Search Results (7)

Background: Hidradenitis suppurativa (HS) is a chronic, disabling, and disfiguring inflammatory disease with a complex, incompletely elucidated pathogenesis. The role of skin dysbiosis in the development and progression of HS has not yet been clarified. Methods: We performed an observational, prospective culture-based study that included 40 HS patients and analyzed the bacterial load and diversity in HS skin lesions, their correlation with disease severity, and several host and environmental factors. Additionally, we investigated the prevalence of antibiotic resistance and determined the resistance profile of bacterial strains isolated from chronic HS lesions. Results: An impressive number and diversity of bacterial strains were isolated from both superficial and deep HS lesions. 201 aerobic and anaerobic bacterial strains were isolated, polymicrobial growth being detected in the majority of samples. The most frequently isolated bacteria were Staphylococcus epidermidis, Staphylococcus aureus, Staphylococcus lugdunensis, Peptoniphilus spp., and Enterococcus faecalis in superficial lesions and Staphylococcus epidermidis, Staphylococcus aureus, and Corynebacterium tuberculostearicum in deep lesions. A significantly higher bacterial density and diversity was found in male patients, regardless of the affected area and in patients with severe HS. The proportion of bacterial strains resistant to antibiotics was lower in our study (8.95%) compared to the previously reported data. Conclusions: Our findings indicate dysbiosis as a key player in the initiation and maintenance of the inflammatory process in HS. Further large-scale, prospective studies are required to comprehensively characterize the microbiological landscape of HS and shed light on its contribution in the pathogenesis of the disease. Full article

Melanin is produced by melanocytes to protect human skin from harmful ultraviolet radiation. During skin cell renewal, melanin and dead skin cells are disposed of. However, prolonged exposure to ultraviolet rays or aging can disturb this cycle, leading to skin hyperpigmentation due to melanin accumulation. Tyrosinase is a crucial enzyme involved in melanin biosynthesis. Although various compounds, including tyrosine inhibitors, that counteract melanin accumulation have been reported, some, such as hydroquinone, are toxic and can cause vitiligo. Meanwhile, the skin is the largest organ and the outermost layer of the immune system, containing a diverse range of bacteria that produce low-toxicity compounds. In the current study, we aim to identify metabolites produced by skin microbiota that inhibit tyrosinase. Specifically, mushroom tyrosinase served as the study model. Following commensal skin bacteria screening, Corynebacterium tuberculostearicum was found to inhibit tyrosinase activity. The active compound was cyclo(l-Pro-l-Tyr); commercially available cyclo(l-Pro-l-Tyr) also exhibited inhibitory activity. Docking simulations suggested that cyclo(l-Pro-l-Tyr) binds to the substrate-binding site of mushroom tyrosinase, obstructing the substrate pocket and preventing its activity. Hence, cyclo(l-Pro-l-Tyr) might have potential applications as a cosmetic agent and food additive. Full article

In this work, we investigated the structure of the airborne bacterial community obtained by 16S rRNA gene sequencing performed on aerosol samples from different indoor and outdoor locations. The 48-h aerosol samples were collected in two laboratories, in the corridors, and on the roof of the Mathematics and Physics Department of the University of Salento (Italy). The investigation was carried out through the application of an innovative compositional data analysis approach, mainly based on a centered log-ratio transformation as a standardization procedure, the Aitchison distance for data ordination, and the principal component analysis via singular value decomposition for data clustering. This methodology allowed us to explore the main relationships among samples, identifying different results between indoor and outdoor samples both at the genus level and at the species level. Bacillus and Pseudomonas represented the most abundant genera identified in the analyzed samples. Out of the 21 identified bacterial species with the highest abundances in the collected aerosol samples, Acinetobacter lwoffii, Propionibacterium acnes, Diplorickettsia massiliensis, and Corynebacterium tuberculostearicum were the only four commonly classified as human opportunistic pathogens. Among the genera mostly associated with indoor environments, Hymenobacter and Arthrobacter could be noted as including many species that are unique in being radiation resistant. Full article

Although dry eye disease (DED) is one of the most common ocular surface diseases worldwide, its pathogenesis is incompletely understood, and treatment options are limited. There is growing evidence that complex interactions between the ocular surface microbiome (OSM) and tear fluid constituents, potentially leading to inflammatory processes, are associated with ocular surface diseases such as DED. In this study, we aimed to find unique compositional and functional features of the OSM associated with human and microbial tear proteins in patients with DED. Applying whole-metagenome shotgun sequencing of forty lid and conjunctival swabs, we identified 229 taxa, with Actinobacteria and Proteobacteria being the most abundant phyla and Propionibacterium acnes the dominating species in the cohort. When DED patients were compared to controls, the species Corynebacterium tuberculostearicum was more abundant in conjunctival samples, whereas the family Propionibacteriaceae was more abundant in lid samples. Functional analysis showed that genes of L-lysine biosynthesis, tetrapyrrole biosynthesis, 5-aminoimidazole ribonucleotide biosynthesis, and the super pathway of L-threonine biosynthesis were enriched in conjunctival samples of controls. The relative abundances of Acinetobacter johnsonii correlated with seven human tear proteins, including mucin-16. The three most abundant microbial tear proteins were the chaperone protein DnaK, the arsenical resistance protein ArsH, and helicase. Compositional and functional features of the OSM and the tear proteome are altered in patients with DED. Ultimately, this may help to design novel interventional therapeutics to target DED. Full article

The skin is a physical barrier to protect the human body and is rich in microbial niches. Skin is damaged due to several factors, including poor nutrition and exposure to harsh environments resulting in dryness, acidic skin, and infections. Studies have shown that probiotics and their derivatives could protect the skin. Skin care products with probiotic components are the latest approach to developing cosmetic products with health benefits. The current study aimed to examine the moisturizing effect of paraprobiotics (moist heat-inactivated Bifidobacterium lactis (B. lactis), Lactobacillus plantarum (L. plantarum))-containing moisturizer (APM) and its influences on the skin microbiome of healthy subjects. Fifty healthy subjects were randomly divided into treatment (n = 25) and control (n = 25) groups. The APM or placebo (without paraprobiotics; PM) was applied on the skin of the right forehand of subjects, and the changes in transepidermal water loss (TEWL) and stratum corneum moisture (SCM) levels every 1 h for 4 h and after 4 weeks of treatment were observed. Skin swab samples were collected before and after the treatments (4 weeks) and subjected to microbiome analysis through next-generation sequencing technology. The results indicated that the APM treatment significantly reduced the TEWL and increased the SCM values compared to the respective baseline values and controls. The sequencing study showed significant changes in Cutibacterium (p = 0.0431), Corynebacterium (p = 0.0431), and Acinetobacter (p = 0.0431) in the treatment group. The changes in phylum were not statistically significant. Still, based on the relative frequency, the abundance of phylum Proteobacteria and Firmicutes and Cyanobacterial was decreased, and the abundance of Planctomycetes, Chloroflexi, Verrucomicrobia, and Gemmatimonadetes was increased after treatment. Additionally, the APM treatment suppressed C. tuberculostearicum in healthy subjects. The results suggested that APM could improve skin hydration and skin-beneficial microbial composition. The study has limitations such as a small sample size and treatment period, so further extensive studies are required to confirm the findings of the current study, which could aid in developing paraprobiotics-based skin care formulations. Full article

Onychomycosis is a fungal disease of the nail that is found worldwide and is difficult to diagnose accurately. This study used metagenomics to investigate the microbiology of 18 clinically diagnosed mycotic nails and two normal nails for fungi and bacteria using the ITS2 and 16S loci. Four mycotic nails were from Bass Coast, six from Melbourne Metropolitan and eight from Shepparton, Victoria, Australia. The mycotic nails were photographed and metagenomically analysed. The ITS2 sequences for T. rubrum and T. interdigitale/mentagrophytes averaged over 90% of hits in 14/18 nails. The high abundance of sequences of a single dermatophyte, compared to all other fungi in a single nail, made it the most likely infecting agents (MLIA). Trichophyton rubrum and T. interdigitale/mentagrophytes were found in Bass Coast and Shepparton while only T. interdigitale/mentagrophytes was found in Melbourne. Two nails with T. interdigitale/mentagrophytes mixed with high abundance non-dermatophyte moulds (NDMs) (Aspergillus versicolor, Acremonium sclerotigenum) were also observed. The two control nails contained chiefly Fusarium oxysporum and Malassezia slooffiae. For bacteria, Staphylococcus epidermidis was in every nail and was the most abundant, including the control nails, with an overall mean rate of 66.01%. Rothia koreensis, Corynebacterium tuberculostearicum, and Brevibacterium sediminis also featured. Full article

The compositional analysis of 16S rRNA gene sequencing datasets is applied to characterize the bacterial structure of airborne samples collected in different locations of a hospital infection disease department hosting COVID-19 patients, as well as to investigate the relationships among bacterial taxa at the genus and species level. The exploration of the centered log-ratio transformed data by the principal component analysis via the singular value decomposition has shown that the collected samples segregated with an observable separation depending on the monitoring location. More specifically, two main sample clusters were identified with regards to bacterial genera (species), consisting of samples mostly collected in rooms with and without COVID-19 patients, respectively. Human pathogenic genera (species) associated with nosocomial infections were mostly found in samples from areas hosting patients, while non-pathogenic genera (species) mainly isolated from soil were detected in the other samples. Propionibacterium acnes, Staphylococcus pettenkoferi, Corynebacterium tuberculostearicum, and jeikeium were the main pathogenic species detected in COVID-19 patients’ rooms. Samples from these locations were on average characterized by smaller richness/evenness and diversity than the other ones, both at the genus and species level. Finally, the ρ metrics revealed that pairwise positive associations occurred either between pathogenic or non-pathogenic taxa. Full article