Journal of Applied Microbiology最新文献

{"title":"Integrating biocontrol efficacy and genomic potential of Bacillus velezensis BJ-1141: from broad-spectrum antagonism to tomato Fusarium wilt suppression.","authors":"Yunyun Chen, Mei Liu, Wei Zhang, Manawaduge Ayesha Madushani, Cong Jiang, Qikai Xing, Chenfang Wang, Jiye Yan","doi":"10.1093/jambio/lxag176","DOIUrl":"10.1093/jambio/lxag176","url":null,"abstract":"<p><strong>Aims: </strong>To isolate and characterize a rhizosphere-derived Bacillus velezensis strain with biocontrol and plant growth-promoting potential, and to evaluate its efficacy against plant pathogens together with its genomic basis.</p><p><strong>Methods and results: </strong>A bacterial strain (BJ-1141) was isolated from the rhizosphere and identified as B. velezensis based on morphological characteristics and phylogenetic analyses of 16S rRNA and gyrA gene sequences. The strain exhibited broad-spectrum antagonistic activity against 24 plant pathogenic fungi, inhibiting 23 pathogens by more than 50%, with a maximum inhibition rate of 95.57%. BJ-1141 produced hydrolytic enzymes (amylase, protease, cellulase, and pectinase) and plant growth-promoting factors, including siderophores and indole-3-acetic acid (IAA). It also demonstrated phosphorus solubilization, nitrogen fixation, and biofilm formation. Greenhouse experiments showed that root application of BJ-1141 effectively controlled tomato Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici, achieving control efficacies of 81.13-85.93%, which were higher than those of chemical and commercial microbial treatments. In addition, BJ-1141 significantly increased plant height, biomass, and chlorophyll content in tomato and lettuce seedlings. Whole-genome sequencing revealed a 3 902 965 bp genome containing 13 biosynthetic gene clusters associated with antimicrobial secondary metabolites, including surfactin, fengycin, bacillaene, difficidin, macrolactin H, bacillibactin, and bacilysin.</p><p><strong>Conclusions: </strong>Bacillus velezensis BJ-1141 is a multifunctional bacterial strain with strong biocontrol efficacy and plant growth-promoting traits, supported by genomic evidence, and represents a promising candidate for sustainable crop disease management.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148470671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metagenome-assembled genomes from northern West Siberia: insights into microbial diversity in permafrost and contemporary soils.","authors":"Darya V Poshvina, Alexander S Balkin, Alexey S Vasilchenko","doi":"10.1093/jambio/lxag182","DOIUrl":"10.1093/jambio/lxag182","url":null,"abstract":"<p><strong>Aims: </strong>Permafrost thawing due to global warming threatens to release long-preserved microbial communities, including potentially novel bacterial lineages. Despite the importance of West Siberian permafrost for climate models, genome-resolved studies of its microbial diversity remain limited. This study aimed to recover and characterize metagenome-assembled genomes (MAGs) from permafrost and contemporary soils of northern West Siberia, and to assess their biosynthetic and antibiotic resistance potential.</p><p><strong>Methods and results: </strong>We reconstructed 117 MAGs from soil samples collected from northern West Siberia, including ancient permafrost deposits (∼10 000 and ∼ 39 000 years old) and contemporary soils. Permafrost deposits exhibited significantly higher biosynthetic gene cluster (BGC) diversity compared to contemporary soils (Shannon H' = 4.15 vs. 3.36-3.59) with terpenes, RiPP-like and NRPS-like clusters being the most abundant. Notably, Vulcanimicrobiota and Verrucomicrobiota were recovered exclusively from permafrost in this dataset. A total of 14 unique antibiotic resistance genes conferring resistance to eight drug classes were detected. The RND efflux pump gene, adeF, dominated the resistome across all biomes, while Van family genes were largely restricted to permafrost at the phylum level. Verrucomiocota showed the highest adeF load followed by Planctomicrobiota and Pseudomonodota. A strong correlation was observed between bacterial genes and antibiotic resistance genes across biomes (Spearman's ρ = 0.893, p = 0.007).</p><p><strong>Conclusions: </strong>This genome-resolved study reveals a high level of undiscovered bacterial diversity in West Siberian permafrost including habitat-specific lineages. Our findings highlight permafrost as a rich repository of novel biosynthetic potential and emphasize the importance of metagenomic exploration of Arctic ecosystems under climate change.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148603368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficiency of controlled UVC dose emission by mercury lamps and LED array against clinically relevant pathogenic bacteria.","authors":"Cassiano R Schavinski, Nicolas W Belmonte, Bruno S Vizzotto, Nelson Jorge Schuch, André P Schuch","doi":"10.1093/jambio/lxag187","DOIUrl":"10.1093/jambio/lxag187","url":null,"abstract":"<p><strong>Aim: </strong>Ultraviolet C radiation (UVC; λ = 100-280 nm) is a well-established physical agent for microbial inactivation, widely applied in surface and environmental disinfection. Considering the increasing demand for efficient, safe, and automated disinfection systems, this study compares the performance of two low-pressure mercury lamps with different wattages and a novel UVC-LED array in terms of UVC irradiance, DNA damage induction, and microbiological inactivation.</p><p><strong>Methods: </strong>DNA photodamage was assessed in vitro via cyclobutane pyrimidine dimer detection, and bacteriological inactivation was evaluated with four relevant pathogenic bacteria (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae carbapenemase (KPC), and Pseudomonas aeruginosa) exposed to increasing UVC doses (0-50 J/m2).</p><p><strong>Results: </strong>All UVC sources induced a dose-dependent increase of DNA lesions and microbial inactivation, with 50 J/m² achieving an average inactivation rate of 99.98%. Although higher-power mercury lamps delivered higher dose rates (J/m2/s), the UVC-LED device showed comparable germicidal efficacy, with advantages in energy efficiency, operational lifespan, and environmental safety.</p><p><strong>Conclusions: </strong>The results presented in this work indicate the feasibility of complementing the use of mercury-based lamps with UVC-LEDs due to its great potential application for point-of-use disinfection approaches. Furthermore, the obtained results also highlight the importance of controlled digital dosimetry to improve the UVC-based technologies application for disinfection of bacteria of hospital concern.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148578675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aptamer-based biosensors for the diagnostics of infectious disease-causing bacteria using spiked and clinical samples: a systematic review.","authors":"Nurul Farzana Ismail, Marimuthu Citartan, Nurul Asyikin Mahbud, Choo Yee Yu, Sharifah Sakinah Syed Alwi, Narcisse Mary Sither Joseph, Syafinaz Amin-Nordin","doi":"10.1093/jambio/lxag189","DOIUrl":"10.1093/jambio/lxag189","url":null,"abstract":"<p><strong>Introduction: </strong>Bacterial infections that cause acute systemic infection are the leading cause of health issues globally. Current diagnostic assays for bacterial infection include culture and nucleic acid amplification methods. However, the culture method is very time-consuming and expensive, while the nucleic acid amplification method, although it is sensitive, requires trained personnel. Aptamer-based biosensors are promising alternatives to these strategies owing to aptamers' advantages: cost-saving, no batch-to-batch variation, and high specificity and sensitivity.</p><p><strong>Aims: </strong>In view of their diagnostic potential, we aim to conduct a systematic review on various biosensors harnessed for the diagnosis of bacteria, which was performed using spiked and clinical samples between 2018 and 2026.</p><p><strong>Methods and results: </strong>Based on the specific inclusion and exclusion criteria, the studies performed in recent years (2018-26) were filtered from two databases, PubMed and Scopus. The inclusion criteria were aptamer-based biosensors for the detection of bacteria in spiked and clinical samples from patients with human infectious diseases. A total of 42 studies were included in this systematic review that involve aptamer-based detection of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Escherichia coli, Mycobacterium tuberculosis, Acinetobacter baumanii, Pseudomonas aeruginosa, Neisseria meningitidis, Streptococcus pneumoniae, Salmonella typhimurium, Salmonella enterica, Helicobacter pylori, Roseburia intestinalis, Group B Streptococcus, and Haemophilus influenzae.</p><p><strong>Conclusion: </strong>Aptamer-based biosensors show immense prospects for the diagnostics of pathogenic bacteria.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148603370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preliminary strain-specific and non-additive effects of single versus mixed DSE inoculation on rhizosphere microbiome and nutrient cycling relative to plant biomass in Chinese yam.","authors":"Zihang Su, Mingfei Li, Yiling Zuo, Jia Guo, Yichen Wei, Shengci Fan, Yu Wang","doi":"10.1093/jambio/lxag165","DOIUrl":"10.1093/jambio/lxag165","url":null,"abstract":"<p><strong>Aims: </strong>To mitigate Chinese yam continuous cropping obstacles, this study assessed single and mixed dark septate endophyte (DSE) inoculation effects on yam growth, soil characteristics and rhizosphere microbial communities, offering references for optimizing rhizosphere microenvironment of continuously cropped medicinal plant soils.</p><p><strong>Methods and results: </strong>9 DSE strains were isolated from yam roots for single/mixed seedling pot inoculation; We found that growth-promoting effects differed by strain. Acrocalymma and Setophoma terrestris were the most commonly isolated DSE species, but strains with lower isolation rates Paraphoma ledniceana, Amesia atrobrunnea, and Zopfiella pilifera exhibited the most pronounced positive effects on yam root biomass. Increasing the number of co-inoculated strains did not proportionally enhance yam growth but progressively restructured soil microbial communities. However, mixed DSE inoculation as a whole showed no obvious growth promotion compared with the control. Fungal co-occurrence networks exhibited higher modularity and clustering, while bacterial communities had greater connectivity, especially under P. ledniceana and Fusarium sp. inoculation. Biosynthesis was the most abundant predicted function of rhizosphere microbes, with bacteria predicted to be enriched in detoxification and fungi in degradation-related pathways. Two strains of Chaetomiaceae and Periconia epilithographicola increased soil pH, organic carbon and available phosphorus, while available nitrogen decreased after DSE inoculation. Importantly, P. epilithographicola inoculation enhanced mycorrhizal fungi and mitigated microbial imbalance.</p><p><strong>Conclusions: </strong>Single and mixed DSE inoculations regulate rhizosphere microbial assembly and nutrient cycling via species-specific effects. Screening beneficial DSE consortia and characterizing their influence on rhizosphere networks provides preliminary theoretical insights and and candidate strains that may relieve yam replant obstacles in future applications.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148396753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasma-activated water generated by bubble spark and dielectric barrier discharges differ in antimicrobial and dye-decolourization efficacy.","authors":"Laura A McClenaghan, Thomas P Thompson, Ross M Duncan, Conor J Gilmore, Brendan F Gilmore","doi":"10.1093/jambio/lxag201","DOIUrl":"10.1093/jambio/lxag201","url":null,"abstract":"<p><strong>Aims: </strong>The requirement for alternative wastewater treatment methods continues to increase as current systems are overwhelmed, leading to accumulation of both microbial and chemical pollutants. The purpose of this study was to evaluate and compare the potential of two distinct PAWs, The bubble spark discharge (BSD) and dielectric barrier discharge diffuser (DBDD), for both microbial inactivation and decolourization of model organic contaminants in wastewater. The potential mechanisms associated with each PAW was explored using ROS and RNS quantification and chemical scavenger assays.</p><p><strong>Methods and results: </strong>Two direct plasma-in-liquid systems generating PAW in situ via microbubble discharge were evaluated: BSD and DBDD, tested for antimicrobial activity against relevant potential wastewater pathogens including Escherichia coli and Salmonella enterica. Their ability to degrade several water-soluble dyes (crystal violet, methylene blue, and Congo red) as relevant surrogates for environmental contaminants of industrial origin, was also assessed. The DBDD achieved the most rapid inactivation of all tested planktonic bacteria within 90 s, while the BSD took up to 5 min. The bactericidal activity of the DBDD was likely due to a greater production of short-lived species, such as O₂⁻ and ¹O₂, which specific scavenger assays (l-histidine and Tiron) confirmed were essential for the antimicrobial activity, while the longer-lived H2O2 contributed significantly to the antibacterial activity of the BSD system.</p><p><strong>Conclusions: </strong>These findings suggest that PAW could be used as a rapid, on-demand advanced oxidation process for the tertiary stage of wastewater treatment, with potential to reduce reliance on conventional UV or chlorine disinfection while targeting both chemical contaminants and microbial bioburdens.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The bacteriocin enterocin EJ97s retains its antibacterial effect upon interaction with human serum albumin.","authors":"Ingvild Reinseth, Krister Gjestvang Grønlien, Thomas Førland Oftedal, Morten Kjos, Harald Carlsen, Hanne Hjorth Tønnesen","doi":"10.1093/jambio/lxag193","DOIUrl":"10.1093/jambio/lxag193","url":null,"abstract":"<p><strong>Aims: </strong>The aim of this study was to investigate the interaction between the anti-enterococcal bacteriocin enterocin EJ97s (EntEJ97s) and human serum albumin (HSA) as a step in the pre-clinical assessment of this bacteriocin.</p><p><strong>Methods and results: </strong>The interactions between EntEJ97s and HSA were investigated using steady-state fluorescence, nano differential scanning calorimetry, and nano isothermal titration calorimetry (nanoITC). The results show low to moderate affinity between EntEJ97s and HSA, with a stoichiometry of less than one EntEJ97s per HSA molecule. NanoITC competition experiments with competitive ligands indicated that the peptide interacts with both the Sudlow I site and the Sudlow II site, the two main drug-binding sites on HSA. Molecular modelling efforts corroborated the findings of an interaction in the vicinity of these sites. The antibacterial effect of the peptide was preserved in the presence of physiological and experimental concentrations of HSA, as indicated by minimum inhibitory concentration experiments and spot-on-lawn assays.</p><p><strong>Conclusions: </strong>Our results suggest that EntEJ97s interacts with HSA without compromising its antibacterial effect. These findings accentuate the potential of this bacteriocin for intravenous treatment.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148619831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formulation, storage stability, and simulated gastrointestinal digestion of a next-generation nutraceutical combining Limosilactobacillus fermentum and Pilosocereus pachycladus (F. Ritter) cacti.","authors":"Jaielison Yandro Pereira da Silva, Evandro Leite de Souza, Viviane Priscila Barros de Medeiros, Andressa Estefany da Silva Nogueira, Rafaela Shayani Lima Pereira, Sabrina Radames Ferreira da Silva, Maiara da Costa Lima, Heloisa Maria Almeida do Nascimento Soares, Sônia Paula Alexandrino de Oliveira, Maria Elieidy Gomes de Oliveira, Kataryne Árabe Rimá de Oliveira","doi":"10.1093/jambio/lxag197","DOIUrl":"10.1093/jambio/lxag197","url":null,"abstract":"<p><strong>Aim: </strong>This study aimed to formulate and characterize a novel next-generation nutraceutical combining a mixture of Limosilactobacillus fermentum strains (139, 263, and 296) candidates for probiotic use and freeze-dried Pilosocereus pachycladus (F. Ritter) (facheiro) cladodes, focusing on its physical, physicochemical, and phytochemical properties, the survival and viability of L. fermentum, and the stability and performance of the nutraceutical under simulated gastrointestinal digestion over 90 days of controlled storage (13% relative humidity; 4°C and 25°C).</p><p><strong>Method and results: </strong>The nutraceutical had high contents of insoluble and soluble fibers, as well as antioxidant phenolic compounds and flavonoids, which supported the survival of L. fermentum strains during freeze-drying (>90%) and conferred protection under gastrointestinal conditions, with survival rates exceeding 50%. Among the storage conditions, refrigerated storage provided superior long-term stability, preserving bioactive compounds and the viability of L. fermentum cells. Simulated gastrointestinal digestion demonstrated effective delivery of antioxidant compounds and viable L. fermentum cells, even in the presence of low pH, digestive enzymes, and bile salts.</p><p><strong>Conclusion: </strong>The combination of L. fermentum strains candidates for probiotic use and freeze-dried facheiro cladodes demonstrated technological stability and functional performance, highlighting facheiro cactus as a valuable bioresource for probiotic delivery. Further studies using advanced in vitro models, such as colonic fermentation, and preclinical trials are warranted to substantiate the health benefits of this nutraceutical.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148669434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and application of lyophilized Bacillus atrophaeus spore pellets as an reference material of enumeration for onsite validation of medical sterilization equipment.","authors":"Wen Zhu, Hongfei Chen, ChengChen Han, Danni Pei, Jiaxin Yang, Sheng Xu, Nana Sun","doi":"10.1093/jambio/lxag180","DOIUrl":"10.1093/jambio/lxag180","url":null,"abstract":"<p><strong>Aims: </strong>To develop a user-friendly and portable reference material (RM) for onsite validation of medical sterilization equipment, addressing the limitations of conventional biological indicators (BIs) that require specialized laboratory facilities.</p><p><strong>Methods and results: </strong>A lyophilized microsphere-based RM containing Bacillus atrophaeus spores was developed by optimizing lyoprotectant formulation. The RM demonstrated excellent homogeneity (F statistic<F critical) and satisfactory stability over 14 days at 4°C and 25°C, rigorously according to ISO 33405: 2024 standard method. When applied to validate UV sterilization devices by quantifying viable spore reduction, it further provided precise and reliable log reduction value measurements. The simple reconstitute-and-culture procedure enabled non-specialists to perform onsite checks. For instance, in UV validation, optimal conditions (e.g. ≥3-log reduction within 30 min at a distance of 150 cm) were easily determined using this RM. Preliminary assessments also confirmed its applicability for ozone and ethylene oxide (EO) sterilizers.</p><p><strong>Conclusions: </strong>This study presents the first preparation of a convenient, lyophilized spore RM that fulfills ISO 33405: 2024 criteria. Its successful application in validating multiple sterilization modalities demonstrates significant potential for routine quality control and compliance testing in healthcare settings, particularly where advanced laboratory facilities are unavailable.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148470711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transmission of Escherichia coli from irrigation water to preharvest leafy greens.","authors":"Leo van Overbeek, Carin Lombaers, Leo Poleij","doi":"10.1093/jambio/lxag185","DOIUrl":"10.1093/jambio/lxag185","url":null,"abstract":"<p><strong>Aim: </strong>The aim of this study was to examine the fate of Escherichia coli strain 0611, used as model for a water-borne bacterial contaminant, in leafy green production systems.</p><p><strong>Methods and results: </strong>Irrigation water from two different sources was inoculated with the strain and applied via overhead irrigation to endive and spinach plants grown under open-field conditions. Inoculum levels were 10³ CFU mL⁻¹, representing occasional water contamination, and a 1000-fold higher density to enable detailed quantification across plant compartments. Three experiments assessed bacterial persistence after single or double irrigation events at varying intervals, and under continuous irrigation. Colony-forming units were measured on leaves and in rhizosphere soils. Under continuous irrigation with the low inoculum dose, E. coli 0611 was only sporadically detected on leaves. At the higher dose, the interval between irrigation and harvest had a greater impact on bacterial presence than water source. Decline patterns on leaves and in endive rhizosphere soil followed double-exponential models. Rhizosphere soil represents an additional risk factor for transmission of human pathogens to fresh produce. Although bacterial populations declined rapidly on leaves, they did not completely disappear from rhizosphere soil.</p><p><strong>Conclusions: </strong>A preharvest interval of at least 4 days after the final irrigation substantially reduces the risk of pathogen transfer to fresh produce. The experimental data support evidence-based recommendations for producers to reduce the risk of microbial contamination of fresh produce, thereby contributing to safer production of ready-to-eat vegetables.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148562034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}