Search Results (1,274)

Hafnia alvei, which belongs to the Enterobacteriaceae family, has been occasionally documented in animal infections but is still not well characterized in the context of bovine mastitis. This research examined the prevalence and antimicrobial resistance characteristics of H. alvei in dairy cows suffering from subclinical mastitis in South Africa’s Free State Province. In the Thabo Mofutsanyana District, a total of 174 milk samples were obtained from cows on six different dairy farms. The California Mastitis Test (CMT) was used to screen for subclinical mastitis, and somatic cell count was used to confirm it. Standard culture methods were used for bacterial isolation, and presumptive Enterobacteriaceae isolates were identified through matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Out of the 174 samples, 84 (48.2%) tested positive for CMT, and 68 (39.1%) met the SCC criteria for subclinical mastitis at a cow level, while 96/336 (28.5%) were infected at a quarter level. Of the 100 presumptive Enterobacteriaceae isolates, 33 (33.0%) were identified as H. alvei (p = 0.0034). Antimicrobial susceptibility testing showed that 50% of the isolates were resistant to penicillin, followed by tetracycline and erythromycin with 25% and 10%, respectively. Furthermore, the results showed that 17 (51.5%) isolates exhibited multidrug-resistant profiles. The results suggest that H. alvei could be a contaminant in raw milk associated with bovine subclinical mastitis in this area, necessitating additional epidemiological research that includes healthy matched controls. Full article

Background/Objectives: Severe and recurrent infections due to multidrug-resistant (MDR) Pseudomonas aeruginosa necessitate alternative antimicrobial strategies. Fermented cacao beans represent a niche microbial ecosystem with the potential to harbor beneficial lactic acid bacteria (LAB). This study aimed to isolate and characterize LAB strains from fermented cacao beans in southern Thailand and to evaluate their probiotic potential and antimicrobial activity against MDR P. aeruginosa. Methods and Results: Five Lactiplantibacillus plantarum isolates were identified via MALDI-TOF MS and whole-genome sequencing (WGS). All strains demonstrated antimicrobial activity against 17 clinical MDR P. aeruginosa isolates and CR14 exhibited the largest inhibition zone. The isolates displayed robust probiotic traits, including survival under simulated gastrointestinal conditions. Acid tolerance (pH 2.0) reached 61.15 ± 7.75%, while resistance to pepsin, pancreatin, and bile salts exceeded 88%, 91%, and 92%, respectively. Strong adhesion was confirmed via auto-aggregation (55.02 ± 1.75%), hydrophobicity (45.58 ± 0.96%) and Caco-2 cell attachment (up to 98.11 ± 3.28%). WGS revealed multiple plantaricin-encoding clusters. Coarse-grained molecular dynamic simulations showed that two-peptide plantaricins (plnJ/K and plnNC8-αβ) self-assembled and formed stable pores in bacterial membrane models, confirming a pore-forming antimicrobial mechanism. The strains lacked acquired resistance genes and virulence factors, confirmed by in silico safety assessments. Conclusions: Thus, these L. plantarum strains are promising probiotics for managing MDR P. aeruginosa via functional foods or adjunct therapies. Full article

Clostridium tertium is an emerging opportunistic pathogen typically associated with immunocompromised hosts, yet it can also cause serious infections in non-neutropenic individuals. We present a case of postoperative peritonitis and bacteremia caused by C. tertium in a non-neutropenic 75-year-old woman following emergency obturator hernia repair. Diagnosis was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and successful treatment was achieved with piperacillin–tazobactam combined with levornidazole alongside surgical source control. A review of 128 cumulative cases (including ours) revealed two distinct patterns: bacteremia in severely neutropenic patients versus a broader spectrum of localized and bloodstream infections in non-neutropenic hosts, often linked to intestinal barrier disruption. Mortality was largely driven by underlying comorbidities and polymicrobial sepsis. These findings indicate that C. tertium infection should be considered in non-neutropenic patients with postoperative or gastrointestinal barrier-disruptive infections, especially when there is a poor response to initial empiric therapy. Consequently, in such clinical scenarios, empirical therapy should be guided by its unique resistance pattern, favoring carbapenems, vancomycin, or piperacillin–tazobactam, often combined with a nitroimidazole, alongside urgent source control. Full article

Hyaluronic acid (HA)–based nanocapsules containing plant-derived bioactives are promising formulations for dermatological applications. In this study, nanocapsules containing extracts of Arnica montana, Calendula officinalis and Aesculus hippocastanum were synthesized and their structural and functional properties were characterized. Scanning electron microscopy confirmed the formation of spherical nanostructures with uniform morphology, while rheological analyses demonstrated stable viscoelastic behavior suitable for topical application. Their antimicrobial potential was assessed on microorganisms isolated from multiple regions of healthy human skin and opportunistic pathogens. A diverse panel of approx. 100 bacterial and fungal isolates was identified using MALDI-TOF MS. The antimicrobial activity of formulations was compared with commonly used disinfectants: H₂O₂, octenidine, isopropanol and topical ophthalmic antiseptic. Arnica-based formulations showed the strongest inhibitory effect against both Gram-positive and Gram-negative bacteria, whereas chestnut extract demonstrated selective activity against Candida spp. Calendula-based formulations exhibited limited antimicrobial activity. These findings demonstrate that plant-extract-loaded HA nanocapsules exhibit selective antimicrobial properties dependent on extract type and microbial group, supporting their potential as multifunctional components of future dermatological formulations. Full article

Hepatitis B virus (HBV) remains a major global public health challenge, and its early screening is essential for controlling transmission and improving treatment outcomes. We analyzed serum samples from 422 participants via Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to establish a screening model for hepatitis B surface antigen (HBsAg)-positive status. Following multi-bin preprocessing and single-sample spectral aggregation, we assessed three machine learning algorithms—random forest, deep neural network, and light gradient boosting machine (LightGBM). Among them, the LightGBM model achieved the best performance, with an optimized F1 score of 0.87 and an area under the receiver operating characteristic curve (AUC) of 0.94. A 100-iteration ensemble feature stabilization strategy identified twelve distinct m/z peaks as stable biomarkers for HBsAg-positive screening. Independent validation yielded sensitivity of 77.7% and specificity of 76.0%—insufficient for individual diagnosis but potentially suitable for population-level surveillance programs combined with confirmatory testing, particularly in resource-limited settings where conventional methods are impractical. Notably, the method offers a detection time of approximately one minute, a per-sample cost of ~$0.14. In conclusion, the combination of MALDI-TOF MS and machine learning enables a rapid, low-cost screening tool for large-scale HBV detection. Full article

Nontyphoidal Salmonella (NTS) is a zoonotic pathogen that threatens public health worldwide. This study investigated the prevalence, serotype, virulence, and antimicrobial resistance of NTS isolated from chicken meat in Fukuoka, Japan. Of 50 samples, 64% were positive for Salmonella spp., and 32 NTS strains were isolated from positive samples. Serotyping identified three serotypes: S. enterica ser. Schwarzengrund (78.1%), S. enterica ser. Thompson (15.6%), and S. enterica ser. Oranienburg (6.3%). Multilocus sequence typing revealed three sequence types (STs), and MALDI-TOF MS analysis revealed six distinct clusters, reflecting heterogeneity in protein expression among isolates with the same STs. All isolates harbored the virulence genes hilA, spiC, and ssrB, but not spvC. Microplate assays showed that all S. enterica ser. Schwarzengrund and S. enterica ser. Thompson strains formed biofilms with varying strengths. Antimicrobial susceptibility tests demonstrated that S. enterica ser. Thompson and S. enterica ser. Oranienburg strains were sensitive to all the antimicrobials tested. However, S. enterica ser. Schwarzengrund strains showed resistance to multiple antibiotic classes, and 36% of the isolates were multidrug resistant. These findings suggest a potential public health concern, particularly from S. enterica ser. Schwarzengrund, and underscore the importance of continuous surveillance that integrates both genotypic and phenotypic methods. Full article

Background: Rapid diagnostic tests (RDTs) for bloodstream infections (BSIs) reduce time to pathogen identification, yet evidence on their real-world economic and clinical value remains inconsistent. This study aimed to compare clinical outcomes, antibiotic utilization, and hospital costs associated with different rapid microbiological identification methods versus standard culture. Methods: A retrospective observational study was conducted in a tertiary university hospital including 115 hospitalized patients with suspected or confirmed BSIs. Multiplex PCR (mPCR), fluorescence in situ hybridization (FISH), and MALDI-TOF MS were compared with conventional culture. Outcomes included mortality, length of stay, antibiotic-days, and direct and indirect hospital costs. Nonparametric and exploratory adjusted analyses were performed. Results: No significant differences were observed across diagnostic groups for age, sex, mortality, or length of stay. Patients tested with mPCR showed higher empirical and total antibiotic-days and increased antibiotic-related costs (p < 0.05). Median direct and indirect hospital costs were numerically lower with FISH and mPCR but did not reach statistical significance. Adjusted analyses confirmed that diagnostic modality was not independently associated with mortality or costs. Conclusions: Rapid diagnostics accelerate identification but demonstrate heterogeneous downstream clinical and economic effects. Their value appears to depend more on local implementation and antimicrobial stewardship integration than on diagnostic speed alone. Full article

Marine byproducts generated from seafood processing represent valuable reservoirs of structurally and functionally distinct biomolecules, whose composition reflects species, habitat, and processing history. This systematic review identified which marine byproducts have been most extensively studied between 2020 and 2025, with emphasis on their composition, valorisation, and suitability for tracing their geographic origin. Following the PRISMA protocol, 6443 publications were initially retrieved, of which 96 peer-reviewed studies were included for data extraction and analysis. The five most frequently investigated byproducts—skin, bones, scales, shells, and roe—were identified as rich sources of proteins (collagen and gelatin), minerals (hydroxyapatite and calcium carbonate), polysaccharides (chitin), lipids (notably polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)), and vitamin B12. Collagen properties, particularly imino acid content, hydroxylation degree, crosslinking density, and thermal stability, correlate more strongly with environmental temperature than taxonomy, supporting their potential as markers for tracing geographic origin. The mineral fractions, dominated by hydroxyapatite in bones and scales, or calcium carbonate in shells, provided complementary inorganic fingerprints based on calcium-to-phosphorus ratios, carbonate substitution, trace element composition, and thermal analyses. While the lipid profile alone could not completely discriminate fish roe, proteomic techniques, such as MALDI-TOF MS, make it possible to reliably identify species. Collectively, these byproducts offer complementary organic and inorganic markers that support integrated strategies that allow tracing their origin and fostering their sustainable valorisation, overcoming a key technical bottleneck for their use. However, their large-scale conversion into market-ready products remains limited by technical complexity, process variability, and cost-related constraints. Full article

Protein glycosylation plays a pivotal role in breast cancer biology, influencing cell proliferation, adhesion, migration, and immune evasion. Aberrant N- and O-glycosylation are hallmarks of neoplastic transformation and serve as sensitive indicators of disease progression. This review aims to characterize glycoprotein biomarkers in breast cancer identified using Matrix-Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometry. We examine specific glycosylation alterations—including hypersialylation, fucosylation, and truncated O-glycans—across different molecular subtypes (Luminal A/B, HER2-positive, TNBC) and assess their diagnostic and prognostic potential. Methodologically, the review contrasts MALDI-based profiling and Imaging Mass Spectrometry (MALDI-IMS) with other proteomic techniques, highlighting MALDI’s advantages in throughput and spatial resolution alongside its technical limitations. Furthermore, we discuss emerging frontiers in the field, such as the shift from whole-serum analysis to “liquid biopsy” components (e.g., extracellular vesicles). Ultimately, we argue that implementing quantitative glycoproteomics is essential for advancing personalized oncology. Full article

Cecina de León is a traditional Spanish dry-cured beef product whose surface, as in other similar meat products, becomes heavily colonised by fungi during ripening, raising concerns related to possible mycotoxin contamination. This study aimed to characterise the mycobiota associated with cecina and its production environment, with particular emphasis on mycotoxigenic Penicillium species. Seventy-eight cecina samples and 26 air samples were collected from meat-processing plants and local markets in the province of León (Spain) and analysed for fungal counts, water activity and pH. A total of 101 mould isolates and 16 yeasts were recovered, with Penicillium accounting for 88% of all moulds. Sixteen Penicillium species were identified using a polyphasic approach integrating macro- and micromorphological analysis, extrolite production, molecular markers (BenA, CaM and ITS), and MALDI-TOF MS. Mycotoxin screening by HPTLC and HPLC-PDA targeted cyclopiazonic acid, ochratoxin A, patulin, citrinin, griseofulvin and mycophenolic acid, revealing that 51% of the Penicillium isolates were mycotoxin producers, mainly P. commune. The proposed polyphasic strategy, including MALDI-TOF MS as a rapid complementary tool, offers a practical framework for the surveillance of fungal communities and mycotoxin risk in meat-processing environments. Full article

Background/Objectives: Carbapenem-resistant Acinetobacter baumannii poses a critical threat due to its ability to acquire multiple resistance mechanisms and persist under antibiotic pressure. This study aimed to elucidate the molecular basis of imipenem resistance in clinical A. baumannii isolates by integrating phenotypic, molecular, transcriptional, and clonal analyses. Methods: Eleven A. baumannii isolates identified by MALDI-TOF MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry) were investigated. Antimicrobial susceptibility to imipenem and meropenem was assessed, followed by polymerase chain reaction (PCR) detection of Ade efflux pump, outer membrane porin, and OXA-type carbapenemase genes. Transcriptional responses to sub-inhibitory imipenem exposure were evaluated using quantitative real-time PCR, and clonal relatedness was assessed by arbitrarily primed PCR. Results: All isolates were carbapenem-resistant, with bla_OXA-23 detected in all isolates and bla_OXA-24 absent in one isolate. Transcriptional analysis revealed isolate-specific responses to imipenem exposure. Among Ade efflux pump components, only adeR exhibited expression changes, displaying either downregulation or upregulation depending on the isolate, whereas adeA, adeB, adeC, and adeS transcripts were not detected under the tested conditions. Outer membrane porin genes showed heterogeneous regulation, with ompA and carO downregulated, while some isolates showed increased expression. Expression of oprD varied among isolates, and omp33–36 transcripts were detected in a single isolate and were reduced after exposure. Clonal analysis identified nine distinct genotypes, indicating genetic diversity and the absence of clonal dominance. Conclusions: These findings highlight the multifactorial and heterogeneous nature of carbapenem resistance in A. baumannii, emphasizing the interplay between regulatory efflux mechanisms, porin modulation, and carbapenemase carriage. Full article

Termite guts represent a unique microbial habitat harboring bacteria with potential probiotic properties, owing to their ability to inhibit pathogenic microorganisms. This study investigated the probiotic characteristics of lactic acid bacteria newly isolated from the guts of the termite Termes propinquus, aiming to enhance growth performance and reduce the incidence of foodborne pathogen contamination in the commonly consumed edible two-spotted crickets (Gryllus bimaculatus). In this study, five morphologically different bacteria (TPL-1 to TPL-5) were isolated and respectively identified as Levilactobacillus brevis, Lactiplantibacillus plantarum, Streptococcus anginosus, Companilactobacillus alimentarius, and Aerococcus viridans based on 16S rRNA gene sequences and MALDI-TOF MS. All isolates were evaluated for tolerance to stressful conditions (pH 2.5 and 0.3% bile salts), cell surface properties, antioxidant activity, antimicrobial activity against foodborne pathogens, safety profiles, and adhesion to human colon adenocarcinoma cells (Caco-2 and HT-29). Among them, Lactiplantibacillus plantarum TPL-2 demonstrated the strongest probiotic attributes and was further assessed for anti-adhesion activity against foodborne pathogens and in vivo effects on the crickets. Dietary supplementation with Lb. plantarum TPL-2 significantly improved cricket growth, survival, and gut microbiota homeostasis. These findings point to the prospect of termite-derived lactic acid bacteria as beneficial probiotics for use in biotechnological applications and edible insect farming. Full article

Feline conjunctivitis is a common ocular disorder; however, the molecular composition of feline tear fluid and its alterations during ocular surface inflammation remain poorly characterized. This pilot study aimed to explore the tear proteome of cats with conjunctivitis using matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI–TOF/TOF MS) and to compare findings with those from clinically healthy cats. Tear samples were collected using Schirmer tear test strips from healthy cats and cats diagnosed with conjunctivitis. Total protein concentration was measured by ultraviolet absorbance spectrophotometry, and tear proteins were separated by SDS–polyacrylamide gel electrophoresis, followed by in-gel trypsin digestion and MALDI–TOF/TOF MS analysis. Nine distinct tear proteins were identified, including antimicrobial and immune-related components such as lactoperoxidase, lactotransferrin, albumin, and immunoglobulin A constant region. Lactoperoxidase and SBP1 were identified in feline tear fluid for the first time. No proteins uniquely associated with conjunctivitis were detected. The mean total tear protein concentration was numerically higher in cats with conjunctivitis (13.06 ± 0.75 mg/mL) than in healthy cats (9.69 ± 0.67 mg/mL); however, this difference did not reach statistical significance (p = 0.095) and should be interpreted cautiously given the limited sample size. This pilot study provides preliminary insights into tear protein profiles in cats with conjunctivitis and highlights the need for larger quantitative investigations. These findings provide a preliminary framework for future studies aimed at further characterizing molecular alterations associated with feline ocular surface disorders. Full article

Streptococcus suis is an emerging zoonotic pathogen that typically causes bacteremia or meningitis in humans, whereas vertebral osteomyelitis with epidural abscess is exceedingly rare and may be missed. We describe a 65-year-old farmer with fever and severe low back pain after long-term bare-handed handling of raw pig lungs. Pre-treatment blood cultures yielded S. suis identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). After transient improvement on empirical therapy, fever recurred with worsening lumbar pain. Contrast-enhanced magnetic resonance imaging (MRI) demonstrated multilevel thoracolumbar pyogenic spondylitis with an epidural abscess and a sub-ligamentous abscess beneath the posterior longitudinal ligament (PLL) extending from L2 to L5. Computed tomography-guided lumbar biopsy followed by tissue metagenomic next-generation sequencing (mNGS) detected S. suis, providing concordant evidence supporting pathogen involvement at the vertebral focus. The bloodstream isolate (SS-JX2025-01) was serotype 2, sequence type 7 (ST7). It remained susceptible to β-lactams and glycopeptides but was resistant to macrolide–lincosamide and tetracycline classes, consistent with erm(B), tet(O), tet(40), and ant(6)-Ia detected by whole-genome sequencing (WGS). Virulence profiling revealed an epf⁺/sly⁺/mrp⁻ pattern with multiple adhesins and immune-evasion factors, whereas canonical 89K pathogenicity island markers were absent. Core-genome phylogeny placed SS-JX2025-01 within the Chinese ST7 lineage associated with previous outbreaks. This biopsy-supported case expands the clinical spectrum of invasive S. suis infection, highlights the value of tissue mNGS as an adjunct for supporting deep-seated foci in zoonotic infections, and underscores the importance of occupational prevention in small-scale farming households. Full article

This study presents the synthesis and electrochemical characterization of meso-tetracyanobutadiene (TCBD)-functionalized diphenylporphyrin (DPP) complexes incorporating copper (Cu) and nickel (Ni) metals. These push–pull metallo diphenylporphyrin–TCBD complexes were synthesized via a [2 + 2] cycloaddition–retroelectrocyclization reaction between 5-bromo-15-formyl-10,20-diphenylporphyrin metal(II) complexes (M = Cu, Ni) and tributyl(phenylethynyl)stannate, followed by tetracyanoethylene (TCNE) addition. The resulting TCBD-functionalized porphyrins were obtained in moderate yields (70–75%) and thoroughly characterized by ¹H and ¹³C NMR, UV-Vis spectroscopy, MALDI-TOF-MS, and single-crystal XRD. Although the single-crystal X-ray structure of NiDPP was solved, DFT calculations were used to determine the structures of the donor–acceptor MDPP-TCBD systems and to visualize their electronic structures. HOMO on the porphyrin π system and LUMO on the TCBD entity were observed, and energy level diagrams clearly laid out the electron donor and acceptor parts of the molecular systems. As expected, these novel donor–acceptor porphyrinoid assemblies exhibited enhanced push–pull properties in both the ground and excited states. Femtosecond transient absorption studies revealed that both NiDPP-TCBD and CuDPP-TCBD populate the charge-transfer state upon photoexcitation, with lifetimes of 383.1 ps and 484.7 ps, respectively, in benzonitrile. The charge-transfer states populated the triplet or doublet states (in the case of CuDPP) before returning to the ground state. Full article