Search Results (447)

Biofilms are structured microbial communities that pose significant challenges to food safety and quality within the food-processing industry. Their formation on equipment and surfaces enables persistent contamination, microbial resistance, and recurring outbreaks of foodborne illness. This review provides a comprehensive synthesis of current knowledge on biofilm formation mechanisms, genetic regulation, and the unique behavior of multi-species biofilms. The review evaluates modern detection and monitoring technologies, including PCR, biosensors, and advanced microscopy, and compares their effectiveness in industrial contexts. Real-world outbreak data and a global economic impact analysis underscore the urgency for more effective regulatory frameworks and sanitation innovations. The findings highlight the critical need for integrated, proactive biofilm management approaches to safeguard food safety, reduce public health risks, and minimize economic losses across global food sectors. Full article

The increasing demand for fresh fruits and vegetables has been accompanied by a rise in foodborne illness outbreaks linked to fresh produce. Traditional antimicrobial washing treatments, such as chlorine and peroxyacetic acid, have limitations in efficacy and pose environmental and worker health concerns. This study evaluated the effectiveness of organic acids (citric, malic, and lactic acid) and power ultrasound, individually and in combination, for the reduction in Salmonella enterica and Listeria monocytogenes on four fresh produce types: romaine lettuce, cucumber, tomato, and strawberry. Produce samples were inoculated with bacterial cocktails at 8–9 log CFU/unit and treated with organic acids at 2 or 5% for 2 or 5 min, with or without power ultrasound (40 kHz). Results showed that pathogen reductions varied based on the produce matrix with smoother surfaces such as tomato, exhibiting greater reductions than rougher surfaces (e.g., romaine lettuce and strawberry). Lactic and malic acids were the most effective treatments, with 5% lactic acid achieving a reduction of >5 log CFU/unit for S. enterica and 4.53 ± 0.71 log CFU/unit for L. monocytogenes on tomatoes. The combination of organic acids and power ultrasound demonstrated synergistic effects, further enhancing pathogen reduction by <1.87 log CFU/unit. For example, S. enterica on cucumbers was reduced by an additional 1.87 log CFU/unit when treated with 2% malic acid and power ultrasound for 2 min compared to malic acid alone. Similarly, L. monocytogenes on strawberries was further reduced by 1.84 log CFU/unit when treated with 5% malic acid and power ultrasound for 2 min. These findings suggest that organic acids, particularly malic and lactic acids, combined with power ultrasound, may serve as an effective hurdle technology for enhancing the microbial safety of fresh produce. Future research can include validating these treatments in an industrial processing environment. Full article

Food-borne botulism is a rare but serious disease caused by ingestion of botulinum neurotoxin pre-formed in food by Clostridium botulinum. Between 2006 and 2009, no foodborne botulism cases were reported in the UK. However, the period from 2010 to 2024 saw 13 cases, encompassing seven separate incidents and two outbreaks, with no reported fatalities. Cases were predominantly linked to imported, home-made, and artisanal foods, occasionally to commercial products. Diagnostic and public health challenges include delayed clinical diagnosis, delayed sample collection, inadequate specimen volumes, and the frequent unavailability of suspected food sources, hampering epidemiological investigations. The UK has an extremely low incidence of foodborne botulism with an estimated rate of 0.001 cases per 100,000 people per year, but despite this low occurrence, food botulism remains a public health emergency as it requires timely treatment and rapid reactive intervention to be undertaken by multiple regulatory agencies. Continuous professional training of medical staff, up-to-date clinical guidance, rapid diagnostic, and food investigations are essential for optimising patient outcomes and prevention. Full article

Botulism is a severe muscle paralysis disease mediated by the botulinum toxin. Here, we reported a foodborne botulism case caused by Clostridium botulinum subtype A5(b3) from self-packaged vacuum spicy rabbit heads. Treatment for this case was delayed due to misdiagnosis and insufficient diagnostic capacity in three hospitals, which resulted in progressive clinical deterioration, and eventually, the patient was transferred to Shandong Public Health Clinical Center for specialized therapy. The case was suspected as foodborne botulism by the Qilu Medical-Prevention Innovation Integration pathway and multi-disciplinary consultation. An epidemiological investigation and laboratory confirmation revealed that the botulinum neurotoxin originated from vacuum-packaged spicy rabbit heads distributed via interprovincial cold chain logistics. After treatment with botulism antiserum, the patient’s condition significantly improved, and they were discharged after recovery. We revealed that this foodborne botulism outbreak was caused by the Clostridium botulinum A5(b3) subtype from food by whole-genome sequencing and SNP typing. All the strains belonged to Group I carrying the botulinum neurotoxin gene classified as the ha cluster. Toxin A was confirmed by MBA and other methods, while toxin B was non-functional due to the truncated bont/B gene. Other virulence genes and antibiotic resistance genes were also detected. Our findings indicate that self-packaged vacuum meat products represent an emerging risk factor for botulism transmission when stored improperly. Importantly, the recurrent misdiagnosis in this case underscored the urgent need to enhance the training of healthcare professionals in medical institutions to improve the diagnostic accuracy and clinical management of botulism. Full article

Background/Objective: Non-typhoidal Salmonella is a leading cause of foodborne illness worldwide and presents a significant One Health concern due to zoonotic transmission. Although antibiotic therapy remains a standard approach for treating salmonellosis in severe cases in animals, the widespread misuse of antibiotics has contributed to the emergence of multidrug-resistant (MDR) Salmonella strains. This study provides insights into the genotypic and phenotypic characteristics among Salmonella isolates from necropsied cattle. Methods: A total of 1008 samples were collected from necropsied cattle. Salmonella enterica subspecies were identified by MALDI-TOF MS and subsequently confirmed by serotyping. The biofilm-forming ability of the isolated bacteria was assessed using a crystal violet assay. The motility of the isolates was assessed on soft agar plates. Additionally, the antimicrobial resistance genes (ARGs) and virulence genes were investigated. Antimicrobial resistance patterns were investigated against 19 antibiotics representing 9 different classes. Results:Salmonella species were isolated and identified in 27 necropsied cattle. Salmonella Dublin was the most prevalent serotype (29.6%). Additionally, all the isolates were biofilm producers at different levels of intensity, and 96.3% of the isolates exhibited both swarming and swimming motility. Furthermore, virulence genes, including invA, hilA, fimA, and csgA, were detected in all the isolates. The highest resistance was observed to macrolides (azithromycin and clindamycin) (100%), followed by imipenem (92.6%), and chloramphenicol (85.2%). All isolates were multidrug-resistant, with a multiple antibiotic resistance (MAR) index ranging between 0.32 and 0.74. The aminoglycoside resistance gene aac(6′)-Ib was detected in all the isolates (100%), whereas the distribution of other antimicrobial resistance genes (ARGs) varied among the isolates. Conclusions: The increasing prevalence of MDR Salmonella poses a significant public health risk. These resistant strains can reduce the effectiveness of standard treatments and elevate outbreak risks. Strengthening surveillance and regulating antibiotic use in livestock are essential to mitigating these threats. Full article

This study aimed to investigate the prevalence, antimicrobial resistance (AMR), and virulence characteristics of Vibrio parahaemolyticus (V. parahaemolyticus) isolated from olive flounder (Paralichthys olivaceus) and rockfish (Sebastes schlegelii) sashimi samples sold in South Korea from 2021 to 2022. A total of 500 fish samples were analyzed, from which 17 V. parahaemolyticus isolates were obtained. Antibiotic susceptibility testing using the minimum inhibitory concentration method revealed that 58.8% (10/17) of the isolates exhibited resistance to ampicillin, indicating the potential for AMR transmission in seafood-associated pathogens. Whole-genome sequencing (WGS) and a polymerase chain reaction detected the presence of tlh and trh virulence genes in all isolates, suggesting their pathogenic potential. Although the overall isolation rate of V. parahaemolyticus was low, the presence of virulence and AMR genes indicates public health relevance associated with raw seafood consumption. The increasing consumer demand for raw fish, coupled with environmental changes such as rising ocean temperatures, underscores the necessity of continuous surveillance to prevent foodborne outbreaks. These findings emphasize the need for targeted AMR monitoring and further research to mitigate the dissemination of resistant V. parahaemolyticus strains and enhance seafood safety. Full article

Escherichia coli (E. coli) remains a major concern in poultry production due to its ability to incite foodborne illness and public health crisis, zoonotic potential, and the increasing prevalence of antibiotic-resistant strains. The contamination of poultry products with pathogenic E. coli, including avian pathogenic E. coli (APEC) and Shiga toxin-producing E. coli (STEC), presents risks at multiple stages of the poultry production cycle. The stages affected by E. coli range from, but are not limited to, the hatcheries to grow-out operations, slaughterhouses, and retail markets. While traditional detection methods such as culture-based assays and polymerase chain reaction (PCR) are well-established for E. coli detection in the food supply chain, their time, cost, and high infrastructure demands limit their suitability for rapid and field-based surveillance—hindering the ability for effective cessation and handling of outbreaks. Biosensors have emerged as powerful diagnostic tools that offer rapid, sensitive, and cost-effective alternatives for E. coli detection across various stages of poultry development and processing where detection is needed. This review examines current biosensor technologies designed to detect bacterial biomarkers, toxins, antibiotic resistance genes, and host immune response indicators for E. coli. Emphasis is placed on field-deployable and point-of-care (POC) platforms capable of integrating into poultry production environments. In addition to enhancing early pathogen detection, biosensors support antimicrobial resistance monitoring, facilitate integration into Hazard Analysis Critical Control Points (HACCP) systems, and align with the One Health framework by improving both animal and public health outcomes. Their strategic implementation in slaughterhouse quality control and marketplace testing can significantly reduce contamination risk and strengthen traceability in the poultry value chain. As biosensor technology continues to evolve, its application in E. coli surveillance is poised to play a transformative role in sustainable poultry production and global food safety. Full article

Steak tartare is a ready-to-eat (RTE) meat product, prepared with finely chopped or ground raw beef, with a rich culinary history and increasing consumption trend in the last years. Yet, its microbiological safety and technological challenges remain largely under-investigated. This review analyses the regulations, the safety, and technological advances in steak tartare manufacturing, focusing on microbiological risks due to potential contamination by pathogens like Salmonella spp., Listeria monocytogenes, and Escherichia coli O157:H7. From this perspective, the outbreaks associated with the consumption of raw meat products have confirmed the importance of good hygiene practice and process control, currently based on the presence of nitrite in the formulation and accurate cold chain management. Recently, the EU regulations have set stricter limits for the use of nitrites and nitrates in meat products, and this evolution has increased the interest in natural alternatives. The scientific literature indicates that plant-based antimicrobials, high-pressure processing (HPP), and novel starter cultures can be promising tools to improve raw meat safety and shelf life. This review analyses the possible options for nitrite replacement, which might involve combined interventions with natural antimicrobials, starter cultures, and packaging solutions. Future studies need to address the microbial behaviour and dynamics in nitrite-free formulations, including safety validation by challenge testing with foodborne pathogens. In this respect, steak tartare could be a model for innovation in the meat industry. However, considering the challenges that must be faced, collaboration across disciplines will be essential to meet regulatory constraints and consumer expectations while ensuring product quality and safety. Full article

Staphylococcus aureus is a leading cause of foodborne intoxication globally, driven by its heat-stable enterotoxins (SEs), which pose significant public health risks. This review critically evaluates modern and traditional methodologies for detecting S. aureus and its enterotoxins in food matrices, emphasizing their principles, applications, and limitations. The review includes a dedicated section on sample preparation and pretreatment methods for diverse food substrates, addressing a critical gap in practical applications. Immunological techniques, including ELISA and lateral flow assays, offer rapid on-site screening but face matrix interference and variable sensitivity challenges. Molecular methods, such as PCR and isothermal amplification, provide high specificity and speed for bacterial and toxin gene detection but cannot confirm functional toxin production. Sequencing-based approaches (e.g., WGS and MLST) deliver unparalleled genetic resolution for outbreak tracing but require advanced infrastructure. Emerging biosensor technologies leverage nanomaterials and biorecognition elements for ultra-sensitive real-time detection, although scalability and matrix effects remain hurdles. Mass spectrometry (MALDI-TOF MS) ensures rapid species identification but depends on pre-isolated colonies. Traditional microbiological methods, while foundational, lack the precision and speed of molecular alternatives. The review underscores the necessity of context-driven method selection, balancing speed, sensitivity, and resource availability. Innovations in multiplexing, automation, AI-based methods, and integration of complementary techniques are highlighted as pivotal for advancing food safety surveillance. Standardized validation protocols and improved reporting of performance metrics are urgently needed to enhance cross-method comparability and reliability in outbreak settings. Full article

The global consumption of fresh and ready-to-eat (RTE) fruits and vegetables has surged due to increasing awareness of their nutritional benefits. However, this trend has been accompanied by a rise in foodborne illness outbreaks linked to microbial contamination. This narrative review synthesizes current knowledge on the prevalence and diversity of foodborne pathogens in fresh produce, including bacterial, viral, and fungal agents. It critically evaluates both conventional and emerging detection methods, ranging from culture-based techniques and immunoassays to advanced molecular diagnostics, biosensors, flow cytometry (FC), and hyperspectral imaging (HSI). Additionally, this review discusses cutting-edge control strategies, such as natural antifungal agents, essential oils, biocontrol methods, and non-thermal technologies like cold plasma and UV-C treatment. Emphasis is placed on sampling methodologies, sustainability, One Health perspectives, and regulatory considerations. By highlighting recent technological advances and their limitations, this review aims to support the development of integrated, effective, and safe microbial control approaches for the fresh produce supply chain. Full article

Salmonella spp. represent a food safety risk in the production chain because of their potential for biofilm development. This study examined the biofilm formation of eight Salmonella serotypes from diverse foodborne outbreaks on three food-contact surfaces, stainless steel, silicone, and nylon, at 10 °C and 37 °C. The effect of temperature was observed in slower biofilm formation at 10 °C with about 5-log (cfu/cm²) after 24 h, contrasting with 7-log (cfu/cm²) at 37 °C. The material also influenced biofilm formation, with the strongest biofilms on stainless steel at 10 °C and silicone at 37 °C. The serotypes producing the strongest biofilms were S. Enteritidis, S. Saint Paul, and S. Montevideo. The weakest serotypes were S. Senftenberg, S. Anatum, and the avirulent S. Typhimurium. The production of extra-polymeric substances was evident with S. Enteritidis. The biofilm index showed the highest value for low temperature, nylon, and silicone, and for S. Montevideo, S. Enteritidis, and S. Saint Paul. The whole-genome sequencing of each serovar suggested that single nucleotide polymorphisms in the curli (csg) genes may have contributed to the strong biofilm-forming ability of S. Montevideo and S. Saint Paul and the weaker ability of S. Senftenberg. These results can help with the correct development of sanitizing interventions based on the Salmonella strain of concern. Full article

Cryptosporidium spp. oocysts are highly resistant to conventional disinfection methods and have been associated with foodborne outbreaks linked to unpasteurized fruit and vegetable juices. This study aimed to evaluate the effectiveness of Pulsed Electric Fields (PEF) in permeabilizing Cryptosporidium oocysts in water, apple juice, and carrot juice. Oocysts were exposed to monopolar square-wave pulses (3 µs) at electric field strengths ranging from 15 to 35 kV/cm, with treatment times up to 180 µs, and application temperatures between 25 °C and 60 °C. Membrane permeabilization was assessed using propidium iodide uptake via fluorescence microscopy and flow cytometry. Results showed that oocyst permeabilization increased with electric field strength, treatment time, and temperature, with up to 90% permeabilization achieved at 35 kV/cm and 45 °C. Carrot juice treatments yielded higher permeabilization levels than apple juice, attributed to greater electrical conductivity and energy input. Temperatures below 60 °C alone had negligible effects, but synergistically enhanced PEF efficacy. These findings demonstrate that PEF, particularly when combined with mild heat, is a promising non-thermal technology for reducing Cryptosporidium viability in beverages, offering an effective alternative for improving the microbiological safety of minimally processed juices while preserving sensory and nutritional quality. Full article

Vegetables are commodities frequently sold in local markets and have been associated with foodborne outbreaks in short and local supply outlets worldwide. These outbreaks could potentially be mitigated through the implementation of good handling practices (GHPs) at points of sale. Numerous studies have assessed microbiological contamination in small-scale vegetable outlets in developing countries. In contrast, research on these risks in developed countries is comparatively scarce. However, with the increasing demand for vegetables, along with the increasing popularity of local markets, there is potential for an increase in foodborne outbreaks in developed countries. This study aimed to perform a microbiological assessment in local and short supply chain outlets of farmers in Portugal, as a case study, and to observe behaviors regarding GHPs in these outlets. The study was performed before and after the implementation of improved GHPs. This research employed quantitative analysis to measure the microbial load on vegetables, bench surfaces, and vendors’ hands. Additionally, a qualitative analysis was conducted to understand farmers’ behavior regarding GHPs using observational methods. Microbial hazards were detected in vegetables, on surfaces, and on hands both before and after the implementation of these practices, although the implementation of GHPs reduced the number of contaminations potentially associated with the practices used at the outlets. The results of this study highlight the importance of implementing GHPs in local and short supply chain markets for vegetables and fruits in developed countries, not only to protect consumers’ health, but also the farmers’ businesses. Full article

Shiga-toxin-producing E. coli (STEC) is a leading causing of bacterial foodborne and zoonotic illnesses in the USA. Whole-genome sequencing (WGS) is a powerful tool used in public health and microbiology for the detection, surveillance, and outbreak investigation of STEC. In this study, we applied three WGS-based subtyping methods, high quality single-nucleotide polymorphism (hqSNP) analysis, whole genome multi-locus sequence typing using chromosome-associated loci [wgMLST (chrom)], and core genome multi-locus sequence typing (cgMLST), to isolate sequences from 11 STEC outbreaks. For each outbreak, we evaluated the concordance between subtyping methods using pairwise genomic differences (number of SNPs or alleles), linear regression models, and tanglegrams. Pairwise genomic differences were highly concordant between methods for all but one outbreak, which was associated with international travel. The slopes of the regressions for hqSNP vs. allele differences were 0.432 (cgMLST) and 0.966 wgMLST (chrom); the slope was 1.914 for cgMLST vs. wgMLST (chrom) differences. Tanglegrams comprised of outbreak and sporadic sequences showed moderate clustering concordance between methods, where Baker’s Gamma Indices (BGIs) ranged between 0.35 and 0.99 and Cophenetic Correlation Coefficients (CCCs) were ≥0.88 across all outbreaks. The K-means analysis using the Silhouette method showed the clear separation of outbreak groups with average silhouette widths ≥0.87 across all methods. This study validates the use of cgMLST for the national surveillance of STEC illness clusters using the PulseNet 2.0 system and demonstrates that hqSNP or wgMLST can be used for further resolution. Full article

The consumption of fresh produce has significantly increased in recent years, contributing to improved diets through the provision of essential nutrients, vitamins, and fiber. However, there has been a rise in foodborne illness outbreaks linked to fruits and vegetables, often caused by pathogens such as Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes. These outbreaks have led to severe health consequences, including illnesses, hospitalizations, and even deaths. Once produce is contaminated by foodborne pathogens, these pathogens are difficult to eliminate. Traditional decontamination methods, such as water washes and chlorine-based sanitizers, have been widely used to address these microbial concerns. However, these methods may not be effective against pathogens in crevices or biofilms on the surface of produce, and their effectiveness varies depending on the type of produce and pathogens. Moreover, the chemicals used may raise health and environmental concerns. As a result, novel technologies for pathogen inactivation are gaining attention. These include ozone, ultraviolet light, cold plasma, pulsed light, ultrasound, microbubbles, nanobubbles, electrolyzed water, high-pressure processing, chlorine dioxide gas, and among others. This paper reviews a range of emerging and innovative technologies for the sanitization of fresh produce. The mechanisms, advancements, and practical applications of these technologies are examined with a focus on enhancing food safety and preserving produce quality. These innovative methods provide new opportunities for both research and industry to develop practical, affordable, and safe solutions for maintaining produce safety and quality. Recent studies highlight the effectiveness of combining methods, showing that using multiple sanitization techniques can significantly improve pathogen inactivation on fresh produce. For example, more than 5 log reductions of Listeria innocua and E. coli on avocado, watermelon, and mushroom can be achieved with the combined application of pulsed light and malic acid in previous research. In this review, we recommend the application of combined sanitization methods, emphasizing that integrating multiple techniques can provide a more effective and comprehensive approach to pathogen inactivation. This combined-method strategy has become a promising and innovative trend in the ongoing efforts to improve produce safety and quality. Full article