Search Results (143)

Staphylococcus aureus is a major food safety concern because of its ability to produce heat-stable enterotoxins, develop antimicrobial resistance, and express virulence factors associated with persistence and pathogenicity. The present study characterised S. aureus isolates recovered from ready-to-eat (RTE) foods and food handlers’ hands in university food service establishment in northern Portugal, focusing on virulence-associated genes, antimicrobial resistance profiles, and biofilm production. A total of 261 samples were analysed, including 156 RTE food samples and 105 hand swabs. Twenty-nine coagulase-positive staphylococci isolates were recovered and confirmed as S. aureus by detection of the nuc gene, corresponding to an overall prevalence of 11.11% (29/261). Of these, 20 isolates were obtained from food handlers’ hands and 9 from RTE foods. The hla and sei genes were detected in all isolates, while seg and tst were detected in 93.10%; sed was not detected. Biofilm-forming capacity was identified in 44.83% of isolates, with most strains exhibiting weak to moderate biofilm production. Resistance to at least one antimicrobial agent was observed in 31.0% of isolates, and presumptive methicillin-resistant Staphylococcus aureus represented 13.79%, all classified as multidrug-resistant. These findings support the occurrence of handling-related contamination and reinforce the need for strict hygiene practices, temperature control, and continuous monitoring in institutional food service environments. Full article

Buffalo meat is widely consumed in Egypt; however, it may pose serious food safety risks due to microbial contamination during handling, preparation, and processing. This study investigated the prevalence and characterization of multidrug-resistant (MDR) enterotoxigenic Staphylococcus aureus in raw ground buffalo meat and ready-to-eat (RTE) kofta and liver sandwiches marketed in Mansoura, Egypt. S. aureus was detected in 62% (62/100) of raw buffalo ground meat, 41% (41/100) of RTE kofta, and 60% (60/100) of RTE liver samples, with an overall prevalence of 54.3% (163/300). All 660 isolates were confirmed as S. aureus via nuc gene detection, among which 46.8% (309/660) were mecA-positive and verified as methicillin-resistant (MRSA), and 21.8% (144/660) were vanA-positive and verified as vancomycin-resistant (VRSA). Enterotoxigenic strains were identified in 42.7% (282/660) of isolates, with the sea gene being most prevalent (67.7%; 191/282), followed by seb (58.2%; 164/282) and sec (39.7%; 112/282). The highest frequency of enterotoxigenic strains occurred in raw ground meat (47.2%), followed by kofta (45.1%) and liver (36%). Antimicrobial susceptibility testing against 15 antibiotics revealed that 7.6% (50/660) of isolates were extensively drug-resistant (XDR) with a MAR index of 0.9, while 82.9% (547/660) were MDR with MAR values between 0.3 and 0.7, indicating exposure to environments of intensive antibiotic use. The present findings highlight a high contamination level of buffalo meat products with MDR enterotoxigenic MRSA and VRSA, representing a significant public health hazard. Implementation of strict hygiene measures, wise antibiotic usage, and continuous surveillance is essential to control their dissemination through the food chain. Full article

Apple pomace is a widely available food processing by-product that has attracted increasing attention in circular and resource-efficient food systems for its potential in value-added food applications. The use of apple pomace in ready-to-eat (RTE) plant-based meat analogs represents a promising pathway. Unlike plant-based meats intended for cooking, RTE systems impose stricter constraints on structural stability, water retention, flavor integrity, and safety under cold chain conditions. Within this framework, apple pomace represents a compositionally complex material with both opportunities and constraints. This review examines how apple pomace and its derived ingredients can be utilized in RTE plant-based meat analogs, with particular attention to the distinct structural and functional requirements of minced-type and whole-cut products. Current evidence indicates that direct incorporation is more feasible for minced systems, where apple pomace fiber and pectin can support water retention, binding, and refrigerated slice stability when particle size, hydration, and sensory limits are controlled. By contrast, whole-cut applications are more likely to require fractionation, selective extraction, or additional structuring because particulate heterogeneity may disrupt continuous phase integrity and anisotropic structure formation. The review further identifies the main barriers to industrial translation, including water management under refrigerated conditions, flavor and color deviations, challenges in raw material standardization, and techno-economic constraints related to dewatering, processing intensity, and quality control. Overall, this review indicates that apple pomace can function as a technically relevant ingredient in RTE plant-based meat analogs. Its successful implementation depends on converting compositional complexity into predictable functionality through raw material standardization, controlled fraction use, food safety verification, and economically viable processing. In this way, sustainability-driven valorization can be better aligned with the practical requirements of industrial food production. Full article

Obesity has emerged as a significant global public health challenge, yet the clinical utility of existing anti-obesity drugs is often constrained by limited efficacy and adverse safety profiles. Rheum tanguticum Maxim. ex Balf., a traditional medicinal plant, has shown potential in modulating glucose and lipid metabolism; however, its specific anti-obesity mechanisms remain poorly characterized. In this study, the chemical profile of the 60% ethanol-eluted fraction of R. tanguticum (RTE) was characterized via UPLC-QTOF/MS, followed by network pharmacology analysis to predict regulatory targets and enriched pathways. Subsequently, a high-fat diet (HFD)-induced obese mouse model was established to evaluate the anti-obesity effects of RTE by monitoring body weight, Lee’s index, fat-to-body weight ratio, serum lipid profiles, and liver histopathological changes. A total of 14 major compounds, primarily anthraquinone glycosides, were identified. Integrated network analysis identified 10 hub targets, including TNF, EGFR, and TP53. In vivo experiments demonstrated that RTE significantly attenuated body weight gain and reduced Lee’s index, fat-to-body ratios, and serum levels of TC, TG, and LDL-C. Furthermore, RTE treatment markedly alleviated hepatic steatosis and inflammatory infiltration in obese mice. These findings suggest that RTE exerts potent anti-obesity effects through a multi-target and multi-pathway mechanism that regulates lipid metabolism and suppresses inflammation. This study improves our understanding of the pharmacological value of R. tanguticum and provides a scientific basis for its development as a functional food ingredient or therapeutic agent against obesity. Full article

With rising incidence in recent years, Listeriosis, a severe foodborne disease in humans primarily transmitted through ready-to-eat (RTE) foods contaminated with Listeria monocytogenes, became the most severe zoonotic disease in the European Union (EU) in 2024 with the highest hospitalization and mortality rates, prompting stricter regulatory requirements under Regulation (EC) No 2073/2005 and its recent amendments. This systematic literature review aimed to evaluate the availability, validity and quality of published challenge test data on the growth potential and maximum growth rate of Listeria monocytogenes in RTE foods to identify data gaps and, if possible, to support the derivation of a classification of RTE foods into the two existing regulatory categories, a and b (not able and able to support the growth of Listeria monocytogenes). Conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Cochrane Handbook, a comprehensive database search was done to identify eligible challenge test studies on Listeria monocytogenes growth in RTE foods, followed by structured screening and quality assessment based on the EURL Lm Technical Guidance Documents. A limited and heterogeneous body of published challenge test data on the growth potential and maximum growth rate of Listeria monocytogenes in RTE foods was identified, with substantial data gaps across multiple food groups, precluding meta-analysis and limiting regulatory applicability under the current regulations. Overall, the available literature is insufficient to reliably support regulatory classification or to enable direct extrapolation by food business operators (FBO), underscoring the need for product-specific investigations and food group-specific guidance for food safety. Full article

Refrigerated, ready-to-eat (RTE) vegetable foods are widely consumed. Microorganisms may proliferate in these foods during cold chain breaks, increasing the risks for food spoilage and foodborne disease. Despite the increasing use of novel non-thermal preservation technologies, the comprehensive impact of these hurdles on the broad taxonomic structural dynamics of the food microbiota during temperature abuse remains poorly understood. To address this gap, we determined the impact of bacteriocin AS-48 and a high hydrostatic pressure (HHP) treatment, both individually and in combination, on the microbial load and bacterial diversity of a refrigerated vegetable cream upon temperature abuse. Counts of aerobic mesophilic bacteria (37 °C, 24 h) increased significantly (p < 0.05) in controls during temperature abuse, but not in samples treated with bacteriocin, HHP or both. Amplicon-sequencing analysis indicated that the initial microbiota of control samples was composed mainly of Pseudomonadota (74.50%), followed by Bacillota (21.19%) and Actinobacteriota (3.69%). Bacillota became the predominant group during refrigerated storage (87.21 to 99.48%). After temperature abuse, control samples had lower relative abundances of Bacillota during storage and higher relative abundances of Pseudomonadota, Bacteroidota and Actinobacteriota. All treated samples (irrespective of the treatment) showed lower relative abundances of Bacillota during storage compared to untreated controls without temperature abuse. Genus Bacillus was the predominant group in the control samples during storage. Acinetobacter was associated with temperature abuse. In conclusion, both enterocin AS-48 and HHP can be effective hurdles, not only by preventing bacterial proliferation but also by influencing the dynamics of the microbial community associated with spoilage in vegetable creams exposed to inappropriate temperature conditions. Full article

Listeria monocytogenes is considered a highly persistent risk for public health in food production facilities. Food business operators manufacturing ready-to-eat foods (RTE) are required to sample processing areas for L. monocytogenes as part of their environmental monitoring plans. The aim of the study was to identify suitable sampling devices, demonstrating the crucial role of the sampling technique in the method performance for L. monocytogenes monitoring. Detection of Listeria spp. and L. monocytogenes from surfaces in an RTE food production facility was evaluated by using two different sampling methods (swabs and sponges). When using swabs, 46 sampling points were negative for both targets. However, when sampling same points with sponges, 30% samples (14 out of 46) were positive for Listeria spp. with 8 samples (17%) positive for L. monocytogenes. During subsequent in vitro experiments, L. monocytogenes strains spiked onto three different surfaces (stainless steel, Teflon and epoxy) showed recoveries of between 76% and 93% when using sponges, while in swabs, recoveries where always below 50%. All L. monocytogenes strains isolated belonged to the major clonal complexes (CC) circulating in Europe in food industry (e.g., CC121 and CC9) and none of them are considered among the hypervirulent strains. Genomic analysis, including new tools for source tracking (Gene Up Typer, bioMérieux) showed differences between strains isolated from different risk hygienic zones. Full article

Ready-to-eat (RTE) fresh salads are widely consumed for their convenience and nutritional value, but they could represent a relevant food safety concern, as they do not undergo a lethal heat treatment before consumption, and furthermore, they may support the growth of Listeria monocytogenes during refrigerated storage. In this study, the growth potential of L. monocytogenes was evaluated by standardised challenge tests in five commercially available RTE salads: crispy lettuce, baby lettuce, a baby lettuce–spicy mustard mix, and two mâche products from different producers. Three different batches for each product were inoculated with a three-strain cocktail of L. monocytogenes at a target level of approximately 2–3 log CFU/g and stored under conditions simulating reasonably foreseeable refrigerated storage (7 °C for approximately two-thirds of their shelf life, followed by 10 °C for the remaining one-third), in accordance with ISO 20976-1 and EURL L. monocytogenes guidelines. The growth potential (Δ) was calculated as the difference between the highest mean L. monocytogenes concentration observed during storage and the mean of the initial concentration at time zero, both in three replicate samples; Δmax was defined as the highest Δ value among the tested batches. Crispy lettuce, baby lettuce, and the mixed salad supported the growth of L. monocytogenes, with Δmax values of 2.33, 2.60, and 3.65 log CFU/g, respectively. In contrast, both mâche products showed Δmax values ≤ 0.5 log CFU/g, indicating an inability to support pathogen growth under the tested conditions. These results demonstrate that the growth potential of L. monocytogenes in RTE salads is strongly product-specific and likely influenced by intrinsic characteristics and background microbiota, as well as by storage temperature. The findings underline the importance of strict temperature control and product-specific risk assessment to ensure compliance with microbiological criteria throughout shelf life and to mitigate the risk of listeriosis associated with RTE salads. Full article

Background: Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) ST398 poses a significant zoonotic threat, largely due to its capacity to acquire and disseminate antimicrobial resistance through mobile genetic elements (MGEs). Ready-to-eat (RTE) foods may serve as critical interfaces for zoonotic spillover. However, genomic data on ST398-MRSA-Vc isolates from RTE foods remain scarce, leaving the characteristics of their MGEs largely unresolved. Methods: This study performed whole-genome sequencing and comparative genomic analysis of an ST398-MRSA-Vc isolate (NPREF115) from an RTE pork product in China. Using NPREF115 and 134 publicly available S. aureus genomes from diverse sources, we constructed a core genome phylogeny and conducted SNP and pangenome analyses, with a focus on MGEs. Results: Phylogenetic analysis revealed that our foodborne ST398-MRSA-Vc isolate clustered with human, Capra pyrenaica, bovine, and swine-derived ST398-MRSA-Vc isolates. SNP analysis indicated NPREF115 was most closely related to human clinical isolates (132 and 140 SNPs, respectively), consistent with shared ancestry rather than recent cross-host transmission. Genomic divergence was largely confined to MGEs, including SCCmec, prophages, genomic islands, and a chromosomally integrated Tn560 carrying the ant(9)-Ia-lsa(E)-lnu(B) multidrug resistance cluster. Notably, NPREF115 harbored a unique metabolic gene that may facilitate persistence in high-osmolarity food environments. Conclusions: The successful colonization of food by the ST398-MRSA-Vc isolate is likely associated with the acquisition of multiple MGEs harboring antimicrobial resistance genes. Transmission of ST398-MRSA-Vc between food, human, and livestock hosts was accompanied by changes in genes involved in metabolism. These findings underscore the importance of monitoring MGEs in genomic surveillance of foodborne MRSA. Full article

Acinetobacter baumannii is widely recognized as a problematic pathogen in healthcare settings due to its ability to acquire resistance to multiple antimicrobial agents. However, less attention has been given to its presence outside hospitals. In this cross-sectional, laboratory-based surveillance study, we investigated the occurrence of A. baumannii in ready-to-eat (RTE) foods sold at retail outlets in four cities of the Al-Qassim region, Saudi Arabia, during a single season. A total of 240 RTE food samples were analyzed using culture-based and molecular approaches for species confirmation, and antimicrobial susceptibility profiles were determined. A. baumannii was identified in 19 samples (7.9%), spanning several food categories. Most isolates showed resistance to multiple antimicrobial classes, and 16 met the criteria for multidrug resistance (MDR). Among the confirmed isolates, bla_OXA-23-like was detected in 16 (84.2%), bla_{OXA-24/40-like} in 2 (10.5%), and bla_OXA-58-like in 1 (5.3%). Resistance to fluoroquinolones, tetracyclines, and aminoglycosides was common, and OXA-type carbapenemase genes were detected in 16 isolates. These findings indicate that RTE foods can represent non-clinical environments in which MDR A. baumannii may be detected. Including food sources in antimicrobial resistance surveillance may therefore strengthen our understanding of the ecology of this pathogen within a One Health framework. Full article

Low-processed ready-to-eat (RTE) meat products are highly vulnerable to microbial contamination, yet data on in-process dynamics remain limited. This study investigated microbial dynamics and environmental hygiene during the production of vacuum-packed RTE pork bars containing dried plasma, with a focus on identifying process-inherent contamination risks. Samples were collected at successive processing stages and from food-contact and non-food-contact surfaces. Process hygiene was assessed using indicator organisms (Aerobic Plate Count, Enterobacteriaceae, lactic acid bacteria, yeast and mold, E. coli, S. aureus counts), while food safety relevance was addressed by monitoring Listeria monocytogenes and Salmonella spp. Microbial counts increased by approximately 1.5–2.3 log CFU/g between early processing steps, indicating that these operations are critical contamination-prone steps. Environmental monitoring revealed contamination hotspots on frequently handled surfaces, highlighting the vulnerability of pre- and post-lethality stages. Despite the baking achieving a mean microbial reduction of ~3 log CFU/g, consistent with effective thermal processing, low-level microbial reappearance during packaging and maturation indicated the potential for post-process contamination. The results demonstrate that production-inherent factors largely drive microbial contamination patterns and may persist even in facilities operating under implemented GHP, GMP, and HACCP-based procedures, highlighting step-specific limitations rather than system failure. By providing empirical data on in-process microbial dynamics, this study supports both scientifically based and risk-based approaches within Food Safety Management Systems, offering transferable insights applicable to similar RTE meat production environments. The findings may assist food business operators in optimising targeted control measures and strengthening risk-based decision-making in low-processed RTE meat production. Full article

Few studies exist on the handling practices and microbial quality of ready-to-eat (RTE) Filipino steamed rice cakes sold in public markets. This study assessed the correlation between food handling practices of public market vendors (n = 15) and the microbiological quality of steamed rice cakes. Vendors showed very good handling practices (mean = 12), though some observations deviated from self-reports. Physicochemical (pH = 4.82–5.91; aw = 0.94–0.97) and microbial analyses (Aerobic Plate Count (APC) = 8.37–12.7 log CFU/g; Yeast and Mold Count (YMC) = 9.47–10.60 log CFU/g; Escherichia coli = <1.8–3.15 MPN/g) exceeded standards. Weak negative correlations (APC = −0.62; E. coli = −0.18) and low positive correlations (YMC = 0.15) indicate a need for improved food safety guidance. Full article

Listeria monocytogenes poses a significant challenge in ready-to-eat (RTE) foods due to its persistence in processing environments and severe impact on vulnerable populations. Regulatory approaches differ internationally, reflecting distinct conceptual frameworks and tolerance thresholds. These differences arise from the adoption of zero-tolerance or risk-based regulatory models, which define qualitative or quantitative microbiological limits (absence in 25 g or up to 100 cfu/g) based on a product’s growth potential, and vary in the extent of environmental monitoring, sampling plans, and verification intensity across jurisdictions. In 2024, the European Union updated its regulatory framework governing the microbiological criteria for L. monocytogenes. Previous requirements were strengthened, responsibility was extended across the supply chain, and a strategic role was assigned to challenge testing carried out by manufacturers. This review examines how the European Union and the United States apply risk assessment principles, challenge testing, predictive modelling, and environmental monitoring to control L. monocytogenes in RTE foods. By integrating epidemiological trends, regulatory criteria, and experimental evidence, key differences in safety objectives, validation procedures, and risk management strategies are highlighted. This review also identifies gaps and opportunities for harmonisation, providing guidance for improved evidence-based decision-making and regulatory compliance. Full article

Ethylene is a multifunctional phytohormone that regulates plant growth, development, and responses to abiotic/biotic stresses. RTE1 (Reversion-To-Ethylene Sensitivity1) acts as a negative regulator of the ethylene responses in Arabidopsis by positively regulating ethylene receptor ETR1. However, the role of RTE genes in sweet potato (Ipomoea batatas), an import food crop worldwide, remains largely unknown, particularly their involvement in abiotic stress adaptation. In this study, we identified 23 RTE genes in sweet potato, distributed across 21 chromosomes and one scaffold BrgTig00017944. The phylogenetic analysis divided them into two groups, the RTE1 group and RTH (RTE1-Homolog) group. Synteny analysis revealed that whole genome duplication (WGD) was the major force of expansion of the IbRTE gene family. Multiple cis-acting elements responsive to hormones and stress were found in the promoter region of IbRTE genes. The transcriptome expression profiling showed that the majority of IbRTEs have tissue-specific and differential expression under drought and salt stresses. Meanwhile, the qRT–PCR results showed that the 14 representatives IbRTEs have differential expression profilings under salt (NaCl) and drought (PEG) treatments. These findings suggest that the IbRTE genes may be involved in sweet potato’s adaptive responses to salt and drought, providing a valuable foundation for further functional studies. Full article

Ready-to-eat (RTE) sandwiches are consumed globally due to their convenience, availability, and affordability. Sandwich processing practices and their ingredients expose the sandwiches to various sources of contamination, which can enhance their microbial diversity and introduce certain pathogenic and spoilage bacteria, thereby affecting their safety and quality. Sandwiches may not receive safe cooking temperatures sufficient to destroy food poisoning bacteria, as they are often cooked and served quickly to meet high consumer demand. Improper storage temperatures can enhance microbial growth, and frequent improper handling makes this food a good vehicle for various pathogens such as Escherichia coli, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and norovirus. Many pathogenic sandwich-associated bacteria, such as L. monocytogenes, showed resistance to clinically important antibiotics. Sandwich microbiota have been investigated; however, their diversity, antimicrobial resistance, and importance to sandwich safety and quality have been rarely reviewed. Therefore, this review elucidates the diversity of sandwich microbiota as an impact of ingredients, handling practices, and storage, with emphasis on the importance of this diversity on sandwich safety and quality. It also discusses strategies, control measures, and recommendations to reduce the risk of contamination of sandwiches with pathogenic bacteria or their antibiotic resistance genes, thereby safeguarding public health. Full article