Search Results (5,547)

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

Background: Antifungal resistance among Candida species and related genera, coupled with the lack of new drugs, poses a significant threat to public health. Several studies have demonstrated a relationship between virulence factors and resistance. Current objectives include identifying new targets and searching for new natural molecules. Carvacrol, a natural phenolic compound, has been shown to have antimicrobial properties; however, its impact on the virulence of species other than Candida albicans and related yeast genera remains underexplored. Methods: The antifungal activity of carvacrol was evaluated against clinical isolates of Candidozyma auris, Meyerozyma guilliermondii, and Candida dubliniensis, as well as its effect on adhesion, hydrophobicity, biofilm formation and osmotic stress tolerance. In vivo activity was assessed using the Galleria mellonella infection model at MIC concentrations. Results: Carvacrol inhibited adherence and significantly reduced both early and preformed biofilms in M. guilliermondii and C. dubliniensis. In C. auris, the compound produced a modest reduction in biofilm activity but significantly enhanced larval survival in the in vivo model (~20%, p < 0.01). Carvacrol also induced increased tolerance of C. auris to osmotic stress, suggesting activation of adaptive pathways. Conclusions: Carvacrol exhibits species-specific effects, acting as an antivirulence modulator in M. guilliermondii and C. dubliniensis and attenuating virulence in vivo in C. auris. These findings support the potential of carvacrol as an adjuvant antifungal strategy, particularly against C. auris, and highlight the relevance of targeting virulence traits to reduce selective pressure and limit antifungal resistance. Full article

Antimicrobials are common drugs used to treat and prevent infectious diseases in plants, animals, and humans. Since their discovery in the mid-20th century, their use has dramatically increased for the benefit of humanity, and also for animal care. However, antimicrobial resistance soon appeared, which, according to the WHO, will limit or impede their use at the horizon of 2050. Indeed, antimicrobial resistance (AMR), which is a natural phenomenon in bacteria increased dramatically over the last 3 decades mainly due to the overuse and misuse of antibiotics in humans, animals, and plants. Apart from affecting human health, drug-resistant diseases also adversely affect plant and animal health, reduce agricultural productivity, and threaten food security. AMR affects all countries, regardless of economic status, and imposes high costs on health systems and national economies. Therefore, antimicrobial resistance should be studied and analyzed under the One Health paradigm. In mind of the One Health paradigm, to reduce and overcome AMR, we must take at least 3 complementary and integrated actions: (i) monitoring the resistome; (ii) developing protective strategies against antibiotic resistance; (iii) taking curative actions by designing new and original treatments. Moreover, the three actions must be conducted simultaneously due to the continuous adaptation of bacteria. Full article

This study explores the biopreservative and antioxidant potential of lactic acid bacteria (LAB) isolated from low-sodium vegetable fermentations. Five vegetables, green pepper, tomato, eggplant, carrot, and cabbage, were fermented with varying NaCl concentrations (0–3%) for 45 days. Fifty-six presumptive LAB were isolated, and eight LAB strains exhibiting strong antimicrobial activity against Listeria monocytogenes and Staphylococcus aureus were selected for further analysis. The isolates showed significant tolerance to salinity (6.5–18% NaCl), alkaline pH (9.6), and heat stress (45 °C and 60 °C for 30 min). Antimicrobial assays against eight indicator pathogens confirmed a broad inhibition spectrum attributed to bacteriocin-like substances, while antioxidant assays indicated significant antioxidant activity (27–65%), with strain L10 showing the highest radical scavenging potential (p < 0.05). API 20 STREP profiling revealed three dominant taxa: Leuconostoc, Lactococcus lactis, and Enterococcus faecium. These findings highlight LAB as stress-tolerant, multifunctional strains with promising applications as natural biopreservatives and probiotic candidates for developing functional, low-sodium fermented foods. Full article

Methicillin-resistant Staphylococcus aureus (MRSA), a major global public health threat due to its broad resistance, urgently requires the development of new antibiotic alternatives. (‒)‒Epigallocatechin-3-gallate (EGCG) is considered a natural bioactive compound with anti-MRSA properties. The L-Lectin module of serine-rich adhesin for platelets (SraP) is considered an important target for blocking MRSA-infected hosts. This study aims to investigate the mechanism of action of EGCG against MRSA. Surface plasmon resonance (SPR), cell adhesion and invasion, biofilm formation, checkerboard assays, RNA sequencing (RNA-seq) and quantitative real-time polymerase chain reaction (qRT-PCR) were performed. The results showed that EGCG bound to SraP L Lectin with high affinity and effectively inhibited MRSA colonization. Additionally, EGCG significantly suppressed pyrimidine metabolism and downregulated related genes, thereby potentially inhibiting bacterial growth. It also markedly reduced the expression of multiple genes associated with β-lactam resistance and inhibited biofilm formation. A strong synergistic effect was observed between EGCG and the bactericidal agent ceftriaxone (CRO). When combined with 10 μg/mL EGCG, CRO required 75% less dosage and exhibited a prolonged antimicrobial effect. In conclusion, EGCG exerts anti-MRSA effects through multiple pathways and represents a promising candidate as an alternative therapeutic agent against MRSA infections. Full article

Background/Objectives: Tallaga cheese is an artisanal form of traditional Egyptian soft white Damietta cheese, characterized by high moisture, elevated salinity, and a limited shelf life, which collectively increase its vulnerability to microbial contamination. Typically produced from raw or minimally heated cow or buffalo milk, Tallaga cheese represents a relevant model for studying emerging food safety challenges. Methods/Results: This study revealed marked variability among commercial samples and, unexpectedly, a general absence of typical lactic acid bacteria (LAB) such as Lactococcus spp. Instead, enterococci, microorganisms increasingly associated with antimicrobial resistance and virulence traits, emerged as the dominant LAB group, with the detection of Enterococcus faecium strains posing particular concern for dairy safety. To address these challenges, the antimicrobial potential of isolated LAB was evaluated against Latilactobacillus sakei (CECT 906). Twelve bacteriocin-producing strains were identified: ten Enterococcus faecalis, one E. faecium, and one Lactococcus lactis. Enterococci demonstrated robust tolerance to stress conditions, including high salt concentrations, emphasizing their persistence in dairy environments. Given the relevance of controlling resistant and potentially virulent strains such as E. faecium, the bioprotective capacity of two bacteriocinogenic L. lactis strains (IPLA 1064 and AHRI ST9) was assessed using a laboratory-scale cheese model. Both strains effectively inhibited E. faecium AHRI CH4, achieving reductions of 2.6 and 3.6 log units (99.9%). Conclusions: These findings underscore the relevance of bacteriocin-producing L. lactis as natural biopreservatives to mitigate emerging threats related to antimicrobial-resistant food-borne pathogens in dairy products. Full article

Rapid antimicrobial resistance (AMR) prediction from MALDI-TOF mass spectrometry (MS) remains challenging, particularly when training artificial intelligence (AI) models under small-sample constraints. Performance is often hampered by the high dimensionality of spectral data and the subtle nature of resistance-related signals: full-spectrum approaches risk overfitting to high-dimensional noise, whereas peak-selection strategies risk discarding structurally informative, low-intensity signals. Here, we propose ReShuffle-MS, a region-guided data augmentation framework for MS data. Each spectrum is partitioned into a Main Discriminative Region (MDR) and a Peripheral Peak Region (PPR). By recombining signals within the PPR across samples of the same class while keeping the MDR intact, ReShuffle-MS generates structure-preserving augmented samples. On a clinical dataset for Escherichia coli (E. coli) levofloxacin resistance prediction, ReShuffle-MS delivered significant and consistent performance gains. It improved the average accuracy of classical machine learning models by 3.7% and enabled a one-dimensional convolutional neural network (CNN) to achieve 83.25% accuracy and 97.28% recall. Visualization using Grad-CAM revealed a shift from sparse, peak-dependent attention toward broader and more meaningful spectral patterns. Validation on the external DRIAMS-C dataset for ceftriaxone resistance further demonstrated that the method generalizes to a distinct laboratory setting and a different antibiotic target. These findings suggest that ReShuffle-MS can enhance the robustness and clinical utility of AI-based AMR prediction from routinely acquired MALDI-TOF spectra. Full article

In recent years, the incidence of breast cancer has increased significantly; therefore, much attention is being paid to research on natural plant-based raw materials in the treatment and prevention of cancer as well as in the treatment of antibiotic-resistant infections. Therefore, Chlorella vulgaris algae extract and indole-3-acetic acid (IAA)—a plant hormone with potential anticancer and antimicrobial properties—were selected for the study. The main objective was to evaluate the effect of algae extract and IAA on the proliferation of cells from three different breast cancer lines: MCF-7, ZR-75-1, and MDA-MB-231. In addition, an analysis of apoptosis and oxidative stress parameters in cancer cells was performed, as well as an assessment of IAA toxicity towards E. coli, S. aureus, and C. albicans. The results obtained allow us to conclude that the extract is effective against estrogen-dependent cells, while the effect of IAA alone varies depending on the microorganism studied, the cell line analyzed, and the concentration used. The extract in selected concentrations induces apoptosis and activates oxidative stress mechanisms, while IAA exhibits cytotoxicity at higher concentrations and stimulates proliferation at lower concentrations. This indicates the need to investigate the mechanisms of action of both Chlorella vulgaris algae extract and IAA in cancer and bacterial cells. Full article

Fermented sucuk is a fermented food product widely consumed and enjoyed by people in Türkiye. Spices and other additives are used in the production of fermented sucuk. Due to the increasing demand for natural and healthy food consumption, the need for natural additives is also growing. Propolis is naturally obtained from honeybee hives and consists of bioactive compounds with antimicrobial and antioxidant properties. Studies have been conducted on the addition of propolis to various meat and meat products, as well as other food products. However, no studies have been found on the addition of propolis to fermented sucuk. The aim was to investigate the effect of different types of propolis (red, green, brown) on the quality characteristics of fermented sucuks. Microbiological, physicochemical, textural and sensory analyses were performed on the sucuk samples produced. It was observed that propolis did not have an adverse effect on the analysis results of propolis-added sucuks. In particular, it was determined that the growth of pathogenic bacteria was inhibited in propolis-added sucuk, resulting in low TBARS values, and other analyses yielded results in line with these standards. Based on these findings, the addition of propolis has been shown to have a positive effect on the quality of fermented sucuk. Full article

The increasing problem of antibiotic resistance is a critical global health issue, necessitating the development of alternative therapeutic strategies to manage infections effectively. Among the promising solutions are human antimicrobial peptides (AMPs), naturally occurring molecules known for their broad spectrum of antimicrobial activity. Background/Objectives: This study investigates the potential of some AMPs, selected through a bioinformatic approach, as alternatives to conventional antibiotics, particularly focusing on their efficacy against species within the Bacteroidota phylum. These species, including pathogens such as Porphyromonas gingivalis, Capnocytophaga ochracea, and Capnocytophaga canimorsus, are well known for their roles in various human infections and related diseases. Non-pathogenic environmental species, such as Flavobacterium johnsoniae, are also included in this group, frequently used as a model organism. Methods: By analyzing the antimicrobial efficacy, mechanisms of action, and potential therapeutic applications of human AMPs, this research underscores their significance in addressing the challenge of antibiotic resistance. Results: This study identified three peptides, KTL24, LIR23, and MFP22, as particularly interesting. These peptides are derived from specific human proteins, namely SPI1, NAPSA and SCUB1. Conclusions: Their notable antimicrobial potential suggests that AMPs could serve either as a complementary treatment alongside traditional antibiotics or as a standalone therapy, mitigating the ongoing spread of antibiotic resistance and offering an alternative in global health strategies. Full article

Athamanta L. is a small genus of the Apiaceae family, comprising only sixteen species and subspecies, which are distributed in the Canary Islands, Central Europe, and the Mediterranean basin. Background/Objectives: Since the time of Dioscurides, the species of this genus have been reported to have had several ethnopharmacological activities, and some of them are also used currently. Athamanta sicula L., growing in Italy, Tunisia, Algeria, and Morocco, is the only species of this genus present in Sicily. To further explore the phytochemical profile and biological properties of this species, the present study focused on the essential oil (EO) extracted from the aerial parts of wild A. sicula populations collected in central Sicily. Methods: The chemical composition of the EO, obtained by hydrodistillation, was determined by GC–MS analysis. The presence of myristicin was confirmed by isolation and by ¹H-NMR spectroscopic characterization. Results: The EO and its main constituents have been tested for possible antimicrobial properties against several bacterial strains, showing MIC values in the of 15–30 mg/mL range, and the mechanism of action was further investigated, revealing membrane-targeting effects consistent with outer membrane permeabilization. In addition, antibiofilm activity (with up to ~80% inhibition of biofilm formation at sub-MICs), antioxidant potential (demonstrating dose-dependent radical scavenging activity), and biocompatibility with eukaryotic cells were assessed to provide a comprehensive pharmacological profile of A. sicula EO. Specifically, the most abundant constituent was myristicin (62.2%), the principal representative of the phenylpropanoid class (64.4%). Hydrocarbon monoterpenes represented the second class of the EO (27.4%), with β-phellandrene (12.2%) as the main compound. Conclusions: Myristicin emerged as the key contributor to the antimicrobial and antibiofilm activity of the EO. The obtained results highlight the relevance of A. sicula EO as a myristicin-rich essential oil with notable in vitro biological activity. Full article

Lactic acid bacteria (LAB) are increasingly recognized for their role in food biopreservation due to their ability to synthesize antimicrobial compounds. Milk naturally harbors a wide variety of LAB, offering a promising source for identifying strains with biopreservative potential. This study investigated the antagonistic effects, safety characteristics, and technological properties of LAB strains isolated from traditionally fermented milk. Thirty-two dairy samples were analyzed, and the resulting LAB isolates were screened for inhibitory activity against Listeria monocytogenes CECT 4032 and Staphylococcus aureus CECT 976 using agar spot and well diffusion assays. All tested strains exhibited strong antimicrobial effects, with particularly notable inhibition of L. monocytogenes. After phenotypic screening, five representative isolates were selected for molecular identification and further assessment of safety-related attributes, functional capabilities, auto- and co-aggregation properties. 16S rRNA gene sequencing revealed that four strains belonged to the genus Enterococcus, specifically, one E. faecium and three E. durans, while one was classified as a Lactococcus species. Moreover, none of the strains showed proteolytic or lipolytic activities which highlights their potential use in dairy fermentation processes. Full article

Alicyclobacillus acidoterrestris is an acidothermophilic bacterium considered a significant challenge to the food industry, particularly in the production of fruit juices and concentrates. Its ability to survive pasteurization and form spores and biofilms makes it a persistent contaminant that can spoil products and generate off-flavors even during product storage. Recent studies have increasingly focused on developing new strategies to eliminate both vegetative cells and biofilms, with special attention on natural compounds such as plant extracts, essential oils and antimicrobial metabolites. These natural agents offer promising alternatives for controlling A. acidoterrestris and might contribute to improvement in safety and quality of juice products. This article presents a comprehensive overview of current strategies for controlling Alicyclobacillus species in food processing environments, with an emphasis on A. acidoterrestris as a major spoilage organism in the fruit juice industry. It summarizes the established physical and chemical control methods, as well as highlights emerging novel approaches involving natural-origin antimicrobial compounds considered useful for mitigating Alicyclobacillus contamination. Full article

Mammarenaviruses (MaAv) cause persistent infection in their natural rodent hosts across the world and, via zoonotic events, can cause severe disease in humans. Thus, the MaAv Lassa virus (LASV) in Western Africa and the Junin virus (JUNV) in the Argentinean Pampas cause hemorrhagic fever diseases with significant case fatality rates in their endemic regions. In addition, the globally distributed MaAv lymphocytic choriomeningitis virus (LCMV) is an underrecognized human pathogen of clinical significance capable of causing devastating infections in neonates and immunocompromised individuals. Despite their impact on human health, there are currently no FDA-approved vaccines or specific antiviral treatments for MaAv infections. Existing anti-MaAv therapies are limited to the off-label use of ribavirin, whose efficacy remains controversial; hence, the development of novel therapeutics to combat human pathogenic MaAv is vital. We employed a high-throughput cell-based infection assay to screen the Pandemic Response Box, a collection of 400 diverse compounds with established antimicrobial activity, for MaAv inhibitors. We identified Ro-24-7429, an antagonist of the HIV-1 Tat protein and RUNX family transcription factor 1 inhibitor; WO 2006118607 A2, a dihydroorotate dehydrogenase inhibitor; and verdinexor, a novel selective inhibitor of nuclear export (SINE) targeting the XPO1/CRM1, as potent anti-MaAv compounds. Consistent with their distinct validated targets, verdinexor and WO 2006118607 A2 exhibited very strong synergistic antiviral activity when used in combination therapy. Our findings pave the way for the development of verdinexor as a potent host-directed antiviral against MaAv, which could be integrated into the development of combination therapy with direct- or host-acting antivirals to combat human pathogenic MaAv. Full article