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Salmonella is one of the most common pathogens causing foodborne diseases. Eggs and egg products are important food vehicles for its transmission. Among the many serotypes of Salmonella, S. enterica serovar Enteritidis has a unique advantage in surviving egg white because of its resist to antibacterial molecules in egg white, which can lead to food poisoning. In recent years, the survival strategies of S. enteritidis serovar Enteritidis in egg white have been explored by using molecular biological techniques such as transposon mutations, in vivo expression, high-throughput sequencing and omics, and some key metabolic pathways and stress resistance-related genes/proteins have been discovered. However, the function of stress resistance-related genes has not been fully revealed, and there is a lack of a comprehensive summary of the existing research. Therefore, the current situation and transmission routes of Salmonella contaminated eggs are briefly introduced in this review. Furthermore, the latest progress in research on the survival mechanism of S. enteritidis serovar Enteritidis in egg white is summarized from the perspectives of nutrient availability, membrane stress response, deoxyribonucleic acid (DNA) damage repair, alkaline pH adaptation, osmotic stress response and energy metabolism. Finally, the biological control methods for Salmonella are summarized, including vaccines, bacteriophages, and probiotics. Meanwhile, future research directions are discussed. This article will provide an important reference for effective control of Salmonella in eggs and egg products.

Benzalkonium chloride is a quaternary ammonium compound with bactericidal activity, which is widely used in domestic and healthcare settings as well as in food processing environments. It plays an important role in the prevention and control of foodborne pathogens. However, the presence of biofilms or improper use of benzalkonium chloride may enable foodborne pathogens to adapt to bactericides, affecting the tolerance to homologous or heterologous biocidal agents. The review summarizes the relationship between the adaptation of foodborne pathogens to benzalkonium chloride and their tolerance to this biocide. The reasons for the increased tolerance to benzalkonium chloride are explained from the perspectives of the expression of efflux pump genes, cell membrane modification, and the formation of the viable but non-cultivable (VBNC) state. Furthermore, the influence of benzalkonium chloride adaptation on the antibiotic resistance of foodborne pathogens is discussed, and the reasons for the increased antibiotic resistance are summarized from the perspectives of biofilm formation, spontaneous mutations, horizontal gene transfer, and the role of efflux pumps in antibiotic resistance. This review could help understand the mechanism of the adaption of foodborne pathogens to benzalkonium chloride and provide a reference for the rational use of biocides and the prevention and control of foodborne pathogens.

ObjectiveThe contamination of foodborne pathogens in ready-to-eat fruits and vegetables in Shanghai was analyzed to provide a scientific basis for food safety， risk assessment and related supervision.MethodsFrom June to September 2021， a total of 143 batches of 12 kinds of ready-to-eat fruits and vegetables such as lettuce， chicory， and cherry tomatoes were collected from farmers’ markets， supermarkets， and e-commerce platforms. The total number of bacterial colonies， Salmonella， Listeria monocytogenes， Staphylococcus aureus， Cronobacter spp. and Shiga toxin-producing Escherichia coli in the samples were tested according to National Food Contamination and Harmfulness Risk Monitoring Manual.ResultsAmong the 143 batches， foodborne pathogens were detected in 68 batches， with a total detection rate of 47.55% （68/143）. A total of 79 strains of foodborne pathogens were detected. The detection rate of Staphylococcus aureus was the highest （32.87%， 47/143）， followed by Cronobacter spp. （20.98%， 30/143）， Salmonella （0.70%， 1/143）， Listeria monocytogenes （0.70%， 1/143）， Shiga toxin-producing Escherichia coli （0.00%）. Furthermore， the detection rate was higher in different ready-to-eat fruits and vegetables： chicory （17.33%）， cucumber （17.14%）， cherry tomatoes （16.00%）， and honeydew melon （15.38%）， respectively. Meanwhile， the contamination rate of pathogens in ready-to-eat fruits and vegetables from farmers’ markets， supermarkets， and e-commerce platforms was relatively high.ConclusionReady-to-eat fruits and vegetables in Shanghai are contaminated by foodborne pathogens. The prevention and control of the contamination of post-harvest fruits and vegetables should be strengthened to reduce the risk of foodborne disease outbreaks.

Solid bubbles have expanded the SERS assay toolbox, but their detection performance in biofluids is still hampered by the irrational design of the plasmonic sensing interface. A plasmonic bubble aggregate‐driven DNA‐encoded SERS assay is reported here that enables simultaneous, ultrasensitive, and specific detection of multiple miRNAs in blood samples for accurate cancer diagnosis. In this assay, the buoyancy of plasmonic bubbles allows them to self‐aggregate at a droplet apex for SERS reconfiguration, form single‐layer bubble aggregates with plasmonic nanogaps, and prevent the coffee ring effect during evaporation assembly. Furthermore, DNA‐encoded plasmonic bubbles seamlessly couple with dual‐color catalytic hybridization assembly to amplify the specific miRNA‐responsive Raman signal, and function as both an analyte concentrator and a Raman signal aggregator without external forces. Using these merits, this magnet‐free, portable assay achieves femtomolar dual‐miRNA quantitation with single‐base resolution, simultaneous miRNA detection across four cell lines, and accurate cancer diagnosis (AUC = 1) via analyzing 40 blood samples with machine learning, thus providing a promising tool for clinical diagnosis. [ABSTRACT FROM AUTHOR]

Tumor‐derived circulating extracellular vesicles (EVs) provide a non‐invasive solution for cancer diagnostics, but hampered by challenges in EVs isolation and profiling. Herein, this work shows that bioorthogonal microbubbles (click bubbles) combine a panel of fluorescent aptamers for streamlined isolation and profiling of oncologic EVs in a single assay. This click bubble‐driven aptasensor (cBAS) features self‐aggregation, self‐separation and self‐enhancing in fluorescence. The facile protein phase transition renders bubble surface polyvalent with rich clickable motifs, enabling fast enrichment of EVs. Moreover, the buoyancy allows click bubbles to self‐float to the droplet apex for self‐aggregated fluorescence enhancement via a bubble lensing effect, thus achieving a sensitive profiling of EVs without requiring additional signal amplification or ultrasensitive detectors. By using cBAS to profile EVs surface proteins from a cohort (n = 45) across three cancer types, a machine learning algorithm enables cancer diagnosis and classification with an overall accuracy of 91%. This EVs‐on‐a‐bubble assay is fast, sensitive, self‐powered, and provides a promising tool to facilitate EVs‐based cancer diagnosis in clinical settings. [ABSTRACT FROM AUTHOR]