Search Results (4,993)

Origanum L. (Lamiaceae) is a commercially important medicinal and aromatic plant genus worldwide. Endophytic bacterial communities are recognized for promoting plant growth and physiology, although their interactions with host metabolism remain insufficiently understood. In this work, an in vitro model of axenic Origanum heracleoticum plants was established to investigate the relationship between endophytic bacteria and their tissue of origin. Specifically, we evaluated the adaptation of two strains, Bacillus sp. OHL2 and Pseudomonas sp. OHS18, and the potential role of Bacillus sp. OHL2 in modulating plant physiology and secondary metabolism. Bacterial inoculation and re-isolation highlighted niche-specific adaptation and possible co-evolution within the host, suggesting an active role of the plant in regulating bacterial colonization within the endosphere. Inoculation with Bacillus sp. OHL2 significantly enhanced photosynthetic rate, leaf area, dry weight, and chlorophyll content. No substantial overall changes in secondary metabolism were detected. Rosmarinic acid was the predominant phenolic, while monoterpenes dominated, with carvacrol dominant. A significant tissue-by-inoculation interaction was observed for α-humulene, which decreased in leaves of inoculated plants. Overall, the in vitro system provides a valuable platform to study plant–endophyte interactions and bacterial mechanisms underlying the stimulation of plant growth and metabolic responses. Full article

Chronic obstructive pulmonary disease (COPD) represents a major global health issue, characterized by persistent airflow limitation, chronic inflammation, and progressive tissue remodeling. Its clinical and molecular heterogeneity, combined with the lack of resolutive therapies, underscores the urgent need for advanced experimental tools to improve understanding and therapeutic development. Traditional 2D cell culture systems, though historically useful, fail to replicate the complexity of the human lung. In this review, we analyze the remarkable relevance of advanced 3D models for studying COPD pathophysiology, including epithelial injury and regeneration, extracellular matrix remodeling, and interactions with environmental triggers such as cigarette smoke and airborne pollutants. Three-dimensional in vitro models, such as ALI cultures, lung organoids, and lung-on-a-chip platforms, PCLS, and lung ECM-derived hydrogels offer more physiologically relevant environments to investigate epithelial dysfunction, immune responses, and host-pathogen interactions. We discuss the contribution of viral and bacterial infections to COPD exacerbations, and explore how 3D models have become essential tools for modeling these events. We also highlight recent advances in personalized medicine that use patient-derived organoids and ALI cultures for drug screening and biomarker discovery. Furthermore, we examine the therapeutic potential of probiotics and extracellular vesicle-associated microRNAs to modulate inflammation and epithelial repair. Collectively, these innovative systems represent powerful platforms to promote precision medicine in COPD. Full article

Marine microbiomes play an important role in coastal marine environments. This study examined microbial communities in beach waters and sands at six recreational beaches to identify the fingerprints of anthropogenic influences. Samples were collected from four metropolitan areas in the U.S., within Miami, Florida; Seattle, Washington; Newport Beach, California and in Australia within Adelaide. Samples were analyzed for enterococci and fungi by culture. Reverse-transcription droplet digital PCR (RT-ddPCR) was performed for pepper mild mottle virus (PMMoV). Next-generation sequencing was carried out to elucidate the microbial diversity and predict antibiotic resistance. Enterococci concentrations surpassed the U.S. EPA marine water quality guideline value in the seawater samples from Seattle and Adelaide, and fungal concentration exceeded the WHO guideline in the sand of North Star Beach, California. Low levels of PMMoV were detected in seawater and sand from multiple locations. Chloroflexi and Acidobacteria were the most abundant bacterial phyla in sand, while Marinimicrobia and Cyanobacteria dominated in seawater. Beach sand had higher bacterial and fungal diversity than seawater, of which the most abundant fungal genera include taxa of potential pathogens. Predicted antibiotic resistance genes showed high levels of beta-lactam and multidrug resistance genes in all samples. This study contributes to the understanding of anthropogenic impact on the coastal environment, emphasizing the need for human health protection measures. Full article

Background: Healthcare-associated bloodstream infections remain a significant cause of morbidity and mortality in hospitalized children, particularly in intensive care settings. Carbapenem-resistant Gram-negative bacterial (CR-GNB) bloodstream infections and fungemia may present with overlapping clinical features. This can complicate empirical treatment decisions in resource-limited settings. This study evaluated baseline clinical and laboratory characteristics associated with CR-GNB bloodstream infections and fungemia among high-risk pediatric patients. Methods: This retrospective observational cohort study included pediatric patients aged 0–18 years who were evaluated at the time of clinical deterioration and blood culture collection for suspected healthcare-associated bloodstream infection before empirical antifungal therapy initiation for the index episode. Patients who subsequently received empirical antifungal therapy between May 2023 and September 2025 were retrospectively screened. Of the 240 screened patients, 103 met the inclusion criteria and were classified into CR-GNB (n = 56) and fungemia (n = 47) groups based on blood culture results. Clinical, laboratory, and microbiological data were analyzed using univariate and multivariable statistical methods. Results: Observed 90-day all-cause mortality was higher in the CR-GNB group than in the fungemia group (50.0% vs. 29.8%, p = 0.038). Central venous catheter use was more frequent (91.1% vs. 48.9%, p = 0.006), and platelet counts were lower (median: 120 × 10⁹/L vs. 259 × 10⁹/L, p = 0.011) in patients with CR-GNB bloodstream infections. In multivariable analysis, thrombocytopenia (OR: 4.22, 95% CI: 1.35–13.17; p = 0.013) and central venous catheter use (OR: 5.53, 95%: CI 1.89–16.26; p = 0.002) were independently associated with CR-GNB bloodstream infections. The model showed moderate discrimination (AUC = 0.786). Conclusion: In this selected high-risk cohort, thrombocytopenia and central venous catheter use were associated with CR-GNB bloodstream infections. Observed mortality was higher in the CR-GNB group, but this finding should be interpreted with caution as adjusted mortality analysis and standardized severity assessment were not performed. These findings are hypothesis-generating and require validation in larger prospective studies before guiding empirical treatment decisions. Full article

Background: Peri-implant infections remain a major cause of dental implant failure, largely due to bacterial adhesion and biofilm formation on implant surfaces. This study aimed to investigate how surface topography influences bacterial colonisation and osteoblastic response. Methods: Titanium discs with machined (Ma), sandblasted, large-grit, and acid-etched (SLA), and nanostructured (Nano) surfaces were prepared, sterilised, and seeded with pre-differentiated dental follicle mesenchymal stem cells. Co-cultures with Enterococcus faecalis (E. faecalis) and Streptococcus oralis (S. oralis) were established under CO₂-free conditions, and cell–bacteria interactions were evaluated using fluorescence microscopy and quantitative image analysis. Results: Nano surfaces showed the highest osteoblastic adhesion and viability, while significantly reducing bacterial proliferation and biofilm formation compared with Ma and SLA surfaces. The sequence of colonisation influenced cell–bacteria dynamics, with early cell attachment limiting subsequent bacterial adhesion. Conclusions: Nano titanium surfaces may offer a dual benefit by promoting osseointegration while limiting bacterial adhesion. These findings support their potential use as surface modifications to reduce peri-implant infection risk and improve long-term implant success. Full article

Background: Public fitness facilities are high-contact environments that facilitate microbial transfer via shared surfaces; however, temporal dynamics and device-specific contamination patterns remain insufficiently characterized. Methods: A repeated-measures observational study was conducted in a fitness facility over five consecutive weekdays (Monday to Friday). A total of 180 surface samples were collected from 12 gym devices, each sampled three times daily (morning, noon, and evening). Surface-associated cultivable bacteria were recovered using culture-based methods followed by MALDI-TOF MS identification. Ecological metrics, including species richness and Shannon diversity, were calculated, and taxa were classified by origin (skin-associated versus environmental). Device-specific contamination profiles were developed using a composite index incorporating pathogen presence, contamination frequency, and persistence. Temporal trends and predictors of contamination were analyzed using mixed-effects regression models. All statistical analyses were performed in R. Results: A total of 248 bacterial isolates were identified, representing 61 species across 32 families, with a predominance of skin-associated taxa (72.2%). Sampling time point was a strong independent predictor of contamination (adjusted OR for noon vs. morning: 7.19; p < 0.001). While overall microbial diversity remained stable across devices (Shannon index, p = 0.44), substantial heterogeneity was observed in pathogen prevalence, multispecies burden, and persistence. The functional trainer and leg extension showed the highest composite risk scores (42.3%), while the ab crunch machine and upper body ergometer demonstrated significantly increasing contamination trends over the sampling period (p < 0.05). Co-occurrence analysis showed nonrandom microbial associations, with the strongest positive links between Micrococcus luteus and Staphylococcus saprophyticus (Φ = 0.76) and Staphylococcus aureus (Φ = 0.61). Conclusions: Gym equipment surfaces harbor predominantly human-associated microbial communities exhibiting dynamic temporal contamination patterns, and on selected devices, increasing the baseline contamination across consecutive cleaning cycles. The findings indicate that contamination patterns on shared fitness equipment are dominated by taxa commonly associated with human skin and support targeted hygiene interventions focused on frequently contacted devices and periods of elevated contamination. Full article

Background: Atopic dermatitis is a chronic inflammatory skin disease in children, frequently associated with skin barrier dysfunction, immune dysregulation, and dysbiosis. Infected, treatment-resistant lesions may increase disease severity and complicate management, particularly in the presence of Staphylococcus aureus colonization. Objectives: To characterize the microbiological profile of infected, non-responsive pediatric atopic dermatitis, evaluate short-term clinical outcomes following individualized treatment, and identify predictors of disease severity. Methods: This observational analytical study included 41 children with atopic dermatitis recruited at Saint Constantin Hospital, Brașov, Romania, between September 2025 and February 2026. Eligible patients fulfilled the Hanifin and Rajka criteria and presented with infected, treatment-resistant lesions. Skin cultures were subjected to an antibiogram and antifungigram. Disease severity was assessed using the Patient-Oriented Eczema Measure (POEM) and SCORAD at baseline, 7 days, and 30 days. Repeated-measures ANOVA, mixed ANOVA, and hierarchical linear regression were used for statistical analysis. Results: Staphylococcus aureus was the predominant pathogen, followed by other bacterial species. Both POEM and SCORAD scores improved significantly over the 30-day follow-up, with marked improvement after 7 days and further reduction by day 30. Although patients with S. aureus colonization and those receiving systemic therapy tended to have higher disease severity, neither factor significantly influenced the trajectory of clinical improvement. Baseline disease severity was the strongest predictor of 30-day POEM and SCORAD outcomes, whereas demographic and perinatal characteristics did not independently predict short-term clinical outcomes. Conclusions: Individualized management was associated with significant improvements in clinician-assessed disease severity and patient-reported symptoms during the 30-day follow-up. Staphylococcus aureus, particularly methicillin-sensitive S. aureus (MSSA), was the most frequently isolated pathogen. Baseline disease severity was the strongest predictor of short-term clinical outcomes, whereas the evaluated demographic and perinatal characteristics did not provide additional predictive value in this cohort. Larger prospective controlled studies are needed to confirm these findings. Full article

The increasing global demand for energy has intensified the need for lithium, a critical component in rechargeable batteries and electric vehicles. However, conventional lithium extraction methods are associated with significant environmental impacts. In this study, a one-step bioleaching approach for lithium recovery from mineral concentrates was evaluated using native microbial consortia and isolated bacterial strains. A suitable culture medium was selected, individual strains were isolated, and bioleaching experiments were conducted using a Box–Behnken experimental design. Lithium solubilization and cell density were assessed under different agitation conditions, pulp concentrations, and initial pH values. The highest lithium solubilization (99%) was achieved under non-agitated conditions, with a pulp concentration of 30% and an initial pH of 6. Three bacterial strains (ITDB101, ITDR102, and ITDN103) were identified. The native microbial consortium and the biotic control exhibited the highest lithium solubilization efficiencies (94.5% and 96.3%, respectively), outperforming the individual strains, which achieved solubilization values ranging from 91.73% to 93.27%. X-ray diffraction analysis identified five mineral phases in the concentrate, and comparisons among treatments revealed changes in these phases following bioleaching, supporting the potential of this process as an environmentally friendly alternative for lithium extraction. Full article

Background/Objectives: Abnormal vaginal discharge (AVD) is a common complaint among women of reproductive age, often involving multiple, overlapping etiologies, most commonly bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), aerobic vaginitis (AV), and sexually transmitted infections (STIs). We aimed to evaluate a syndromic diagnostic approach by developing qPCR-derived dysbiosis indices for BV, VVC, and AV, subsequently comparing their performance against established reference methods and clinician-assigned diagnoses. Methods: Vaginal swabs were collected in a case–control design from 74 symptomatic and 64 asymptomatic women at two clinics in Slovenia. Commercial qPCR assays quantified the microbial species associated with AVD. Relative abundances were integrated into novel dysbiosis indices. Diagnostic performance was validated against the Nugent scoring system (for BV), semiquantitative Candida culture with clinical symptoms (for VVC), and Hay–Ison criteria (for AV). Results: In this internally validated study, dysbiosis indices demonstrated high agreement with their respective reference tests and outperformed clinician-assigned diagnoses across all three conditions. The syndromic approach further revealed that mixed etiologies were frequent, leading to a diagnostic resolution for this patient subset. Conclusions: qPCR-based microbial dysbiosis indices offer a robust alternative to microscopy, particularly in settings where microscopy is not routinely performed. This method improves the accuracy of AVD evaluation and supports more targeted clinical management. Full article

The aim of this study was to isolate and molecularly identify lactic acid bacteria (LAB) associated with the epiphytic microflora and silage of wheatgrass (Agropyron spp.), as well as to evaluate their biotechnological potential as starter cultures for the ensiling of difficult-to-ensile forage crops under the climatic conditions of northern Kazakhstan. A total of 63 bacterial isolates were obtained and grown on MRS medium under different temperature conditions. Based on growth characteristics, pH values, and titratable acidity, 15 highly active strains were selected, demonstrating stable acidification (pH 3.99–4.75) and high metabolic activity. All isolates were catalase negative and capable of fermenting a wide range of carbohydrates and polyols, although pronounced strain-specific differences were observed. The selected strains exhibited proteolytic and antagonistic activity against test microorganisms and showed high tolerance to osmotic stress, maintaining growth at NaCl concentrations of up to 8–10%. Molecular identification based on 16S rRNA gene sequencing revealed that nine technologically significant strains belonged to the species Lactococcus garvieae, Pediococcus acidilactici, Lactiplantibacillus plantarum, Enterococcus faecalis and Enterococcus faecium. The results obtained in this study demonstrate the high environmental adaptability of the isolated strains and confirm their potential for the development of effective microbial inoculants aimed at improving fermentation processes and enhancing the preservation of difficult-to-ensile forage crops under cold-climate conditions. Full article

Temperature is a key factor shaping microbial growth and community structure, but the effects of fine-scale temperature differences remain insufficiently characterized. A Peltier-based PCR thermocycler was used as a precise micro-incubation platform (±0.1 °C) to evaluate responses of a commercial lactic acid bacterial starter culture at 1 °C intervals. Starter suspensions were incubated at 3, 4, 5, 36, 37, and 38 °C for 48 h, and species-level community composition was assessed by V3–V4 16S rRNA gene sequencing. Low-temperature conditions produced stable communities, whereas high-temperature conditions induced significant species-level differences among 36–38 °C groups, particularly for Limosilactobacillus reuteri, Limosilactobacillus fermentum, Lactobacillus helveticus, and Lactiplantibacillus plantarum (FDR < 0.01). At 37 °C versus 38 °C, the relative abundance of Limosilactobacillus reuteri increased from 4.56% to 9.31% (a 2.04-fold change), while the relative abundance of Limosilactobacillus fermentum decreased from 64.00% to 48.58%. These results highlight condition-dependent temperature sensitivity in lactic acid bacterial communities, with compositional responses differing markedly between the cold (3–5 °C) and warm (36–38 °C) ranges tested. Full article

Background/Objectives: Bacterial contamination of the surgical field during shoulder arthroplasty may contribute to periprosthetic joint infection (PJI), yet data on intraoperative bacterial load and its clinical correlates remain limited. This study aimed to evaluate culture positivity and bacterial load in specimens collected at the end of reverse total shoulder arthroplasty (RTSA) and to explore their association with patient-related factors. Methods: Fifty-five patients undergoing elective RTSA were consecutively enrolled. At the end of surgery, three specimens per patient (two prosthetic swabs and one periprosthetic tissue sample) were collected for qualitative and quantitative microbiological analysis. Associations between bacterial load and clinical variables were assessed using mixed-effects linear regression models, while time to culture positivity was analysed using mixed-effects Cox regression models. Results: Among 165 specimens, Cutibacterium acnes was isolated in 42.4% and coagulase-negative staphylococci in 29.1%. C. acnes showed significantly higher bacterial loads (1.38 × 10³ CFU/mL) compared with aerobic bacteria (6.54 × 10¹ CFU/mL). Higher C. acnes load was associated with male sex, older age, higher body mass index, smoking, and cuff tear arthropathy, whereas massive rotator cuff tear and longer time to positivity were inversely associated. Aerobic bacterial load was primarily associated with longer surgical duration. Time to positivity was shorter for aerobes than for C. acnes. Conclusions: Intraoperative bacterial contamination during RTSA is frequent and characterized by marked differences in bacterial load and growth kinetics. Quantitative assessment of bacterial burden may improve the interpretation of unexpected positive cultures. Full article

Bovine mastitis caused by Streptococcus uberis (S. uberis) remains a major challenge of dairy production system worldwide. This study aimed to develop a colorimetric loop-mediated isothermal amplification (LAMP) assay and a conventional PCR assay targeting the 16S rRNA gene for detection of S. uberis in bovine milk. Both assays were evaluated with a simplified HotSHOT (HS) DNA preparation method that can be completed in under 10 min and was compared with a commercial DNA extraction kit before LAMP and PCR testing. LAMP reactions using HS-extracted DNA required an extended incubation time of 30 min, compared with the standard 60 min, to account for the crude DNA preparation. Using tenfold serial dilutions of purified DNA in nuclease-free water, the limit of detection was 1.84 × 10⁻⁴ ng/µL for LAMP and 1.84 × 10⁻⁵ ng/µL for PCR. In pasteurised milk spiked with S. uberis DNA and extracted by HS, the limit of detection was 10 ng/mL for LAMP and 1 ng/mL for PCR. Using the commercial kit, both methods achieved 1 ng/mL. Among 17 culture-confirmed clinical milk samples extracted by HS, LAMP detected S. uberis in 14 samples (82.35%; 95% CI: 0.56 to 0.96), while PCR detected 15 samples (88.24%; 95% CI: 0.64 to 0.99), with no significant difference between methods (McNemar’s test, p > 0.05). Both LAMP and PCR showed 100% analytical specificity against 10 non-target bacterial species under the conditions tested. These findings support HS combined with colorimetric LAMP as a practical diagnostic workflow that warrants further validation under field conditions. Full article

Perennially ice-covered lakes in the McMurdo Dry Valleys, Antarctica, are shaped by permanent stratification, extreme oligotrophy, and salinity gradients, yet these features are vulnerable to climate-driven hydrologic change. Because phytoplankton and associated bacteria regulate carbon flow and nutrient cycling, understanding how algal–bacterial consortia respond to disturbance is key to predicting ecosystem change. We used enrichment cultures from Lakes Bonney and Fryxell to test responses to nutrient deprivation and salinity alteration, two perturbations relevant to climate-driven changes in hydrologic connectivity and expansion of open water moats. Autotrophic enrichments lacking added organic carbon were used to enrich algal–bacterial consortia dependent on photosynthetically derived substrates. Community responses were assessed with 16S rRNA amplicon sequencing of size-fractionated samples, allowing comparison of particle-associated and planktonic communities. Short-term nutrient limitation produced only limited shifts in community composition, indicating resistance to transient nutrient stress. However, bacterial communities were strongly structured by size fraction: particle-associated assemblages separated clearly from planktonic communities and were enriched in taxa linked to algal surfaces and polysaccharide-rich microhabitats, including Flavobacteriales, Sphingobacteriales, Rhizobiales, and Rhodobacterales. Salinity perturbation drove stronger restructuring of bacterial communities, with shallow Lake Bonney enrichments showing greater sensitivity than deeper communities. These findings suggest that algae-associated bacterial communities help structure Antarctic algal enrichment cultures and may influence microbial responses to climate-linked disturbance. Full article

Foodborne bacterial pathogens, including S. aureus, L. monocytogenes, C. sakazakii, and M. bovis, pose significant threats to dairy safety and public health. Current detection methods, such as culture-based techniques and real-time quantitative PCR (qPCR), are either time-consuming or limited in absolute quantification accuracy. Herein, we developed and validated a novel quadruplex droplet digital PCR (ddPCR) assay for simultaneous detection and absolute quantification of these four pathogens in dairy products. The assay targets the femA, hly, ompA, and esxA genes, respectively, with optimized primer/probe concentrations of 500 nM/400 nM and an annealing temperature of 58 °C. The established method demonstrated high specificity, with no cross-reactivity against common dairy-associated bacteria. The limits of detection (LoDs) ranged from 7.04 to 10.31 copies/reaction, with coefficients of variation (CVs) below 14% for intra-assay and 10% for inter-assay repeatability. Notably, the ddPCR assay detected a 25% co-contamination rate compared to 13% by qPCR among 120 dairy samples, suggesting higher sensitivity for low-abundance targets. This quadruplex ddPCR platform offers a rapid, sensitive, and high-throughput solution for food safety surveillance, particularly in high-risk dairy matrices such as infant formula. Full article