Search Results (1,013)

Introduction: Periprosthetic joint infections (PJI) are among the most serious and costly complications in orthopedic surgery, significantly affecting patient prognosis and healthcare systems. Despite rigorous aseptic measures, intraoperative contamination of sterile fields, instruments, and air remains a persistent source of potential infection. This study investigates the relationship between the microbial contamination of sterile fields during arthroplasty and postoperative inflammatory markers, with the objective of determining whether the contamination of sterile fields correlates with the presence of periprosthetic joint infection (PJI). Material and Methods: This prospective observational study included 33 patients undergoing total hip or knee arthroplasty in a university-affiliated orthopedic center. Intraoperative samples were collected from sterile fields and equipment to detect microbial contamination, while postoperative monitoring involved the C-reactive protein (CRP); erythrocyte sedimentation rate (ESR); leukocyte count; temperature; and wound assessment on days 1, 3 and 7. All patients received 48 h of prophylactic cefuroxime. Statistical analysis was conducted using the International Business Machines (IBM) Statistical Product and Service Solutions (SPSS) software for Windows, version 30.0 (IBM Corporation, Armonk, New York, United States of America) with significance set at p ≤ 0.05. Results: Postoperative inflammatory markers showed distinct patterns depending on the isolated microorganism, with Proteus vulgaris and Staphylococcus hominis ssp. consistently associated with higher CRP and leukocyte values, indicating a more intense systemic response. Staphylococcus epidermidis was the most frequently isolated species but showed moderate inflammatory profiles, suggesting its potential role in subclinical colonization. A strong correlation between CRP on day 3 and leukocyte count (r = 0.81) confirms their combined utility in the early detection of infectious complications, while ESR appeared less dynamic and more complementary in nature. Discussion: This study highlights the significant role of intraoperative contamination and microbial virulence in shaping the postoperative inflammatory response after arthroplasty. Elevated CRP and leukocyte levels, particularly on day 3, were closely associated with pathogens known for biofilm formation and chronic infections. Despite prophylactic antibiotic use, confirmed infections still occurred, suggesting the need to reassess current protocols and enhance intraoperative contamination control. Conclusions: Pathogen presence in sterile fields during arthroplasty increases the risk of periprosthetic joint infections, often without early clinical symptoms. CRP on day 3 and leukocyte count were the most reliable early indicators of persistent inflammation. 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

The objective of this study is to evaluate the efficiency of surgical instruments’ manual cleaning versus automated cleaning in an ultrasonic cleaner for the removal of biofilms on surgical forceps contaminated with Staphylococcus epidermidis and Pseudomonas aeruginosa. Subsequently, the residual microbial load was quantified through microbiological culture, aiming to evaluate the effectiveness of biofilm removal under different reprocessing conditions. Cleaning is an essential step in the processing of surgical instruments to ensure the effective removal of dirt and microorganisms. Through adhesion, microorganisms can attach to surfaces and form biofilms, organized structures surrounded by an extracellular matrix consisting of various components, which favor metabolic exchanges, adaptation, resistance, and bacterial dispersion. These biofilms increase the pathogenic potential of microorganisms, contributing to the occurrence of Healthcare-Associated Infections, and to avoid these, it is essential that preventive measures aimed at microbial reduction are adopted. Automated cleaning proved more effective than manual cleaning, and the combined approach achieved the greatest microbial reduction, though persistent contamination was still observed. The ability of adhesion and biofilm formation on the surfaces of surgical instruments is regarded as a challenge for complete microbial removal. These findings enhance the need for more rigorous reprocessing protocols and complementary strategies to ensure greater safety in the use of reusable instruments in clinical practice. 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/Objectives: Nature-inspired therapeutic strategies that promote biological regenerative mechanisms and replicate the native structural microenvironment conductive to formation of healthy tissue are increasingly recognized as a promising platform for skin tissue regeneration and wound healing. This study proposes an innovative design of novel multifunctional scaffolds composed entirely of natural components—gelatin, L-ascorbic (ASA) acid and allantoin—as a bioinspired approach for skin tissue regeneration through pro-regenerative, antimicrobial, and keratinocyte-supportive properties. Methods: The biocompatible, skin-adhesive scaffolds were prepared via a simple and environmentally friendly heat-induced crosslinking of gelatin with varying ASA contents, and by enriching the system with allantoin. The influence of ASA content on scaffold properties was investigated through characterization of their morphology, porosity, swelling behavior, skin tissue adhesion, and allantoin release potential. Biocompatibility was evaluated in vitro using human keratinocyte (HaCaT) cells, while antibacterial activity was assessed against Escherichia coli and Staphylococcus epidermidis. Results: The scaffolds revealed a highly porous, interconnected structure with tunable porosity (87.37–92.39%) and soft-tissue-matched mechanical properties (0.81–1.47 MPa). Incorporation of allantoin into the scaffolds enhanced their mechanical performance and swelling capacity. All scaffolds demonstrated antibacterial activity against both tested bacteria, supported keratinocyte viability and provided sustained release of allantoin for up to 76 h, confirming their multifunctional pro-regenerative potential. Conclusions: The novel gelatin/ascorbic acid scaffolds enriched with allantoin combine a porous replicated structure of native extracellular matrix, fluid absorption capacity, soft-tissue-like mechanical properties, stable skin tissue adhesion, cytocompatibility and antibacterial functionality with the pro-regenerative properties of allantoin, thereby representing a multifunctional and biologically inspired platform for advanced skin tissue regeneration and wound-healing applications. 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

Staphylococcus epidermidis is a leading opportunistic pathogen in medical device-associated infections due to its ability to adhere to abiotic materials and develop biofilms that are difficult to eradicate. This study investigated the antibiofilm potential of an ethanolic extract of the red seaweed Gracilaria fisheri and its purified constituent, N-benzylcinnamamide, against S. epidermidis. Antibacterial activity was determined, and antibiofilm effects were assessed using the crystal violet assay and confocal laser scanning microscopy (CLSM). Early bacterial adhesion on glass and polyurethane (PU) surfaces was measured. The effect on catheter-associated biofilms was evaluated by scanning electron microscopy (SEM). Transcripts of biofilm- and quorum-sensing-associated genes (icaA and luxS) were assessed by semi-quantitative RT-PCR. Cytotoxicity was evaluated by MTT assay. At 200 µg/mL, biofilm biomass decreased to 48.21 ± 5.52% with the extract and to 36.65 ± 6.82% with N-benzylcinnamamide. CLSM time-course imaging showed delayed biofilm maturation and less consolidated, discontinuous structures. Surface exposure to the extract markedly reduced early attachment on both materials. On PU catheter segments, SEM demonstrated that N-benzylcinnamamide markedly reduced surface coverage and disrupted three-dimensional biofilm architecture. At the molecular level, transcription of icaA and luxS was reduced. Both the extract and N-benzylcinnamamide showed minimal cytotoxicity in HeLa cells. These findings support further evaluation of these marine-derived agents as candidates for antibiofilm surface treatments to reduce early medical device colonization. Full article

Lactoferrin (Lf) and Lf-derived peptides are multifunctional milk components with potential applications in food preservation due to their antibacterial and antioxidant properties. In this study, the antibacterial and antioxidant activities of bovine lactoferrin and Lf-derived peptides obtained by enzymatic hydrolysis with pepsin, trypsin, and chymotrypsin were evaluated. Antibacterial activity was assessed against four foodborne pathogens and spoilage microorganisms (Escherichia coli, Listeria monocytogenes, Staphylococcus epidermidis, and Latilactobacillus sakei), while antioxidant activity was determined using four complementary assays. Lf showed stronger antibacterial activity than the corresponding hydrolysates against all tested strains, while the hydrolysates notably inhibited Listeria monocytogenes and Latilactobacillus sakei. Both Lf and its peptides showed lower antioxidant capacity than Trolox, although native Lf and its peptides markedly inhibited lipid peroxidation. Lf peptides demonstrated greater antioxidant activity in the superoxide scavenging and FRAP assays. Low-molecular-weight peptides (<10 kDa) contributed most to antioxidant activity, while mass spectrometry analysis revealed peptide sequences rich in hydrophobic and electron-donating amino acid residues, providing mechanistic insight into the observed activities. Overall, these findings highlight the potential of lactoferrin and its enzymatic hydrolysates as natural antimicrobial and antioxidant agents for food preservation. Full article

Background/Objectives: Bacterial conjunctivitis is a common ocular infection requiring prompt treatment, particularly in vulnerable patients, and may influence perioperative outcomes. This study aimed to characterize conjunctival bacterial isolates phenotypically and genotypically, to evaluate their biofilm-forming capacity, and to investigate the relationship between resistance gene carriage, resistance phenotypes, and biofilm-associated antimicrobial resistance (AMR). Methods: A prospective, single-center, cross-sectional study was conducted on bacterial isolates from conjunctival samples of patients examined in an ophthalmology department. Antimicrobial susceptibility testing (AST) was performed to determine the minimum inhibitory concentrations (MICs). Resistance genes were detected by quantitative PCR. Biofilm-forming capacity was assessed using the microtiter plate assay, and biofilm susceptibility to amikacin (AK) and levofloxacin (LEV) was evaluated using a biofilm susceptibility assay. Results: A total of 78 isolates were analyzed; Gram-positive cocci prevailed (GPC, 84.6%), being significantly more frequent than Gram-negative bacilli (GNB, p < 0.001). Among GPC, 65.2% were multidrug-resistant, with Staphylococcus epidermidis emerging as the most frequent species (p < 0.001). Resistance gene carriage was detected in 33.3% of GNB. Strong biofilm formation was observed in 22.7% of GPC versus 58.3% of GNB. It should be noted that the relatively small number of GNB may limit the statistical robustness of comparisons between Gram-positive and Gram-negative groups. A statistically significant association between resistance genes and biofilm capacity was found only in Staphylococcus aureus (p = 0.027). Biofilm-embedded bacteria showed increased antimicrobial tolerance, particularly for AK in S. aureus and for both AK and LEV in S. epidermidis (p < 0.001). Conclusions: The prevalence of multidrug-resistant conjunctival isolates and their biofilm-forming capacity highlights the clinical importance of biofilm-related resistance and support integrating AMR profiling with biofilm assessment to optimize empirical therapy in bacterial conjunctivitis. Full article

Rapid and actionable pathogen identification remains a major unmet need in the diagnosis of prosthetic joint infection (PJI). Current diagnostic approaches either provide rapid host response information without pathogen specificity or identify pathogens with delays of days to weeks. Here, we report a chemiresistive nanosensor array combined with machine learning analysis for same-day, pathogen-specific detection based on volatile organic compound (VOC) profiling. A 19-channel nanosensor array was first validated in vitro against a panel of ESKAPEE pathogens, achieving 96% mean classification accuracy using a radial-basis-function support vector machine (SVM) classifier. Data-driven optimization yielded a reduced six-sensor array with high signal-to-noise performance. The optimized platform was evaluated using pooled, uninfected human synovial fluid enriched 1:1 with nutrient media and spiked with Staphylococcus aureus, Staphylococcus epidermidis, or Pseudomonas aeruginosa across a range of 1–10⁶ CFU/mL. All infected samples were detected within 9 h, with distinct VOC signatures enabling accurate pathogen differentiation. Time-to-detection (TTD) demonstrated a strong inverse correlation with initial bacterial concentration, supporting semi-quantitative estimation of bacterial load. Negative controls remained at baseline throughout testing. This chemiresistive VOC-based biosensor platform demonstrates the potential to deliver rapid, integrated detection, identification, and burden estimation of metabolically active PJI pathogens, highlighting its promise for future point-of-care diagnostic applications. Full article