Search Results (201)

Pterospartum tridentatum (L.) Willk. (carqueja) is widely used in traditional medicine and culinary practices in the Iberian Peninsula; however, most studies have focused on its flowers, while its stems remain largely unexplored, despite representing a significant proportion of the plant biomass. This study aimed to evaluate the potential of P. tridentatum stems as a source of bioactive compounds using different extraction methodologies. Aqueous, hydroethanolic, ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) were applied, and the resulting extracts were characterized in terms of their extraction yield, protein and carbohydrate content, phenolic composition, antioxidant capacity, antimicrobial activity, and cytotoxicity in HaCaT and Caco-2 cell lines. Phenolic profiling by LC-ESI-QqTOF-HRMS tentatively identified 37 compounds, mainly corresponding to flavonoid and isoflavonoid glycosides, with genistein derivatives representing the dominant constituents across all extracts. Although extraction yields differed among methods, phenolic profiles were broadly similar. UAE and PLE extracts showed slightly higher antioxidant activity, while antimicrobial activity was limited, with only moderate inhibition observed against Staphylococcus epidermidis and Malassezia furfur. Additionally, cytotoxicity assays indicated low toxicity. Overall, the results demonstrate that P. tridentatum stems represent a promising yet underutilized biomass source of phenolic compounds with antioxidant potential and low cytotoxicity under the tested in vitro conditions. Full article

Atopic dermatitis (AD) is a chronic inflammatory skin disease influenced by several factors, including immune system imbalance, impairment of the epidermal barrier, and alterations in the composition of the gut and skin bacterial and fungal microbiota. This study combines metagenomic sequencing and culture-based methods to explore the impact of probiotic supplementation on the cutaneous microbiota and mycobiota of AD patients. Twenty-five adults diagnosed with AD were enrolled, and skin swabs were analyzed to characterize microbial diversity and load. Culturomic analyses identified 42 bacterial and 6 fungal species, confirming Staphylococcus aureus and Candida parapsilosis as predominant taxa. High-throughput sequencing revealed Staphylococcus spp. and Malassezia spp. as dominant genera, with notable interindividual variability. While probiotic use did not significantly influence bacterial diversity, it was associated with higher richness and evenness in fungal communities, as shown by alpha and beta diversity metrics. Malassezia restricta was more prevalent among probiotic users, whereas Candida parapsilosis and Rhodotorula mucilaginosa were enriched in non-users. These findings indicate an association between probiotic use and differences in the composition and diversity of the skin mycobiota compared with the bacterial microbiota, suggesting that fungal communities may be more responsive to probiotic-associated factors. Integrating metagenomic and culturomic approaches offers valuable insights into the complex interactions among host factors, microbial communities, and probiotic use in AD, paving the way for targeted microbiome-based therapeutic strategies. Full article

This study assessed the impact of a topical phytocomplex on the acne skin microbiota, encompassing bacterial, fungal, and phage communities. Skin samples obtained from participants exhibiting a positive response to the treatment were analyzed using high-throughput sequencing and bioinformatic approaches including taxonomic profiling, metagenome assembly, functional annotation, and phage identification. Results showed that after treatment, microbial diversity increased, reflecting a more balanced microbial composition. Cutibacterium acnes levels were reduced, particularly virulent IA1/IA2 phylotypes, whereas non-pathogenic or unclassified strains increased. Opportunistic pathogens such as Klebsiella pneumoniae were no longer detected, and beneficial genera including Psychrobacter and Dermabacter were enriched. Functional analysis showed reduced virulence- and biofilm-related pathways, alongside enhanced tryptophan metabolism, SCFA production, lipid synthesis, and riboflavin and folate biosynthesis. Fungal populations, dominated by Malassezia, became more evenly distributed, with notable post-treatment reductions in M. arunalokei, Exophiala spinifera, and Wickerhamomyces anomalus. Phage populations mirrored bacterial changes, with enrichment of Cutibacterium-associated phages post-treatment. These findings demonstrate that the phytocomplex promotes functional rebalancing of the skin microbiota by reducing pathogenic features while maintaining ecosystem stability. The inhibition of quorum sensing, potentially mediated by N-acyl-homoserine lactone acetylation, emerged from metabolic pathway annotation as a hypothetic key mechanism impairing bacterial communication and virulence associated with acne vulgaris. Full article

Malassezia pachydermatis is a yeast pathogen associated with recurrent skin and ear infections in dogs, often complicated by biofilm formation and reduced antifungal susceptibility. We aimed to evaluate the in vitro antifungal activity of essential oils and nanoemulsions of Zingiber cassumunar and Cymbopogon citratus compared with conventional antifungal agents against planktonic and biofilm forms of M. pachydermatis. Preliminary screening of six plant extracts was performed using 12 clinical isolates identified Z. cassumunar and C. citratus for nanoemulsion formulation. Antifungal susceptibility testing of conventional antifungal agents and nanoemulsions was subsequently conducted using 31 clinical isolates, and nanoemulsions were prepared by high-pressure homogenization. Both essential oils exhibited antifungal activity, and nanoemulsion formulations showed enhanced inhibitory effects compared with the crude oils. Biofilm-associated cells demonstrated reduced susceptibility, particularly to conventional antifungal agents. Terbinafine was the most potent agent against planktonic cells but showed reduced efficacy in biofilms. Nanoemulsions of Z. cassumunar and C. citratus exhibited improved activity against both forms. These findings suggest that nanoemulsification may enhance the in vitro antifungal performance of essential oils against M. pachydermatis biofilms. However, further studies, including mechanistic investigations and in vivo evaluations, are required to confirm their therapeutic potential and safety. Full article

Background/Objectives: Antimicrobial resistance (AMR) in companion animals is an emerging public health threat due to zoonotic potential and limited therapeutic options. Dogs with otitis externa may harbor multidrug-resistant (MDR) bacteria, including Escherichia coli (E. coli), Proteus mirabilis (P. mirabilis), and Enterobacter cloacae complex (E. cloacae complex), some producing extended-spectrum beta-lactamase (ESBL) or AmpC β-lactamases. This study aimed to assess the prevalence, AMR patterns, MDR occurrence, β-lactamase production, and co-infection profiles of these pathogens in canine otitis externa. Methods: Ear canal samples were collected from 592 dogs presenting clinical signs of otitis externa, with one sample per dog included in the analysis. Samples were collected from veterinary clinics in Timiș County, Romania, from 2022 to 2025. Samples were cultured on blood agar and MacConkey agar, followed by biochemical testing and MALDI-TOF mass spectrometry for bacterial identification. Antimicrobial susceptibility testing against 15 agents across six classes was performed using the VITEK^® 2 system. MDR and β-lactamase production (ESBL, AmpC) were determined according to CLSI 2018 veterinary guidelines. Co-isolation with bacterial and fungal species were recorded. Results: E. coli, P. mirabilis, and E. cloacae complex were isolated in 9.12%, 6.25%, and 1.2% of cases, respectively. E. coli exhibited the highest resistance to aminoglycosides (tobramycin 72.2%, gentamicin 61.1%) and full susceptibility to carbapenems. P. mirabilis showed the highest resistance to ampicillin (54%) and trimethoprim + sulfamethoxazole (46%), with complete susceptibility to carbapenems and fluoroquinolones. E. cloacae complex displayed universal resistance to cephalosporins but remained susceptible to non-cephalosporin β-lactams (piperacillin–tazobactam), carbapenems and aminoglycosides. MDR prevalence was 35.2% for E. coli, 18.9% for P. mirabilis, and 14.3% for the E. cloacae complex. ESBL production was detected in 13% of E. coli and 8.1% of P. mirabilis isolates, while all E. cloacae complex isolates were AmpC-positive. Co-isolations were common, primarily involving Staphylococcus pseudintermedius (S. pseudintermedius) and Malassezia pachydermatis (M. pachydermatis). Conclusions: MDR and β-lactamase-producing bacteria were identified in dogs with otitis externa, emphasizing the importance of routine antimicrobial susceptibility testing, targeted therapy based on local resistance profiles, and continuous AMR surveillance to prevent treatment failure and mitigate zoonotic risk. Full article

Background: Pityriasis versicolor (PV) is a common superficial mycosis caused by Malassezia species. To describe the clinical and epidemiological characteristics of PV in Acapulco, Mexico, and to identify the associated Malassezia species using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP). Methods: A cross-sectional study was conducted in 2024 at Acapulco General Hospital and a private dermatology clinic. Patients with clinically suspected PV and no recent antifungal or immunosuppressive treatment were enrolled. Skin scales were examined microscopically and cultured on modified Dixon agar. Isolates were identified using conventional methods and PCR-RFLP with HhaI and BstCI enzymes. Results: Sixty-nine patients were included; 68.1% were male, and the most affected age group was 11–20 years (34.8%). The hypochromic variant predominated (63.8%). PCR-RFLP identified M. globosa (33.3%) and M. furfur (31.9%) as the most frequent species, followed by M. restricta, M. sympodialis, and M. slooffiae. Species identification was unsuccessful in 11.6% of isolates. No statistically significant associations were found between clinical variants, gender, or species distribution. Conclusions: M. globosa and M. furfur were the predominant species in this tropical Mexican cohort. PCR-RFLP is a practical option for species-level identification, highlighting the diversity of Malassezia in PV. Full article

Although increasingly studied feline otitis externa (OE) prevalence is not yet well defined. The aim of this study was to assess the prevalence of OE in a population of privately owned cats in Northern Italy. Cats were clinically, otoscopically and cytologically evaluated. Diagnosis of OE was based on clinical findings along with abnormal ear cytology. The influence of the main demographic variables was examined. The prevalence of OE was 17% with a positive correlation to being European, and having short hair, a dermatological history, pruritus and multiple clinical signs. Ear cytology was abnormal in 19% of cats. Mites were found in 6% of the cats, about half of which were exclusively indoor cats and completely asymptomatic. Pathological numbers of bacteria and/or yeasts were found on cytology in 15% of cats and, of these, 29% had only Malassezia spp., 65% only cocci, and 6% a mixed population of these microorganisms. The prevalence of OE in owned cats in Northern Italy is relatively high. The identification of parasitic OE in asymptomatic and exclusively indoor cats, and a correlation between OE and dermatological history highlights the importance of systematic ear evaluation as part of routine feline health assessments. Full article

Cutibacterium acnes, a major skin commensal bacterium, induces inflammatory cytokine production in keratinocytes through Toll-like receptor 2 (TLR2) signaling and contributes to acne vulgaris pathogenesis. Although glucocorticoids, e.g., dexamethasone (Dex), exert anti-inflammatory effects in related treatments, prolonged glucocorticoid exposure paradoxically induces acneiform eruptions, a phenomenon referred to as steroid-induced acne. Moreover, how commensal fungi influence bacterial-driven inflammatory signaling under glucocorticoid treatment remains unclear. In this study, we investigated how the lipophilic skin yeast Malassezia restricta affects C. acnes-induced TLR2 expression under Dex treatment using normal human epidermal keratinocytes. We discovered that M. restricta selectively suppressed Dex-enhanced C. acnes-induced TLR2 expression both at the transcriptional level and cell surface. Mechanistically, M. restricta enhanced p38 MAPK phosphorylation and inhibited NF-κB p65 nuclear translocation, indicating context-dependent glucocorticoid-primed TLR2 signaling modulation rather than simple inhibition. These results demonstrate that M. restricta modulates bacterial-induced inflammatory responsiveness in keratinocytes under glucocorticoid exposure and highlight the importance of fungal–bacterial interactions in shaping host immune signaling in steroid-treated skin. Our study provides new insight into the mechanistic basis of steroid-induced acne and the polymicrobial regulation of cutaneous innate immunity. Full article

Microorganisms residing on the skin play a crucial role in maintaining both the integrity of the skin barrier and immune function. This study examined the effects of culture supernatants from canine-derived Bifidobacterium animalis subsp. lactis DS008 on canine keratinocytes in vitro. To induce cytokine production, canine progenitor epidermal keratinocytes (CPEK) were indirectly co-cultured with Malassezia pachydermatis using an insert well system to prevent direct cell-to-yeast contact, and CPEK were supplemented with 0.1%, 1%, and 10% of DS008 supernatants. mRNA expression levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-13, thymic stromal lymphopoietin (TSLP), IL-31, and keratin 10 were analyzed by real-time PCR. The protein concentrations of TSLP and IL-31 were measured by ELISA. Additionally, DS008 supernatants were applied to reconstructed canine epidermis (RCE) models exposed to lipopolysaccharide to evaluate changes in epidermal architecture. Treatment with DS008 supernatants showed significant reductions in mRNA expression of TNF-α, IL-13, TSLP, and IL-31, as well as decreased protein levels of TSLP and IL-31. Furthermore, keratin 10 mRNA expression was significantly increased, and RCE analysis demonstrated that DS008 supernatants ameliorated stratum corneum deformation. These findings suggest that postbiotics derived from canine-derived Bifidobacterium animalis subsp. lactis DS008 is a potential candidate with anti-inflammatory properties. Full article

In recent years, active monomers derived from Chinese herbal medicine and their derivatives have attracted significant attention in the field of skincare product development. Artemisinin and its derivatives, including dihydroartemisinin (DHA), exhibit diverse pharmacological activities such as anti-inflammatory, antibacterial, immunomodulatory, and antitumor effects, showing promising therapeutic potential in skin-related diseases. However, systematic studies on artemisinins in cosmetics are lacking. This study aimed to evaluate the cosmetic potential of DHA by investigating its anti-aging, anti-hair loss, antibacterial, whitening, and anti-glycation activities. Results showed that DHA exhibits multiple biological activities: DHA exhibits anti-aging activity by promoting collagen I synthesis in HDF cell, exhibits anti-hair loss effect by modulating VEGF and DKK1 expression in DPC cell, exhibits antibacterial activity against Malassezia furfur, exhibits whitening activity by suppressing melanin synthesis, and exhibits anti-glycation activity by suppressing glycation reactions. Overall, with the broad biological activities, we believe that DHA holds encouraging promise in the cosmetics industry. Full article

Background: The scalp represents a distinct ecological niche within the skin, and the structure of its microbiota, together with the factors shaping it, is considered important for the maintenance of scalp health. Methods: This study systematically analyzed the bacterial and fungal community structures on the scalps of 63 healthy Chinese women aged 18–25, and examined their associations with scalp type, sensitivity, and lifestyle factors. Scalp samples were collected, questionnaire surveys were administered, scalp physiological parameters were measured, and high-throughput sequencing of 16S rRNA and ITS genes was performed. Results: The results showed that, in this unique scalp skin niche, the dominant bacterial phylum was Actinobacteria, while the dominant fungal phylum was Ascomycota. The predominant bacterial genera were Cutibacterium and Staphylococcus, and the fungal community was dominated by Malassezia. When scalp types were categorized according to sebum content, dry scalps showed enrichment of Micrococcus, Streptococcus, Delftia, Staphylococcus aureus, and Staphylococcus hominis, whereas oily scalps, on the other hand, are primarily colonized by Cutibacterium and Staphylococcus species. In addition, we observed microbial interactions under different physiological conditions. The relative abundance of Cutibacterium decreased with increasing scalp sensitivity. Higher psychological stress, insufficient sleep, and high-sugar/high-fat dietary patterns tended to coincide with shifts in the relative abundance of Malassezia, implying that these influences may act through fungal rather than bacterial components of the scalp microbiota. Scalp sensitivity showed the strongest association with β-diversity among the variables examined, although the effect size was modest and did not reach conventional significance in the multivariable PERMANOVA. Conclusions: In young women, the scalp constitutes a distinct cutaneous niche whose microbiota is jointly shaped by sebum level, barrier sensitivity, and lifestyle factors, with sensitivity emerging as one of the more influential dimensions of community variation. These findings provide guidance for future in-depth research on the scalp microbiome network and offer a foundational reference for preventing suboptimal and pathological scalp conditions. Full article

Malassezia spp. has been recognized among neonatal intensive care unit (NICU) patients’ commensals and pathogens, accounting for a significant number of invasive fungal infections. The Random Amplified Polymorphic DNA (RAPD) may be used for Malassezia spp. strains typing from clinical isolates, demonstrating high resolution and specificity. Herein, we propose a retrospective analysis of Malassezia spp. isolates, aiming to investigate their identity and transmission pathways. Moreover, we documented Malassezia spp. prevalence within the University Hospital Policlinico of Catania, Italy. The analysis collected a total number of 16 M. pachydermatis and categorized them into four different clusters, hypothesizing a horizontal transmission. Although the essential role of microbiological sample cultures, our data suggested further environmental surveillance protocols to prevent NICU patients’ colonization due to the Malassezia spp. persistence and adhesion within healthcare surfaces. Full article

The Yungang Grottoes, a World Heritage Site, face biodeterioration risks. This study analyzed microbial communities in five microenvironments within Cave 6 using high-throughput sequencing (16S/18S rRNA). Communities showed high microenvironment specificity. Ascomycota and Proteobacteria dominated fungi and bacteria, respectively. Areas near the lighting window, with high external interaction, showed the highest diversity, while red pigment areas, likely under heavy metal stress, had the lowest diversity. Human-associated microbes (e.g., Escherichia-Shigella, Malassezia) indicated anthropogenic pollution on statue surfaces. Core microbiome and functional prediction (PICRUSt2) suggested high biodegradation risk in dust accumulation and inter-statue areas, enriched with organic-degrading and acid-producing taxa (e.g., Rubrobacter, Cladosporium). Microbial distribution and function were driven by openness, substrate, and human impact. This study identifies key risk zones and informs targeted conservation strategies for the Yungang Grottoes. Full article

Background: Pruritus is burdensome across dermatoses. Beyond Staphylococcus, broader components of the cutaneous microbiome—bacteria, fungi, and viruses—and their products shape itch via barrier disruption, immune polarization, and direct neurosensory activation. Methods: We conducted a narrative review of human and translational studies. PubMed/MEDLINE, Scopus, and Web of Science were searched from inception to 27 August 2025 using terms for itch, skin microbiome, bacteriotherapy, proteases, PAR, TRP channels, IL-31, Malassezia, and AHR ligands. English and Italian records were screened; randomized trials, systematic reviews, and mechanistic studies were prioritized; and unsupported single case reports were excluded. Results: Beyond Staphylococcus aureus, microbial drivers include secreted proteases activating PAR-2/4; pore-forming peptides and toxins engaging MRGPRs and sensitizing TRPV1/TRPA1; and metabolites, especially tryptophan-derived AHR ligands, that recalibrate barrier and neuro-immune circuits. Commensal taxa can restore epidermal lipids, tight junctions, and antimicrobial peptides. Early studies of topical live biotherapeutics—Roseomonas mucosa and Staphylococcus hominis A9—report reductions in disease severity and itch. Fungal communities, particularly Malassezia, contribute via lipases and bioactive metabolites with context-dependent effects. Across studies, heterogeneous itch metrics, small samples, and short follow-up limit certainty. Conclusions: The cutaneous microbiome actively contributes to itch and is targetable. Future studies should prioritize standardized itch endpoints, responder stratification, and robust safety for live biotherapeutics. Full article

Malassezia pachydermatis, an important opportunistic secondary pathogen, is often associated with atopic dermatitis or otitis externa in dogs. Recent studies indicate an increase in resistance of this yeast to commonly used antifungal agents. Therefore, the search for new antifungal agents is a challenge. In the present study, the susceptibility of M. pachydermatis strains to 10 plant essential oils—EOs (bergamot, grapefruit, coriander, hyssop, lavender, tea tree, nutmeg, oregano, rosemary, and Spanish sage) was determined using the broth microdilution method. All 15 clinical strains tested were susceptible to coriander (100%). A good antifungal activity was shown for EO from nutmeg (93.33%), bergamot (86.66), Spanish sage and hyssop (73.33%) and rosemary (66.67%). Lower antifungal efficacy was identified in EOs from grapefruit, lavender, tea tree and oregano (53.33%). The obtained results indicate promising prospects for the clinical use of essential oils in the treatment of M. pachydermatis infections. Full article