International journal of food microbiology最新文献

{"title":"Oil-in-water emulsion and acid concentrations impact Bacillus weihenstephanensis KBAB4 growth and culturability","authors":"Agathe Dutoit,&nbsp;Clément Trunet,&nbsp;Nicolas Decourcelle,&nbsp;Anne-Gabrielle Mathot,&nbsp;Louis Coroller","doi":"10.1016/j.ijfoodmicro.2025.111132","DOIUrl":"10.1016/j.ijfoodmicro.2025.111132","url":null,"abstract":"<div><div>Organic acids have long been used to limit microbial growth and preserve food products from spoilage and pathogens. However, the food complexity can affect the efficiency of preservatives in inhibiting bacterial growth. The inhibitory activity of acetic, lactic, caprylic and lauric acid in nutrient broth and in a model food system, i.e. an oil-in-water (O/W) emulsion at two pH levels, were compared using the plate count method.</div><div>The fate of <em>B. weihenstephanensis</em> KBAB4 cells incubated in O/W emulsions revealed a loss of culturability on Brain Heart Infusion agar (BHI agar) medium, occurring at different times according to the tested conditions. Cell viability in O/W emulsion was assessed through flow cytometry measurements which confirmed that a large majority of cells possessed an intact membrane, despite only 3 % being able to recover on BHI agar. Decreasing the pH of the emulsions delayed the time at which cells lost their culturability as well as the time at which it was restored. Using acetic, caprylic and lauric acid in the emulsion impacted strain recovery on BHI agar whereas using lactic acid enhanced the cell recovery from the emulsion exposure, on BHI agar surface.</div><div>The culturability of <em>B. weihenstephanensis</em> KBAB4 cells incubated in an O/W emulsion without acid has been restored using other recovery media, highlighting ROS involvement and limited strain catalase activity in the recovery ability. This study put in evidence the susceptibility of this strain to oxidative stress and challenges the use of given media for enumerating spore-forming bacteria in food and other complex matrices.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"434 ","pages":"Article 111132"},"PeriodicalIF":5.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic features and pathogenicity of atypical diarrheagenic Escherichia coli from a large foodborne outbreak","authors":"Kenji Ohya ,&nbsp;Shouhei Hirose ,&nbsp;Kohei Nishikaku ,&nbsp;Takahiro Ohnishi ,&nbsp;Kenichi Lee ,&nbsp;Sunao Iyoda ,&nbsp;Akiko Kubomura ,&nbsp;Yukihiro Akeda ,&nbsp;Katsumi Mizukami ,&nbsp;Tomikatsu Suzuki ,&nbsp;Kenji Takinami ,&nbsp;Yuhji Taquahashi ,&nbsp;Makiko Kuwagata ,&nbsp;Satoshi Kitajima ,&nbsp;Takashi Inoue ,&nbsp;Yukiko Hara-Kudo","doi":"10.1016/j.ijfoodmicro.2025.111134","DOIUrl":"10.1016/j.ijfoodmicro.2025.111134","url":null,"abstract":"<div><div>An outbreak of diarrheal illness related to milk cartons served in school lunches, occurred in June 2021, involving more than 1800 cases from 25 schools. A strain of <em>Escherichia coli</em> OUT (OgGp9):H18 was implicated in the outbreak. This strain does not possess virulence factors typical of other <em>E. coli</em> pathotypes. In this study, we examined the pathogenicity of the <em>E. coli</em> OUT (OgGp9):H18 strain using genomic analysis and animal models. A core genome-based phylogenetic analysis revealed that this strain belongs to a clade comprising ST1380 strains and is distinct from enteroaggregative <em>E. coli</em> 042 and uropathogenic <em>E. coli</em> UMN026, which were previously considered to be phylogenetically related to this strain. In addition, the strain harbors a plasmid similar to that of atypical enterotoxigenic <em>E. coli</em>, encoding Coli Surface antigen CS8 and a type VI secretion system (T6SS). The strain caused mortality in mice following intraperitoneal inoculation. Marmosets inoculated orally, experienced diarrhea and long-term shedding. Curing the strain of the 103 Kbp plasmid it carries reduced mortality rates and colonization in the experimental animals, indicating that the plasmid encodes virulence factors. However, the mortality of mice treated with the plasmid-cured strain was higher than that of those treated with nonvirulent <em>E. coli</em> K-12, indicating that the chromosome also encodes virulence factors. Identified chromosomal virulence factors include a T6SS, the second type III secretion system in <em>E. coli</em>, ETT2, and the capsule gene cluster <em>kps</em>. These findings suggest that atypical diarrheagenic <em>E. coli</em>, such as the strain investigated in this study, may be the cause of foodborne illness in patients with diarrhea with an unknown cause.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"434 ","pages":"Article 111134"},"PeriodicalIF":5.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552058","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}

{"title":"Mycotoxigenic fungi, OTA and fumonisin B2 production by Aspergillus section Nigri isolated from wine grapes and natural occurrence of OTA in wines of Northern Argentinean Patagonia","authors":"Carolina Temperini ,&nbsp;Minna Kemppainen ,&nbsp;Mónica Moya ,&nbsp;Mariana Greco ,&nbsp;Alejandro Pardo ,&nbsp;Graciela Pose","doi":"10.1016/j.ijfoodmicro.2025.111135","DOIUrl":"10.1016/j.ijfoodmicro.2025.111135","url":null,"abstract":"<div><div>The Northern Argentinean Patagonia is the southernmost producing region of wine grapes and wine in Argentina. Their wines possess distinctive features due to the wide variety of red and white grapes and weather conditions, achieving great acceptance in local and international markets. The aims of the present study were to determine and characterize the mycobiota present in wine grapes from Northern Patagonia, to analyse the ability of the isolates to produce mycotoxins, and to determine the natural occurrence of OTA and monitoring its presence in wine over time. A wide diversity of fungal contamination was found on grape berries surface. The most abundant genera isolated were: <em>Alternaria</em> (55.8 %), <em>Aspergillus</em> (12.7 %), <em>Trichoderma</em> (6.5 %), <em>Penicillium</em> (5.3 %), <em>Fusarium</em> (4.4 %), <em>Epiccocum</em> (4.2 %), <em>Acremonium</em> (2.6 %) and <em>Botrytis</em> (2.5 %). <em>Alternaria</em> was the predominant genus with the highest proportion during the three years of study and <em>A. tenuissima</em> was the most frequent species isolated. In contrast, a low incidence of <em>Aspergillus</em> section <em>Nigri</em> was found. Isolates identified belonged to <em>Aspergillus niger</em> aggregate and, more specifically, to <em>A. tubingensis</em> species<em>.</em> No <em>Aspergillus carbonarius</em> isolates were found. A low percentage of <em>A. tubingensis</em> isolates were ochratoxin A producers (4.7 %) in the range of 14.6–233.3 μg/Kg and FB2 producers (3.7 %) in the range of 79.7–277.8 μg/Kg. None of the OTA producer isolates were able to produce FB2 and vice versa. Analysis of OTA content in wine samples from Northern Patagonia showed negative results: OTA was not detected in any of the samples analysed. Our findings suggest a low risk of wine contamination with OTA.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"433 ","pages":"Article 111135"},"PeriodicalIF":5.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510107","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}

{"title":"Development of predictive models of biofilm formation by C. sakazakii, E. cloacae on surfaces used in the food industry and medicine","authors":"Mateusz Gemba,&nbsp;Elżbieta Rosiak,&nbsp;Danuta Kołożyn-Krajewska","doi":"10.1016/j.ijfoodmicro.2025.111131","DOIUrl":"10.1016/j.ijfoodmicro.2025.111131","url":null,"abstract":"<div><div><em>Cronobacter sakazakii</em> and <em>Enterobacter cloacae</em> exhibit the ability to form biofilms, making them resistant to drying, antibiotics, and changes in pH. These biofilms can adhere to different surfaces, including tissues, catheters, enteral feeding tubes, and work surfaces, potentially leading to cross-infection risks in both the food and medical sectors. The objective of this study was to develop a predictive model of biofilm formation over time by <em>C. sakazakii</em> and <em>E. cloacae</em> on medical polyvinyl chloride (PVC) at 37 °C and stainless steel (SS), polypropylene (PP) surfaces at 4 °C and different microbial inoculum concentration. A staining method and spectrophotometric measurement were used to assess biofilm formation. SyStat Software Inc. for Windows Table curve 3D v.4.0.05 and non-linear functions were used to develop predictive models. Analysis of biofilm formation on SS and PP surfaces at 4 °C by all analyzed bacteria suggests that hygiene procedures in refrigeration equipment should be performed daily, the maximum safe storage time for bottled milk is 24 h. At 37 °C <em>E. cloacae</em> posed the highest risk of biofilm formation on the surface of PVC tubing at 6–36 h. The six best response surface models of biofilm formation were selected for presentation. The majority of these models demonstrated good accuracy, as evidenced low mean standard errors (MSE), high coefficient R² and Adjusted R(<span><span>Aung and Chang, 2014</span></span>²⁾. These models can be utilized to evaluate the microbiological risks in settings such as human milk banks, neonatal intensive care units and food industry plants.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"434 ","pages":"Article 111131"},"PeriodicalIF":5.0,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528691","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}

{"title":"The genomic characteristics of dominant Salmonella enterica serovars from retail pork in Sichuan province, China","authors":"Lanqi Li ,&nbsp;Honghu Sun ,&nbsp;Jianyun Zhao ,&nbsp;Huanjing Sheng ,&nbsp;Menghan Li ,&nbsp;Lanxin Zhao ,&nbsp;Shiwei Liu ,&nbsp;Séamus Fanning ,&nbsp;Lu Wang ,&nbsp;Yang Wang ,&nbsp;Yongning Wu ,&nbsp;Hao Ding ,&nbsp;Li Bai","doi":"10.1016/j.ijfoodmicro.2025.111129","DOIUrl":"10.1016/j.ijfoodmicro.2025.111129","url":null,"abstract":"<div><div>Foodborne <em>Salmonella</em> is the main cause of salmonellosis in China. Porcine animals are a reservoir for this bacterium consequently posing a threat to food safety and public health. In this study, 157 out of 240 pork samples (65.42 %) were identified as <em>Salmonella</em>-positive. From these, after isolation and deduplication, 376 <em>Salmonella</em> isolates were collected. Twenty four serovars were identified based on WGS, among which <em>S.</em> London/ST155 (24.47 %), <em>S.</em> Rissen/ST469 (23.40 %), <em>S.</em> Derby/ST40 (13.56 %), and <em>S.</em> 4,[5],12:i:- (monophasic <em>S.</em> Typhimurium)/ST34 (13.30 %) were dominant. In all, 69.68 % (262/376) of these isolates expressed multidrug resistance (MDR, defined as resistance to compounds in three or more antimicrobial classes) phenotypes with <em>S</em>. London (54.35 %, 50/92) accounting for the highest proportion of these. Notably, the resistance to front-line critically important antimicrobial agents (CIA), including cephalosporins, ciprofloxacin, and azithromycin was 0.80 %. Based on <em>in silico</em> analysis, antimicrobial resistant-encoding genes (ARG) identified in the MDR isolates included <em>aac(3)-IId</em>, <em>aac(6′)-Iaa</em>, <em>bla</em>_TEM-1B, <em>mph</em>(A), <em>qnrB6</em>, <em>aac(6′)-Ib-cr</em>, <em>sul1</em>, <em>sul2</em>, and <em>tet</em>(A), which expressed resistance to aminoglycosides, β-lactams, macrolides, quinolones, sulfonamides, and tetracyclines. Furthermore, diverse biocide and heavy metal resistance-encoding genes were distributed across different serovars with <em>triC</em> encoding triclosan resistance being identified exclusively in <em>S.</em> London. Moreover, monophasic <em>S.</em> 4,[5],12:i:- carried the greatest number of virulence factors and heavy metal resistance genes among the dominant serovars. This study extended our understanding of the genomic epidemiology and multidrug resistance of <em>Salmonella</em> derived from pork and highlighted the potential risk to human health, posed by commonly encountered serovars.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"434 ","pages":"Article 111129"},"PeriodicalIF":5.0,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519116","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}

{"title":"Evaluation of antimicrobial efficacy against spoilage microorganisms and impact on beverage color and turbidity of commercial preservatives derived from edible mushrooms","authors":"Yupawadee Galasong ,&nbsp;Ann Charles-Vegdahl ,&nbsp;Randy W. Worobo","doi":"10.1016/j.ijfoodmicro.2025.111130","DOIUrl":"10.1016/j.ijfoodmicro.2025.111130","url":null,"abstract":"<div><div>The antimicrobial efficacy and the impact on sensory quality of preservatives from different natural sources can vary dramatically. This makes it challenging for manufacturers to incorporate natural preservatives in shelf-stable beverage formulation. This study compares new-to-market natural glycolipids (NG) derived from <em>Dacryopinax spathularia</em> and white button mushroom extract (WBME) containing chitosan from <em>Agaricus bisporus</em>. The antimicrobial efficacy was evaluated in a microbial spoilage challenge study wherein three-species suspensions of yeasts (<em>Saccharomyces cerevisiae</em> YG25, <em>Zygosaccharomyces bailii</em> DSM 70492 and <em>Candida parapsilosis</em> TD-0020), bacteria (<em>Lactiplantibacillus plantarum</em> DSM 12028, <em>Lactococcus lactis</em> DSM 20481 and <em>Gluconobacter oxydans</em> AC39) and fungal spores (<em>Aspergillus brasiliensis</em> DSM 1988, <em>Byssochlamys nivea</em> DSM 1824 and <em>Penicillium roqueforti</em> DSM 1079) were inoculated (100 CFU/mL per species) in acidified iced tea and juice drink. The preservatives were tested at concentrations within the range proposed by their respective manufacturers. They were also benchmarked against sodium benzoate (SB) and potassium sorbate (PS). Beverage samples were maintained at ambient temperature for 12 weeks and analyzed for microbial counts, pH, total soluble solids (TSS) at week 0, 1, 2, 4, 8 and 12. The impact on color and turbidity was assessed in a separate trial without spoilage microorganisms. Overall, NG was more effective and consistent than WBME and PS + SB in preventing spoilage by selected bacteria, yeasts, and molds in this study without significant impact on pH and TSS. WBME counterproductively supported the growth <em>G. oxydans</em> AC39 in acidified iced tea. WBME at high concentration appeared to reduce growth of <em>S. cerevisiae</em> YG25 and <em>Z. bailii</em> DSM 70492, but not <em>C. parapsilosis</em> TD-0020 whereas PS + SB could not inhibit any yeast species. WBME reduced mold spoilage for 4 weeks, after which the antifungal effects wore off. Finally, WBME and NG at high concentrations may cause separation, which increases beverage turbidity upon remixing and lightens the beverage color, especially if the beverage contains a significant amount of pectin.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"433 ","pages":"Article 111130"},"PeriodicalIF":5.0,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Control of meat spoilage with ozone nano-bubbles: Insights from laboratory model systems and commercial scale treatments","authors":"Zhaohui S. Xu ,&nbsp;Janik Hettinger ,&nbsp;Alex Athey ,&nbsp;Xianqin Yang ,&nbsp;Michael G. Gänzle","doi":"10.1016/j.ijfoodmicro.2025.111128","DOIUrl":"10.1016/j.ijfoodmicro.2025.111128","url":null,"abstract":"<div><div>Ozone nanobubbles represent an environmentally friendly sanitation agent. In this study, we compared the bactericidal effect of ozone nanobubbles on pork muscle and adipose tissue to peracetic acid treatments. Pork samples were surface-inoculated with a cocktail of common meat-spoilage-associated microorganisms composed of <em>Brochothrix thermosphacta</em>, <em>Latilactobacillus sakei</em>, <em>Leuconostoc gelidum</em>, <em>Carnobacterium maltaromaticum</em>, <em>Hafnia paralvei</em> and <em>Yersinia rohdei</em> at a viable cell count of 10² CFU/cm² or 10⁴ CFU/cm². Both freshly inoculated and stored pork samples were treated with the two sanitation agents, followed by differential enumeration of viable bacteria. Ozone nanobubbles were comparable to peracetic acid solution, achieving a reduction between 1 and 2 log (CFU/cm²), regardless of the initial inoculum concentration and sample type. The efficacy of ozone nanobubble increased with increased solution volume and flow rate. Moreover, the sanitizing agents differentially impacted the members of the microbiota and shifted the composition of tested strains during storage. Gram-negative <em>Y. rohdei</em> and <em>H. paralvei</em> were more sensitive to peracetic acid than Gram-positive strains. Microbial profiling using 16S rRNA gene amplicon analysis of samples that were treated at a commercial processing scale revealed that <em>Serratia</em>, <em>Carnobacterium</em>, <em>Yersinia</em>, <em>Vagococcus</em>, <em>Morganella</em>, <em>Dellaglioa</em> were the dominant taxa (relative abundance &gt;1 %) on stored pork samples. The use of ozone nanobubbles significantly reduced the relative abundance of <em>Vagococcus</em> and <em>Clostridium</em> when compared to control samples. In summary, ozone nanobubbles are an effective tool to reduce bacterial counts on meat and show promise to extend the shelf life of fresh meat.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"433 ","pages":"Article 111128"},"PeriodicalIF":5.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spoilage potential of Bacillus isolated from cooked sausage: Bidirectional verification from in vitro to in situ","authors":"Lijun Tan ,&nbsp;Yong Xie ,&nbsp;Wendi Zhang ,&nbsp;Shasha Zheng ,&nbsp;Ying Wu ,&nbsp;Yunhao Ma ,&nbsp;Jinsong Zhao ,&nbsp;Cong Li ,&nbsp;Baocai Xu","doi":"10.1016/j.ijfoodmicro.2025.111114","DOIUrl":"10.1016/j.ijfoodmicro.2025.111114","url":null,"abstract":"<div><div>Understanding the role of common microorganisms in the spoilage of cooked sausages is essential for developing effective preservation strategies. In the framework of this study, six potential spoilage microorganisms were isolated from spoiled cooked sausages, identified through morphological, physiological, and genetic analyses as <em>Bacillus cereus</em> (two strains), <em>Bacillus safensis</em>, <em>Bacillus altitudinis</em>, <em>Bacillus megaterium</em>, and <em>Bacillus infantis</em>. All isolates exhibited significant protein or lipid degradation activities, except for <em>B. infantis</em>. The spoilage potential of <em>Bacillus</em> was systematically evaluated using a cooked sausage inoculation model <em>in situ</em> based on physical, chemical, and biological changes. Results indicated that <em>Bacillus</em> rapidly colonized cooked sausages, accelerating protein and lipid degradation and thereby deteriorating appearance and texture. Additionally, 74 volatile organic compounds (VOCs) were identified in both <em>Bacillus</em>-inoculated and control samples, revealing that <em>Bacillus</em> transformed aroma compounds such as terpenes into off-flavor compounds like alcohols, aldehydes, and acids (<em>e.g.</em>, 1-octen-3-ol, nonanal, and phenylacetic acid). Correlation analysis confirmed the association of <em>Bacillus</em> with spoilage characteristics and VOCs evolution. This study elucidates the spoilage potential and mechanisms of <em>Bacillus</em> in cooked sausages, providing a foundation for developing an effective quality control strategy.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"433 ","pages":"Article 111114"},"PeriodicalIF":5.0,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464816","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}

{"title":"Salmonella enterica Senftenberg (IOC 2319) and Salmonella enterica Typhimurium (ATCC 14028) under low water activity stress: Effects on culturability and cell viability","authors":"Syllas B.S. Oliveira ,&nbsp;Mayara M. Oliveira ,&nbsp;Leticia S. Lopes ,&nbsp;Arthur K.R. Pia ,&nbsp;João Victor Virgilio-da-Silva ,&nbsp;Anderson S. Sant'Ana","doi":"10.1016/j.ijfoodmicro.2025.111117","DOIUrl":"10.1016/j.ijfoodmicro.2025.111117","url":null,"abstract":"<div><div><em>Salmonella enterica</em> is one of the most important foodborne pathogens for public health worldwide. When <em>Salmonella enterica</em> is exposed to low water activity, changes in cellular behavior may occur. These changes can impact the cells that form a colony on specific nutrient media (culturability) and the metabolically or physiologically active cells (viability) of <em>Salmonella</em> cells, with consequences for the analytical methods and food safety management. Thus, this study studied the impact of continuous and recurrent exposure of <em>S.</em> Senftenberg IOC 2319 and <em>S.</em> Typhimurium ATCC 14028 to water activity (a_w) treatments between 0.4 and 0.99 over 24 h and five days. The culturability was determined using the plate count technique, and cell viability was measured by flow cytometry. <em>S.</em> Senftenberg IOC 2319 was shown to be more resistant to a_w stress than <em>S.</em> Typhimurium ATCC 14028. A total of 6.9 and 8.5 log CFU/mL reductions were observed for <em>S.</em> Senftenberg IOC 2319 and <em>S.</em> Typhimurium ATCC 14028. Although both bacteria lost culturability on plate counting, the flow cytometry results demonstrated that they remained viable between 7.09 and 9.23 log CFU/mL for <em>S.</em> Senftenberg IOC 2319 and <em>S.</em> Typhimurium ATCC 14028, respectively. This result opens questions about whether they can recover and adapt a food matrix, causing a greater risk to the consumer. In conclusion, low water activity stresses can cause significant changes in <em>Salmonella</em> strains, and the use of Flow cytometry can be a valuable technique to understand the physiological status of microorganisms better and suggest the importance of safer and faster methods for standard microbiological evaluation.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"433 ","pages":"Article 111117"},"PeriodicalIF":5.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464817","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}

{"title":"Design of a nitrite-free dry-cured fermented “salchichón” process preventing growth of Salmonella, Listeria monocytogenes, and Staphylococcus aureus","authors":"Juan C. Pulido,&nbsp;Irene Martín,&nbsp;Cristina Castaño,&nbsp;José M. Martín-Miguélez,&nbsp;Josué Delgado,&nbsp;Juan J. Córdoba","doi":"10.1016/j.ijfoodmicro.2025.111116","DOIUrl":"10.1016/j.ijfoodmicro.2025.111116","url":null,"abstract":"<div><div>The processing of nitrite-free dry-cured fermented “salchichón” has been modified and evaluated to know its efficacy in preventing the growth of the pathogenic bacteria <em>L</em>. <em>monocytogenes</em>, <em>Salmonella,</em> and <em>S. aureus</em>. For this, two ripening processes of “salchichón” were performed: a first ripening process to design the best conditions of cold ripening, for preventing the growth of the mentioned pathogens; and a second one with the already established most optimal cold conditions of processing. In both ripening processes <em>L</em>. <em>monocytogenes</em>, <em>Salmonella,</em> and <em>S. aureus</em> and two lactic acid bacteria (LAB) (a selected <em>Latilactobacillus sakei</em> and a commercial culture), were inoculated. The decrease of moisture and pH of the “salchichón” during initial cold ripening for 22 days at 5 °C, to reach values of 40 % (a_w below 0.93) and 5.5, respectively, were critical for the reduction of <em>L</em>. <em>monocytogenes</em>, <em>Salmonella,</em> and <em>S. aureus</em> in all of the inoculated batches, even after further ripening at 15 °C for 30 days. In addition, inoculated LAB acted summatively with the decrease of a_w and pH in the reduction of these pathogenic bacteria. In the second ripening process of “salchichón” using the above selection conditions, significant reductions of 2.8, 4.4, and 2.9 log CFU/g of <em>L</em>. <em>monocytogenes</em>, <em>Salmonella,</em> and <em>S. aureus</em>, respectively were found throughout the complete ripening process. Thus, the processing of nitrite-free “salchichón” combining an initial cold ripening at 5 °C and the use of LAB cultures prevents the growth of accidental contaminations of <em>L</em>. <em>monocytogenes</em>, <em>Salmonella</em> and <em>S. aureus</em> that could take place during processing.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"433 ","pages":"Article 111116"},"PeriodicalIF":5.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453008","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}