Search Results (725)

Wound-associated infections persist as a major global health concern, particularly in the context of increasing antimicrobial resistance and reduced efficacy of conventional therapies. Essential oils (EOs) obtained from medicinal plants represent promising alternatives due to their antimicrobial and wound-healing properties. This study evaluated the chemical composition, antimicrobial activity, and interaction effects of Hypericum perforatum (HP) and Achillea millefolium (AM) EOs, tested individually and in fixed-ratio combinations. Chemical profiling by GC–MS revealed that HP EO is dominated by caryophyllene (20.74%) and β-thujone (18.47%), while AM EO is characterized by aromadendrene (19.12%), caryophyllene (12.97%), and chamazulene (10.13%). Antimicrobial activity was assessed against wound-associated microorganisms using MIC and MBC/MFC assays, and interactions were assessed by the fractional inhibitory concentration index (FICI) and heatmap analysis. The results displayed higher susceptibility of Gram-positive bacteria, particularly Staphylococcus epidermidis, with MIC values as low as 0.56 µL/mL in EO combinations. Synergistic effects were observed exclusively for S. epidermidis in mixtures enriched in HP EO (60:40 and 70:30; FICI = 0.34), while Gram-negative bacteria and Candida albicans exhibited predominantly indifferent responses. These findings indicate that optimized EO combinations may enhance antimicrobial efficacy and support their potential application in wound management. Full article

According to the National Cancer Institute, approximately 3.9 billion people worldwide suffer from non-communicable oral diseases, with head and neck cancer patients experiencing exacerbated oral mucositis primarily from radiotherapy. This condition manifests as painful, debilitating mucosal lesions, necessitating effective antimicrobial interventions. This study developed and characterized stable mouthwash formulations containing green-synthesized silver nanoparticles (AgNPs) derived from Baccharis trimera (carqueja) extract for the management of oral mucositis, evaluating their physicochemical stability, antimicrobial efficacy, and biosafety. AgNPs formation was confirmed by color change to brown and a surface plasmon resonance band at 407 nm (UV-Vis), with dynamic light scattering revealing a monomodal hydrodynamic diameter of ~25 nm and stable dispersion; scanning electron microscopy showed spherical particles of 25–35 nm. Four formulations (22–85 ppm AgNPs) in a commercial vehicle exhibited excellent stability over 60 days at 5 °C and 25 °C, maintaining near-neutral pH (~7), low surface tension (<5 mN/m), and unchanged spectral profiles, with no phase separation under centrifugation or thermal stress (up to 70 °C). Antimicrobial assays via broth microdilution demonstrated broad-spectrum activity for the 85 ppm formulation: MICs of 125 µg/mL (S. epidermidis, E. faecalis), 62.5 µg/mL (E. coli, P. aeruginosa), and 250 µg/mL (S. aureus), with MBC of 125 µg/mL (bactericidal) against P. aeruginosa; no activity against C. albicans (MIC > 500 µg/mL). Against human oral microbiota (n = 4 volunteers), it reduced bacterial growth by 14–156% relative to controls (e.g., −5% to 156% inhibition). Cytogenotoxicity tests (A. cepa) confirmed non-toxicity (mitotic index 79–93% of control, low cellular alteration index). These findings establish the carqueja-mediated instant green AgNPs mouthwash as a stable, potent antimicrobial agent, poised to mitigate mucositis-related infections and enhance the quality of life of cancer patients. Full article

Microorganisms can aggregate and organise into structured communities embedded within an exopolysaccharide-based matrsix, which serves as a protective barrier and a functional environment around microbial cells. The formation of biofilms is widely recognised as a pivotal factor in bacterial virulence, impeding the efficacy of antimicrobial agents and hindering immune responses, whilst concomitantly contributing to the development of antimicrobial resistance and the onset of persistent infections. Biofilm formation is a tightly regulated and dynamic process, controlled by quorum-sensing mechanisms and profoundly influenced by environmental factors and nutrient availability. The objective of this review is to elucidate the significance of biofilms in clinical settings, with a particular focus on their role in the pathogenesis of infectious diseases. Particular attention is devoted to biofilm-associated infections and infections related to invasive medical devices, with a particular emphasis on the most prevalent microbial pathogens, which include S. aureus, S. epidermidis, P. aeruginosa, E. coli, K. pneumoniae, A. baumannii and various species of Candida. Furthermore, the present review encompasses biofilm-associated chronic infections, conditions manifesting in predisposed patients, including individuals affected by cystic fibrosis. This review further examines the most recent strategies for combating antibiotic resistance in bacterial biofilms. This review focuses on recent biofilm pathogenesis advancements, with a focus on diagnosis challenges and the need for new ways to disrupt biofilm integrity. Full article

Polyurethanes (PUs) are widely used in biomedical applications; however, their surface properties critically determine bacterial colonization and cell response. In this study, medical-grade PU films were modified using low-pressure C₃H₂F₄ plasma (50 W, 300 s, 0.2 mbar), and the resulting changes in surface chemistry, wettability, topography, bacterial adhesion, and cell compatibility were evaluated. X-ray photoelectron spectroscopy (XPS) analysis confirmed the incorporation of fluorine-containing groups (CF₂, CF₃) and the appearance of an F 1s signal at ~688.3 eV. Plasma treatment increased the water contact angle from 92.6° ± 5.6° to 97.9° ± 3.1° and elevated the root mean square (RMS) surface roughness (Sq) from 39.0 nm to 77.3 nm. Surface free energy slightly decreased after plasma treatment due to reductions in both polar and dispersive components. Quantitative adhesion assays revealed strain-dependent effects. For S. aureus DSM 4910, S. epidermidis DSM 28319, and P. aeruginosa DSM 22644, no consistent reduction in adhesion was observed on plasma-treated surfaces. In contrast, E. coli DSM 18039 demonstrated significantly higher adhesion on modified PU at all incubation times, reaching 5.96 ± 0.44 logCFU/mL after 240 min compared to 5.05 ± 0.27 log colony-forming units per milliliter (logCFU/mL) on unmodified PU. Fluorescence microscopy confirmed increased surface coverage by E. coli on fluorinated samples. Biocompatibility studies using A549 cells showed no cytotoxic effects. Cell spreading area remained comparable between surfaces (1188.6 vs. 1185.1 µm²; p = 0.958). However, cells on plasma-treated PU exhibited reduced major axis length (38.6 vs. 46.7 µm; p < 0.001) and decreased focal adhesion area (8.88 vs. 10.94 µm²; p = 0.002), indicating moderate alterations in cell morphology without compromised viability. These results demonstrate that C₃H₂F₄ plasma fluorination moderately increases PU hydrophobicity and nanoscale roughness, induces strain-dependent changes in bacterial adhesion—particularly enhancing E. coli colonization—while fully preserving mammalian cell viability and showing no cytotoxic effects of the modified surface. Full article

Eye cosmetic products are widely used and applied in close proximity to the ocular surface, making their microbiological safety particularly important. The aim of this study was to assess bacterial contamination in used eye cosmetic products, characterize the antimicrobial resistance profiles of the isolated bacteria, and perform molecular genotypic analysis. A total of 71 samples, including mascara, eyeliner, and eyeshadow, were analyzed. Microbiological analysis revealed that Bacillus spp. and coagulase-negative staphylococci (CoNS) were the predominant microorganisms, while no major pathogens such as Staphylococcus aureus, Escherichia coli, or Pseudomonas aeruginosa were detected. Antimicrobial susceptibility testing demonstrated high susceptibility of isolates to gentamicin, vancomycin, and linezolid, whereas resistance to benzylpenicillin and clindamycin was observed among Staphylococcus spp. Molecular identification based on 16S rRNA gene sequencing confirmed the presence of Bacillus licheniformis, Bacillus subtilis, Staphylococcus epidermidis, and Staphylococcus warneri, with sequences showing high similarity to globally distributed strains. Although the detected microorganisms were predominantly opportunistic, their presence in products applied near the eyes suggests a potential risk of microbial transfer to the ocular surface. These findings highlight the importance of proper hygiene practices, regular product replacement, and effective quality control measures to minimize microbial contamination and associated health risks. Full article

Plant foods have been the cornerstone of human diets since ancient times, fueling civilization and shaping cultures. Plants became central to sustainable food systems, offering diverse and nutritious options for the future. Sea buckthorn (Hippophae rhamnoides L.) has attracted growing scientific interest due to the presence of bioactive compounds, polyphenols, fatty acids, phytosterols, carotenoids, vitamins, and minerals in its fruit, seeds, and leaves. Moreover, sea buckthorn exhibit antioxidant, anti-inflammatory, antimicrobial, antidiabetic, antihyperlipidemic, anticancer, hepatoprotective, neuroprotective, and metabolic regulatory properties supported by in vitro and in vivo models. The biological activity of these phytochemical compounds plays a crucial role in regulating the AMP-activated protein kinase (AMPK) and phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathways, as well as pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), cell proliferation, and apoptosis. Furthermore, its potential against microbial growth, including S. aureus, S. epidermidis, S. intermedius, and S. pyogenes, among others, not only expands its applications in the pharmaceutical industry but also attracts researchers to incorporate it into food products. This could lead to the discovery of plant-based therapeutic products without significant adverse effects. However, further exploration of each component’s potential side effects is necessary to support the commercialization of formulated products in either the pharmaceutical or food industries, ensuring the highest safety standards for consumers. Including studies on bioavailability and pharmacodynamics could further strengthen the scientific evidence supporting the specific phytochemicals in sea buckthorn and their mechanistic interactions. Full article

The interest in the use of phytochemicals and herbal medicines for the treatment of acne vulgaris has grown steadily over recent decades. The research on the secondary metabolites and biological properties of bearberry (Arctostaphylos uva-ursi (L.) Spreng.) has been intensified in recent years, but the range of bacterial strains tested, many of which are highly relevant to human health, remains very limited. Therefore, the aim of this study was to evaluate the chemical composition and the antioxidant, antimicrobial, and cytotoxic activities of water and ethanolic bearberry leaf extracts. Compared with the ethanolic extract, the water extract was characterized by higher concentrations of arbutin, hydroquinone, corilagin, and hyperoside and the absence of ursolic acid and oleanolic acid. However, it exhibited lower total phenolic content and reduced levels of penta-O-galloyl-β-d-glucose (PGG). The ethanolic extract of bearberry leaves showed higher antioxidant activity and the most favorable overall biological properties. The therapeutic index (TI) values for the water and ethanolic extracts, respectively, were as follows: Cutibacterium acnes ATCC 11827 (10.70; 21.57), Propionibacterium acnes PCM 2334 (10.70; 43.13), P. acnes PCM (5.33; 21.57), Staphylococcus aureus ATCC 25923 (10.70; 21.57), and S. epidermidis ATCC 12228 (5.33; 10.78). The present findings further support the medicinal and cosmetic use of A. uva-ursi and highlight its potential as a source of natural antibacterial agents for acne treatment. Full article

An abnormal increase in acne-causing bacteria is the main cause of acne. This study aimed to investigate Piper griffithii C.DC. as a new source of compounds for inhibiting acne-causing bacteria and to provide the first elucidation of the mechanism of action against these bacteria. The antibacterial efficacy of 27 Piper species was examined against acne-causing clindamycin-resistant bacterial strains. Antibacterial activity of various crude extracts derived from leaves or stems extracted using hexane, ethyl acetate, or ethanol was evaluated. Ethyl acetate leaf extract of P. griffithii exhibited the greatest antibacterial effect against all tested bacteria. Zeylenone, an antibacterial substance isolated, purified, and characterized from the ethyl acetate leaf extract of P. griffithii, disrupts cell walls and membranes. Minimum bactericidal concentration (MBC) values were 1.25, 2.5, and 7.5 mg/mL for Cutibacterium acnes, Staphylococcus aureus, and S. epidermidis, respectively. Zeylenone derived from P. griffithii leaves was nontoxic to human skin keratinocytes (HaCaT). A formulated anti-acne gel with zeylenone was effective in controlling acne-causing bacteria. These results suggest that zeylenone isolated from P. griffithii leaves can be further developed as a natural ingredient in anti-acne products. This is the first report of the use of zeylenone from P. griffithii for eliminating acne-causing bacteria. Full article

Objective: The objective of this study is to evaluate the ability of silver oxide nanoparticle (Ag₂ONP)-functionalized high-efficiency particulate air (HEPA) filters and colloidal Ag₂ONP suspensions to inhibit biofilm formation by major respiratory pathogens causing infections at operating rooms. Background: Respiratory infections caused by bacterial pathogens such as Streptococcus pneumoniae, Pseudomonas aeruginosa and Staphylococcus species are often associated with the formation of biofilms, which confer increased resistance to antibiotics and host immune responses. Effective strategies to prevent biofilm formation on biological surfaces and in air filtration systems are urgently needed in clinical settings. Methods: The biofilm-forming ability of each bacterial strain was assessed by crystal violet microplate assay, viable count or confocal microscopy after prior incubation of the culture medium with Ag₂ONP-coated HEPA filter material or colloidal Ag₂ONP suspension. Results: Both silver-functionalized filters and silver nanoparticle suspensions significantly inhibited biofilm formation by S. pneumoniae and P. aeruginosa, with near-complete suppression observed. In the case of S. aureus and S. epidermidis, the silver nanoparticle suspension showed partial inhibition of biofilm development. Conclusions: Ag₂ONP-functionalized HEPA filters and colloidal Ag₂ONP suspensions effectively prevent biofilm formation by major respiratory pathogens, for both Gram-negative and Gram-positive bacteria. These materials show promise for integration with air filtration and surface coating systems to reduce microbial load and transmission in healthcare environments such as operating room facilities. Full article

Animal health is a key pillar of the One Health framework, which emphasizes the interconnectedness of humans, animals, and the environment. Staphylococcus spp., common commensals of skin and mucosa, are clinically important due to their virulence factors and increasing antimicrobial resistance. This cross-sectional study aimed to isolate and characterize Staphylococcus spp. from dogs and their owners and to assess correlations within their nasal microbiota. Nasal swabs were collected from at least 100 dog–owner pairs at two Veterinary Teaching Hospitals located in Northern (Turin Province) and Southern (Naples Province) Italy. In both study areas, S. pseudintermedius was the most common species in dogs. Among owners, S. epidermidis was predominant in Naples, while S. epidermidis and S. aureus were most frequent in Turin. A subset of 54 dog–owner pairs sharing the same Staphylococcus species (42 from Turin and 12 from Naples; in total 108 isolates) was included in this analysis, with a focus on antimicrobial patterns. S. aureus was the species most frequently shared between dogs and owners, followed by S. epidermidis, with no significant differences between the two sites. In particular, methicillin resistance (phenotypically inferred) was detected in 16.7% of isolates in Turin (19.0% in dogs; 14.3% in owners) and 41.7% of isolates in Naples (33.3% in dogs; 50.0% in owners). Multidrug resistance was detected in 34.3% of paired isolates overall, with a higher prevalence in Naples (58.3%) compared to Turin (27.4%). No significant association emerged between biofilm production and multidrug resistance (MDR). Overall, these findings suggest possible species sharing between dogs and owners, while biofilm formation did not predict MDR. Full article

Background/Objectives: Staphylococcus epidermidis (RP62A) and Staphylococcus aureus (UAMS-1) are clinically relevant pathogens frequently implicated in implant-associated infections due to their ability to form biofilms. RP62A is typically linked to persistent, chronic, low-grade infections, whereas UAMS-1 is associated with acute, invasive disease. Both strains serve as representative models for chronic and acute periprosthetic joint infections (PJIs). The objective of this study was to examine and compare in vitro biofilm formation by RP62A and UAMS-1 on orthopaedic materials/disc surfaces of defined composition. Methods: In vitro biofilm formation assays were performed using orthopaedic disc surfaces composed of cobalt–chromium alloy (CoCr), titanium alloy (Ti), and polyethylene (PE) after 72 h of incubation. Biofilm biomass was quantified using crystal violet staining, with absorbance measured at OD₅₇₀. A polystyrene (PS) surface served as a control. Additionally, retrieved orthopaedic explant components were used as substrates for in vitro biofilm assays, in which RP62A was incubated for 72 h on the explanted surfaces. Supporting assays on glass slides were conducted to examine strain-specific biofilm-related architecture. Results: In vitro biofilm mass quantification assays showed strong biofilm formation by RP62A across all tested surfaces, with the highest absorbance on CoCr (OD₅₇₀ = 5.80 ± 0.19). Notably, biofilm formation on CoCr was 76% higher compared to PS (p < 0.0001). No significant differences were observed among all three surface discs (p > 0.1). Biofilm formation was highest on PE for UAMS-1 (OD₅₇₀ = 1.29 ± 0.09) and was significantly greater than on Ti (178%, p < 0.001) and CoCr (196%, p < 0.0001). In the in vitro assays performed on retrieved explant components, RP62A showed pronounced biofilm accumulation on polyethylene tibial inserts, particularly in regions of mechanical wear and friction. Supporting assays on glass slides were performed to examine strain-specific surface microstructural, revealing dense network-like structures for RP62A and thinner, discontinuous layers for UAMS-1. Conclusions: RP62A formed dense biofilms in vitro on multiple orthopaedic implant materials and retrieved explant components, consistent with its association with chronic periprosthetic joint infections. Increased biofilm accumulation was observed on mechanically worn polyethylene surfaces. In contrast, UAMS-1 showed lower biofilm formation on metallic disc surfaces, indicating strain- and material-dependent differences. These findings highlight the relevance of implant material selection and surface integrity for strategies targeting biofilm-associated implant infections. Full article

Background: Chronic sclerosing osteomyelitis of Garré (CSO) is a rare, non-suppurative form of primary chronic osteomyelitis characterized by reactive periosteal bone formation and cortical thickening. It most commonly involves the mandibular bones, whereas long-bone localization is uncommon. Material and Methods: We report a 4-year-old girl who developed progressive right thigh pain and limping six months after receiving intramuscular ampicillin injections. Subsequent evaluation revealed femoral changes consistent with chronic sclerosing osteomyelitis. Surgical decompression and targeted antimicrobial therapy were performed. Results: Microbiological analysis of intraoperative specimens obtained prior to antibiotic therapy yielded Staphylococcus epidermidis (S. epidermidis) and Staphylococcus capitis (S. capitis). After three years of follow-up, the patient exhibited no functional impairment or growth disturbance of the affected limb. Conclusions: Although coagulase-negative staphylococci (CoNS) are commonly regarded as skin commensals, their repeated isolation from deep surgical specimens, together with clinical findings and response to treatment, raises the possibility of their involvement in the disease process in this case. Full article

Staphylococcus epidermidis (S. epidermidis) poses a significant clinical challenge, particularly in the context of biofilm-associated infections, with increasing antibiotic resistance further complicating infection eradication. In the present study, the effects of cinnamic acid and its derivatives (ferulic acid, p-coumaric acid, and sinapic acid), alone and in combination with the β-lactam antibiotic cloxacillin, on biofilm formation by a single methicillin-resistant S. epidermidis (MRSE) clinical strain were explored. The expression of the biofilm-associated icaADBC operon genes and the icaR repressor gene was assessed using Real-Time PCR as an exploratory analysis under sub-minimal inhibitory concentrations (sub-MICs) of the tested compounds. Furthermore, confocal microscopy was used to qualitatively assess selected structural changes in the biofilm. Their occurrence was demonstrated depending on the fractional inhibitory concentration (FIC) levels used. The results revealed variable and nonlinear patterns of gene expression in response to the tested concentrations. Additionally, compound-dependent differences in anti-biofilm-related responses were observed. Overall, the findings provide insight into the potential influence of cinnamic acid derivatives combined with cloxacillin on biofilm-associated processes in S. epidermidis. Full article

Background: The global rise in antimicrobial resistance (AMR) has created an urgent need for innovative antibacterial strategies and localized delivery systems. This study aimed to develop and characterize electrospun poly (vinyl alcohol) (PVA) nanofibers co-loaded with atorvastatin (ATR) and zinc oxide (ZnO) nanoparticles for use as a multifunctional topical platform for wound healing and infection control. Methods: ZnO nanoparticles were prepared via ball milling and characterized for size and zeta potential. Four PVA-based nanofiber formulations were fabricated using electrospinning: blank (F1), ZnO-loaded (F2), ATR-loaded (F3), and ATR/ZnO co-loaded (F4). The nanofibers were evaluated for morphology, thermal properties, crystallinity, and drug release. Antibacterial efficacy was tested against S. aureus, S. epidermidis, MRSA, and P. aeruginosa using broth microdilution and checkerboard assays. Biocompatibility and wound healing potential were assessed via MTT and fibroblast scratch assays on human foreskin fibroblasts (hFFs). Results: SEM imaging confirmed the production of uniform, bead-free nanofibers. ATR and ZnO nanoparticles were successfully incorporated in the nanofiber. The co-loaded formulation (F4) demonstrated a sustained release profile, releasing approximately 78.7% of ATR over 24 h. While all treatments showed limited activity against P. aeruginosa, the ATR/ZnO co-loaded nanofibers exhibited significantly enhanced antibacterial activity against Gram-positive strains, achieving the lowest MIC values (1.5–2.0 mg/mL). Synergy analysis confirmed an enhanced effect with ATR and ZnO against MRSA. Furthermore, F4 achieved the highest wound closure rate of 92.41% in 24 h while maintaining acceptable cytocompatibility. Conclusions: The integration of ATR and ZnO into PVA nanofibers provides an enhanced antibacterial effect consistent with the synergistic potential observed between free agents targeting Gram-positive wound pathogens. The platform’s ability to simultaneously inhibit bacterial growth and promote rapid fibroblast migration positions it as a promising localized therapeutic for managing infected wounds. Full article

Antimicrobial metabolite production in basidiomycetes varies by strain and growing conditions. This study compared the antimicrobial activity of extracts from nine fungal strains at both their vegetative and reproductive stages. Wild-growing fungal fruiting bodies were collected and identified through both morphological characterization and molecular sequencing. Extracts from fruiting bodies, mycelia, and culture liquids were tested using the agar well diffusion method and by determining the minimum inhibitory concentration (MIC). Analysis revealed that the highest antimicrobial activity was associated with culture liquid extracts. Antimicrobial properties were detected in the submerged mycelium extracts of only two strains: Stereum hirsutum 1 and Flammulina rossica 16. For fruiting bodies, activity was restricted to extracts of strains from the genus Fomitopsis. The strain S. hirsutum 1 was determined to be the most effective producer of antibacterial compounds. The highest activity was exhibited by the S. hirsutum 1 culture liquid extract, with an MIC of 320 µg/mL against clinical Gram-positive strains (Staphylococcus aureus, S. epidermidis, S. haemolyticus, vancomycin-resistant Enterococcus faecium) and Gram-negative Proteus vulgaris. The studied strains demonstrated higher production of antimicrobial metabolites during vegetative growth, with the active compounds being primarily extracellular. Submerged cultivation of basidiomycetes offers an efficient method for obtaining antimicrobial metabolites, permitting their subsequent isolation, physicochemical characterization, and biomedical evaluation. Full article