Search Results (5,244)

Honey antibacterial activity reflects both the properties of the honey matrix and the susceptibility of the target microorganism, but the consistency with which these sources of variation are reflected across antimicrobial endpoints remains insufficiently characterised. This study investigated whether species-dependent differences in antibacterial responses were detected more consistently than differences among declared botanical honey types and whether the integration of antimicrobial and biochemical traits could reveal botanical-type-associated bioactivity patterns not apparent from individual endpoints. Thirty-seven honey samples representing seven declared botanical types from Western Pomerania, Poland, were analysed for total phenolic content (TPC), ferric-reducing antioxidant power (FRAP), operational minimum inhibitory concentration producing ≥90% growth inhibition (MIC90), and minimum bactericidal concentration (MBC) against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Proteus vulgaris. Buckwheat honeys showed the highest observed TPC and FRAP values among the analysed samples. Species-dependent differences in MIC90 and MBC were detected more consistently than differences among declared botanical types, whereas significant botanical-type effects for individual antimicrobial endpoints were observed only for S. aureus. P. vulgaris was generally the most susceptible species, although susceptibility patterns differed between inhibitory and bactericidal endpoints. Associations between biochemical parameters and antimicrobial activity were limited and directionally inconsistent. In contrast, the integration of five MIC90 variables, five MBC variables, FRAP activity, and TPC revealed significant botanical-type-associated structuring of the overall bioactivity profile. This association remained significant after the exclusion of botanical types represented by single samples (pseudo-F = 2.66, R² = 0.283, p = 0.0001), while multivariate dispersion no longer differed significantly among groups. The resulting bioactivity fingerprint should be regarded as a descriptive multidimensional representation of the investigated samples rather than as a validated classification or prediction tool. Within the present dataset, combined species-resolved microbiological and biochemical profiling provided a more comprehensive description of honey bioactivity than individual antimicrobial or biochemical endpoints considered separately. Full article

Endophytic fungi have emerged as an important source of bioactive metabolites. Phallus rubrovolvatus is an edible and medicinal mushroom; however, the diversity and biological activities of its endophytic fungi have not yet been studied. This study aimed to evaluate the diversity of endophytic fungi associated with different parts of P. rubrovolvatus, assess their biological activities, and identify the chemical constituents produced by these fungi. In total, 35 endophytic fungal strains were isolated from the cap, volva, stipe, and indusium of P. rubrovolvatus. These isolates belonged to 2 phyla, 4 classes, and 14 genera, with most strains identified belonging to the genera Penicillium and Cladosporium. The antibacterial and antioxidant activities of crude extracts obtained from endophytic fungal fermentation broth were subsequently evaluated. Among the isolates, HTZST13 and HTZST24 exhibited moderate antibacterial activity against Pseudomonas aeruginosa, with inhibition zone diameters of 13.67 mm and 11.67 mm, respectively. Moreover, two strains HTZSB1 and HTZST29 exhibited the strongest antioxidant activities against ABTS, with free radical-scavenging rates of 97.48% and 93.45%, respectively. Liquid chromatography–mass spectrometry analysis revealed that the crude extract of strain HTZSB1 predominantly contained gibberellin A41 and 20-nor-3α-acetoxy-12-hydroxy-abieta-5,7,9,11,13-pentaene. The crude extract of strain HTZST29 predominantly contained 2β-hydroxyjatropholone and 1-[6-(benzyloxy)-3-(tert-butyl)-2-hydroxyphenyl]ethan-1-one. Together, the findings broaden our understanding of the diversity of endophytic fungi associated with P. rubrovolvatus, highlight their antibacterial and antioxidant potential, and provide a foundation for the further development and utilization of endophytic fungal resources from P. rubrovolvatus. Full article

Medicinal plants in the Acanthaceae family have long been used in Thai traditional medicine. In this study, ethanolic extracts of four plant species, Andrographis paniculata, Thunbergia laurifolia, Acanthus ebracteatus, and Rhinacanthus nasutus, were prepared and their phytochemical and pharmacological properties were evaluated. Total phenolic and flavonoid content assays were used to investigate phytochemical content and phytochemical profiles were characterized with LC-MS, while antioxidant activities were assessed via colorimetric methods. The extracts were also tested for antibacterial activity against several skin pathogens, such as Pseudomonas aeruginosa, Cutibacterium acnes, Micrococcus luteus, Staphylococcus aureus, and methicillin-resistant S. aureus, using agar well diffusion and broth dilution methods. Cytotoxic effects on the RAW 264.7 macrophage cell were assessed using the MTT assay. The extracts were further evaluated for anti-inflammatory activity in an LPS-stimulated RAW 264.7 cell. Inflammatory gene expression was assessed by quantifying the mRNA levels of iNOS, COX-2, TNF-α, IL-1β, IL-6, and NF-κB genes using RT-qPCR. The results revealed that among the four species, T. laurifolia extract showed the highest phenolic and flavonoid levels, consistent with the greatest antioxidant activity. Moreover, LC-MS profiling annotated a range of secondary metabolites in the extracts. The inhibition zones were observed for all plant extracts when tested against the skin pathogenic bacteria except C. acnes, and A. paniculata did not inhibit P. aeruginosa, indicating the antibacterial activity of the extracts. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values differed across the extracts and bacterial strains. T. laurifolia exhibited the most potent activity against various bacterial pathogens, while A. paniculata was most effective against C. acnes at 0.98 mg/mL. In addition, all plant extracts reduced nitric oxide production and downregulated the expression of inflammatory genes. Among all plant species, A. paniculata showed the most potent activity with the highest NO inhibition of 65.68% at 60 µg/mL. Therefore, these findings support the antioxidant, antibacterial, and anti-inflammatory potential of A. paniculata, T. laurifolia, A. ebracteatus and R. nasutus, which are traditionally used in folk medicine. Full article

The presence of antimicrobial-resistant bacteria in fresh produce constitutes a significant public health concern, particularly in rural areas where untreated water is commonly used for irrigation. Certain Enterobacter species have been reported as causal agents of onion bulb rot, with Enterobacter cloacae experimentally demonstrated to cause bulb rot in onions. However, there is poor documentation of its effects in the Vhembe District, South Africa. This study investigated the detection and identification of enteric bacteria in onions, soil, and irrigation water, as well as the characterisation of the identified isolates. Thirty-six samples were analysed, comprising 13 onion samples, 4 irrigation water samples, and 9 soil specimens collected from three farms using selective and differential agar. Identification and enumeration in water and onion samples were performed with the Colilert Quanti-Tray. Physicochemical analysis of irrigation water indicated that Farm 3 had the highest electrical conductivity (EC) and total dissolved solids (TDS), as well as the lowest pH, while Farm 2 exhibited the greatest diversity of pathogenic Escherichia coli pathotypes, including enteroinvasive E. coli (EIEC), which was absent in Farm 3. Culture-based methods yielded 72 presumptive bacterial isolates, which were characterized using the VITEK 2 system. Identified species included Pseudomonas aeruginosa, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter amalonaticus, Raoultella ornithinolytica, and members of the Enterobacter cloacae complex. Phylogenetic analysis revealed that most Enterobacter isolates closely matched reference strains of Enterobacter ludwigii. Antimicrobial susceptibility testing against 19 antibiotics demonstrated varied resistance patterns among the isolates. The Enterobacter cloacae complex exhibited the highest resistance (10/19 antibiotics), followed by Klebsiella pneumoniae (9/19) and Citrobacter amalonaticus (7/19). All isolates were resistant to colistin but remained susceptible to ciprofloxacin, with most also sensitive to gentamicin and amikacin. Future research should include additional farms and investigate antibiotic resistance at the genetic level to elucidate its origins. Full article

Background: β-lactam/β-lactamase inhibitor combinations (BL/BLIs) and siderophore cephalosporin serve as critical polymyxin alternatives for carbapenem-resistant Pseudomonas aeruginosa (CRPA). However, systematic multicenter clinical data from China and the resistance mechanisms underlying non-susceptibility to these agents remain poorly defined. Methods: We collected 442 CRPA isolates from 10 hospitals across eight Chinese provinces (2017–2025), determined minimum inhibitory concentrations (MICs) for cefiderocol (FDC), ceftazidime–avibactam (CZA), imipenem–relebactam (IMR), and ceftolozane–tazobactam (CT) through broth microdilution, and performed whole-genome sequencing. Resistance genes, virulence factors, and sequence types (STs) were identified. A chromosomal co-selection score (eight non-mobile resistance genes) was constructed. Multivariable regression and receiver operating characteristic (ROC) analysis identified predictors of non-susceptibility. Results: Carbapenemase genes were detected in only 33 isolates (7.5%): metallo β lactamase (MBL) genes in 28, bla_KPC-2 in 2, and bla_{GES 5/14} in 3; the ST463 clone was absent. MBL producers were resistant to CZA, IMR, and CT (0–4% susceptible) but 100% susceptible to FDC. KPC 2 and GES producers were CZA-susceptible (100%) but IMR- and CT-resistant. Among 127 CZA non-susceptible isolates, 99 (78%) lacked carbapenemase genes; ST270 (from a single center) accounted for 64.6% of these. The chromosomal score independently predicted MIC (ρ: CT 0.64, FDC 0.59, IMR 0.50, CZA 0.25—largely attributable to ST270; all p < 0.001). ExoU positive isolates had lower MICs (FDC median 0.12 vs. 0.25 mg/L, p < 0.001). FDC remained active against 97.3% of all isolates and 100% of carbapenemase-positive ones. Genotype-based prediction yielded area under the ROC curve (AUC) values of 0.86 (CT) and 0.80 (CZA). Conclusions: Mechanisms other than acquired carbapenemases—consistent with chromosomal determinants—accounted for most non-susceptibility in this predominantly northern Chinese respiratory tract CRPA collection. Carbapenemase types determine distinct drug susceptibility patterns. Routine carbapenemase detection fails to identify most CZA-resistant strains. FDC retained the broadest in vitro activity and is a reliable therapeutic option pending clinical outcome data, and ST270-associated resistance deserves continuous surveillance. Full article

Background: Antimicrobial resistance is a major global health challenge, with multidrug-resistant organisms (MDROs) emerging faster than new antimicrobial agents are being developed. The epidemiology of MDROs varies substantially across healthcare settings; however, newly established hospitals remain understudied. This study aimed to characterise the epidemiology and temporal trends of MDROs in a newly established tertiary hospital. Methods: A five-year retrospective longitudinal surveillance study was conducted from 2019 to 2023 in a newly established tertiary hospital in Southern China. Clinical isolates were collected from intensive care unit (ICU) and non-ICU wards. Nine major MDROs were investigated, including extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) and Escherichia coli (ESBL-ECO); carbapenem-resistant Klebsiella pneumoniae (CRKP), Escherichia coli (CRECO), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPA); methicillin-resistant Staphylococcus aureus (MRSA); and vancomycin-resistant Enterococcus faecium (VREfm) and Enterococcus faecalis (VREfa). Results: A total of 1533 MDRO isolates were identified during the study period. The predominant pathogens were ESBL-ECO (48.1%), ESBL-KP (16.4%), MRSA (11.4%), and CRPA (11.1%). Most isolates were recovered from non-ICU wards (85.4%), and more than half (51.5%) were community-onset. Isolation rates of ESBL-ECO, CRECO, CRAB, and CRPA were significantly higher in the ICU than in non-ICU wards (all p < 0.05). The incidence density rate of hospital-acquired infections caused by ESBL-KP, CRAB, and CRPA was also significantly higher in the ICU (all p < 0.05). Longitudinal analysis revealed divergent trends among MDROs. While most MDRO isolation rates remained below provincial and national benchmark levels, CRKP and CRAB showed significant increasing trends. CRPA exhibited a distinct pattern, increasing rapidly during the early years after hospital opening, exceeding both provincial and national benchmarks by the second year and remaining elevated thereafter. Conclusions: MDRO epidemiology during the first five complete calendar years after hospital opening was characterised by a predominance of ESBL-ECO, ESBL-KP, MRSA, and CRPA, together with substantial non-ICU and community-onset burdens and heterogeneous temporal patterns across organisms. CRPA increased rapidly and remained above the available external benchmark thereafter. These findings highlight the need for hospital-wide, organism-specific MDRO surveillance, while maintaining intensified infection prevention and control in ICUs and continued vigilance for carbapenem-resistant pathogens, particularly CRPA. Full article

Tradescantia pendula is a medicinal plant traditionally used in Mexico to treat inflammatory and infectious conditions. This study evaluated the phytochemical composition, antimicrobial activity, toxicity, and cytotoxicity of T. pendula extracts. Plant material was sequentially extracted using hexane, chloroform, and methanol, followed by phytochemical screening, antimicrobial evaluation against clinically relevant bacterial strains, toxicity assessment using the Artemia salina model, cytotoxicity analysis in HaCaT and U937 cell lines, and GC–MS characterization. Phytochemical screening of the chloroform extract revealed the presence of flavonoids, tannins, triterpenes, and glycosides. Antimicrobial activity was observed mainly against Escherichia coli and Pseudomonas aeruginosa, with bacterial viability reduced by up to 95.2%. Toxicity assays in Artemia salina demonstrated marked biological activity, with LC50 values of 63.54, 23.12, and 23.05 μg/mL for the hexane, chloroform, and methanol extracts, respectively. Cytotoxicity assays revealed cell type-dependent responses, with U937 monocytic cells exhibiting greater sensitivity than HaCaT keratinocytes. All three extracts produced non-monotonic concentration–response profiles, with enhanced metabolic activity at intermediate concentrations and substantial decreases in cell viability at lower concentrations. GC–MS analysis revealed lipophilic metabolites, including phytol-related compounds and fatty acid esters. These findings suggest that T. pendula is a promising source of bioactive metabolites with antimicrobial and cytotoxic properties, supporting its ethnopharmacological relevance and potential pharmacological applications. Full article

Background/Objectives: Pseudomonas aeruginosa is a notorious multidrug-resistant pathogen that causes serious acute and chronic infections by employing quorum sensing (QS)-regulated virulence, biofilm formation, and host-damaging inflammation. To overcome the yield limitation of two previously identified marine secondary metabolites with dual QS inhibitory and PPAR-γ agonistic activities, we further screened marine-derived natural products for more abundant candidates with similar anti-virulence and anti-inflammatory properties. Methods: In this study, isoflavones were evaluated for anti-QS and PPAR-γ transactivation activities using reporter gene assays, and for antibacterial, anti-virulence, and anti-inflammatory effects via broth microdilution, biofilm, G. mellonella infection, and ELISA cytokine assays. Results: Daidzein and genistein were selected for their optimal anti-QS and PPAR-γ activation activities. They inhibited a key QS regulator and suppressed pyocyanin production and biofilm formation in P. aeruginosa without affecting bacterial growth, indicating minimal selective pressure for resistance. In addition, daidzein and genistein were found to synergistically sensitize the wild-type P. aeruginosa strain to gentamicin, carbenicillin, tobramycin, ampicillin, and polymyxin B, and synergistically or partially synergistically sensitize a multidrug-resistant strain to gentamicin, tobramycin, and ampicillin. Moreover, a Galleria mellonella infection model confirmed that daidzein and genistein significantly enhance the efficacy of gentamicin against P. aeruginosa infection in vivo. Furthermore, in host macrophages, daidzein and genistein significantly inhibited LPS-induced production of NO, IL-6, and IL-1β when combined with an RXR agonist, implying a protective effect on host tissues through PPAR-γ activation. Conclusions: These findings demonstrate that daidzein and genistein serve as effective adjuncts to conventional antibiotics, exerting multifaceted actions against P. aeruginosa infection. Full article

Traditional fermented vegetables are important resources for screening excellent antibacterial lactic acid bacteria (LAB). In this study, a strain of Lactiplantibacillus plantarum JC2211 with broad-spectrum antibacterial activity against Salmonella Typhimurium (S.T), Staphylococcus aureus (S.a), Listeria monocytogenes (L.m), and Pseudomonas aeruginosa (P.a) was isolated from Yangzhou pickles. The minimum inhibitory concentration (MIC) of its cell-free supernatant (CFS) against all four pathogens was 25 μL/mL. The strain exhibited favorable biosafety and strong environmental adaptability, tolerating 8% NaCl, pH 3.0–10.0, and 0.3% bile salt. The CFS exerted synergistic antibacterial effects via multiple pathways, including increasing cell membrane permeability, reducing membrane potential, decreasing intracellular ATP levels, and inducing ROS accumulation. Metabolite identification indicated that organic acids (dominated by D-lactic acid at 9.37%, citric acid at 8.00%, and phenyllactic acid at 4.42%) were the main components. Using chitosan (CS) as the base material, composite preservation films were fabricated by incorporating 10–50% CFS. The composite film containing 40% CFS (CS/CFS40) exhibited the optimal comprehensive performance, with ABTS and DPPH radical scavenging rates of 90.24% and 79.17%, respectively, along with satisfactory tensile strength (18.70 MPa) and elongation at break (22.93%). In chilled pork preservation, the CS/CFS40 film significantly inhibited the proliferation of spoilage microorganisms, and effectively retarded lipid oxidation. Moreover, the film suppressed the colonization of L.m and S.T on meat surfaces, with bacterial loads maintained at 2.07–2.67 lg CFU/g and 2.92–2.99 lg CFU/g, respectively, over 7 days of refrigeration. Collectively, the CS/CFS40 composite film extended the shelf life of chilled pork to approximately 6 days. This study provides a novel natural biological preservative and eco-friendly active packaging material for chilled meat preservation. Full article

Species belonging to the genus Seseli have long been known to be used as herbal remedies in traditional medicine for various purposes such as colds, inflammation, pain, and gastrointestinal disorders. Therefore, in this study, the flower parts of Seseli transcaucasicum (Schischk.) Pimenov & Sdobnina were extracted using methanol and acetone to investigate their phytochemical composition and antioxidant, antimicrobial, and cytotoxic activities. For this purpose, total phenolic content (TPC), DPPH free radical scavenging activity (RSA), phenolic component (PCs) profile, volatile component composition, antimicrobial effect, and cytotoxic potential on the HT29 human colorectal adenocarcinoma cell line were evaluated. When the results were examined, HPLC analysis of phenolic components revealed that both extracts contained particularly high levels of rosmarinic acid, catechin, and quercetin. Among these, rosmarinic acid was detected in the highest amount, with 15.195 mg/g in the methanol extract and 14.929 mg/g in the acetone extract. The volatile components of this plant were determined by GC-MS, and a total of 29 volatile compounds were identified. Among these, β-pinene (220.792 mg/kg), Δ3-carotene (81.898 mg/kg), α-sedrene (63.331 mg/kg), elixen (44.535 mg/kg), sabinene (40.822 mg/kg), and D-limonene (38.422 mg/kg) were identified as the most dominant compounds. It was observed that the methanol extract had a higher total phenolic content (77.389 ± 1.389 mg gallic acid equivalent/g extract) and higher free radical scavenging activity (40.933 ± 0.067 mg trolox equivalent/g extract) compared to the acetone extract. Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans strains were used to determine the antimicrobial activities of plant extracts, and moderate inhibitory effects were observed against these microorganisms. The highest antimicrobial activity was determined by the 16 mm inhibition zone created against S. aureus by the methanol extract at a concentration of 100 mg/mL. The cytotoxic activity of the plant was determined by measuring its dose-dependent antiproliferative effect on HT29 cells. When the difference between solvents was examined, it was observed that the acetone extract at a concentration of 500 µg/mL reduced cell viability by 18.03%, while the methanol extract at the same concentration reduced viability by 30.56%. According to the results, S. transcaucasicum is rich in phenolic and terpenic compounds and exhibits antioxidant, antimicrobial, and cytotoxic effects. Therefore, this plant species is considered a promising resource for the development of naturally occurring biologically active compounds. Full article

Mosquito antimicrobial peptides (AMPs) contribute to innate defense against bacteria, fungi, parasites, and, in some experimental contexts, arboviruses. This narrative review evaluates endogenous mosquito AMP families across Aedes, Anopheles, and Culex species and clearly separates them from heterologous peptides introduced into mosquitoes for transmission-blocking studies. The best-supported endogenous families are cecropins, defensins, gambicin, attacin, and diptericin, although gene repertoires vary among mosquito lineages. Mechanistic evidence is strongest for membrane interaction by individual cecropins and defensins. Evidence for intracellular or redox mechanisms is more limited and peptide- and assay-specific; for example, mitochondrial effects have been demonstrated for Anopheles albimanus cecropin 3 in isolated rat cardiac mitochondria, whereas DNA binding and membrane permeabilization have been shown for an Aedes aegypti cecropin A derivative in Pseudomonas aeruginosa. Scorpine, magainin, and human defensin 5 are not mosquito AMPs and are considered separately as heterologous antiplasmodial effectors. Toll and immune deficiency (IMD) pathways regulate mosquito immune genes through NF-κB-family transcription factors, whereas Janus kinase–signal transducer and activator of transcription (JAK–STAT) is a distinct cytokine-signaling pathway. Translational approaches—including transgenic expression, paratransgenesis, Wolbachia-based control, and peptide engineering—remain promising but require cautious interpretation because efficacy, mechanism, ecological safety, horizontal gene transfer, regulatory oversight, and durability have not been resolved uniformly. By distinguishing direct peptide activity from genetic, expression-only, and inferential evidence, this review provides a more rigorous framework for evaluating mosquito AMPs and their potential use in vector-borne disease control. Full article

Waste cooking oil (WCO) was investigated as a waste-derived reactive precursor for a cured organic binder in highly mineral-filled composites containing turmeric. Ten formulations selected from a broader experimental screening were prepared from WCO, sulfuric acid, quartz sand, and turmeric added at 1–7% relative to the dry mass of quartz sand. Formulation-specific thermal curing was conducted at 190–210 °C for 12–20 h. Because the binder content, acid-to-binder ratio, turmeric content, curing temperature, and curing time varied simultaneously, the study was designed as an exploratory multifactorial screening rather than as a controlled assessment of individual processing variables. FTIR, ¹H NMR analysis of acetone-soluble constituents, TGA, and SEM-EDS were combined with mechanical screening, water-absorption, contact-angle, and microbiological measurements. Bending and splitting tensile strengths ranged from 1.15 to 2.42 MPa and from 0.30 to 0.52 MPa, respectively. Water absorption ranged from approximately 4.8% to 9.0%, while water contact angles exceeded 90° for all investigated formulations. Selected formulations reduced the surviving fraction by more than 90% for Staphylococcus epidermidis and by approximately 70% for Pseudomonas aeruginosa under the applied suspension-assay conditions. The estimated C₅₀ values of 60.6–83.3 mg mL⁻¹ indicated measurable concentration-dependent responses at relatively high nominal composite concentrations. The available results support curing-associated transformation and consolidation of the WCO-derived binder phase but do not quantify crosslink density or retained organic content. Because no matched turmeric-free composite or surface/eluate pH measurements were available, the biological effects are attributed to the complete composite formulations rather than specifically to turmeric or intact curcumin. The results provide an exploratory basis for the further development of waste-derived, non-load-bearing polymer–mineral composites with functional surface and biological properties. Full article

Implant-associated infections remain a major challenge in bone-related biomedical applications, where bacterial colonization and biofilm formation can compromise tissue integration and clinical performance. This study reports the mechanochemical synthesis, physicochemical characterization, antimicrobial activity, antibiofilm performance, and short-term fibroblast cytocompatibility of a TiO₂-containing bovine-derived biogenic hydroxyapatite ceramic composite (BHAp-TiO₂). The composite was prepared by high-energy mechanical milling using 10 wt% TiO₂ and characterized by X-ray diffraction, Rietveld refinement, Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. XRD/Rietveld analysis identified a multiphase ceramic composite composed of hydroxyapatite, whitlockite, and rutile TiO₂, with no evidence of Ti⁴⁺ substitution into the hydroxyapatite lattice or detectable anatase within the XRD/Rietveld detection limit. SEM-EDS confirmed the granular agglomerated morphology of the powders and the elemental presence of Ti in BHAp-TiO₂. Compared with pristine BHAp, BHAp-TiO₂ produced a concentration-dependent reduction in AlamarBlue^®-derived bacterial metabolic activity against five clinically relevant planktonic strains. At 200 µg/mL, residual metabolic activity decreased to 10.90–32.90%, depending on the bacterial species, with the strongest response observed for Escherichia coli. In crystal violet assays, BHAp-TiO₂ markedly inhibited Pseudomonas aeruginosa biofilm biomass, reaching 91.9 ± 3.4% inhibition at 200 µg/mL. In NIH/3T3 fibroblasts, BHAp-TiO₂ preserved short-term cytocompatibility after 24 h of direct exposure within the 0.1–100 µg/mL range, with MTT- and AlamarBlue^®-derived responses remaining close to or above the 80% cytotoxicity limit. Overall, BHAp-TiO₂ is best interpreted as a rutile TiO₂-containing biogenic calcium phosphate ceramic composite with enhanced antimicrobial and antibiofilm performance while maintaining short-term fibroblast cytocompatibility under the evaluated conditions. Full article

Background: Canine otitis externa caused by Pseudomonas aeruginosa is frequently chronic and treatment refractory, yet integrated historical phenotype–genotype data remain limited. We characterized an archival Hungarian collection obtained in 2010 and 2017. Methods: Broth microdilution minimum inhibitory concentrations (MICs) were determined for 67 isolates against 13 antimicrobial agents and chlorhexidine, and 59 isolates had matched long-read whole-genome assemblies. Resistance-associated determinants were identified using the Comprehensive Antibiotic Resistance Database, and their predicted proximity to mobile genetic elements and plasmid-like contigs was evaluated. Results: Current canine Clinical and Laboratory Standards Institute breakpoints classified 59/67 isolates (88.1%) as enrofloxacin resistant and 43/67 (64.2%) as marbofloxacin resistant. European Committee on Antimicrobial Susceptibility Testing epidemiological cut-off values identified non-wild-type subsets for ciprofloxacin (7/67), tobramycin (4/67), imipenem (1/67), and piperacillin–tazobactam (51/67), whereas all isolates remained within the available wild-type distributions for ceftazidime, gentamicin, and amikacin. No continuous MIC distribution changed significantly between sampling years after false-discovery-rate correction, although categorical marbofloxacin resistance decreased from 87.5% in 2010 to 42.9% in 2017. Resistance-gene screening identified 64 unique determinants, including near-universal efflux-system components, PDC and OXA-50-like β-lactamases, APH(3′)-IIb, arnA, and basS. The fluoroquinolone-associated determinant crpP occurred in 37/59 genomes and was located on plasmid-predicted contigs in six isolates. No determinant–MIC association remained significant after correction for multiple testing. Conclusions: The discordance between conserved resistance-gene repertoires and heterogeneous MICs demonstrates that sequence-based detection alone is insufficient for therapeutic inference. Integrated phenotypic and genomic surveillance is therefore required to support evidence-based antimicrobial stewardship in canine pseudomonal otitis. Full article

Background: Antimicrobial resistance (AMR) remains a major public health threat in Italy, where high incidence and mortality persist. In this study we aimed to describe national and regional trends in AMR rates from 2015 to 2024. Methods: We conducted an ecological time-series analysis using publicly available data from the Italian AMR surveillance system (AR-ISS). We included six priority pathogens: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE-faecium), third-generation cephalosporin-resistant Escherichia coli (3GCREC), carbapenem-resistant Klebsiella pneumoniae (CRKP), Pseudomonas aeruginosa (CRPA), and Acinetobacter spp. (CRAS). We analyzed annual resistance rates at national and regional level. Temporal trends were estimated using linear regression models, with calendar year as the independent variable. Regression coefficients, 95% CIs, and p-values were used to assess direction and significance. Relative percentage changes were calculated for 2015–2024 and, when relevant, for 2023–2024. Results: Resistance declined over time for four of six pathogens, but increased markedly for VRE-faecium, from 11.1% to 34.9%. Significant downward trends were observed for MRSA (β = −0.91, 95% CI: −1.35; −0.48, p = 0.0013), 3GCREC (β = −0.53, 95% CI: −0.99; −0.06, p = 0.0304), CRKP (β = −0.94, 95% CI: −1.35; −0.53, p = 0.0008), and CRPA (β = −0.86, 95% CI: −1.44; −0.27, p = 0.0095); VRE-faecium showed a strong upward trend (β = +2.76, 95% CI: 2.58; 2.94, p < 0.0001). CRAS remained consistently high throughout the study period. Considerable regional heterogeneity was observed across pathogens and geographical areas. Conclusions: Despite progress for several pathogens, AMR remains a critical challenge in Italy. The persistent increase in VRE-faecium and the high burden of CRAS support the need for strengthened surveillance, stewardship, and region-specific infection prevention interventions. Full article