomized (1:1), double-blind, vehicle-controlled study was conducted. Coprimary end points were the absolute change in inflammatory lesion count from baseline and the rate of treatment success (Investigator's Global Assessment score of 0 or 1 with a ≥2-grade improvement).

RESULTS

There were 1488 participants in the intent-to-treat population. The FMX101 4% group had significantly greater reductions in the number of inflammatory lesions from baseline (P < .0001) and a greater rate of treatment success based on Investigator's Global Assessment (P < .0001) versus the foam vehicle group at week 12. FMX101 4% was generally safe and well tolerated.

LIMITATIONS

The efficacy and safety of FMX101 4% were not characterized in participants with mild AV.

CONCLUSION

FMX101 4% topical minocycline foam was effective and safe for the treatment of moderate to severe AV.

A novel topical minocycline foam for the treatment of moderate-to-severe acne vulgaris: Results of 2 randomized, double-blind, phase 3 studies

BACKGROUND

FMX101 4% is a topical minocycline foam for the treatment of moderate-to-severe acne.

OBJECTIVE

Evaluate the efficacy and safety of FMX101 4% in treating moderate-to-severe acne vulgaris.

METHODS

Two identical phase 3 studies were conducted. Subjects were randomized 2:1 to once-daily FMX101 4% or foam vehicle for 12 weeks. The coprimary end points were the change in inflammatory lesion count from baseline and the rate of treatment success according to the Investigator's Global Assessment (a score of 0 or 1 for clear or almost clear, with a ≥2-grade improvement) at week 12.

RESULTS

A total of 961 subjects were enrolled (study 04, N = 466; study 05, N = 495). Compared with vehicle, FMX101 4% demonstrated a significantly greater reduction in inflammatory lesions in both studies (P < .05) and a greater rate of treatment success in study 05 according to the Investigator's Global Assessment (P < .05). Pooled analyses of the 2 studies demonstrated statistical significance for both coprimary end points (all P < .05). Noninflammatory lesion count was also significantly reduced with FMX101 4% versus with vehicle in both studies. FMX101 4% was generally safe and well tolerated. Skin-related adverse events were reported in less than 1% of subjects treated with FMX101 4%.

LIMITATIONS

Longer-term efficacy and safety outcomes are needed (ongoing).

CONCLUSION

FMX101 4% topical minocycline foam significantly reduced both inflammatory and noninflammatory lesions and improved Investigator's Global Assessment scores in patients with moderate-to-severe acne.