Decolonization of Staphylococcus aureus in Healthcare: A Dermatology Perspective

Extracellular Vehicles from Commensal Skin Malassezia restricta Inhibit Staphylococcus aureus Proliferation and Biofilm Formation

The colonizing microbiota on the body surface play a crucial role in barrier function. Staphylococcus aureus (S. aureus) is a significant contributor to skin infection, and the utilization of colonization resistance of skin commensal microorganisms to counteract the invasion of pathogens is a viable approach. However, most studies on colonization resistance have focused on skin bacteria, with limited research on the resistance of skin fungal communities to pathogenic bacteria. Extracellular vehicles (EVs) play an important role in the colonization of microbial niches and the interaction between distinct strains. This paper explores the impact of Malassezia restricta (M. restricta), the fungus that dominates the normal healthy skin microbiota, on the proliferation of S. aureus by examining the distribution disparities between the two microorganisms. Based on the extraction of EVs, the bacterial growth curve, and biofilm formation, it was determined that the EVs of M. restricta effectively suppressed the growth and biofilm formation of S. aureus. The presence of diverse metabolites was identified as the primary factor responsible for the growth inhibition of S. aureus, specifically in relation to glycerol phospholipid metabolism, ABC transport, and arginine synthesis. These findings offer valuable experimental evidence for understanding microbial symbiosis and interactions within healthy skin.

Virulence adaption to environment promotes the age-dependent nasal colonization of Staphylococcus aureus

Staphylococcus aureus is an important human commensal bacteria colonizing the human body, especially the nasal cavity. The nasal carriage can be a source of S. aureus bacteremia. However, the bacterial factors contributing to nasal colonization are not completely understood. By analysing S. aureus strains from the nasal cavity of the children, young adults, and seniors, we found that the low activity of the SaeRS two-component system (TCS) is an important determinant for S. aureus to colonize in seniors. The senior group isolates of S. aureus showed a rather distinct sequence type composition as compared with other age group isolates. The senior group isolates showed not only a lower gene carriage of enterotoxins a, c, and q but also lower hemolytic activity against human red blood cells. Of regulators affecting hemolysin production (i.e. agr, saeRS, rot, rsp, and sarS), only the SaeRS TCS showed an age-dependent decrease of activity. The decreased virulence and better colonization ability of the senior group isolates of S. aureus were confirmed in the mouse model. The senior group isolates showed the lowest survival and the best adhesion and colonizing ability. Also, the senior nasal secretions supported S. aureus survival better than the child and young adult nasal secretions. These results indicated that the senior nasal cavity favours colonization of S. aureus with higher adhesion and lower virulence, to which the reduced SaeRS TCS activity contributes. Taken together, our results illustrate an example of bacterial adaptation to the changing host environment.

Photodynamic Inactivation of Bacteria in Ionic Environments Using the Photosensitizer SAPYR and the Chelator Citrate

Many studies show that photodynamic inactivation (PDI) is a powerful tool for the fight against pathogenic, multi-resistant bacteria and the closing of hygiene gaps. However, PDI studies have been frequently performed under standardized in vitro conditions comprising artificial laboratory settings. Under real life conditions, however, PDI encounters substances like ions, proteins, amino acids, and fatty acids, potentially hampering the efficacy PDI to an unpredictable extent. Thus, we investigated PDI with the phenalene-1-one based photosensitizer SAPYR against Escherichia coli and Staphylococcus aureus in the presence of calcium or magnesium ions, which are ubiquitous in potential fields of PDI applications like in tap water or on tissue surfaces. The addition of citrate should elucidate the potential as a chelator. The results indicate that PDI is clearly affected by such ubiquitous ions depending on its concentration and the type of bacteria. The application of citrate enhanced PDI especially for Gram-negative bacteria at certain ionic concentrations (e.g. CaCl₂ or MgCl₂ : 7.5 to 75 mmol l^-1 ). Citrate also improved PDI efficacy in tap water (especially for Gram-negative bacteria) and synthetic sweat solution (especially for Gram-positive bacteria). In conclusion, the use of chelating agents like citrate may facilitate the application of PDI under real life conditions.

Adipose-derived stem cells decolonize skin Staphylococcus aureus by enhancing phagocytic activity of peripheral blood mononuclear cells in the atopic rats

Staphylococcus aureus (S. aureus) is known to induce apoptosis of host immune cells and impair phagocytic clearance, thereby being pivotal in the pathogenesis of atopic dermatitis (AD). Adipose-derived stem cells (ASCs) exert therapeutic effects against inflammatory and immune diseases. In the present study, we investigated whether systemic administration of ASCs restores the phagocytic activity of peripheral blood mononuclear cells (PBMCs) and decolonizes cutaneous S. aureus under AD conditions. AD was induced by injecting capsaicin into neonatal rat pups. ASCs were extracted from the subcutaneous adipose tissues of naïve rats and administered to AD rats once a week for a month. Systemic administration of ASCs ameliorated AD-like symptoms, such as dermatitis scores, serum IgE, IFN-γ⁺/IL-4⁺ cell ratio, and skin colonization by S. aureus in AD rats. Increased FasL mRNA and annexin V⁺/7-AAD⁺ cells in the PBMCs obtained from AD rats were drastically reversed when co-cultured with ASCs. In contrast, both PBMCs and CD163⁺ cells bearing fluorescent zymosan particles significantly increased in AD rats treated with ASCs. Additionally, the administration of ASCs led to an increase in the mRNA levels of antimicrobial peptides, such as cathelicidin and β-defensin, in the skin of AD rats. Our results demonstrate that systemic administration of ASCs led to decolonization of S. aureus by attenuating apoptosis of immune cells in addition to restoring phagocytic activity. This contributes to the improvement of skin conditions in AD rats. Therefore, administration of ASCs may be helpful in the treatment of patients with intractable AD.

Methicillin-resistant Staphylococcus aureus colonization of infectious and non-infectious skin and soft tissue lesions in patients in Tehran

Background

The most common clinical manifestations of Staphylococcus aureus strains in the community are skin and soft-tissue infections. S. aureus could colonize the body sites and complicate the pathogenesis of skin diseases. S. aureus colonization is a risk factor for severe conditions such as bone and joint infections, pneumonia, bacteremia, and endocarditis. This study aimed to investigate the prevalence of S. aureus strains in skin and soft tissue infections and other skin disorders in patients referring to dermatology clinics and to evaluate the antibiotic resistance pattern and molecular characteristics of S. aureus isolates.

Methods

Skin swabs were collected from the lesional sites in 234 outpatients referring to dermatology clinics in three hospitals in Tehran. Antibiotic susceptibility, biofilm formation, and hemolysis tests were performed for isolates. PCR was done for SCCmec typing, agr grouping, and virulence genes detecting.

Results

The prevalence of S. aureus strains among patients with skin and soft-tissue infections and other skin lesions was 44.77% (30/67) and 44.91% (75/167), respectively. Also, 59 (56.19%) isolates were MRSA, 35.57% were HA-MRSA, and 30.5% were CA-MRSA. The psmα gene was more prevalent (62.8%) among isolates, followed by hlaα (56.1%), tsst-1 (15.2%) eta (13.3%), etb (6.6%), and pvl (2.8%). The agr specificity groups I, II, III, and IV were identified in 49.5, 21.9, 11.4, and 14.2% of S. aureus isolates, respectively. Most (56%) S. aureus isolates produced a moderate biofilm, and 23.8% of them produced strong biofilms. α-hemolysin (46.6%), β-hemolysin (25.7%), γ-hemolysin (19%), and both α and β-hemolysin (5.7%) were also produced by isolates.

Conclusion

The present study results indicated high colonization of skin lesions by HA-MRSA and CA-MRSA clones; MRSA strains were more resistant to antibiotics, contained various toxin genes, and were able to form biofilms. Therefore, they could play a vital role in the pathogenesis of various skin diseases; also, they could spread and cause infections in other body sites. Eradication and decolonization strategies could prevent recurrent infections and the spread of resistant strains and improve skin conditions.

Antifungal activity of boric acid, triclosan and zinc oxide against different clinically relevant Candida species

BACKGROUND

The genus Candida includes about 200 different species, but only a few are able to produce disease in humans. The species responsible for the highest proportion of human infections is Candida albicans. However, in the last two decades there has been an increase in the proportion of infections caused by other Candida species, including C. glabrata (Nakaseomyces glabrata), C. parapsilosis, C. tropicalis, C. krusei (Pichia kudriavzevi) and more recently C. auris. Decolonisation of patients has been used as an infection control strategy for bacterial infections, but information about decolonisation products used in clinical practice for Candida and other fungal pathogens is limited. Compounds with antimicrobial activity, such as triclosan (TR), boric acid (BA) and zinc oxide (ZO), are mainly used in personal care products. These products can be used for long periods of time without an abrasive skin effect and are a possible alternative for patient decolonisation in healthcare settings.

OBJECTIVE

The aim of this study was to evaluate the antifungal activity of boric acid (BA), triclosan (TR) and zinc oxide (ZO), individually and combined, against clinically relevant Candida species.

MATERIALS AND METHODS

Compounds to be screened for antifungal activity were evaluated at different concentrations, alone, and combined, using a well diffusion assay. The statistical evaluation was performed using analysis of variance (ANOVA) and a post hoc analysis using the multiple comparisons method.

RESULTS

Individually, BA and TR showed antifungal activity against all Candida species evaluated but ZO did not show any antifungal activity. Mixtures of BA [5%]-TR [0.2%]; BA [5%]-TR [0.3%]; BA [5%]-TR [0.2%]-ZO [8.6%]; and BA [5%]-TR [0.2%]-ZO [25%] yielded the highest antifungal activity. An increased antifungal effect was observed in some mixtures when compared with individual compounds.

CONCLUSIONS

We demonstrated antifungal activity of BA and TR against multiple Candida species, including against a clade of the emerging healthcare-associated pathogen C. auris. Additionally, this study shows enhancement of the antifungal effect and no antagonism among the mixtures of these compounds. Further research is needed to determine whether these compounds can reduce the burden of Candida on skin.

The 10-Point Plan 2021: Updated Concepts for Improved Procedural Safety During Facial Filler Treatments

Dermal filler treatments require constant reassessment for improving and safeguarding the rapidly evolving aesthetic field. Suboptimal injection technique, patient selection and product knowledge have touted a concerning increase in filler complications, with new challenges such as the COVID-19 pandemic leading to new paradigms in the understanding, prevention, diagnosis and treatment of complications. The updated 10-point plan has been developed to curtail complications through consideration of causative factors, categorized as patient, product, and procedure-related. Patient-related factors include a preprocedural consultation with careful elucidation of skin conditions (acne, rosacea, dermatitis), systemic disease (allergies, autoimmune disease, underlying bacterial and viral disease (herpes simplex virus, COVID-19 infection), medications (antineoplastic drugs, recreational drugs) and previous cosmetic procedures (including fillers and energy-based devices). Patient assessment should include standardized photography and also evaluate the role of social media, ethnicity, gender, generational, and LGBTQ+ needs. Specified informed consent for both adverse events and their treatment is essential due to the increase in vascular complications, including the risk of blindness. Product-related factors include the powerful advantage of reversibility when using hyaluronic acid (HA) products. Product characteristics such as molecular weight and filler degradation should be understood. Product layering over late or minimally degradable fillers is still inadvisable due to the initial filler being teased into reactivity. Procedural factors such as consistent photographic documentation, procedural planning, aseptic non-touch technique (ANTT), knowledge of topographical anatomy and angiosomes, and technical dexterity including pinch anatomy and needle skills are of pivotal importance. The final section is dedicated to algorithms and checklists for managing and treating complications such as allergic hypersensitivity reactions, vascular events, infection, edema and late-onset adverse events (LOAEs). The updated 10-point plan is a methodical strategy aimed at further minimising the risk of dermal filler complications.

Zinc(II) Complexes with Amino Acids for Potential Use in Dermatology: Synthesis, Crystal Structures, and Antibacterial Activity

The multifunctional profile of Zn²⁺ has influenced its great popularity in various pharmaceutical, food, and cosmetic products. Despite the use of different inorganic and organic zinc derivatives, the search for new zinc-containing compounds with a safer skin profile still remains an open issue. The present paper describes the synthesis, structural characterization, and antibacterial activity of zinc(II) complexes with proteinogenic amino acids as potential candidates for dermatological treatments. The obtained complexes are of the general formula [Zn(AA)₂], where AA represents an amino acid (L-Glu, Gly, L-His, L-Pro, L-Met, and L-Trp). Their synthesis was designed in such a way that the final bis(aminoacidate) zinc(II) complexes did not contain any counter-ions such as Cl⁻, NO₃⁻, or SO₄²⁻ that can cause some skin irritations. The chemical structure and composition of the compounds were identified by ¹H NMR spectroscopy and elemental analysis, and four were also characterized by single-crystal X-ray diffraction. The Hirshfeld surface analysis for the Zn²⁺ metallic center helped to determine its coordination number and geometry for each complex. Finally, the antibacterial properties of the complexes were determined with respect to three Gram-positive strains, viz. Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, and Streptococcus pyogenes ATCC 19615, and two Gram-negative bacteria, viz. Escherichia coli ATCC 25992 and Pseudomonas aeruginosa ATCC 27853, and were compared with the activity of zinc 2-pirrolidone 5-carboxylate (ZnPCA), commonly applied in dermatology. It was found that the Zn(II) complexes with methionine and glycine exhibited a higher antibacterial activity than the tested standard, and the antimicrobial properties of complex with Trp were satisfactory. The results of the antimicrobial activity examination allow us to postulate that the obtained zinc complexes might become new active substances for use in dermatological products.