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Kong Y, Deering AJ, Nemali K. Minimizing Escherichia coli O157:H7 contamination in indoor farming: effects of cultivar type and ultra-violet light quality. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:4218-4225. [PMID: 38294189 DOI: 10.1002/jsfa.13303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/31/2023] [Accepted: 01/07/2024] [Indexed: 02/01/2024]
Abstract
BACKGROUND Bacterial contamination of produce is a concern in indoor farming due to close plant spacing, recycling irrigation, warm temperatures, and high relative humidity during production. Cultivars that inherently resist contamination and photo-sanitization using ultraviolet (UV) radiation during the production phase can reduce bacterial contamination. However, there is limited information to support their use in indoor farming. RESULTS Lettuce (Lactuca sativa) cultivars with varying plant architectures grown in a custom-built indoor farm exhibited differences in E. coli O157:H7 survival after inoculation. The survival of E. coli O157:H7 was lowest in the leaf cultivar (open architecture) and highest in the romaine and oakleaf cultivars (compact architecture). Of the different UV wavelengths that were tested (UV-A, UV-A + B, UV-A + C), UV A + C at an intensity of 54.5 μmol m-2 s-1 (with 3.5 μmol m-2 s-1 of UV-C), provided for 15 min every day, was found to be most efficacious in reducing the E. coli O157:H7 survival on romaine lettuce with no negative effects on plant growth and quality. CONCLUSION Contamination of E. coli O157:H7 on lettuce plants can be reduced and the food safety levels in indoor farms can be increased by selecting cultivars with an open leaf architecture coupled with photo-sanitization using low and frequent exposure to UV A + C radiation. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Yuyao Kong
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, USA
| | - Amanda J Deering
- Department of Food Science, Purdue University, West Lafayette, IN, USA
| | - Krishna Nemali
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, USA
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2
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Ding Q, Gu G, Nou X, Micallef SA. Cultivar was more influential than bacterial strain and other experimental factors in recovery of Escherichia coli O157:H7 populations from inoculated live Romaine lettuce plants. Microbiol Spectr 2024; 12:e0376723. [PMID: 38363139 PMCID: PMC10986467 DOI: 10.1128/spectrum.03767-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 01/22/2024] [Indexed: 02/17/2024] Open
Abstract
The varied choice of bacterial strain, plant cultivar, and method used to inoculate, retrieve, and enumerate Escherichia coli O157:H7 from live plants could affect comparability among studies evaluating lettuce-enterobacterial interactions. Cultivar, bacterial strain, incubation time, leaf side inoculated, and sample processing method were assessed for their influence in recovering and quantifying E. coli O157:H7 from live Romaine lettuce. Cultivar exerted the strongest effect on E. coli O157:H7 counts, which held up even when cultivar was considered in interactions with other factors. Recovery from the popularly grown green Romaine "Rio Bravo" was higher than from the red variety "Outredgeous." Other modulating variables were incubation time, strain, and leaf side inoculated. Sample processing method was not significant. Incubation for 24 hours post-lettuce inoculation yielded greater counts than 48 hours, but was affected by lettuce cultivar, bacterial strain, and leaf side inoculated. Higher counts obtained for strain EDL933 compared to a lettuce outbreak strain 2705C emphasized the importance of selecting relevant strains for the system being studied. Inoculating the abaxial side of leaves gave higher counts than adaxial surface inoculation, although this factor interacted with strain and incubation period. Our findings highlight the importance of studying interactions between appropriate bacterial strains and plant cultivars for more relevant research results, and of standardizing inoculation and incubation procedures. The strong effect of cultivar exerted on the E. coli O157:H7-lettuce association supports the need to start reporting cultivar information for illness outbreaks to facilitate the identification and study of plant traits that impact food safety risk.IMPORTANCEThe contamination of Romaine lettuce with Escherichia coli O157:H7 has been linked to multiple foodborne disease outbreaks, but variability in the methods used to evaluate E. coli O157:H7 association with live lettuce plants complicates the comparability of different studies. In this study, various experimental variables and sample processing methods for recovering and quantifying E. coli O157:H7 from live Romaine lettuce were assessed. Cultivar was found to exert the strongest influence on E. coli O157:H7 retrieval from lettuce. Other modulating factors were bacterial incubation time on plants, strain, and leaf side inoculated, while sample processing method had no impact. Our findings highlight the importance of selecting relevant cultivars and strains, and of standardizing inoculation and incubation procedures, in these types of assessments. Moreover, results support the need to start reporting cultivars implicated in foodborne illness outbreaks to facilitate the identification and study of plant traits that impact food safety risk.
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Affiliation(s)
- Qiao Ding
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland, USA
| | - Ganyu Gu
- Environmental Microbial and Food Safety Laboratory, USDA ARS, Beltsville, Maryland, USA
| | - Xiangwu Nou
- Environmental Microbial and Food Safety Laboratory, USDA ARS, Beltsville, Maryland, USA
| | - Shirley A. Micallef
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland, USA
- Center for Food Safety and Security Systems, University of Maryland, College Park, Maryland, USA
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Xylia P, Chrysargyris A, Botsaris G, Skandamis P, Tzortzakis N. Salmonella Enteritidis survival in different temperatures and nutrient solution pH levels in hydroponically grown lettuce. Food Microbiol 2022; 102:103898. [PMID: 34809930 DOI: 10.1016/j.fm.2021.103898] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/23/2021] [Accepted: 09/08/2021] [Indexed: 11/04/2022]
Abstract
Due to climate change, with contaminated and less fertile soils, and intense weather phenomena, a turn towards hydroponic vegetable production has been made. Hydroponic cultivation of vegetables is considered to be a clean, safe and environmentally friendly growing technique; however, incidence of microbial contamination i.e. foodborne pathogens, might occur, endangering human health. The aim of this study was to investigate the effects of different plant growth stages, pH (values 5, 6, 7, 8) and bacterial inoculum levels (3 and 6 log cfu/mL) on hydroponically cultivated lettuce spiked with Salmonella Enteritidis. The results revealed that the pH and inoculum levels affected the internalization and survival of the pathogen in the hydroponic environment and plant tissue. Younger plants were found to be more susceptible to pathogen internalization compared to older ones. Under the current growing conditions (hydroponics, pH and inoculum levels), no leaf internalization was observed at all lettuce growth stages, despite the bacterium presence in the hydroponic solution. Noticeably, bacteria load at the nutrient solution was lower in low pH levels. These results showed that bacterium presence initiates plant response as indicated by the increased phenols, antioxidants and damage index markers (H2O2, MDA) in order for the plant to resist contamination by the invader. Nutrient solution management can result in Taylor-made recipes for plant growth and possible controlling the survival and growth of S. Enteritidis by pH levels.
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Affiliation(s)
- Panayiota Xylia
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol, Cyprus
| | - Antonios Chrysargyris
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol, Cyprus
| | - George Botsaris
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol, Cyprus
| | - Panagiotis Skandamis
- Faculty of Food Science & Technology, Agricultural University of Athens, Athens, Greece
| | - Nikolaos Tzortzakis
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol, Cyprus.
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4
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Macieira A, Barbosa J, Teixeira P. Food Safety in Local Farming of Fruits and Vegetables. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18189733. [PMID: 34574658 PMCID: PMC8469988 DOI: 10.3390/ijerph18189733] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/06/2021] [Accepted: 09/11/2021] [Indexed: 11/26/2022]
Abstract
The world’s population will be around 9 billion people by 2050. Humans need to feed in order to survive and thus the high demographic growth may impact the sustainability of our food systems. Sustainable food production practices such as local farming have been explored. Consumption of vegetables and fruits has been increasing due to their health benefits, but this increase is also related to a significant number of foodborne outbreaks. Foodborne outbreaks pose a threat to public health and the economy on a local and national scale. Food safety begins on the farm and proceeds over the supply chain. Thus, to provide safe products, food producers must follow specific procedures to avoid food hazards along the supply chain. This work aimed to present the importance of food safety in vegetables and fruits in local farming, as this form of production and consumption has increased in several countries of the northern hemisphere and as these are considered a form of providing more sustainable food products.
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Survival of Escherichia coli and Listeria innocua on Lettuce after Irrigation with Contaminated Water in a Temperate Climate. Foods 2021; 10:foods10092072. [PMID: 34574181 PMCID: PMC8468451 DOI: 10.3390/foods10092072] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/26/2021] [Accepted: 08/28/2021] [Indexed: 12/20/2022] Open
Abstract
Microbial disease outbreaks related to fresh produce consumption, including leafy green vegetables, have increased in recent years. Where contamination occurs, pathogen persistence may represent a risk for consumers' health. This study analysed the survival of E. coli and L. innocua on lettuce plants watered with contaminated irrigation water via a single irrigation event and within stored irrigation water. Separate lettuce plants (Lactuca sativa var. capitata) were irrigated with water spiked with Log10 7 cfu/mL of each of the two strains and survival assessed via direct enumeration, enrichment and qPCR. In parallel, individual 20 L water microcosms were spiked with Log10 7 cfu/mL of the individual strains and sampled at similar time points. Both strains were observed to survive on lettuce plants up to 28 days after inoculation. Direct quantification by culture methods showed a Log10 4 decrease in the concentration of E. coli 14 days after inoculation, and a Log10 3 decrease in the concentration of L. innocua 10 days after inoculation. E. coli was detected in water samples up to 7 days after inoculation and L. innocua was detected up to 28 days by direct enumeration. Both strains were recovered from enriched samples up to 28 days after inoculation. These results demonstrate that E. coli and L. innocua strains are able to persist on lettuce after a single contamination event up until the plants reach a harvestable state. Furthermore, the persistence of E. coli and L. innocua in water for up to 28 days after inoculation illustrates the potential for multiple plant contamination events from stored irrigation water, emphasising the importance of ensuring that irrigation water is of a high quality.
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Polymicrobial Interactions Operative during Pathogen Transmission. mBio 2021; 12:mBio.01027-21. [PMID: 34006664 PMCID: PMC8262881 DOI: 10.1128/mbio.01027-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Pathogen transmission is a key point not only for infection control and public health interventions but also for understanding the selective pressures in pathogen evolution. The “success” of a pathogen lies not in its ability to cause signs and symptoms of illness but in its ability to be shed from the initial hosts, survive between hosts, and then establish infection in a new host. Recent insights have shown the importance of the interaction between the pathogen and both the commensal microbiome and coinfecting pathogens on shedding, environmental survival, and acquisition of infection. Pathogens have evolved in the context of cooperation and competition with other microbes, and the roles of these cooperations and competitions in transmission can inform novel preventative and therapeutic strategies.
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Lenzi A, Marvasi M, Baldi A. Agronomic practices to limit pre- and post-harvest contamination and proliferation of human pathogenic Enterobacteriaceae in vegetable produce. Food Control 2021. [DOI: 10.1016/j.foodcont.2020.107486] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Yin HB, Gupta N, Chen CH, Boomer A, Pradhan A, Patel J. Persistence of Escherichia coli O157:H12 and Escherichia coli K12 as Non-pathogenic Surrogates for O157:H7 on Lettuce Cultivars Irrigated With Secondary-Treated Wastewater and Roof-Collected Rain Water in the Field. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2020. [DOI: 10.3389/fsufs.2020.555459] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Treated wastewater (TW) and roof-collected rain water (RW) that meet the required microbial quality as per Food Safety Modernization Act (FSMA) regulation may serve as alternative irrigation water sources to decrease the pressure on the current water scarcity. Alternative water sources may have different water characteristics that influence the survival and transfer of microorganisms to the irrigated produce. Further, these water sources may contain pathogenic bacteria such as Shiga-toxigenic Escherichia coli. To evaluate the risk associated with TW and RW irrigation on the fresh produce safety, the effect of TW and RW irrigation on the transfer of two non-pathogenic E. coli strains as surrogates for E. coli O157:H7 to different lettuce cultivars grown in the field was investigated. Lettuce cultivars “Annapolis,” “Celinet,” and “Coastline” were grown in the field at the Fulton farm (Chambersburg, PA). Approximately 10 days before harvest, lettuce plants were spray-irrigated with groundwater (GW), TW, or RW containing 6 log CFU ml−1 of a mixture of nalidixic acid-resistant E. coli O157:H12 and chloramphenicol-resistant E. coli K12 in fecal slurry as non-pathogenic surrogates for E. coli O157:H7. On 0, 1, 3, 7, and 10 days post-irrigation, four replicate lettuce leaf samples (30 g per sample) from each group were collected and pummeled in 120 ml of buffered peptone water for 2 min, followed by spiral plating on MacConkey agars with antibiotics. Results showed that the recovery of E. coli O157:H12 was significantly greater than the populations of E. coli K12 recovered from the irrigated lettuce regardless of the water sources and the lettuce cultivars. The TW irrigation resulted in the lowest recovery of the E. coli surrogates on the lettuce compared to the populations of these bacteria recovered from the lettuce with RW and GW irrigation on day 0. The difference in leaf characteristics of lettuce cultivars significantly influenced the recovery of these surrogates on lettuce leaves. Populations of E. coli O157:H12 recovered from the RW-irrigated “Annapolis” lettuce were significantly lower than the recovery of this bacterium from the “Celinet” and “Coastline” lettuce (P < 0.05). Overall, the recovery of specific E. coli surrogates from the RW and TW irrigated lettuce was comparable to the lettuce with the GW irrigation, where GW served as a baseline water source. E. coli O157:H12 could be a more suitable surrogate compared to E. coli K12 because it is an environmental watershed isolate. The findings of this study provide critical information in risk assessment evaluation of RW and TW irrigation on lettuce in Mid-Atlantic area.
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9
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Belias AM, Sbodio A, Truchado P, Weller D, Pinzon J, Skots M, Allende A, Munther D, Suslow T, Wiedmann M, Ivanek R. Effect of Weather on the Die-Off of Escherichia coli and Attenuated Salmonella enterica Serovar Typhimurium on Preharvest Leafy Greens following Irrigation with Contaminated Water. Appl Environ Microbiol 2020; 86:e00899-20. [PMID: 32591379 PMCID: PMC7440809 DOI: 10.1128/aem.00899-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/21/2020] [Indexed: 11/25/2022] Open
Abstract
The Food Safety Modernization Act (FSMA) includes a time-to-harvest interval following the application of noncompliant water to preharvest produce to allow for microbial die-off. However, additional scientific evidence is needed to support this rule. This study aimed to determine the impact of weather on the die-off rate of Escherichia coli and Salmonella on spinach and lettuce under field conditions. Standardized, replicated field trials were conducted in California, New York, and Spain over 2 years. Baby spinach and lettuce were grown and inoculated with an ∼104-CFU/ml cocktail of E. coli and attenuated Salmonella Leaf samples were collected at 7 time points (0 to 96 h) following inoculation; E. coli and Salmonella were enumerated. The associations of die-off with study design factors (location, produce type, and bacteria) and weather were assessed using log-linear and biphasic segmented log-linear regression. A segmented log-linear model best fit die-off on inoculated leaves in most cases, with a greater variation in the segment 1 die-off rate across trials (-0.46 [95% confidence interval {95% CI}, -0.52, -0.41] to -6.99 [95% CI, -7.38, -6.59] log10 die-off/day) than in the segment 2 die-off rate (0.28 [95% CI, -0.20, 0.77] to -1.00 [95% CI, -1.16, -0.85] log10 die-off/day). A lower relative humidity was associated with a faster segment 1 die-off and an earlier breakpoint (the time when segment 1 die-off rate switches to the segment 2 rate). Relative humidity was also found to be associated with whether die-off would comply with FSMA's specified die-off rate of -0.5 log10 die-off/day.IMPORTANCE The log-linear die-off rate proposed by FSMA is not always appropriate, as the die-off rates of foodborne bacterial pathogens and specified agricultural water quality indicator organisms appear to commonly follow a biphasic pattern with an initial rapid decline followed by a period of tailing. While we observed substantial variation in the net culturable population levels of Salmonella and E. coli at each time point, die-off rate and FSMA compliance (i.e., at least a 2 log10 die-off over 4 days) appear to be impacted by produce type, bacteria, and weather; die-off on lettuce tended to be faster than that on spinach, die-off of E. coli tended to be faster than that of attenuated Salmonella, and die-off tended to become faster as relative humidity decreased. Thus, the use of a single die-off rate for estimating time-to-harvest intervals across different weather conditions, produce types, and bacteria should be revised.
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Affiliation(s)
| | - Adrian Sbodio
- Department of Plant Sciences, University of California, Davis, California, USA
| | - Pilar Truchado
- Department of Food Science and Technology, CEBAS-CSIC (Spanish National Research Council), Murcia, Spain
| | - Daniel Weller
- Department of Food Science, Cornell University, Ithaca, New York, USA
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, New York, USA
| | - Janneth Pinzon
- Department of Plant Sciences, University of California, Davis, California, USA
| | - Mariya Skots
- Department of Plant Sciences, University of California, Davis, California, USA
| | - Ana Allende
- Department of Food Science and Technology, CEBAS-CSIC (Spanish National Research Council), Murcia, Spain
| | - Daniel Munther
- Department of Mathematics, Cleveland State University, Cleveland, Ohio, USA
| | - Trevor Suslow
- Department of Plant Sciences, University of California, Davis, California, USA
- Produce Marketing Association, Newark, Delaware, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Renata Ivanek
- Department of Population Medicine and Diagnostic Sciences, Cornell University, New York, USA
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Yin H, Chen C, Karanth S, Byun S, Mayer C, Harriger D, Pradhan A, Patel J. Effect of cultivars and irrigation waters on persistence of indicator bacteria on lettuce grown in high tunnel. J Food Saf 2020. [DOI: 10.1111/jfs.12795] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Hsin‐Bai Yin
- Environmental Microbial and Food Safety LaboratoryUSDA ARS, BARC Beltsville Maryland USA
| | - Chi‐Hung Chen
- Environmental Microbial and Food Safety LaboratoryUSDA ARS, BARC Beltsville Maryland USA
| | - Shraddha Karanth
- Department of Food Science and NutritionUniversity of Maryland College Park Maryland USA
| | - Suyeun Byun
- Environmental Microbial and Food Safety LaboratoryUSDA ARS, BARC Beltsville Maryland USA
| | | | | | - Abani Pradhan
- Department of Food Science and NutritionUniversity of Maryland College Park Maryland USA
| | - Jitendra Patel
- Environmental Microbial and Food Safety LaboratoryUSDA ARS, BARC Beltsville Maryland USA
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11
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Henriquez T, Lenzi A, Baldi A, Marvasi M. Frontiers in Plant Breeding: Perspectives for the Selection of Vegetables Less Susceptible to Enteric Pathogens. Front Microbiol 2020; 11:1087. [PMID: 32547520 PMCID: PMC7270193 DOI: 10.3389/fmicb.2020.01087] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 04/30/2020] [Indexed: 11/17/2022] Open
Abstract
Fresh vegetables including baby greens, microgreens, and sprouts can host human pathogens without exhibiting any visible signs of spoilage. It is clear that the vast majority of foodborne disease outbreaks associated with vegetable produce are not simply a result of an oversight by a producer, as it was shown that zoonotic pathogens from Enterobacteriaceae can contaminate produce through various routes throughout the entire production cycle. In this context, phenotypic and genotypic signatures have been used since early ages in agriculture to obtain better produce, and can be used today as a strategy to reduce the risk of outbreaks through plant breeding. In this mini-review, we provide an updated view and perspectives on to what extent the selection of biological markers can be used to select safer cultivars of vegetable crops such as tomato (the most studied), leafy greens and cabbage. Once this knowledge will be better consolidated, these approaches should be integrated into the development of comprehensive farm-to-fork produce safety programs.
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Affiliation(s)
- Tania Henriquez
- Biozentrum, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Anna Lenzi
- Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Florence, Italy
| | - Ada Baldi
- Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Florence, Italy
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12
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Determining common contributory factors in food safety incidents – A review of global outbreaks and recalls 2008–2018. Trends Food Sci Technol 2020. [DOI: 10.1016/j.tifs.2019.12.030] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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13
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Astill GM, Kuchler F, Todd JE, Page ET. Shiga Toxin-Producing Escherichia coli (STEC) O157:H7 and Romaine Lettuce: Source Labeling, Prevention, and Business. Am J Public Health 2020; 110:322-328. [PMID: 31944843 PMCID: PMC7002929 DOI: 10.2105/ajph.2019.305476] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2019] [Indexed: 11/04/2022]
Abstract
From May to November most romaine lettuce shipments in the United States come from California's Central Coast region, whereas from December to April most come from the Yuma, Arizona, region. During 2017-2018, the 3 outbreaks of Shiga toxin-producing Escherichia coli (STEC) O157:H7 in US romaine lettuce all occurred at the tail end of a region's production season. During the fall 2018 outbreak, the US Food and Drug Administration (FDA) recommended that suppliers begin labeling romaine packaging so that consumers can identify the product's harvest region.We used publicly available data to show that labels may not avert many illnesses in future outbreaks but may reduce suppliers' financial losses and reduce food loss.Market data available during both 2018 outbreak investigations showed that there was no romaine production from one of the 2 regions when the first illness onset occurred. That is, at the beginning of an outbreak investigation, market data may allow the FDA to quickly rule out an entire production region as a source of contamination.
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Affiliation(s)
- Gregory M Astill
- Gregory M. Astill is with the Markets and Trade Economics Division, Economic Research Service, US Department of Agriculture, Kansas City, MO. Fred Kuchler, Jessica E. Todd, and Elina T. Page are with the Food Economics Division, Economic Research Service, US Department of Agriculture, Washington, DC
| | - Fred Kuchler
- Gregory M. Astill is with the Markets and Trade Economics Division, Economic Research Service, US Department of Agriculture, Kansas City, MO. Fred Kuchler, Jessica E. Todd, and Elina T. Page are with the Food Economics Division, Economic Research Service, US Department of Agriculture, Washington, DC
| | - Jessica E Todd
- Gregory M. Astill is with the Markets and Trade Economics Division, Economic Research Service, US Department of Agriculture, Kansas City, MO. Fred Kuchler, Jessica E. Todd, and Elina T. Page are with the Food Economics Division, Economic Research Service, US Department of Agriculture, Washington, DC
| | - Elina T Page
- Gregory M. Astill is with the Markets and Trade Economics Division, Economic Research Service, US Department of Agriculture, Kansas City, MO. Fred Kuchler, Jessica E. Todd, and Elina T. Page are with the Food Economics Division, Economic Research Service, US Department of Agriculture, Washington, DC
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14
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Melotto M, Brandl MT, Jacob C, Jay-Russell MT, Micallef SA, Warburton ML, Van Deynze A. Breeding Crops for Enhanced Food Safety. FRONTIERS IN PLANT SCIENCE 2020; 11:428. [PMID: 32351531 PMCID: PMC7176021 DOI: 10.3389/fpls.2020.00428] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/24/2020] [Indexed: 05/12/2023]
Abstract
An increasing global population demands a continuous supply of nutritious and safe food. Edible products can be contaminated with biological (e.g., bacteria, virus, protozoa), chemical (e.g., heavy metals, mycotoxins), and physical hazards during production, storage, transport, processing, and/or meal preparation. The substantial impact of foodborne disease outbreaks on public health and the economy has led to multidisciplinary research aimed to understand the biology underlying the different contamination processes and how to mitigate food hazards. Here we review the knowledge, opportunities, and challenges of plant breeding as a tool to enhance the food safety of plant-based food products. First, we discuss the significant effect of plant genotypic and phenotypic variation in the contamination of plants by heavy metals, mycotoxin-producing fungi, and human pathogenic bacteria. In addition, we discuss the various factors (i.e., temperature, relative humidity, soil, microbiota, cultural practices, and plant developmental stage) that can influence the interaction between plant genetic diversity and contaminant. This exposes the necessity of a multidisciplinary approach to understand plant genotype × environment × microbe × management interactions. Moreover, we show that the numerous possibilities of crop/hazard combinations make the definition and identification of high-risk pairs, such as Salmonella-tomato and Escherichia coli-lettuce, imperative for breeding programs geared toward improving microbial safety of produce. Finally, we discuss research on developing effective assays and approaches for selecting desirable breeding germplasm. Overall, it is recognized that although breeding programs for some human pathogen/toxin systems are ongoing (e.g., Fusarium in wheat), it would be premature to start breeding when targets and testing systems are not well defined. Nevertheless, current research is paving the way toward this goal and this review highlights advances in the field and critical points for the success of this initiative that were discussed during the Breeding Crops for Enhanced Food Safety workshop held 5-6 June 2019 at University of California, Davis.
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Affiliation(s)
- Maeli Melotto
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
- *Correspondence: Maeli Melotto,
| | - Maria T. Brandl
- United States Department of Agriculture-Agricultural Research Service, Produce Safety and Microbiology Research, Albany, CA, United States
| | - Cristián Jacob
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Michele T. Jay-Russell
- Western Center for Food Safety, University of California, Davis, Davis, CA, United States
| | - Shirley A. Micallef
- Department of Plant Science and Landscape Architecture, Center for Food Safety and Security Systems, University of Maryland, College Park, MD, United States
| | - Marilyn L. Warburton
- United States Department of Agriculture-Agricultural Research Service, Corn Host Plant Research Resistance Unit Mississippi State, Starkville, MS, United States
| | - Allen Van Deynze
- Plant Breeding Center, Department of Plant Sciences, University of California, Davis, Davis, CA, United States
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Lee D, Tertuliano M, Harris C, Vellidis G, Levy K, Coolong T. Salmonella Survival in Soil and Transfer onto Produce via Splash Events. J Food Prot 2019; 82:2023-2037. [PMID: 31692392 DOI: 10.4315/0362-028x.jfp-19-066] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Nearly one-half of foodborne illnesses in the United States can be attributed to fresh produce consumption. The preharvest stage of production presents a critical opportunity to prevent produce contamination in the field from contaminating postharvest operations and exposing consumers to foodborne pathogens. One produce-contamination route that is not often explored is the transfer of pathogens in the soil to edible portions of crops via splash water. We report here on the results from multiple field and microcosm experiments examining the potential for Salmonella contamination of produce crops via splash water, and the effect of soil moisture content on Salmonella survival in soil and concentration in splash water. In field and microcosm experiments, we detected Salmonella for up to 8 to 10 days after inoculation in soil and on produce. Salmonella and suspended solids were detected in splash water at heights of up to 80 cm from the soil surface. Soil-moisture conditions before the splash event influenced the detection of Salmonella on crops after the splash events-Salmonella concentrations on produce after rainfall were significantly higher in wet plots than in dry plots (geometric mean difference = 0.43 CFU/g; P = 0.03). Similarly, concentrations of Salmonella in splash water in wet plots trended higher than concentrations from dry plots (geometric mean difference = 0.67 CFU/100 mL; P = 0.04). These results indicate that splash transfer of Salmonella from soil onto crops can occur and that antecedent soil-moisture content may mediate the efficiency of microbial transfer. Splash transfer of Salmonella may, therefore, pose a hazard to produce safety. The potential for the risk of splash should be further explored in agricultural regions in which Salmonella and other pathogens are present in soil. These results will help inform the assessment of produce safety risk and the development of management practices for the mitigation of produce contamination.
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Affiliation(s)
- Debbie Lee
- Department of Environmental Health, Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, Georgia 30322
| | | | | | | | - Karen Levy
- Department of Environmental Health, Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, Georgia 30322
| | - Timothy Coolong
- Department of Horticulture, College of Agricultural & Environmental Sciences, University of Georgia, 2360 Rainwater Road, Tifton, Georgia 31793, USA
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Erickson MC, Liao JY, Payton AS, Cook PW, Adhikari K, Wang S, Bautista J, Pérez JCD. Efficacy of Acetic Acid or Chitosan for Reducing the Prevalence of Salmonella- and Escherichia coli O157:H7-Contaminated Leafy Green Plants in Field Systems. J Food Prot 2019; 82:854-861. [PMID: 31013166 DOI: 10.4315/0362-028x.jfp-18-347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Outbreaks associated with fresh-cut leafy greens continue to occur despite efforts to implement horticultural practices that minimize introduction of enteric pathogens to the crop. The experimental trials in this study were designed to examine the efficacy of an acetic acid (AA)- and chitosan-based spray treatment, applied 1 day prior to harvest, for reducing the prevalence of Escherichia coli O157:H7 (O157) and Salmonella in field-grown leafy greens contaminated at levels detectable only through enrichment culture. Responses to the treatment solution were variable and depended on the type of leafy green (leafy lettuce, spinach, or cabbage), cultivar, pathogen, and AA concentration (0.3 to 0.7%). No significant differences in E. coli O157 prevalence were found for untreated and treated cabbage heads and spinach plants (P > 0.05). In contrast, treatment significantly affected Salmonella on 'Bravo F1' green cabbage and '7-Green' spinach (P < 0.05), with odds ratios of 2.2 and 3.3 for finding the pathogen on untreated versus treated greens, respectively. Salmonella was also 7.1 times more likely to be found on an untreated lettuce plant than on a lettuce plant sprayed with a 0.7% AA treatment solution (95% confidence interval [CI], 4.1 to 12.2; P < 0.0001). In studies addressing the efficacy of chitosan (0.1 or 0.3%), this chemical failed to reduce the prevalence of either pathogen on lettuce (P > 0.05). Similarly, spraying with 0.3% AA did not affect the prevalence of Salmonella on lettuce plants (P > 0.05); however, treatment solutions with 0.4% AA reduced the likelihood of detecting Salmonella in treated versus untreated plants by 6.6 times (95% CI, 2.1 to 20.9; P = 0.0007). After the lettuce was harvested and hand washed, consumers failed to distinguish either visually or organoleptically between untreated lettuce and lettuce sprayed with an acetic acid solution (P > 0.05). These results indicate that acetic acid could be used to reduce the microbiological risk of preharvest leafy greens.
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Affiliation(s)
- Marilyn C Erickson
- 1 Center for Food Safety, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797
| | - Jye-Yin Liao
- 1 Center for Food Safety, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797
| | - Alison S Payton
- 1 Center for Food Safety, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797
| | - Peter W Cook
- 1 Center for Food Safety, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797
| | - Koushik Adhikari
- 2 Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797
| | - Shangci Wang
- 2 Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797
| | - Jesus Bautista
- 3 Department of Horticulture, University of Georgia, 2360 Rainwater Road, Tifton, Georgia 31793-5766, USA
| | - Juan Carlos Díaz Pérez
- 3 Department of Horticulture, University of Georgia, 2360 Rainwater Road, Tifton, Georgia 31793-5766, USA
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Risk of Human Pathogen Internalization in Leafy Vegetables During Lab-Scale Hydroponic Cultivation. HORTICULTURAE 2019. [DOI: 10.3390/horticulturae5010025] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Controlled environment agriculture (CEA) is a growing industry for the production of leafy vegetables and fresh produce in general. Moreover, CEA is a potentially desirable alternative production system, as well as a risk management solution for the food safety challenges within the fresh produce industry. Here, we will focus on hydroponic leafy vegetable production (including lettuce, spinach, microgreens, and herbs), which can be categorized into six types: (1) nutrient film technique (NFT), (2) deep water raft culture (DWC), (3) flood and drain, (4) continuous drip systems, (5) the wick method, and (6) aeroponics. The first five are the most commonly used in the production of leafy vegetables. Each of these systems may confer different risks and advantages in the production of leafy vegetables. This review aims to (i) address the differences in current hydroponic system designs with respect to human pathogen internalization risk, and (ii) identify the preventive control points for reducing risks related to pathogen contamination in leafy greens and related fresh produce products.
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