Search Results (1,618)

The growing prevalence of multidrug-resistant (MDR) Candida spp. necessitates the development of new antifungal strategies. Photodynamic therapy (PDT), already widely used in the treatment of various oral infections, is based on the synergistic interaction of three key elements: a photosensitizer capable of selectively binding to microbial cells, a light source with the appropriate wavelength, and the presence of molecular oxygen. This interaction results in the production of singlet oxygen and reactive oxygen species, responsible for the selective destruction of microorganisms. In recent years, numerous natural compounds have been explored as potential photosensitizers. Olive oil, a cornerstone of the Mediterranean diet, was recently recognized by the U.S. Food and Drug Administration as a medicinal substance thanks to its soothing, immunomodulatory, and antimicrobial properties, which have also been documented in regard to oral administration. Materials and Methods: The aim of this in vitro study was to evaluate the efficacy of activated olive oil as a novel photosensitizer in PDT against Candida species. Oral MDR clinical isolates of C. albicans, C. krusei, and C. glabrata were analyzed using the Kirby–Bauer method according to EUCAST protocols. Six different experimental conditions were considered for each strain: (i) 100 μL of extra-virgin olive oil (EVOO); (ii) 100 μL of EVOO pre-activated with 3% H₂O₂ (EVOO-H); (iii) 100 μL of EVOO irradiated for 5 min with polarized light (480–3400 nm, 25 W); (iv) 100 μL of EVOO-H subjected to the same polarized light; (v) 100 μL of EVOO irradiated for 5 min with a 660 nm diode laser (100 mW); and (vi) 100 μL of EVOO-H irradiated with the same laser. All plates were incubated at 37 °C for 48 h. Results: The results showed a variable response among the different Candida species. C. glabrata showed sensitivity to all experimental conditions, with a 50% increase in the diameter of the inhibition zone in the presence of polarized light. C. krusei showed no sensitivity under any of the conditions tested. C. albicans showed antifungal activity exclusively when EVOO-H was activated by light. In particular, activation of EVOO and EVOO-H with polarized light resulted in the largest inhibition zones. Conclusions: In conclusion, olive oil, both alone and pre-activated with hydrogen peroxide, can be considered an effective photosensitizer against drug-resistant Candida spp., especially when combined with polarized light. Full article

Protective cultures are an increasingly industrially relevant biopreservation tool for meat and meat products, responding to simultaneous demands for microbiological safety, extended shelf life, and reduced reliance on synthetic preservatives within clean-label frameworks. This review summarizes current advances in protective cultures applied to meat systems, with emphasis on technological functions, efficacy boundaries, and safety-related due diligence. We discuss the dominant inhibitory mechanisms of lactic acid bacteria and related protective taxa—acidification, competitive exclusion, and antimicrobial metabolites (including bacteriocins)—and highlight why performance is strongly strain- and matrix-dependent under realistic storage conditions. Practical applications are reviewed across raw meats (spoilage delay under refrigeration and vacuum/MAP) and processed or ready-to-eat products, where post-processing surface application emerges as a critical control point for limiting Listeria monocytogenes outgrowth during chilled storage. Key implementation constraints include technological compatibility and sensory neutrality, which are influenced by product buffering capacity, salt content, available fermentable substrates, packaging atmosphere, and temperature. From a safety perspective, we synthesize evidence on antimicrobial resistance in food-associated cultures and outline contemporary qualification strategies combining phenotypic susceptibility testing with genome-based screening to exclude acquired and potentially transferable resistance determinants. Overall, protective cultures should be viewed as a targeted hurdle integrated into holistic preservation systems rather than a standalone substitute for hygiene and process control. Full article

The global dissemination of multidrug-resistant (MDR) Salmonella through the international food trade poses a major One Health concern. We used whole-genome sequencing to characterize Salmonella isolates from poultry meat sold in Chile, including domestic and imported products from Brazil and Argentina. Sixty-one Salmonella isolates were recovered from poultry meat; S. Infantis predominated (59%), followed by S. Heidelberg. Among S. Heidelberg from imported-meat poultry, 92% carried the bla_CMY-2 gene, conferring resistance to β-lactams. Given the predominance of S. Infantis in poultry meat, we performed an additional in-depth genomic analysis of 73 S. Infantis isolates obtained from poultry meat (n = 32), surface water (n = 30), and human clinical cases (n = 11). Across sources, phenotypic resistance to ciprofloxacin and third-generation cephalosporins reached 93% and 70%, respectively, and MDR (≥3 antimicrobial classes) occurred in 71% of isolates, largely associated with bla_CTX-M-65 and gyrA mutations. The pESI (plasmid of emerging S. Infantis)-like plasmid, harboring antimicrobial resistance and virulence genes, appeared in 94% of isolates. Phylogenetic analyses showed close genetic relationships among food, environmental, and clinical isolates, suggesting potential transmission through contaminated poultry meat or water. These findings emphasize the emergence of MDR S. Infantis in Chile and underscore the need for integrated One Health surveillance and prudent antimicrobial use to mitigate foodborne AMR risks. Full article

The escalating threat of antibiotic resistance, particularly from Staphylococcus aureus (S. aureus), has become a critical challenge in both public health and animal husbandry. The extensive use of conventional antibiotics in livestock production accelerates the emergence of resistant strains, heightening risks to food safety and human health. Although plant-derived bioactive compounds are increasingly recognized as promising alternatives to synthetic antimicrobials, the mechanisms underlying their efficacy—and the potential for synergistic action among different plant parts—remain poorly understood. In particular, the antibacterial interactions among extracts from different tissues of Cyperus esculentus L. (C. esculentus), a plant rich in flavonoids and phenolics, have yet to be systematically evaluated. Here, we investigated the antibacterial properties and mechanisms of ethanol extracts from the tubers, stems–leaves and their mixture of C. esculentus against S. aureus. Using Oxford cup diffusion assays, scanning electron microscopy (SEM), bacterial growth kinetics, and untargeted metabolomics, we assessed both phenotypic inhibition and metabolic disruption. The mixed extract exhibited the strongest antibacterial effect, producing a 26.15 mm inhibition zone—approximately 7% greater than that of single-part extracts—and induced cell wall rupture and disintegration as observed by SEM. Growth curve analyses revealed time-dependent bacterial suppression, while metabolomic profiling identified 845 differential metabolites, indicating disturbances in amino acid, lipid, and nucleotide metabolism. Flavonoids such as acacetin, diosmetin, naringenin, and silybin A were identified as principal active compounds contributing to these effects. Full article

Listeria monocytogenes is a high-risk pathogenic bacterium associated with ready-to-eat foods and poses a potential threat to consumer health. This study aimed to investigate the prevalence, characterization and genetic diversity of L. monocytogenes in ready-to-eat raw salmon and trout products obtained from physical stores and online stores in China. Out of 150 samples analyzed, 23 (15.3%) were positive for L. monocytogenes. Among these positive samples, three (12%) were from Japanese restaurants, four (16%) from farmers markets, one (2.9%) from large supermarkets and fifteen (30%) from e-commerce platforms, and only one sample showed a contamination level exceeding 100 most probable number (MPN)/g. The isolates from positive samples demonstrated a concrete public health risk through several findings: twenty-three L. monocytogenes exhibited varying degrees of cytotoxicity, ranging from 7.6% to 71.8%. Compared with the reference strain ATCC 19115, five of these isolates were highly cytotoxic, a result that was validated by mouse survival rate experiment, which also confirmed their high virulence at tested dose. All isolates were resistant to cefuroxime sodium, ceftriaxone, cefepime and nalidixic acid, and 13% showed resistance to sulphamethoxazole-trimethoprim. Three serogroups were identified, with serogroup Ⅰ.1 (1/2a, 3a) being the most prevalent (65.2%). These isolates were grouped into eight sequence types, with ST8 (34.8%) and ST87 (30.4%) dominating. All isolates carried virulence genes associated with LIPI-1 andmultiple internalin genes (inlA, inlB, inlJ and inlK), confirming their potential pathogenicity. Additionally, the isolates harbored antimicrobial resistance genes lin and FosX. The five highly virulent isolates exhibited the highest genetic similarity to J2-031 (GCA_000438645.1) and C1-387 (GCA_000438605.1). The results provided valuable information for Chinese regulatory authorities to strengthen the risk monitoring of L. monocytogenes in ready-to-eat raw salmon and trout products. Full article

Pathogens that have developed resistance to antibiotics pose a threat to public health. The primary goal in preventing foodborne infections is to inhibit the growth of and, subsequently, eliminate antibiotic-resistant pathogens at every stage from production to consumption. Escherichia coli, which has acquired resistance to most known antibiotics, is frequently found in chicken meat. In many countries, due to unregulated antibiotic use in poultry farming, poor hygiene in slaughterhouses, or cross-contamination, extended-spectrum beta-lactamase (ESBL)-producing E. coli has been identified as the causative agent in poultry-associated food poisoning. The need for more effective antimicrobial agents against this pathogen, which is resistant to existing antibiotics, has led to increased attention being paid to postbiotics produced by lactic acid bacteria, particularly bacteriocins. This study aimed to determine the antimicrobial effects of postbiotics obtained from kefir-derived Lactiplantibacillus plantarum and Lactococcus lactis against ESBL-positive E. coli. To achieve this, E. coli strains were isolated from raw chicken meat samples collected from the market using culture-based methods, and their antimicrobial resistance profiles were determined using the disk diffusion method. The ESBL positivity of the isolates was assessed using the double-disk synergy test. The antimicrobial activities of the postbiotics against the identified ESBL-positive E. coli strains were tested using the macro-dilution method to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. ESBL-positive E. coli was detected in 48% of raw chicken meat samples. The antimicrobial effects of postbiotics were examined by disk diffusion, and postbiotics produced by 18 Lb. plantarum strains and 20 Lc. lactis strains showed strong antimicrobial activity. Significant differences in the antimicrobial effects of postbiotics were observed between the two species. Lb. plantarum postbiotics exhibited both bacteriostatic (concentration 60%) and bactericidal (concentration 80%) effects on ESBL-positive E. coli strains, whereas Lc. lactis postbiotics showed only bacteriostatic effects (80% concentration). Postbiotics derived from probiotic bacteria offer promising effects against multidrug-resistant E. coli due to their heat resistance, activity across different pH values, strong antimicrobial effects, affordability, and ease of production. Full article

Listeria monocytogenes is a persistent foodborne pathogen capable of surviving in food processing environments, often in association with diverse environmental microflora. This study examines genomic determinants of persistence, specifically stress adaptation and biofilm-associated traits, in environmental Listeria species and other environmental microflora from a dairy processing facility by analyzing whole-genome sequences of 6 environmental Listeria isolates, 4 ATCC reference strains, and 22 air and floor swab cultures, annotated using the RAST platform. Subsystem analysis revealed that Listeria isolates carried a defined set of genes linked to biofilm formation, antimicrobial resistance, and stress response, though in lower abundance than environmental cultures. Listeria exhibited fewer flagellar genes but greater consistency in core stress-related genes, including those for disinfectant and osmotic stress resistance, with SigB operon and RpoN genes highlighting strong stress tolerance. In contrast, environmental cultures exhibited broader transcriptional regulators (RpoE, RpoH) and greater diversity in acid and heat shock response genes, indicating distinct survival strategies. All examined Listeria species harbor biofilm and stress-resistance genes enabling independent survival, while environmental microbiota show greater genetic diversity that may promote persistence and multispecies biofilm formation. This study underscores the complex genetic landscape that may contribute to the persistence of Listeria and environmental microbiota in dairy processing environments, providing foundational insights for environmental cross contamination control strategies. Full article

Background/Objectives: Antimicrobial resistance (AMR) surveillance is a cornerstone of national AMR strategies but requires sustained, cross-sectoral financing. While the need for such financing is well recognized, its quantification remains scarce in low- and middle-income countries. This study aimed to estimate the full costs of AMR surveillance across the human health, animal health, and food sectors (2021–2030) in selected facilities in Nepal and generate evidence to inform sustainable financing. Methods: A bottom-up micro-costing approach was used to analyze data from five sites. Costs were adjusted for inflation using projected gross domestic product deflators, and probabilistic sensitivity analyses were conducted to assess uncertainty in laboratory sample volumes under four scenarios. Results: The total cost of AMR surveillance in Nepal was $6.7 million: $3.4 million for human health (50.3% out of the aggregated costs), $2.7 million for animal health (39.8%), and $0.7 million for the food sector (9.9%). Laboratories accounted for >90% of total costs, with consumables and personnel as the main cost drivers. Average cost per sample was $150 (animal), $64 (food), and $6 (human). Conclusions: This study offers the first robust, multi-sectoral 10-year cost estimates of AMR surveillance in Nepal. The findings highlight that sustaining AMR surveillance requires predictable domestic financing, particularly to cover recurrent laboratory operations as donor support declines. These results provide cost evidence to support future budgeting and policy planning toward sustainable, nationally financed AMR surveillance in Nepal. Full article

Modern agriculture faces the critical need to develop sustainable, safe, and effective strategies for enhancing productivity, protecting plants and animals, and ensuring food security. Challenges posed by antibiotic resistance and the adverse environmental and consumer health impacts of chemical agents are driving the search for eco-friendly alternatives. In this context, bacteriocins—naturally occurring antimicrobial peptides synthesized by diverse bacteria—represent a promising alternative to traditional chemical compounds. This article reviews the potential and current advances in bacteriocin applications across agricultural sectors, with particular focus on their targeted antagonistic activity, structural diversity, commercial bacteriocin-based products, and their utilization in livestock farming, crop production, poultry farming, and aquaculture. Key findings demonstrate that bacteriocins, particularly nisin and pediocin PA-1, exhibit potent activity against major agricultural pathogens including Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens, and Escherichia coli, with efficacy rates reaching 90% in mastitis treatment and significantly reducing pathogen loads in poultry and aquaculture systems. Commercial products such as Nisaplin, Wipe Out, and ALTA 2431 have been successfully implemented in veterinary medicine and food production. In aquaculture, bacteriocins effectively control Lactococcus garvieae, Aeromonas spp., Vibrio spp., and Pseudomonas aeruginosa, contributing to sustainable disease management with minimal environmental impact. It can be suggested that bacteriocins may play an essential role in combating pathogens and offer viable alternatives to conventional antibiotics across primary food production systems, though optimization of production methods and regulatory frameworks remains essential for broader commercial adoption. Full article

(1) Background: Listeria monocytogenes (Lm) is recognized by the World Health Organization (WHO) as one of the four principal foodborne pathogens. This study aimed to investigate the molecular characteristics of Lm isolates from Jiaxing, China, using whole-genome sequencing (WGS) to enhance our understanding of their molecular epidemiology. (2) Methods: A total of 39 foodborne Lm isolates and 7 clinical Lm isolates were analyzed via WGS to identify resistance genes, virulence factors, lineage, sequence type (ST), and clonal complex (CC). Antibiotic susceptibility was assessed using Minimum Inhibitory Concentration (MIC) testing, and serotypes were confirmed via multiplex PCR. (3) Results: We found that 39 food isolates were mainly lineage II (66.67%), with 13 STs; ST8 was the dominant ST, and 2 new types, ST3210 and ST3405, were found. Among the seven clinical isolates, lineage I was dominant (57.14%), and ST87 was the dominant ST. Serotype 1/2a was dominant, accounting for 54.35%, followed by 1/2b, which accounted for 36.96%. The overall antimicrobial resistance rate was 13.04%, with a multidrug resistance rate of 2.17%. All strains harbored LIPI-1 and LIPI-2, and five strains carried LIPI-3 genes: one strain belonged to ST619 of lineage I, two strains belonged to ST224 of lineage I, and two strains belonged to ST11 of lineage II. (4) Conclusions: This study clarified the genotype and serotype characteristics of Listeria monocytogenes in Jiaxing, as well as their molecular characteristics relating to drug resistance and virulence, thus providing a technical basis for improving exposure risk assessment of Listeria monocytogenes. Continuous monitoring, prevention, and control are recommended to further improve regional public health and safety. Full article

Recent studies have shown that wood tar exhibits excellent potential as an additive to polymers for food packaging. In this study, we demonstrated that the differential temperature of dry pyrolysis of wood affects the antioxidant and antibacterial activities of the liquid pyrolysis products (LPP). Birch LPP showed, on average, approximately 16% higher reducing power in the ferric-reducing antioxidant power (FRAP) assay and, on average, approximately 29% lower free radical scavenging activity than pine LPP. Thermal characterization suggests a qualitatively similar chemical composition among the tested fractions, with the 500 °C pyrolysis fraction showing the highest thermal resistance (lowest mass loss). Thermal characterization indicated similarities in the qualitative chemical composition of the tested fractions. Analyzed products demonstrated bactericidal activity against human- or plant-pathogenic bacteria and exhibited poor antimicrobial activity towards probiotic bacteria. Specifically, Lactoplantibacillus sp. and L. rhamnosus were, on average, approximately 61% and 45% less affected, respectively, compared to the most sensitive E. coli. We demonstrate apparent, predominantly substrate-driven differences in antibacterial activity, with Gram-negative bacteria being more susceptible to pine products and Gram-positive bacteria being more susceptible to birch products. Full article

Fungal secondary metabolites are valuable sources of natural antioxidants and antimicrobials. This study evaluated the submerged fermentation of Penicillium crustosum OR889307 supplemented with lemon peel as a co-substrate to enhance the production of bioactive compounds. Lemon peel was selected for its phenolic precursors and sustainable availability as an agro-industrial byproduct. Crude extracts, aqueous and organic fractions, and molecular-weight partitions were assessed for antioxidant activity using the DPPH assay and for antimicrobial activity against Escherichia coli, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa, and Candida albicans. Semi-purified extracts from co-substrate fermentations exhibited enhanced bioactivity, showing MIC values of 185 µg/mL against P. aeruginosa and 225 µg/mL against MRSA, along with strong ABTS radical-scavenging capacity (238.95 ± 2.17 µmol TE). RP-HPLC-ESI-MS profiling revealed phenolic acids, flavanones, flavonols, and lignans, including ferulic acid 4-O-glucoside, bisdemethoxycurcumin, secoisolariciresinol, and quercetin 3-O-xylosyl-glucuronide. These findings demonstrate that lemon peel supplementation promotes the biosynthesis of antimicrobial and antioxidant metabolites by P. crustosum. This approach supports sustainable agro-waste valorization and offers a promising strategy for obtaining natural bioactive compounds with potential applications in food preservation and health-related formulations. Full article

Background/Objectives. Lactiplantibacillus plantarum CRL681 has previously demonstrated a strong antagonistic effect against Escherichia coli O157:H7 in food matrices; however, the molecular mechanisms underlying this activity remain poorly understood. Since initial interactions between beneficial bacteria and pathogens occur mainly at the cell surface and in the extracellular environment, the characterization of the bacterial secretome is essential for elucidating these mechanisms. In this study, the secretome of L. plantarum CRL681 was comprehensively characterized using an integrated in silico and in vitro approach. Methods. The exoproteome and surfaceome were analyzed by LC-MS/MS under pure culture conditions and during co-culture with E. coli O157:H7. Identified proteins were functionally annotated, classified according to subcellular localization and secretion pathways, and evaluated through protein–protein interaction network analysis. Results. A total of 275 proteins were proposed as components of the CRL681 secretome, including proteins involved in cell surface remodeling, metabolism and nutrient transport, stress response, adhesion, and genetic information processing. Co-culture with EHEC induced significant changes in the expression of proteins associated with energy metabolism, transport systems, and redox homeostasis, indicating a metabolic and physiological adaptation of L. plantarum CRL681 under competitive conditions. Notably, several peptidoglycan hydrolases, ribosomal proteins with reported antimicrobial activity, and moonlighting proteins related to adhesion were identified. Conclusions. Overall, these findings suggest that the antagonistic activity of L. plantarum CRL681 against E. coli O157:H7 would be mediated by synergistic mechanisms involving metabolic adaptation, stress resistance, surface adhesion, and the production of non-bacteriocin antimicrobial proteins, supporting its potential application as a bioprotective and functional probiotic strain. Full article

Background/Objectives: The increasing trend of foodborne zoonotic pathogens exhibiting antimicrobial resistance (AMR) represents a growing threat to food safety and public health in sub-Saharan Africa (SSA). Resistant strains of foodborne zoonotic pathogens compromise treatment efficacy, raise illness, and threaten sustainable food systems in human and animal health. However, regional understanding and policy response are limited due to the fragmentation of data and the inadequacy of surveillance. This systematic review and meta-analysis aimed to achieve the following: (1) estimate the pooled prevalence of AMR, including multidrug resistance (MDR) in selected foodborne pathogens; (2) compare subgroup variations across countries, pathogen species, and antibiotic classes; and (3) evaluate temporal trends. Methods: Following PRISMA 2020 guidelines, studies published between 2010 and June 2025 reporting AMR and MDR in Salmonella, Campylobacter, or E. coli from food or animal sources in SSA were systematically reviewed. Data on pathogen prevalence, AMR profile, and MDR were extracted. Random-effects meta-analysis using R software was implemented to estimate the pooled prevalence and the 95% confidence intervals (95% CI). Subgroup analyses were performed to explore heterogeneity across countries, antibiotic class, and bacterial species. Results: Ninety studies from 16 sub-Saharan African countries were included, encompassing 104,086 positive isolates. The pooled foodborne pathogen prevalence was 53.1% (95% CI: 51.5–54.7), AMR prevalence was 61.6% (95% CI: 59.4–63.9), and MDR prevalence was 9.1% (95% CI: 8.3–10.0). The highest resistance was reported in Campylobacter spp. (43.6%), followed by Salmonella spp. (29.1%) and E. coli (22.8%). High heterogeneity was observed across studies (I² = 95–99%, p < 0.001). Conclusions: It is concluded that substantial AMR burden exists in food systems, highlighting an urgent need for integrated One Health surveillance, antimicrobial stewardship, and policy harmonization in SSA. Strengthening laboratory capacity, enforcing prudent antimicrobial use, and promoting regional data sharing are critical for the management of antimicrobial resistance in sub-Saharan Africa. Full article

The increasing prevalence of multidrug-resistant (MDR) Campylobacter species poses a serious threat to food safety and public health, highlighting the urgent need for natural antimicrobial alternatives to conventional antibiotics. This study investigated the antibacterial potential and mechanism of action of seven essential oils (EOs), Cymbopogon citratus, Mentha pulegium, Artemisia absinthium, Myrtus communis, Thymus algeriensis, Thymus capitatus, and Eucalyptus globulus, against multidrug-resistant Campylobacter jejuni and Campylobacter coli. The antimicrobial activity was first assessed by the agar disk diffusion and broth microdilution methods to determine inhibition zones, minimum inhibitory concentrations (MICs), and minimum bactericidal concentrations (MBCs). The most active EOs were further evaluated through time–kill kinetics, cell lysis, salt tolerance, and membrane integrity assays to elucidate their bactericidal mechanisms. Results showed that E. globulus, T. algeriensis, and M. communis exhibited the strongest inhibitory effects, particularly against C. jejuni, with MIC values ranging from 3.125% to 6.25%, while C. coli was more resistant. Time–kill and lysis experiments demonstrated rapid bacterial reduction and significant decreases in optical density, indicating cell disruption. Additionally, EO treatments reduced salt tolerance and induced leakage of cytoplasmic materials, confirming membrane damage. Overall, these findings suggest that selected essential oils exert potent antimicrobial effects through membrane disruption and osmotic imbalance, offering promising natural strategies to control MDR Campylobacter in food systems. The application of such bioactive compounds could contribute significantly to improving food quality, extending shelf life, and enhancing food safety. Full article