Food microbiology最新文献_第2页

Enhanced environmental stress tolerance in reoccurring, emerging, and persistent (REP) Escherichia coli O157:H7 strains from leafy green associated outbreaks 绿叶相关暴发中复发、新发和持续性（REP）大肠杆菌O157:H7菌株的环境应激耐受性增强

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-21 DOI: 10.1016/j.fm.2026.105041

Yishan Yang , Irene Falco , Xiangwu Nou

Escherichia coli O157:H7, historically associated with undercooked beef, has increasingly been linked to leafy green associated outbreaks in the United States. A subset of strains, termed reoccurring, emerging, and persistent (REP), represented by REPEXH01 and REPEXH02, has repeatedly caused multistate outbreaks since 2017, raising concerns about their enhanced environmental fitness and persistence in leafy green production regions. In this study, we evaluated the stress tolerance profiles of representative REPEXH01 (PNUSAE013458) and REPEXH02 (2705C and PNUSAE019890) strains, using the meat-associated strain EDL933 and the spinach outbreak strain EC4115 as references. REPEXH01 strains exhibited elevated tolerance to starvation, arsenic, gastric acid, and antibiotics, traits consistent with genomic islands encoding multiple resistance determinants. REPEXH02 strains showed increased tolerance to UV-C irradiation, potentially linked to mutations in DNA repair genes. Both REP groups showed significantly higher survival than EDL933 under desiccation and blue light exposure (major antimicrobial spectrum in sunlight), underscoring their enhanced persistence in agricultural and processing environments. These findings highlight distinct adaptation strategies between REPEXH01 and REPEXH02 that may facilitate their continued recurrence in leafy green outbreaks. Understanding these stress response mechanisms provides critical insights into REP strain ecology and informs the development of improved intervention strategies to reduce produce-associated E. coli O157:H7 contamination.

大肠杆菌O157:H7历来与未煮熟的牛肉有关，现在越来越多地与美国与绿叶蔬菜有关的疫情联系在一起。自2017年以来，以REPEXH01和REPEXH02为代表的一组菌株被称为重复性、新兴和持久性（REP），多次引起多州暴发，引发了人们对它们在绿叶蔬菜生产区增强的环境适应性和持久性的担忧。本研究以肉类相关菌株EDL933和菠菜爆发菌株EC4115为参考，对具有代表性的REPEXH01 （PNUSAE013458）和REPEXH02 （pnusae02705c和PNUSAE019890）菌株的耐受性进行了评价。REPEXH01菌株对饥饿、砷、胃酸和抗生素的耐受性提高，这些特征与编码多种抗性决定因素的基因组岛一致。REPEXH02菌株对UV-C照射的耐受性增强，可能与DNA修复基因突变有关。两个REP组在干燥和蓝光暴露（阳光中的主要抗菌光谱）下的存活率均显著高于EDL933，这表明它们在农业和加工环境中的持久性增强。这些发现突出了REPEXH01和REPEXH02之间不同的适应策略，这可能促进它们在绿叶植物暴发中持续复发。了解这些应激反应机制有助于深入了解REP菌株生态学，并为制定改进的干预策略提供信息，以减少与农产品相关的大肠杆菌O157:H7污染。

{"title":"Enhanced environmental stress tolerance in reoccurring, emerging, and persistent (REP) Escherichia coli O157:H7 strains from leafy green associated outbreaks","authors":"Yishan Yang , Irene Falco , Xiangwu Nou","doi":"10.1016/j.fm.2026.105041","DOIUrl":"10.1016/j.fm.2026.105041","url":null,"abstract":"<div><div><em>Escherichia coli</em> O157:H7, historically associated with undercooked beef, has increasingly been linked to leafy green associated outbreaks in the United States. A subset of strains, termed reoccurring, emerging, and persistent (REP), represented by REPEXH01 and REPEXH02, has repeatedly caused multistate outbreaks since 2017, raising concerns about their enhanced environmental fitness and persistence in leafy green production regions. In this study, we evaluated the stress tolerance profiles of representative REPEXH01 (PNUSAE013458) and REPEXH02 (2705C and PNUSAE019890) strains, using the meat-associated strain EDL933 and the spinach outbreak strain EC4115 as references. REPEXH01 strains exhibited elevated tolerance to starvation, arsenic, gastric acid, and antibiotics, traits consistent with genomic islands encoding multiple resistance determinants. REPEXH02 strains showed increased tolerance to UV-C irradiation, potentially linked to mutations in DNA repair genes. Both REP groups showed significantly higher survival than EDL933 under desiccation and blue light exposure (major antimicrobial spectrum in sunlight), underscoring their enhanced persistence in agricultural and processing environments. These findings highlight distinct adaptation strategies between REPEXH01 and REPEXH02 that may facilitate their continued recurrence in leafy green outbreaks. Understanding these stress response mechanisms provides critical insights into REP strain ecology and informs the development of improved intervention strategies to reduce produce-associated <em>E. coli</em> O157:H7 contamination.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"137 ","pages":"Article 105041"},"PeriodicalIF":4.6,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146073586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessing the use of acid-based sanitizers for enhancing the microbial safety and quality of collard greens and kale 评估使用酸基杀菌剂提高羽衣甘蓝和羽衣甘蓝的微生物安全性和质量

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-21 DOI: 10.1016/j.fm.2026.105040

Chenxi Guo, Yucen Xie, Jaqueline Oliveira de Moraes, Luxin Wang

The consumption of collard greens (CG) and kale (KA) and different formats of their products, e.g. juices, has increased significantly. However, there have been limited studies focusing on the enhancement of the microbial quality and safety of dark leafy green vegetables (DLGVs), especially large DLGVs, despite the occurrence of several outbreaks. The larger and more rough leaf surface is one major characteristically difference between CG/KA and other DLGVs (e.g. spinach). This study evaluated the antimicrobial effectiveness of acid-based washing (vinegar, lemon juice, and peracetic acid [PAA]) in controlling the populations of native microorganisms and artificially inoculated bacteria (Enterococcus faecium) on CG and KA during washing and storage. The washing procedure included a 5 min soaking (w/v ration 1:50) and a 15 s rinsing. Results showed that PAA (80 ppm, pH ∼ 4.00) ed to the greatest reductions in native fungi (∼1.2 and 1.4 log reductions) and bacteria (∼1.0 and 1.2 log reductions on CG and KA respectively) compared to 35 % vinegar (pH ∼2.75) and 13 % lemon juice wash (pH ∼2.83). PAA-washed CG and lemon juice-washed KA also exhibited the greatest additional reductions in fungal and bacterial populations during storage. E. faecium, used as a pathogen surrogate, had the largest reductions on CG and KA washed by PAA, ∼1.5 and 2.3 log reductions respectively. Lemon juice-washed CG and PAA-washed KA showed the greatest additional reductions in E. faecium during storage. Acid washing showed promising potential in protecting the microbial safety and quality of large DLGVs; the tested washing steps can be used at retail and home settings.

羽衣甘蓝（CG）和羽衣甘蓝（KA）及其不同形式的产品（例如果汁）的消费量显著增加。然而，尽管发生了几次暴发，但关于提高深叶绿色蔬菜（DLGVs），特别是大型DLGVs的微生物质量和安全性的研究仍然有限。更大更粗糙的叶片表面是CG/KA与其他dlgv（如菠菜）之间的一个主要特征区别。本研究评估了酸基洗涤（醋、柠檬汁和过乙酸[PAA]）在洗涤和储存过程中控制天然微生物和人工接种细菌（屎肠球菌）对CG和KA的抑菌效果。洗涤过程包括5分钟浸泡（w/v比1:50）和15秒冲洗。结果表明，与35%的醋（pH ~ 2.75）和13%的柠檬汁洗涤液（pH ~ 2.83）相比，PAA （80 ppm, pH ~ 4.00）对天然真菌（降低~ 1.2和1.4对数）和细菌（分别对CG和KA降低~ 1.0和1.2对数）的影响最大。聚丙烯酸洗涤的CG和柠檬汁洗涤的KA在储存期间也表现出最大的真菌和细菌数量的额外减少。作为替代病原体的粪肠杆菌经PAA洗涤后，对CG和KA的降低幅度最大，分别为1.5和2.3 log。柠檬汁洗涤的CG和paa洗涤的KA在储存期间显示出最大的额外粪便减少。酸洗在保护大型DLGVs的微生物安全和质量方面具有广阔的应用前景；测试的洗涤步骤可用于零售和家庭设置。

{"title":"Assessing the use of acid-based sanitizers for enhancing the microbial safety and quality of collard greens and kale","authors":"Chenxi Guo, Yucen Xie, Jaqueline Oliveira de Moraes, Luxin Wang","doi":"10.1016/j.fm.2026.105040","DOIUrl":"10.1016/j.fm.2026.105040","url":null,"abstract":"<div><div>The consumption of collard greens (CG) and kale (KA) and different formats of their products, e.g. juices, has increased significantly. However, there have been limited studies focusing on the enhancement of the microbial quality and safety of dark leafy green vegetables (DLGVs), especially large DLGVs, despite the occurrence of several outbreaks. The larger and more rough leaf surface is one major characteristically difference between CG/KA and other DLGVs (e.g. spinach). This study evaluated the antimicrobial effectiveness of acid-based washing (vinegar, lemon juice, and peracetic acid [PAA]) in controlling the populations of native microorganisms and artificially inoculated bacteria (<em>Enterococcus faecium)</em> on CG and KA during washing and storage. The washing procedure included a 5 min soaking (w/v ration 1:50) and a 15 s rinsing. Results showed that PAA (80 ppm, pH ∼ 4.00) ed to the greatest reductions in native fungi (∼1.2 and 1.4 log reductions) and bacteria (∼1.0 and 1.2 log reductions on CG and KA respectively) compared to 35 % vinegar (pH ∼2.75) and 13 % lemon juice wash (pH ∼2.83). PAA-washed CG and lemon juice-washed KA also exhibited the greatest additional reductions in fungal and bacterial populations during storage. <em>E. faecium</em>, used as a pathogen surrogate, had the largest reductions on CG and KA washed by PAA, ∼1.5 and 2.3 log reductions respectively. Lemon juice-washed CG and PAA-washed KA showed the greatest additional reductions in <em>E. faecium</em> during storage. Acid washing showed promising potential in protecting the microbial safety and quality of large DLGVs; the tested washing steps can be used at retail and home settings.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"137 ","pages":"Article 105040"},"PeriodicalIF":4.6,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geographical origin authentication of whole garlic using 16S ribosomal RNA profiling of garlic microbiota and machine learning 基于大蒜微生物群16S核糖体RNA图谱和机器学习的大蒜产地鉴定

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-15 DOI: 10.1016/j.fm.2026.105039

Zhihan Xian , Shaoting Li , David A. Mann , Xiangyu Deng

Food fraud through false declarations of geographical origin poses major economic and regulatory challenges, particularly for commodities subject to trade restrictions or premium provenance labeling. Fresh garlic (Allium sativum L.), a globally traded crop, is vulnerable to origin fraud because of long-standing antidumping duties on Chinese imports to the United States. Here, we present a proof-of-concept study demonstrating that microbiota profiling provides a robust and accessible alternative to conventional chemometric approaches for garlic origin authentication. We characterized the surface bacterial communities of 153 garlic samples collected between 2021 and 2024 from China (n = 60), the United States (n = 50), and multiple other countries (n = 43) using 16S rRNA gene amplicon sequencing. Comparative analyses revealed significant differences in alpha and beta diversity across countries, with U.S. samples exhibiting the highest microbial richness and Chinese samples the lowest. Dimensionality reduction methods showed clear clustering by country of origin, supporting the presence of distinct microbial signatures. Machine-learning classifiers trained on 16S profiles achieved >0.87 accuracy across Random Forest, k-nearest neighbors, logistic regression, and support vector machine models using only five genus-level microbial features. Multi-year sampling confirmed that these microbial signals remained stable across harvest seasons. Differential abundance analyses further identified ecologically relevant taxa driving country-level separation. Together, these results establish microbiota profiling as an additional laboratory tool to help investigate garlic origin fraud.

通过虚假地理来源声明的食品欺诈构成了重大的经济和监管挑战，特别是对于受贸易限制或优质原产地标签约束的商品。新鲜大蒜（Allium sativum L.）是一种全球贸易作物，由于长期以来对中国进口到美国的商品征收反倾销税，它很容易受到原产地欺诈的影响。在这里，我们提出了一项概念验证研究，证明微生物群分析为大蒜原产地认证提供了一种强大且可访问的替代传统化学计量方法。我们利用16S rRNA基因扩增子测序技术，对2021年至2024年间从中国（n = 60）、美国（n = 50）和其他多个国家（n = 43）采集的153份大蒜样品的表面细菌群落进行了表征。比较分析显示，不同国家的α和β多样性存在显著差异，美国样品的微生物丰富度最高，中国样品的微生物丰富度最低。降维方法显示了原产地国家的清晰聚类，支持不同微生物特征的存在。仅使用5个属级微生物特征，机器学习分类器在随机森林、k近邻、逻辑回归和支持向量机模型上训练的准确率为0.87。多年的采样证实，这些微生物信号在收获季节保持稳定。差异丰度分析进一步确定了驱动国家级分离的生态相关类群。总之，这些结果建立了微生物群分析作为帮助调查大蒜原产地欺诈的额外实验室工具。

{"title":"Geographical origin authentication of whole garlic using 16S ribosomal RNA profiling of garlic microbiota and machine learning","authors":"Zhihan Xian , Shaoting Li , David A. Mann , Xiangyu Deng","doi":"10.1016/j.fm.2026.105039","DOIUrl":"10.1016/j.fm.2026.105039","url":null,"abstract":"<div><div>Food fraud through false declarations of geographical origin poses major economic and regulatory challenges, particularly for commodities subject to trade restrictions or premium provenance labeling. Fresh garlic (<em>Allium sativum</em> L.), a globally traded crop, is vulnerable to origin fraud because of long-standing antidumping duties on Chinese imports to the United States. Here, we present a proof-of-concept study demonstrating that microbiota profiling provides a robust and accessible alternative to conventional chemometric approaches for garlic origin authentication. We characterized the surface bacterial communities of 153 garlic samples collected between 2021 and 2024 from China (n = 60), the United States (n = 50), and multiple other countries (n = 43) using 16S rRNA gene amplicon sequencing. Comparative analyses revealed significant differences in alpha and beta diversity across countries, with U.S. samples exhibiting the highest microbial richness and Chinese samples the lowest. Dimensionality reduction methods showed clear clustering by country of origin, supporting the presence of distinct microbial signatures. Machine-learning classifiers trained on 16S profiles achieved >0.87 accuracy across Random Forest, k-nearest neighbors, logistic regression, and support vector machine models using only five genus-level microbial features. Multi-year sampling confirmed that these microbial signals remained stable across harvest seasons. Differential abundance analyses further identified ecologically relevant taxa driving country-level separation. Together, these results establish microbiota profiling as an additional laboratory tool to help investigate garlic origin fraud.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"137 ","pages":"Article 105039"},"PeriodicalIF":4.6,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Why is Bacillus cereus group enriched in sufu? -A study on prevalence, characterization and traceability 为什么蜡样芽孢杆菌群在腐殖质中富集？-流行、特征和可追溯性研究

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-10 DOI: 10.1016/j.fm.2026.105038

Zekun Jin , Li Li , Yin Zheng , Peipei An , Liling Lu , Zhaohui Zhou

This study aims to investigate the characteristics and contamination sources of the Bacillus cereus group in sufu to enhance food safety control. A total of 90 commercial sufu samples were analyzed, revealing a high contamination rate of 97.8 %, with 6.7 % exceeding the safety limit of 5 log CFU/g. 43 representative isolates from white, red, and spicy sufu varieties were further characterized using PCR-based virulence gene profiling, MLST, and panC gene sequence analysis. Virulence gene profiling revealed universal presence of nheABC and entFM (100 %), with cytK and the complete hblACD cluster present in 44.8 % and 11.6 % of isolates, respectively. Isolates harboring the complete nheABC or hblACD genes were confirmed to produce the corresponding Nhe or Hbl enterotoxins in soymilk. MLST and panC sequencing revealed distinct phylogenetic profiles among the isolates, with heat-resistant strains being frequently identified. To trace contamination routes, samples from a production facility, including environmental surfaces, equipment, raw materials, and semi-finished products, were analyzed using microbial culture and RAPD. The solid-state fermentation stage was identified as the critical control point for B. cereus proliferation, with raw soybeans and air serving as primary reservoirs. B. cereus introduced via raw materials adhered to equipment, forming persistent biofilms that facilitated cross-contamination. Conventional cleaning and disinfection procedures (on-site cleaning, standard food disinfectants) demonstrated limited efficacy against these biofilms. These findings systematically clarify the hazard characteristics, genetic background, and contamination pathways of B. cereus in sufu production, providing a scientific basis for targeted intervention and sanitation optimization in industrial processing.

本研究旨在了解豆腐乳中蜡样芽孢杆菌群的特点及其污染源，以加强食品安全控制。对90份商品腐乳样品进行分析，发现污染率高达97.8%，其中6.7%超过5 log CFU/g的安全限值。采用pcr法、MLST法和panC基因序列分析对43株代表性的白、红、辣腐腐素品种分离物进行了毒力基因分析。毒力基因分析显示nheABC和entFM普遍存在（100%），cytK和完整的hblACD集群分别存在于44.8%和11.6%的分离株中。携带完整的nheABC或hblACD基因的分离株被证实在豆浆中产生相应的Nhe或Hbl肠毒素。MLST和panC测序显示了不同菌株的系统发育特征，其中耐热菌株经常被鉴定出来。为了追踪污染途径，使用微生物培养和RAPD分析了生产设施的样品，包括环境表面、设备、原材料和半成品。固体发酵阶段被确定为蜡样芽孢杆菌增殖的关键控制点，生大豆和空气是主要储存库。蜡样芽孢杆菌通过附着在设备上的原料引入，形成持久的生物膜，促进交叉污染。传统的清洁和消毒程序（现场清洁，标准食品消毒剂）对这些生物膜的效果有限。这些发现系统地阐明了腐乳生产中蜡样芽孢杆菌的危害特征、遗传背景和污染途径，为工业加工中的针对性干预和卫生优化提供了科学依据。

{"title":"Why is Bacillus cereus group enriched in sufu? -A study on prevalence, characterization and traceability","authors":"Zekun Jin , Li Li , Yin Zheng , Peipei An , Liling Lu , Zhaohui Zhou","doi":"10.1016/j.fm.2026.105038","DOIUrl":"10.1016/j.fm.2026.105038","url":null,"abstract":"<div><div>This study aims to investigate the characteristics and contamination sources of the <em>Bacillus cereus</em> group in sufu to enhance food safety control. A total of 90 commercial sufu samples were analyzed, revealing a high contamination rate of 97.8 %, with 6.7 % exceeding the safety limit of 5 log CFU/g. 43 representative isolates from white, red, and spicy sufu varieties were further characterized using PCR-based virulence gene profiling, MLST, and <em>panC</em> gene sequence analysis. Virulence gene profiling revealed universal presence of <em>nheABC</em> and <em>entFM</em> (100 %), with <em>cytK</em> and the complete <em>hblACD</em> cluster present in 44.8 % and 11.6 % of isolates, respectively. Isolates harboring the complete <em>nheABC</em> or <em>hblACD</em> genes were confirmed to produce the corresponding Nhe or Hbl enterotoxins in soymilk. MLST and <em>panC</em> sequencing revealed distinct phylogenetic profiles among the isolates, with heat-resistant strains being frequently identified. To trace contamination routes, samples from a production facility, including environmental surfaces, equipment, raw materials, and semi-finished products, were analyzed using microbial culture and RAPD. The solid-state fermentation stage was identified as the critical control point for <em>B. cereus</em> proliferation, with raw soybeans and air serving as primary reservoirs. <em>B. cereus</em> introduced via raw materials adhered to equipment, forming persistent biofilms that facilitated cross-contamination. Conventional cleaning and disinfection procedures (on-site cleaning, standard food disinfectants) demonstrated limited efficacy against these biofilms. These findings systematically clarify the hazard characteristics, genetic background, and contamination pathways of <em>B. cereus</em> in sufu production, providing a scientific basis for targeted intervention and sanitation optimization in industrial processing.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"137 ","pages":"Article 105038"},"PeriodicalIF":4.6,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Adaptive hydrophobicity shifts in Listeria monocytogenes under subinhibitory exposure to benzalkonium chloride, peracetic acid and sodium hypochlorite 亚抑制暴露于苯扎氯铵、过氧乙酸和次氯酸钠下单核增生李斯特菌的适应性疏水性发生变化

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-08 DOI: 10.1016/j.fm.2025.105035

Aminta Vega-Sánchez, Josep-Maria deDios-Pont, Paula Cruz-Vera, Carolina Ripolles-Avila

The phospholipid layer is central to Listeria monocytogenes tolerance to disinfectants. We profiled surface hydrophobicity by Microbial Adhesion to Solvents (MATS) in 19 strains, tested in wild type and after adaptation to ½ MIC of benzalkonium chloride (BKC), peracetic acid (PAA), or sodium hypochlorite (SHY). We first compared two hydrocarbons for MATS (i.e. xylene vs hexadecane) to optimize solvent choice. Wild strains measured with xylene clustered near zero or negative affinity, whereas hexadecane shifted distributions to positive values with lower intra-strain variability. Across three representative strains adapted to each disinfectant, hexadecane showed significantly greater affinity than xylene (P < 0.001), and overall solvent effects were significant (P < 0.05), supporting hexadecane as the analytical solvent. Using hexadecane, wild strains were weakly hydrophobic (<20 % MATS) and not different among themselves (P > 0.05). BKC adaptation produced minimal change as most strains remained <20 %; the only shift to moderate hydrophobicity was S2-1 (22.32 ± 2.57 %). Adaptation to PAA increased hydrophobicity in a subset of strains, being EDG-e, A7, and S2bac the ones that reached intermediate levels (26.87 ± 7.02 % to 49.46 ± 11.00 %) whereas 11 of the 19 strains remained below 20 %. SHY drove the largest changes with 11/19 strains transitioning to strong hydrophobicity (>50 %), with MATS means ranging from 50.58 ± 18.75 % to 73.54 ± 7.64 %. Moreover, four strains (i.e. CECT 5672, 4423, R6, S1(R)) stayed weakly hydrophobic (6.64 ± 39.49 % to 17.97 ± 23.61 %), and two (Lm4, Lm5) were moderate (20–50 %). Overall, adaptation to subinhibitory disinfectant concentrations revealed distinct, strain-dependent surface responses that may influence bacterial persistence potential. These findings contribute to understanding how routine disinfectant exposure can shape the phenotypic resilience of L. monocytogenes, providing insights relevant to food safety management and contamination control in food-processing environments.

磷脂层是单核增生李斯特菌对消毒剂耐受的核心。我们通过微生物黏附溶剂（MATS）分析了19株菌株的表面疏水性，这些菌株在野生型和适应1 / 2 MIC的苯扎氯铵（BKC）、过氧乙酸（PAA）或次氯酸钠（SHY）后进行了测试。我们首先比较了两种碳氢化合物（即二甲苯和十六烷），以优化溶剂的选择。二甲苯测量的野生菌株聚集在接近零或负亲和的地方，而十六烷将分布转移到正值，具有较低的菌株内变异性。在适应每种消毒剂的三个代表性菌株中，十六烷的亲和力显著高于二甲苯（P < 0.001），并且总体溶剂效应显著（P < 0.05），支持十六烷作为分析溶剂。使用十六烷时，野生菌株呈弱疏水性（< 20% MATS），彼此间无差异（P > 0.05）。BKC适应产生的变化很小，因为大多数菌株保持在20%；唯一向中等疏水性转变的是S2-1（22.32±2.57%）。对PAA的适应提高了部分菌株的疏水性，其中EDG-e、A7和S2bac达到了中间水平（26.87±7.02% ~ 49.46±11.00 %），而19株菌株中有11株仍低于20%。其中，有11/19的菌株向强疏水性转变（> 50%），其中SHY的变化最大，MATS平均值为50.58±18.75% ~ 73.54±7.64%。4株（CECT 5672、4423、R6、S1(R)）为弱疏水性（6.64±39.49% ~ 17.97±23.61%），2株（Lm4、Lm5）为中度疏水性（20 ~ 50%）。总的来说，对亚抑制性消毒剂浓度的适应揭示了不同的、菌株依赖的表面反应，这可能影响细菌的持久性潜力。这些发现有助于理解常规消毒剂暴露如何塑造单核增生乳杆菌的表型弹性，为食品加工环境中的食品安全管理和污染控制提供相关见解。

{"title":"Adaptive hydrophobicity shifts in Listeria monocytogenes under subinhibitory exposure to benzalkonium chloride, peracetic acid and sodium hypochlorite","authors":"Aminta Vega-Sánchez, Josep-Maria deDios-Pont, Paula Cruz-Vera, Carolina Ripolles-Avila","doi":"10.1016/j.fm.2025.105035","DOIUrl":"10.1016/j.fm.2025.105035","url":null,"abstract":"<div><div>The phospholipid layer is central to <em>Listeria monocytogenes</em> tolerance to disinfectants. We profiled surface hydrophobicity by Microbial Adhesion to Solvents (MATS) in 19 strains, tested in wild type and after adaptation to ½ MIC of benzalkonium chloride (BKC), peracetic acid (PAA), or sodium hypochlorite (SHY). We first compared two hydrocarbons for MATS (<em>i.e.</em> xylene <em>vs</em> hexadecane) to optimize solvent choice. Wild strains measured with xylene clustered near zero or negative affinity, whereas hexadecane shifted distributions to positive values with lower intra-strain variability. Across three representative strains adapted to each disinfectant, hexadecane showed significantly greater affinity than xylene (<em>P</em> < 0.001), and overall solvent effects were significant (<em>P</em> < 0.05), supporting hexadecane as the analytical solvent. Using hexadecane, wild strains were weakly hydrophobic (<20 % MATS) and not different among themselves (<em>P</em> > 0.05). BKC adaptation produced minimal change as most strains remained <20 %; the only shift to moderate hydrophobicity was S2-1 (22.32 ± 2.57 %). Adaptation to PAA increased hydrophobicity in a subset of strains, being EDG-e, A7, and S2bac the ones that reached intermediate levels (26.87 ± 7.02 % to 49.46 ± 11.00 %) whereas 11 of the 19 strains remained below 20 %. SHY drove the largest changes with 11/19 strains transitioning to strong hydrophobicity (>50 %), with MATS means ranging from 50.58 ± 18.75 % to 73.54 ± 7.64 %. Moreover, four strains (<em>i.e.</em> CECT 5672, 4423, R6, S1(R)) stayed weakly hydrophobic (6.64 ± 39.49 % to 17.97 ± 23.61 %), and two (Lm4, Lm5) were moderate (20–50 %). Overall, adaptation to subinhibitory disinfectant concentrations revealed distinct, strain-dependent surface responses that may influence bacterial persistence potential. These findings contribute to understanding how routine disinfectant exposure can shape the phenotypic resilience of <em>L. monocytogenes</em>, providing insights relevant to food safety management and contamination control in food-processing environments.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"137 ","pages":"Article 105035"},"PeriodicalIF":4.6,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Aldo/keto reductase regulates L-lactate dehydrogenase activity as a key target for yogurt post-acidification Aldo/keto还原酶调节l -乳酸脱氢酶活性，是酸奶后酸化的关键靶点

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-05 DOI: 10.1016/j.fm.2026.105037

Qingqing Mu , Sitong Jia , Dongyao Li , Whenhao Zhao , Na Zhang , Miaoshu Wang , Hongtao Tian , Chen Li

Post-acidification during refrigeration is a critical determinant of yogurt quality. Although it is known that niacin (NA) can influence this process via aldehyde-ketone reductase (AKR) in Lactobacillus bulgaricus, its precise regulatory mechanism remains unclear. By non-targeted metabolomics analysis revealed that nicotinic acid reshapes the metabolic profile during storage, significantly reducing the accumulation of organic acids such as L-lactic acid, fumaric acid, and succinic acid. This indicates that post-acidification processes are inhibited through relevant metabolic pathways. Concurrently, the yeast two-hybrid screening identified 21 proteins interacting with AKR, confirming L-lactate dehydrogenase (L-LDH) as a key interaction partner of AKR. This enzyme directly regulates L-LDH activity. Subsequent enzyme activity assays and AKR mutation confirmed that niacin acts as a potent inhibitor of L-LDH activity by promoting the formation of an AKR-L-LDH-NA ternary complex. Regulation of L-LDH activity by AKR without altering the structure and intrinsic catalytic properties of L-LDH is expected to realize the AKR-L-LDH-NA ternary complex as a key target for the future regulation of the post-acidification process. Our study establishes a technological method to accurately regulate the post-acidification of yogurt, which provides a theoretical basis for controlling acidity in lactic acid fermented foods.

冷藏过程中的后酸化是酸奶质量的关键决定因素。虽然已知烟酸（NA）可以通过保加利亚乳杆菌中的醛酮还原酶（AKR）影响这一过程，但其确切的调控机制尚不清楚。通过非靶向代谢组学分析发现，烟酸重塑了储存过程中的代谢谱，显著减少了l -乳酸、富马酸和琥珀酸等有机酸的积累。这表明后酸化过程通过相关的代谢途径受到抑制。同时，酵母双杂交筛选鉴定出21个与AKR相互作用的蛋白，证实l -乳酸脱氢酶（L-LDH）是AKR的关键相互作用伙伴。这种酶直接调节L-LDH活性。随后的酶活性测定和AKR突变证实，烟酸通过促进AKR-L-LDH- na三元络合物的形成，作为L-LDH活性的有效抑制剂。通过AKR调控L-LDH活性而不改变L-LDH的结构和固有催化性能，有望实现AKR-L-LDH- na三元配合物作为未来调控后酸化过程的关键靶点。本研究建立了准确调控酸奶后酸化的工艺方法，为控制乳酸发酵食品的酸度提供了理论依据。

{"title":"Aldo/keto reductase regulates L-lactate dehydrogenase activity as a key target for yogurt post-acidification","authors":"Qingqing Mu , Sitong Jia , Dongyao Li , Whenhao Zhao , Na Zhang , Miaoshu Wang , Hongtao Tian , Chen Li","doi":"10.1016/j.fm.2026.105037","DOIUrl":"10.1016/j.fm.2026.105037","url":null,"abstract":"<div><div>Post-acidification during refrigeration is a critical determinant of yogurt quality. Although it is known that niacin (NA) can influence this process via aldehyde-ketone reductase (AKR) in <em>Lactobacillus bulgaricus,</em> its precise regulatory mechanism remains unclear. By non-targeted metabolomics analysis revealed that nicotinic acid reshapes the metabolic profile during storage, significantly reducing the accumulation of organic acids such as L-lactic acid, fumaric acid, and succinic acid. This indicates that post-acidification processes are inhibited through relevant metabolic pathways. Concurrently, the yeast two-hybrid screening identified 21 proteins interacting with AKR, confirming L-lactate dehydrogenase (L-LDH) as a key interaction partner of AKR. This enzyme directly regulates L-LDH activity. Subsequent enzyme activity assays and AKR mutation confirmed that niacin acts as a potent inhibitor of L-LDH activity by promoting the formation of an AKR-L-LDH-NA ternary complex. Regulation of L-LDH activity by AKR without altering the structure and intrinsic catalytic properties of L-LDH is expected to realize the AKR-L-LDH-NA ternary complex as a key target for the future regulation of the post-acidification process. Our study establishes a technological method to accurately regulate the post-acidification of yogurt, which provides a theoretical basis for controlling acidity in lactic acid fermented foods.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"137 ","pages":"Article 105037"},"PeriodicalIF":4.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Control of residual maltose in low-alcohol beer produced by non-Saccharomyces yeast with enzymatic treatment 酶法控制非酵母菌低醇啤酒中麦芽糖残留量

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-05 DOI: 10.1016/j.fm.2025.105036

Mohini Basu , Nataliia Voloshchuk , Jacob Simmons , Josephine Wee , Ryan J. Elias , Darrell W. Cockburn

Non-alcoholic and low-alcohol beer (NABLAB) production by maltose-negative non-Saccharomyces yeast (NSY) runs the risk of excessive sweetness due to the high residual maltose in the finished beer which may overshadow the unique flavors produced by the NSY. The goal of this study was to modify the fermentable sugar profile in wort to better suit maltose-negative NSY, resulting in low residual maltose worts while maintaining low ethanol levels. This was achieved by adding amyloglucosidase (AMG) to increase the proportion of glucose by partially hydrolyzing maltose and maltotriose. Two treatments were selected from AMG-treated time-course mash experiment to produce either moderately elevated or highly elevated glucose levels with either barley malt or barley malt extract. Fermentation was then performed using nine different NSY and compared to Saccharomyces cerevisiae. Most NSY produced significantly less ethanol than S. cerevisiae under these conditions, while leaving behind relatively low levels of maltose (<10 g/L). Lower ethanol production was found to be partially driven by diversion of sugar-derived carbon to non-ethanol pathways, including organic acids and glycerol. Overall, the use of high-glucose worts appears to be a promising approach to produce NABLAB by NSY with the potential for improved sensory properties.

由麦芽糖阴性的非saccharomyces酵母（NSY）生产的无酒精和低酒精啤酒（NABLAB）存在过度甜味的风险，因为成品啤酒中残留的高麦芽糖可能会掩盖NSY产生的独特风味。本研究的目的是修改麦汁中的可发酵糖谱，以更好地适应麦芽糖阴性NSY，从而在保持低乙醇水平的同时降低麦芽糖残留。这是通过添加淀粉葡糖苷酶（AMG）通过部分水解麦芽糖和麦芽糖来增加葡萄糖的比例来实现的。从amg处理的时间过程醪试验中选择两种处理，分别用大麦麦芽或大麦麦芽提取物产生中度升高或高度升高的葡萄糖水平。然后使用9种不同的NSY进行发酵，并与酿酒酵母进行比较。在这些条件下，大多数NSY产生的乙醇明显少于酿酒酵母，而留下相对较低水平的麦芽糖（10克/升）。研究发现，较低的乙醇产量部分是由于糖衍生碳转向非乙醇途径，包括有机酸和甘油。总的来说，使用高糖麦汁似乎是一种很有前途的方法，通过NSY生产NABLAB，具有改善感官特性的潜力。

{"title":"Control of residual maltose in low-alcohol beer produced by non-Saccharomyces yeast with enzymatic treatment","authors":"Mohini Basu , Nataliia Voloshchuk , Jacob Simmons , Josephine Wee , Ryan J. Elias , Darrell W. Cockburn","doi":"10.1016/j.fm.2025.105036","DOIUrl":"10.1016/j.fm.2025.105036","url":null,"abstract":"<div><div>Non-alcoholic and low-alcohol beer (NABLAB) production by maltose-negative non-<em>Saccharomyces</em> yeast (NSY) runs the risk of excessive sweetness due to the high residual maltose in the finished beer which may overshadow the unique flavors produced by the NSY. The goal of this study was to modify the fermentable sugar profile in wort to better suit maltose-negative NSY, resulting in low residual maltose worts while maintaining low ethanol levels. This was achieved by adding amyloglucosidase (AMG) to increase the proportion of glucose by partially hydrolyzing maltose and maltotriose. Two treatments were selected from AMG-treated time-course mash experiment to produce either moderately elevated or highly elevated glucose levels with either barley malt or barley malt extract. Fermentation was then performed using nine different NSY and compared to <em>Saccharomyces cerevisiae</em>. Most NSY produced significantly less ethanol than <em>S. cerevisiae</em> under these conditions, while leaving behind relatively low levels of maltose (<10 g/L). Lower ethanol production was found to be partially driven by diversion of sugar-derived carbon to non-ethanol pathways, including organic acids and glycerol. Overall, the use of high-glucose worts appears to be a promising approach to produce NABLAB by NSY with the potential for improved sensory properties.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"137 ","pages":"Article 105036"},"PeriodicalIF":4.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Population structure of Bacillus cereus sensu lato associated with foodborne outbreaks in France between 2004 and 2023. 与2004年至2023年法国食源性疫情相关的蜡样芽孢杆菌的种群结构

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-01 Epub Date: 2025-07-30 DOI: 10.1016/j.fm.2025.104882

Ksenia Mozhaitseva, Sylvie Pairaud, Olivier Firmesse, Mathilde Bonis

Bacillus cereus sensu lato (Bcsl) is a group of closely related bacterial species known for their resistant spores, enabling them to persist in a dormant state and thereby colonize and adapt across diverse environments. Bcsl is known for its harmful impact on human health, producing toxins that cause emetic and diarrheal syndromes or provoking extradigestive infections. Importantly, Bcsl is the most frequent confirmed or presumptive causative agent associated with foodborne outbreaks (FBOs) in France. In our study, we assessed the population structure of a large collection of Bcsl isolated during FBOs investigation in France between 2004 and 2023, focusing on the association between distinct populations and food categories. Using 294 genomes from 183 FBOs, we applied genomic clustering and phylogenomic analysis and then identified three predominant Bcsl populations. B. cereus sensu stricto (17.0 %) prevailed in composite dishes, B. paranthracis (16.1 %) was positively associated with cereals, and B. thuringiensis subsp. kurstaki (7.6 %) was predominantly found in vegetable-based salads. Some strains were phylogenetically closely related to clinical isolates, highlighting the need to assess the antibiotic susceptibility of Bcsl. Notably, one Bcsl clade, B. cytotoxicus, lacking beta-lactamase-encoding genes showed a greatly increased sensitivity to ampicillin than other Bcsl considered to be naturally resistant to beta-lactams. Additionally, various strains from distinct populations showed reduced susceptibility to macrolides and cyclins. Finally, accurately differentiated populations will be used in further epidemiological studies and in dose-response modeling.

蜡样芽孢杆菌（Bacillus cereus sensu lato, Bcsl）是一组密切相关的细菌物种，它们具有抗性孢子，使它们能够在休眠状态下持续存在，从而在不同的环境中定植和适应。Bcsl因其对人体健康的有害影响而闻名，它产生的毒素会导致呕吐和腹泻综合征，或引发消化系统感染。重要的是，Bcsl是法国与食源性暴发（FBOs）相关的最常见的确诊或推定病原体。在我们的研究中，我们评估了2004年至2023年在法国FBOs调查期间分离的大量Bcsl的种群结构，重点关注不同种群与食物类别之间的关联。利用183只fbo的294个基因组进行基因组聚类和系统基因组分析，确定了3个优势种群。严感蜡样芽孢杆菌（17.0%）在复合菜中流行，副食芽孢杆菌（16.1%）与谷物呈正相关，苏云金芽孢杆菌亚种呈正相关。库尔斯塔基（7.6%）主要存在于蔬菜沙拉中。一些菌株在系统发育上与临床分离株密切相关，突出了评估Bcsl抗生素敏感性的必要性。值得注意的是，缺乏β -内酰胺酶编码基因的Bcsl分支细胞毒杆菌对氨苄西林的敏感性大大高于其他被认为对β -内酰胺具有天然抗性的Bcsl。此外，来自不同种群的不同菌株对大环内酯类和细胞周期蛋白的敏感性降低。最后，准确区分的人群将用于进一步的流行病学研究和剂量反应模型。

{"title":"Population structure of Bacillus cereus sensu lato associated with foodborne outbreaks in France between 2004 and 2023.","authors":"Ksenia Mozhaitseva, Sylvie Pairaud, Olivier Firmesse, Mathilde Bonis","doi":"10.1016/j.fm.2025.104882","DOIUrl":"https://doi.org/10.1016/j.fm.2025.104882","url":null,"abstract":"<p><p>Bacillus cereus sensu lato (Bcsl) is a group of closely related bacterial species known for their resistant spores, enabling them to persist in a dormant state and thereby colonize and adapt across diverse environments. Bcsl is known for its harmful impact on human health, producing toxins that cause emetic and diarrheal syndromes or provoking extradigestive infections. Importantly, Bcsl is the most frequent confirmed or presumptive causative agent associated with foodborne outbreaks (FBOs) in France. In our study, we assessed the population structure of a large collection of Bcsl isolated during FBOs investigation in France between 2004 and 2023, focusing on the association between distinct populations and food categories. Using 294 genomes from 183 FBOs, we applied genomic clustering and phylogenomic analysis and then identified three predominant Bcsl populations. B. cereus sensu stricto (17.0 %) prevailed in composite dishes, B. paranthracis (16.1 %) was positively associated with cereals, and B. thuringiensis subsp. kurstaki (7.6 %) was predominantly found in vegetable-based salads. Some strains were phylogenetically closely related to clinical isolates, highlighting the need to assess the antibiotic susceptibility of Bcsl. Notably, one Bcsl clade, B. cytotoxicus, lacking beta-lactamase-encoding genes showed a greatly increased sensitivity to ampicillin than other Bcsl considered to be naturally resistant to beta-lactams. Additionally, various strains from distinct populations showed reduced susceptibility to macrolides and cyclins. Finally, accurately differentiated populations will be used in further epidemiological studies and in dose-response modeling.</p>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"133 ","pages":"104882"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144948654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of physiological transitions during forward processing on Shiga-toxin producing Escherichia coli risks in lettuce. 正加工过程中生理变化对生菜产志贺毒素大肠杆菌风险的影响。

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-01 Epub Date: 2025-08-06 DOI: 10.1016/j.fm.2025.104892

Joshua Ombaka Owade, Teresa M Bergholz, Jade Mitchell

Cold stress during forward processing delays of lettuce can induce the formation of viable but nonculturable (VBNC) cells of Shiga toxin-producing Escherichia coli (STEC) O157:H7 and pose risks of foodborne disease outbreaks. This study investigated the effect of physiological changes during the forward processing cold chain on the risks of illness from consuming lettuce contaminated with STEC O157:H7. A probabilistic quantitative microbial risk assessment model was developed to quantify the risks associated with consuming field-bagged Romaine hearts and shredded and packaged lettuce contaminated with STEC O157:H7. The exposure assessment included the farm-to-consumer pathway, with probability distributions generated using 10⁵ Monte Carlo simulations. The risk of illness was calculated using a previously published beta-Poisson model. Scenario analysis was conducted to account for transition to VBNC over 5 days of cold storage. The median risk of consuming field-bagged Romaine hearts and shredded and packaged lettuce was 1.88×10^-8 (95 % CI = 1.59×10^-11; 4.97×10^-4) and 9.12×10^-7 (95 % CI = 2.41×10^-8, 3.90×10^-5), respectively. Convolution tests showed the distribution of risks of consuming Romaine hearts and shredded and packaged lettuce were not significantly (p > 0.05) different. Physiological changes due to cold stress during forward processing did not significantly increase the risk of illness for either field-bagged Romaine hearts or shredded and packaged lettuce (p > 0.05). While post-processing factors were the most important uncertainty factors influencing the risks from shredded and packaged lettuce, both pre- and postharvest factors most influenced the risks from field-bagged Romaine hearts. We concluded that cold stress along the lettuce distribution chain, despite inducing physiological changes in the cells, did not significantly increase the risks of illness.

生菜前加工延迟期间的冷胁迫可诱导产志贺毒素大肠杆菌（STEC） O157:H7存活但不可培养（VBNC）细胞的形成，并造成食源性疾病暴发的风险。本研究调查了前加工冷链过程中生理变化对食用被产STEC O157:H7污染的生菜患病风险的影响。建立了一个概率定量微生物风险评估模型，以量化与食用被产大肠杆菌O157:H7污染的田间袋装生菜心和切碎和包装生菜相关的风险。暴露评估包括从农场到消费者的途径，并使用105个蒙特卡罗模拟生成概率分布。患病风险是使用先前发表的β -泊松模型计算的。进行情景分析，以解释在5天的冷库中向VBNC的过渡。食用田间袋装生菜心和切碎包装生菜的中位风险分别为1.88×10-8 （95% CI = 1.59×10-11; 4.97×10-4）和9.12×10-7 （95% CI = 2.41×10-8, 3.90×10-5）。卷积检验显示，食用长叶心和切碎、包装生菜的风险分布无显著差异（p > 0.05）。无论是田间袋装生菜还是切碎包装生菜，在加工过程中由于冷胁迫引起的生理变化都没有显著增加患病风险（p > 0.05）。虽然后处理因素是影响切碎生菜和包装生菜风险的最重要的不确定性因素，但采前和采后因素对田间袋装生菜风险的影响最大。我们的结论是，沿生菜分销链的冷胁迫，尽管诱导了细胞的生理变化，但并没有显著增加患病的风险。

{"title":"Impact of physiological transitions during forward processing on Shiga-toxin producing Escherichia coli risks in lettuce.","authors":"Joshua Ombaka Owade, Teresa M Bergholz, Jade Mitchell","doi":"10.1016/j.fm.2025.104892","DOIUrl":"https://doi.org/10.1016/j.fm.2025.104892","url":null,"abstract":"<p><p>Cold stress during forward processing delays of lettuce can induce the formation of viable but nonculturable (VBNC) cells of Shiga toxin-producing Escherichia coli (STEC) O157:H7 and pose risks of foodborne disease outbreaks. This study investigated the effect of physiological changes during the forward processing cold chain on the risks of illness from consuming lettuce contaminated with STEC O157:H7. A probabilistic quantitative microbial risk assessment model was developed to quantify the risks associated with consuming field-bagged Romaine hearts and shredded and packaged lettuce contaminated with STEC O157:H7. The exposure assessment included the farm-to-consumer pathway, with probability distributions generated using 10<sup>5</sup> Monte Carlo simulations. The risk of illness was calculated using a previously published beta-Poisson model. Scenario analysis was conducted to account for transition to VBNC over 5 days of cold storage. The median risk of consuming field-bagged Romaine hearts and shredded and packaged lettuce was 1.88×10<sup>-8</sup> (95 % CI = 1.59×10<sup>-11</sup>; 4.97×10<sup>-4</sup>) and 9.12×10<sup>-7</sup> (95 % CI = 2.41×10<sup>-8</sup>, 3.90×10<sup>-5</sup>), respectively. Convolution tests showed the distribution of risks of consuming Romaine hearts and shredded and packaged lettuce were not significantly (p > 0.05) different. Physiological changes due to cold stress during forward processing did not significantly increase the risk of illness for either field-bagged Romaine hearts or shredded and packaged lettuce (p > 0.05). While post-processing factors were the most important uncertainty factors influencing the risks from shredded and packaged lettuce, both pre- and postharvest factors most influenced the risks from field-bagged Romaine hearts. We concluded that cold stress along the lettuce distribution chain, despite inducing physiological changes in the cells, did not significantly increase the risks of illness.</p>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"133 ","pages":"104892"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144948615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tomato leaf microstructure affects the adhesion and localization of Salmonella enterica as shown using biomimetics. 仿生学显示，番茄叶片微观结构影响肠沙门氏菌的粘附和定位。

IF 4.6 1区农林科学 Q1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Food microbiology

Pub Date : 2026-01-01 Epub Date: 2025-08-07 DOI: 10.1016/j.fm.2025.104893

Orian Dayan, Yulia Kroupitski, Tali Sayas, Shlomo Sela Saldinger, Maya Kleiman

Non-typhoidal Salmonella enterica serovars are a major cause of diarrheal diseases worldwide and represent a significant health concern. Several Salmonella outbreaks worldwide originated from bacteria residing on plants, specifically on leaves. Understanding the adhesion and survival of Salmonella upon the leaf surface is, hence, of great importance. Among other factors involved in the localization and adhesion of Salmonella to the leaf surface, the surface microstructure did not receive significant attention. Here, we study the localization and adhesion of Salmonella to the surface of tomato leaves, with emphasis on the role of the leaf surface microstructure. To do so, we use biomimetics, a field in chemistry and material sciences aimed at mimicking biological systems. We formed synthetic replication of the leaf surface microstructure, to isolate the microstructure property from all other leaf properties. We found that the distribution of Salmonella upon the leaf surface is not random and there is a clear localization preference to the intercellular spaces and the trichomes. We found that this localization repeats in the synthetic system, suggesting this phenomenon is due to the microstructural features of the leaf. The localization of Salmonella on the trichome is independent of flagella, curli or cellulose, and does not require bacterial viability. However, the overall adhesion of Salmonella to both natural and synthetic leaf surfaces decreased in the cellulose mutant. This result emphasizes the strength of the model synthetic system we developed. A better understanding of Salmonella interaction with leaf surfaces could yield new directions for prevention methods. The findings in this research could assist in the development of such directions.

非伤寒肠炎沙门氏菌血清型是世界范围内腹泻疾病的主要原因，是一个重大的健康问题。世界范围内的几次沙门氏菌爆发起源于植物上的细菌，特别是叶子上的细菌。因此，了解沙门氏菌在叶片表面的粘附和存活是非常重要的。在影响沙门氏菌在叶片表面的定位和粘附的其他因素中，叶片表面的微观结构没有受到重视。在此，我们研究了沙门氏菌在番茄叶片表面的定位和粘附，重点研究了叶片表面微观结构的作用。为了做到这一点，我们使用了仿生学，这是化学和材料科学的一个领域，旨在模仿生物系统。我们形成了叶片表面微观结构的合成复制，将其微观结构特性从所有其他叶片特性中分离出来。我们发现沙门氏菌在叶片表面的分布并不是随机的，并且对细胞间隙和毛状体有明显的定位偏好。我们发现这种定位在合成系统中重复，这表明这种现象是由于叶片的微观结构特征。沙门氏菌在毛状体上的定位与鞭毛、卷毛或纤维素无关，也不需要细菌的生存能力。然而，在纤维素突变体中，沙门氏菌对天然和合成叶片表面的整体粘附都有所下降。这一结果强调了我们开发的模型综合系统的强度。更好地了解沙门氏菌与叶片表面的相互作用可以为预防方法提供新的方向。本研究的发现有助于这些方向的发展。

{"title":"Tomato leaf microstructure affects the adhesion and localization of Salmonella enterica as shown using biomimetics.","authors":"Orian Dayan, Yulia Kroupitski, Tali Sayas, Shlomo Sela Saldinger, Maya Kleiman","doi":"10.1016/j.fm.2025.104893","DOIUrl":"https://doi.org/10.1016/j.fm.2025.104893","url":null,"abstract":"<p><p>Non-typhoidal Salmonella enterica serovars are a major cause of diarrheal diseases worldwide and represent a significant health concern. Several Salmonella outbreaks worldwide originated from bacteria residing on plants, specifically on leaves. Understanding the adhesion and survival of Salmonella upon the leaf surface is, hence, of great importance. Among other factors involved in the localization and adhesion of Salmonella to the leaf surface, the surface microstructure did not receive significant attention. Here, we study the localization and adhesion of Salmonella to the surface of tomato leaves, with emphasis on the role of the leaf surface microstructure. To do so, we use biomimetics, a field in chemistry and material sciences aimed at mimicking biological systems. We formed synthetic replication of the leaf surface microstructure, to isolate the microstructure property from all other leaf properties. We found that the distribution of Salmonella upon the leaf surface is not random and there is a clear localization preference to the intercellular spaces and the trichomes. We found that this localization repeats in the synthetic system, suggesting this phenomenon is due to the microstructural features of the leaf. The localization of Salmonella on the trichome is independent of flagella, curli or cellulose, and does not require bacterial viability. However, the overall adhesion of Salmonella to both natural and synthetic leaf surfaces decreased in the cellulose mutant. This result emphasizes the strength of the model synthetic system we developed. A better understanding of Salmonella interaction with leaf surfaces could yield new directions for prevention methods. The findings in this research could assist in the development of such directions.</p>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"133 ","pages":"104893"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144948597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0