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Hu X, Lee S, Manohar M, Chen J. Efficacy of Ascaroside #18 Treatments in Control of Salmonella enterica on Alfalfa and Fenugreek Seeds and Sprouts. J Food Prot 2023; 86:100064. [PMID: 36916549 PMCID: PMC10807822 DOI: 10.1016/j.jfp.2023.100064] [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: 11/29/2022] [Revised: 02/02/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023]
Abstract
A novel, natural, and effective antimicrobial intervention is in demand for improving the microbial safety of vegetable seeds/sprouts. This study assessed the efficacy of ascaroside treatment in the control of Salmonella enterica on alfalfa and fenugreek sprouts. Sanitized commercial seeds were treated with 1 mM or 1 µM ascaroside (ascr)#18, a plant immunity modulator (PIM) and dried for an hour before being inoculated with lyophilized S. Cubana or S. Stanley cells in sandy soil (104 CFU/g). Treated and untreated seeds were spouted on 1% water agar at 25°C in the dark. Seed or sprout samples were collected on days 0, 1, 3, 5, and 7, and the population of Salmonella was determined. Data were fit into the general linear arrangement, and means were separated using Fisher's least significant difference test. Seed type, strain type, treatment type, and sprouting time were significant factors (P ≤ 0.05) influencing Salmonella growth on sprouts. The populations of Salmonella were significantly higher on fenugreek than on alfalfa sprouts. S. Stanley had a significantly higher population than S. Cubana. The population of Salmonella increased from day 0 to day 3 and reached the peak population on Day 5. Treatments with both concentrations of ascaroside significantly decreased the populations of Salmonella compared to the controls. The mean Salmonella population reduction was ca. 4 or 1 log CFU/g by treatment with 1 mM and 1 µM of the PIM, respectively. Treatment with the PIM could be potentially used to improve the microbial safety of vegetable seeds and sprouts.
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Affiliation(s)
- Xueyan Hu
- Department of Food Science and Technology, The University of Georgia, Griffin, GA 30223-1797, USA
| | - Seulgi Lee
- Department of Food Science and Technology, The University of Georgia, Griffin, GA 30223-1797, USA
| | | | - Jinru Chen
- Department of Food Science and Technology, The University of Georgia, Griffin, GA 30223-1797, USA.
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Combined effects of intermittent radio frequency heating with cinnamon oil vapor on microbial control and quality changes of alfalfa seeds. Int J Food Microbiol 2022; 367:109586. [DOI: 10.1016/j.ijfoodmicro.2022.109586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/25/2022] [Accepted: 02/12/2022] [Indexed: 12/18/2022]
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Miyahira RF, Antunes AEC. Bacteriological safety of sprouts: A brief review. Int J Food Microbiol 2021; 352:109266. [PMID: 34111728 DOI: 10.1016/j.ijfoodmicro.2021.109266] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 05/06/2021] [Accepted: 05/23/2021] [Indexed: 12/01/2022]
Abstract
The germination process causes changes in the chemical composition of seeds that improves the nutritional value of sprouts, while decreasing their microbiological safety, since the germination conditions are ideal for bacterial growth as well. This review explores the bacteriological safety of sprouts and their involvement in foodborne illness outbreaks, worldwide. Additionally, approaches to improve the shelf-life and microbiological safety of sprouts are discussed. According to the literature, sprout consumption is associated with more than 60 outbreaks of foodborne illness worldwide, since 1988. Alfalfa sprouts were most commonly involved in outbreaks and the most commonly implicated pathogens were Salmonella and pathogenic Escherichia coli (especially, Shiga toxin producing E. coli). In the pre-harvest stage, the implementation of good agricultural practices is an important tool for producing high-quality seeds. In the post-harvest stage, several methods of seed decontamination are used commercially, or have been investigated by researchers. After germination, seedlings should be kept under refrigeration and, if possible, cooked before consumption. Finally, microbiological analyses should be performed at all stages to monitor the hygiene of the sprout production process.
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Affiliation(s)
- Roberta Fontanive Miyahira
- Department of Basic and Experimental Nutrition, Institute of Nutrition, State University of Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil; School of Applied Sciences, State University of Campinas (FCA/UNICAMP), Limeira, SP, Brazil.
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Machado-Moreira B, Tiwari BK, Richards KG, Abram F, Burgess CM. Application of plasma activated water for decontamination of alfalfa and mung bean seeds. Food Microbiol 2020; 96:103708. [PMID: 33494890 DOI: 10.1016/j.fm.2020.103708] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/25/2020] [Accepted: 11/27/2020] [Indexed: 10/22/2022]
Abstract
Microbial contamination of fresh produce is a major public health concern, with the number of associated disease outbreaks increasing in recent years. The consumption of sprouted beans and seeds is of particular concern, as these foodstuffs are generally consumed raw, and are produced in conditions favourable for the growth of zoonotic pathogens, if present in seeds prior to sprouting or in irrigation water. This work aimed to evaluate the activity of plasma activated water (PAW) as a disinfecting agent for alfalfa (Medicago sativa) and mung bean (Vigna radiata) seeds, during seed soaking. Each seed type was inoculated with Escherichia coli O157, E. coli O104, Listeria monocytogenes or Salmonella Montevideo, and treated with PAW for different times. A combination of PAW and ultrasound treatment was also evaluated. The germination and growth rate of both seeds were assessed after PAW treatments. PAW was demonstrated to have disinfecting ability on sprouted seeds, with reductions of up to Log10 1.67 cfu/g in alfalfa seeds inoculated with E. coli O104, and a reduction of Log10 1.76 cfu/g for mung bean seeds inoculated with E. coli O157 observed. The germination and growth rate of alfalfa and mung bean sprouts were not affected by the PAW treatments. The combination of a PAW treatment and ultrasound resulted in increased antimicrobial activity, with a reduction of Log10 3.48 cfu/g of S. Montevideo in mung bean seeds observed. These results demonstrate the potential for PAW to be used for the inactivation of pathogenic microorganisms which may be present on sprouted seeds and beans, thereby providing greater assurance of produce safety.
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Affiliation(s)
- Bernardino Machado-Moreira
- Teagasc Food Research Centre, Ashtown, Dublin, Ireland; Functional Environmental Microbiology, National University of Ireland Galway, Galway, Ireland
| | | | - Karl G Richards
- Teagasc Johnstown Castle Environmental Research Centre, Wexford, Ireland
| | - Florence Abram
- Functional Environmental Microbiology, National University of Ireland Galway, Galway, Ireland
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Mohammad Z, Kalbasi-Ashtari A, Riskowski G, Juneja V, Castillo A. Inactivation of Salmonella and Shiga toxin-producing Escherichia coli (STEC) from the surface of alfalfa seeds and sprouts by combined antimicrobial treatments using ozone and electrolyzed water. Food Res Int 2020; 136:109488. [PMID: 32846570 DOI: 10.1016/j.foodres.2020.109488] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 06/20/2020] [Accepted: 06/23/2020] [Indexed: 01/24/2023]
Abstract
Individual chemical and non-chemical treatments have failed to disinfect alfalfa seeds and sprouts from pathogens thoroughly. This study investigated the disinfection of alfalfa seeds and sprouts using a procedure combining ozone with acidic (pH 3.0) electrolyzed water (AEW). Inoculated alfalfa seeds with a cocktail of 3 strains Salmonella and 3 strains of STEC were treated sequentially with aqueous ozone followed by AEW. Treatment started by immersing the samples into ozonated water (5 mg/L ozone) for 15 or 20 min with persistent oxygen feeding pressurized with 10 psi. The samples then were immersed in 1 L of AEW for 15 min. Salmonella and STEC were significantly (P < 0.05) reduced by 3.6 and 2.9 log CFU/g on seeds respectively, and by 3.1 and 3.0 log CFU/g reduction on sprouts. Significant differences (P < 0.05) were found in the magnitude of the log reduction between Salmonella and STEC on seeds and between seeds and sprouts. Using combined treatments showed no significant changes in the quality, including shelf life, weight, and color in sprouts as compared to controls. The findings suggest that the combination of ozone and AEW is effective in inactivation of Salmonella and STEC on alfalfa seeds and sprouts with no adverse effects on sprouts quality.
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Affiliation(s)
- Zahra Mohammad
- Department of Nutrition and Food Science, Texas A&M University, 373 Olsen Blvd, College Station, TX 77843, United States
| | - Ahmed Kalbasi-Ashtari
- Department of Biological and Agricultural Engineering, Texas A&M University, 333 Spence St, College Station, TX 77843, United States
| | - Gerald Riskowski
- Department of Biological and Agricultural Engineering, Texas A&M University, 333 Spence St, College Station, TX 77843, United States
| | - Vijay Juneja
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038, United States
| | - Alejandro Castillo
- Department of Animal Sciences, Texas A&M University, 474 Olsen Blvd., College Station, TX 77845, United States.
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Chen J, Wang Y. Genetic determinants of Salmonella enterica critical for attachment and biofilm formation. Int J Food Microbiol 2020; 320:108524. [PMID: 32000116 DOI: 10.1016/j.ijfoodmicro.2020.108524] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 12/21/2022]
Abstract
Salmonella is a bacterial pathogen frequently involved in human gastrointestinal infections including those associated with low-moisture foods such as dehydrated food powders/spices, vegetable seeds, and tree nuts. The survival/persistence of Salmonella on low moisture foods and in dry environments is enhanced by its ability in developing biofilms. This study was undertaken to identify the genetic determinants critical for Salmonella attachment and biofilm formation. E. coli SM10 lambda pir, with a kanamycin resistant marker on mini-Tn10 (mini-Tn10:lacZ:kanr), an ampicillin resistant marker on the mini-Tn10-bearing suicidal plasmid pLBT and a streptomycin sensitive marker on the SM10 chromosome, was used as a donor (ampr, kanr, streps), and three Salmonella strains (amps, kans, strepr) were used as recipients in a transposon mutagenesis study. The donor and each recipient were co-incubated overnight on tryptic soy agar at 37 °C, and mutant colonies (amps, kanr, strepr) were subsequently selected. A single-banded degenerate PCR product, amplified from each mutant genome using oligonucleotide primers derived from the end of min-Tn10 and restriction enzyme EcoR I- or Pst I-recognizing sequence, were analyzed using the Sanger sequencing technology. Acquired DNA sequences were compared to those deposited in the Genbank using BLAST search. Cells of Salmonella mutants accumulated either significantly more or less (P < 0.05) biofilms than their parent cells on polystyrene surface. Sequence analysis of degenerate PCR products revealed that the mini-Tn10 from pLBT had inserted into the cdg, trx, fadI or rxt on Salmonella chromosomes. Results of the research will likely help strategize future antimicrobial intervention for control of pathogen attachment and biofilm formation.
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Affiliation(s)
- Jinru Chen
- Department of Food Science and Technology, The University of Georgia, 1109 Experiment St., Griffin, GA 30223-1797, USA.
| | - Yin Wang
- Department of Food Science and Technology, The University of Georgia, 1109 Experiment St., Griffin, GA 30223-1797, USA
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Kim WI, Choi SY, Han I, Cho SK, Lee Y, Kim S, Kang B, Choi O, Kim J. Inhibition of Salmonella enterica growth by competitive exclusion during early alfalfa sprout development using a seed-dwelling Erwinia persicina strain EUS78. Int J Food Microbiol 2020; 312:108374. [DOI: 10.1016/j.ijfoodmicro.2019.108374] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/27/2019] [Accepted: 09/22/2019] [Indexed: 11/16/2022]
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Kintz E, Byrne L, Jenkins C, McCARTHY N, Vivancos R, Hunter P. Outbreaks of Shiga Toxin-Producing Escherichia coli Linked to Sprouted Seeds, Salad, and Leafy Greens: A Systematic Review. J Food Prot 2019; 82:1950-1958. [PMID: 31638410 DOI: 10.4315/0362-028x.jfp-19-014] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Shiga toxin-producing Escherichia coli (STEC) outbreaks involving ready-to-eat salad products have been described in the scientific literature since 1995. These products typically do not undergo a definitive control step such as cooking to eliminate pathogens. To reduce the number of STEC infections from salad products, efforts will need to focus on preventing and reducing contamination throughout the food chain. We performed a systematic review of STEC outbreaks involving sprouted seeds, salad, or leafy green products to determine whether there were recurrent features, such as availability of microbiological evidence or identification of the contamination event, which may inform future investigations and prevention and control strategies. Thirty-five STEC outbreaks linked to contaminated leafy greens were identified for inclusion. The outbreaks occurred from 1995 to 2018 and ranged from 8 to more than 8,500 cases. Detection of STEC in the food product was rare (4 of 35 outbreaks). For the remaining outbreaks, the determination of leafy greens as the source of the outbreak mainly relied on analytical epidemiology (20 of 35) or descriptive evidence (11 of 35). The traceback investigation in 21 of 32 outbreaks was not able to identify possible routes leading to where the STEC bacteria came from or how the leaves were contaminated. Investigations in eight outbreaks found poor practice during processing that may have contributed to the outbreak, such as insufficient postharvest disinfection of the product. Six outbreak investigations were able to identify the outbreak strain in animal feces near the growing fields; two of these were also able to find it in irrigation water on the farms, providing a likely route of contamination. These results highlight the limitations of relying on microbiological confirmation as a basis to initiate investigations of upstream production to understand the source of contamination. This review also demonstrates the importance of, and difficulties associated with, food-chain traceback studies to inform control measures and future prevention.
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Affiliation(s)
- Erica Kintz
- Norwich Medical School, University of East Anglia, Norwich, Norfolk NR4 7TJ, UK (ORCID: https://orcid.org/0000-0002-6829-5701 [E.K.]).,NIHR Health Protection Research Unit in Gastrointestinal Infections, UK
| | - Lisa Byrne
- National Infection Service, Public Health England, London NW9 5EQ, UK
| | - Claire Jenkins
- National Infection Service, Public Health England, London NW9 5EQ, UK
| | - Noel McCARTHY
- NIHR Health Protection Research Unit in Gastrointestinal Infections, UK.,Department of Zoology, University of Oxford, UK.,Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Roberto Vivancos
- NIHR Health Protection Research Unit in Gastrointestinal Infections, UK.,National Infection Service, Public Health England, London NW9 5EQ, UK.,NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, UK
| | - Paul Hunter
- NIHR Health Protection Research Unit in Gastrointestinal Infections, UK.,Department of Environmental Health, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa
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Machado-Moreira B, Richards K, Brennan F, Abram F, Burgess CM. Microbial Contamination of Fresh Produce: What, Where, and How? Compr Rev Food Sci Food Saf 2019; 18:1727-1750. [PMID: 33336968 DOI: 10.1111/1541-4337.12487] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/07/2019] [Accepted: 07/10/2019] [Indexed: 01/02/2023]
Abstract
Promotion of healthier lifestyles has led to an increase in consumption of fresh produce. Such foodstuffs may expose consumers to increased risk of foodborne disease, as often they are not subjected to processing steps to ensure effective removal or inactivation of pathogenic microorganisms before consumption. Consequently, reports of ready-to-eat fruit and vegetable related disease outbreak occurrences have increased substantially in recent years, and information regarding these events is often not readily available. Identifying the nature and source of microbial contamination of these foodstuffs is critical for developing appropriate mitigation measures to be implemented by food producers. This review aimed to identify the foodstuffs most susceptible to microbial contamination and the microorganisms responsible for disease outbreaks from information available in peer-reviewed scientific publications. A total of 571 outbreaks were identified from 1980 to 2016, accounting for 72,855 infections and 173 deaths. Contaminated leafy green vegetables were responsible for 51.7% of reported outbreaks. Contaminated soft fruits caused 27.8% of infections. Pathogenic strains of Escherichia coli and Salmonella, norovirus, and hepatitis A accounted for the majority of cases. Large outbreaks resulted in particular biases such as the observation that contaminated sprouted plants caused 31.8% of deaths. Where known, contamination mainly occurred via contaminated seeds, water, and contaminated food handlers. There is a critical need for standardized datasets regarding all aspects of disease outbreaks, including how foodstuffs are contaminated with pathogenic microorganisms. Providing food business operators with this knowledge will allow them to implement better strategies to improve safety and quality of fresh produce.
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Affiliation(s)
- Bernardino Machado-Moreira
- Teagasc Food Research Centre, Ashtown, Dublin, Ireland.,Functional Environmental Microbiology, National Univ. of Ireland Galway, Galway, Ireland
| | - Karl Richards
- Teagasc Johnstown Castle Environmental Research Centre, Wexford, Ireland
| | - Fiona Brennan
- Teagasc Johnstown Castle Environmental Research Centre, Wexford, Ireland
| | - Florence Abram
- Functional Environmental Microbiology, National Univ. of Ireland Galway, Galway, Ireland
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Mohammad Z, Kalbasi-Ashtari A, Riskowski G, Castillo A. Reduction of Salmonella and Shiga toxin-producing Escherichia coli on alfalfa seeds and sprouts using an ozone generating system. Int J Food Microbiol 2019; 289:57-63. [DOI: 10.1016/j.ijfoodmicro.2018.08.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 08/09/2018] [Accepted: 08/21/2018] [Indexed: 11/16/2022]
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Cui Y, Walcott R, Chen J. Differential Attachment of Salmonella enterica and Enterohemorrhagic Escherichia coli to Alfalfa, Fenugreek, Lettuce, and Tomato Seeds. Appl Environ Microbiol 2017; 83:e03170-16. [PMID: 28130295 PMCID: PMC5359487 DOI: 10.1128/aem.03170-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/14/2017] [Indexed: 11/20/2022] Open
Abstract
Vegetable seeds have the potential to disseminate and transmit foodborne bacterial pathogens. This study was undertaken to assess the abilities of selected Salmonella and enterohemorrhagic Escherichia coli (EHEC) strains to attach to fungicide-treated versus untreated, and intact versus mechanically damaged, seeds of alfalfa, fenugreek, lettuce, and tomato. Surface-sanitized seeds (2 g) were exposed to four individual strains of Salmonella or EHEC at 20°C for 5 h. Contaminated seeds were rinsed twice, each with 10 ml of sterilized water, before being soaked overnight in 5 ml of phosphate-buffered saline at 4°C. The seeds were then vortexed vigorously for 1 min, and pathogen populations in seed rinse water and soaking buffer were determined using a standard plate count assay. In general, the Salmonella cells had higher attachment ratios than the EHEC cells. Lettuce seeds by unit weight had the highest numbers of attached Salmonella or EHEC cells, followed by tomato, alfalfa, and fenugreek seeds. In contrast, individual fenugreek seeds had more attached pathogen cells, followed by lettuce, alfalfa, and tomato seeds. Significantly more Salmonella and EHEC cells attached to mechanically damaged seeds than to intact seeds (P < 0.05). Although, on average, significantly more Salmonella and EHEC cells were recovered from untreated than fungicide-treated seeds (P < 0.05), fungicide treatment did not significantly affect the attachment of individual bacterial strains to vegetable seeds (P > 0.05), with a few exceptions. This study fills gaps in the current body of literature and helps explain bacterial interactions with vegetable seeds with differing surface characteristics.IMPORTANCE Vegetable seeds, specifically sprout seeds, have the potential to disseminate and transmit foodborne bacterial pathogens. This study investigated the interaction between two important bacterial pathogens, i.e., Salmonella and EHEC, and vegetable seeds with differing surface characteristics. This research helps understand whether seed surface structure, integrity, and fungicide treatment affect the interaction between bacterial cells and vegetable seeds.
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Affiliation(s)
- Yue Cui
- Department of Food Science and Technology, The University of Georgia, Griffin, Georgia, USA
| | - Ronald Walcott
- Department of Plant Pathology, The University of Georgia, Athens, Georgia, USA
| | - Jinru Chen
- Department of Food Science and Technology, The University of Georgia, Griffin, Georgia, USA
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Kamble NM, Lee JH. Homologous prime-boost immunization with live attenuated Salmonella enterica serovar Senftenberg and its preventive efficacy against experimental challenge with various strains of S. Senftenberg. BMC Vet Res 2017; 13:39. [PMID: 28143524 PMCID: PMC5282702 DOI: 10.1186/s12917-017-0960-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 01/21/2017] [Indexed: 12/03/2022] Open
Abstract
Background The heterogeneity observed regarding persistence, and subsequent fecal shedding pattern of the Salmonella Senftenberg (S. Senftenberg) serovar in chicken’s calls for development of the optimized immunization strategy which can provide protection against various S. Senftenberg isolated. Optimization of an immunization strategy with a live attenuated S. Senftenberg (Δlon and ΔcpxR) vaccine candidate (JOL1587) was undertaken in this study to evaluate the ability of a homologous prime-boost immunization strategy (using JOL1587) to confer protection against four different S. Senftenberg isolates in chickens. Results After oral immunization with JOL1587, the humoral, mucosal and cell-mediated immune responses were significantly higher in double immunized chickens than in single immunized and control group chickens. A significant increase in the multifunctional cytokine IL-6 and in helper and cytotoxic T cell populations after a booster immunization also indicated the advantage of double over single immunization. The four different S. Senftenberg field isolates were characterized by their persistence levels in chickens, and were subsequently used for challenge experiments to evaluate the differences in protective efficacy conferred by single and double immunization. Chickens from the doubleimmunized group exhibited significant reduction in the shedding of all four wild-type S. Senftenberg challenge strains below the detection limit in the fecal samples. Single immunized chickens showed a decrease in fecal shedding, but failed to exhibit complete protection against all the challenge strains. Conclusion Although single immunization with JOL1587 showed a reduction in the fecal shedding of challenge strains, only the homologous prime-boost immunization strategy provided an adequate immune response for increased protection against all four challenge strains of S. Senftenberg from the feces of chickens.
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Affiliation(s)
- Nitin M Kamble
- College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Iksan Campus, 570-752, Republic of Korea
| | - John Hwa Lee
- College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Iksan Campus, 570-752, Republic of Korea.
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Song M, Kim H, Rhee M. Optimization of heat and relative humidity conditions to reduce Escherichia coli O157:H7 contamination and maximize the germination of radish seeds. Food Microbiol 2016; 56:14-20. [DOI: 10.1016/j.fm.2015.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/05/2015] [Accepted: 12/08/2015] [Indexed: 10/22/2022]
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Chen D, Zhao T, Doyle MP. Single- and mixed-species biofilm formation by Escherichia coli O157:H7 and Salmonella, and their sensitivity to levulinic acid plus sodium dodecyl sulfate. Food Control 2015. [DOI: 10.1016/j.foodcont.2015.04.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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15
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Kim YB, Kim HW, Song MK, Rhee MS. Decontamination method using heat and relative humidity for radish seeds achieves a 7-log reduction of Escherichia coli O157:H7 without affecting product quality. Int J Food Microbiol 2015; 201:42-6. [PMID: 25732001 DOI: 10.1016/j.ijfoodmicro.2015.02.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 02/16/2015] [Accepted: 02/17/2015] [Indexed: 10/24/2022]
Abstract
We developed a novel decontamination method to inactivate Escherichia coli O157:H7 on radish seeds without adversely affecting seed germination or product quality. The use of heat (55, 60, and 65 °C) combined with relative humidity (RH; 25, 45, 65, 85, and 100%) for 24h was evaluated for effective microbial reduction and preservation of seed germination rates. A significant two-way interaction of heat and RH was observed for both microbial reduction and germination rate (P<0.0001). Increases in heat and RH were associated with corresponding reductions in E. coli O157:H7 and in germination rate (P<0.05). The order of lethality for the different treatments was generally as follows: no treatment <55 °C/25-65% RH ≒60 °C/25-45% RH ≒65 °C/25% RH <55 °C/85% RH =60 °C/65% RH <55 °C/100% RH =60 °C/85-100% RH =65 °C/45-100% RH. The most effective condition, 65 °C/45% RH, completely inactivated E. coli O157:H7 on the seeds (7.0 log CFU/g reduction) and had no significant effect on the germination rate (85.4%; P>0.05) or product quality. The method uses only heat and relative humidity without chemicals, and is thus applicable as a general decontamination procedure in spout producing plants where the use of growth chambers is the norm.
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Affiliation(s)
- Y B Kim
- Department of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea
| | - H W Kim
- Department of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea
| | - M K Song
- Department of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea
| | - M S Rhee
- Department of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea.
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Hoelzer K, Pouillot R, Van Doren J, Dennis S. Reduction of Listeria monocytogenes contamination on produce – A quantitative analysis of common liquid fresh produce wash compounds. Food Control 2014. [DOI: 10.1016/j.foodcont.2014.06.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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17
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Soto-Arias JP, Groves RL, Barak JD. Transmission and retention of Salmonella enterica by phytophagous hemipteran insects. Appl Environ Microbiol 2014; 80:5447-56. [PMID: 24973069 PMCID: PMC4136094 DOI: 10.1128/aem.01444-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 06/19/2014] [Indexed: 11/20/2022] Open
Abstract
Several pest insects of human and livestock habitations are known as vectors of Salmonella enterica; however, the role of plant-feeding insects as vectors of S. enterica to agricultural crops remains unexamined. Using a hemipteran insect pest-lettuce system, we investigated the potential for transmission and retention of S. enterica. Specifically, Macrosteles quadrilineatus and Myzus persicae insects were fed S. enterica-inoculated lettuce leaf discs or artificial liquid diets confined in Parafilm sachets to allow physical contact or exclusively oral ingestion of the pathogen, respectively. After a 24-h acquisition access period, insects were moved onto two consecutive noninoculated leaf discs or liquid diets and allowed a 24-h inoculation access period on each of the two discs or sachets. Similar proportions of individuals from both species ingested S. enterica after a 24-h acquisition access period from inoculated leaf discs, but a significantly higher proportion of M. quadrilineatus retained the pathogen internally after a 48-h inoculation access period. S. enterica was also recovered from the honeydew of both species. After a 48-h inoculation access period, bacteria were recovered from a significantly higher proportion of honeydew samples from M. quadrilineatus than from M. persicae insects. The recovery of S. enterica from leaf discs and liquid diets postfeeding demonstrated that both species of insects were capable of transmitting the bacteria in ways that are not limited to mechanical transmission. Overall, these results suggest that phytophagous insects may serve as potential vectors of S. enterica in association with plants.
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Affiliation(s)
- José Pablo Soto-Arias
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Russell L Groves
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jeri D Barak
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Ge C, Rymut S, Lee C, Lee J. Salmonella internalization in mung bean sprouts and pre- and postharvest intervention methods in a hydroponic system. J Food Prot 2014; 77:752-7. [PMID: 24780329 DOI: 10.4315/0362-028x.jfp-13-370] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mung bean sprouts, typically consumed raw or minimally cooked, are often contaminated with pathogens. Internalized pathogens pose a high risk because conventional sanitization methods are ineffective for their inactivation. The studies were performed (i) to understand the potential of internalization of Salmonella in mung bean sprouts under conditions where the irrigation water was contaminated and (ii) to determine if pre- and postharvest intervention methods are effective in inactivating the internalized pathogen. Mung bean sprouts were grown hydroponically and exposed to green fluorescence protein-tagged Salmonella Typhimurium through maturity. One experimental set received contaminated water daily, while other sets received contaminated water on a single day at different times. For preharvest intervention, irrigation water was exposed to UV, and for postharvest intervention-contaminated sprouts were subjected to a chlorine wash and UV light. Harvested samples were disinfected with ethanol and AgNO3 to differentiate surface-associate pathogens from the internalized ones. The internalized Salmonella Typhimurium in each set was quantified using the plate count method. Internalized Salmonella Typhimurium was detected at levels of 2.0 to 5.1 log CFU/g under all conditions. Continuous exposure to contaminated water during the entire period generated significantly higher levels of Salmonella Typhimurium internalization than sets receiving contaminated water for only a single day (P < 0.05). Preintervention methods lowered the level of internalized Salmonella by 1.84 log CFU/g (P < 0.05), whereas postintervention methods were ineffective in eliminating internalized pathogens. Preintervention did not completely inactivate bacteria in sprouts and demonstrated that the remaining Salmonella Typhimurium in water became more resistant to UV. Because postharvest intervention methods are ineffective, proper procedures for maintaining clean irrigation water must be followed throughout production in a hydroponic system.
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Affiliation(s)
- Chongtao Ge
- Department of Food Science and Technology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Susan Rymut
- Department of Food Science and Technology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Cheonghoon Lee
- College of Public Health, Division of Environmental Health Sciences, The Ohio State University, Columbus, Ohio 43210, USA
| | - Jiyoung Lee
- Department of Food Science and Technology, The Ohio State University, Columbus, Ohio 43210, USA; College of Public Health, Division of Environmental Health Sciences, The Ohio State University, Columbus, Ohio 43210, USA.
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19
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Crossing Over. Food Saf (Tokyo) 2014. [DOI: 10.1128/9781555816186.ch8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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20
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van Overbeek LS, van Doorn J, Wichers JH, van Amerongen A, van Roermund HJW, Willemsen PTJ. The arable ecosystem as battleground for emergence of new human pathogens. Front Microbiol 2014; 5:104. [PMID: 24688484 PMCID: PMC3960585 DOI: 10.3389/fmicb.2014.00104] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 02/27/2014] [Indexed: 01/10/2023] Open
Abstract
Disease incidences related to Escherichia coli and Salmonella enterica infections by consumption of (fresh) vegetables, sprouts, and occasionally fruits made clear that these pathogens are not only transmitted to humans via the "classical" routes of meat, eggs, and dairy products, but also can be transmitted to humans via plants or products derived from plants. Nowadays, it is of major concern that these human pathogens, especially the ones belonging to the taxonomical family of Enterobacteriaceae, become adapted to environmental habitats without losing their virulence to humans. Adaptation to the plant environment would lead to longer persistence in plants, increasing their chances on transmission to humans via consumption of plant-derived food. One of the mechanisms of adaptation to the plant environment in human pathogens, proposed in this paper, is horizontal transfer of genes from different microbial communities present in the arable ecosystem, like the ones originating from soil, animal digestive track systems (manure), water and plants themselves. Genes that would confer better adaptation to the phytosphere might be genes involved in plant colonization, stress resistance and nutrient acquisition and utilization. Because human pathogenic enterics often were prone to genetic exchanges via phages and conjugative plasmids, it was postulated that these genetic elements may be hold key responsible for horizontal gene transfers between human pathogens and indigenous microbes in agroproduction systems. In analogy to zoonosis, we coin the term phytonosis for a human pathogen that is transmitted via plants and not exclusively via animals.
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Affiliation(s)
- Leonard S van Overbeek
- Plant Research International, Wageningen University and Research Centre Wageningen, Netherlands
| | - Joop van Doorn
- Applied Plant Research, Wageningen University and Research Centre Lisse, Netherlands
| | - Jan H Wichers
- Food and Biobased Research, Wageningen University and Research Centre Wageningen, Netherlands
| | - Aart van Amerongen
- Food and Biobased Research, Wageningen University and Research Centre Wageningen, Netherlands
| | - Herman J W van Roermund
- Central Veterinary Institute, Wageningen University and Research Centre Lelystad, Netherlands
| | - Peter T J Willemsen
- Central Veterinary Institute, Wageningen University and Research Centre Lelystad, Netherlands
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21
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Wang Q, Hirneisen KA, Markland SM, Kniel KE. Survival of murine norovirus, Tulane virus, and hepatitis A virus on alfalfa seeds and sprouts during storage and germination. Appl Environ Microbiol 2013; 79:7021-7. [PMID: 24014537 PMCID: PMC3811553 DOI: 10.1128/aem.01704-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 09/01/2013] [Indexed: 02/02/2023] Open
Abstract
Human norovirus (huNoV) and hepatitis A virus (HAV) have been involved in several produce-associated outbreaks and identified as major food-borne viral etiologies. In this study, the survival of huNoV surrogates (murine norovirus [MNV] and Tulane virus [TV]) and HAV was investigated on alfalfa seeds during storage and postgermination. Alfalfa seeds were inoculated with MNV, TV, or HAV with titers of 6.46 ± 0.06 log PFU/g, 3.87 ± 0.38 log PFU/g, or 7.01 ± 0.07 log 50% tissue culture infectious doses (TCID50)/g, respectively. Inoculated seeds were stored for up to 50 days at 22°C and sampled during that storage period on days 0, 2, 5, 10, and 15. Following storage, virus presence was monitored over a 1-week germination period. Viruses remained infectious after 50 days, with titers of 1.61 ± 0.19 log PFU/g, 0.85 ± 0.21 log PFU/g, and 3.43 ± 0.21 log TCID50/g for MNV, TV, and HAV, respectively. HAV demonstrated greater persistence than MNV and TV, without a statistically significant reduction over 20 days (<1 log TCID50/g); however, relatively high levels of genomic copies of all viruses persisted over the testing time period. Low titers of viruses were found on sprouts and were located in all tissues as well as in sprout-spent water sampled on days 1, 3, and 6 following seed planting. Results revealed the persistence of viruses in seeds for a prolonged period of time, and perhaps of greater importance these data suggest the ease of which virus may transfer from seeds to sprouts and spent water during germination. These findings highlight the importance of sanitation and prevention procedures before and during germination.
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Affiliation(s)
- Qing Wang
- Department of Animal and Food Sciences, University of Delaware, Newark, Delaware, USA
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22
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Soto-Arias JP, Groves R, Barak JD. Interaction of phytophagous insects with Salmonella enterica on plants and enhanced persistence of the pathogen with Macrosteles quadrilineatus infestation or Frankliniella occidentalis feeding. PLoS One 2013; 8:e79404. [PMID: 24205384 PMCID: PMC3812026 DOI: 10.1371/journal.pone.0079404] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 10/01/2013] [Indexed: 12/04/2022] Open
Abstract
Recently, most foodborne illness outbreaks of salmonellosis have been caused by consumption of contaminated fresh produce. Yet, the mechanisms that allow the human pathogen Salmonella enterica to contaminate and grow in plant environments remain poorly described. We examined the effect of feeding by phytophagous insects on survival of S. enterica on lettuce. Larger S. enterica populations were found on leaves infested with Macrosteles quadrilineatus. In contrast, pathogen populations among plants exposed to Frankliniella occidentalis or Myzus persicae were similar to those without insects. However, on plants infested with F. occidentalis, areas of the infested leaf with feeding damage sustained higher S. enterica populations than areas without damage. The spatial distribution of S. enterica cells on leaves infested with F. occidentalis may be altered resulting in higher populations in feeding lesions or survival may be different across a leaf dependent on local damage. Results suggest the possibility of some specificity with select insects and the persistence of S. enterica. Additionally, we demonstrated the potential for phytophagous insects to become contaminated with S. enterica from contaminated plant material. S. enterica was detected in approximately 50% of all M. quadrilineatus, F. occidentalis, and M. persicae after 24 h exposure to contaminated leaves. Particularly, 17% of F. occidentalis, the smallest of the insects tested, harbored more than 10(2) CFU/F. occidentalis. Our results show that phytophagous insects may influence the population dynamics of S. enterica in agricultural crops. This study provides evidence of a human bacterial pathogen interacting with phytophagous insect during plant infestation.
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Affiliation(s)
- José Pablo Soto-Arias
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Russell Groves
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jeri D. Barak
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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23
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Kim WJ, Kim S, Kim AR, Yoo DJ. Direct Detection System for Escherichia coli Using Au–Ag Alloy Microchips. Ind Eng Chem Res 2013. [DOI: 10.1021/ie3022797] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Wan-Joong Kim
- Biosensor Research Team, Electronics and Telecommunications Research Institute, Daejeon 305-700,
Republic of Korea
| | - Sanghee Kim
- Department
of Mechanical Systems Engineering, Hansung University, Seoul 136-792, Republic of Korea
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24
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25
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Waldner LL, MacKenzie KD, Köster W, White AP. From Exit to Entry: Long-term Survival and Transmission of Salmonella. Pathogens 2012; 1:128-55. [PMID: 25436767 PMCID: PMC4235688 DOI: 10.3390/pathogens1020128] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 09/15/2012] [Accepted: 10/10/2012] [Indexed: 02/01/2023] Open
Abstract
Salmonella spp. are a leading cause of human infectious disease worldwide and pose a serious health concern. While we have an improving understanding of pathogenesis and the host-pathogen interactions underlying the infection process, comparatively little is known about the survival of pathogenic Salmonella outside their hosts. This review focuses on three areas: (1) in vitro evidence that Salmonella spp. can survive for long periods of time under harsh conditions; (2) observations and conclusions about Salmonella persistence obtained from human outbreaks; and (3) new information revealed by genomic- and population-based studies of Salmonella and related enteric pathogens. We highlight the mechanisms of Salmonella persistence and transmission as an essential part of their lifecycle and a prerequisite for their evolutionary success as human pathogens.
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Affiliation(s)
- Landon L Waldner
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
| | - Keith D MacKenzie
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
| | - Wolfgang Köster
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
| | - Aaron P White
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
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26
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Barak JD, Schroeder BK. Interrelationships of food safety and plant pathology: the life cycle of human pathogens on plants. ANNUAL REVIEW OF PHYTOPATHOLOGY 2012; 50:241-66. [PMID: 22656644 DOI: 10.1146/annurev-phyto-081211-172936] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Bacterial food-borne pathogens use plants as vectors between animal hosts, all the while following the life cycle script of plant-associated bacteria. Similar to phytobacteria, Salmonella, pathogenic Escherichia coli, and cross-domain pathogens have a foothold in agricultural production areas. The commonality of environmental contamination translates to contact with plants. Because of the chronic absence of kill steps against human pathogens for fresh produce, arrival on plants leads to persistence and the risk of human illness. Significant research progress is revealing mechanisms used by human pathogens to colonize plants and important biological interactions between and among bacteria in planta. These findings articulate the difficulty of eliminating or reducing the pathogen from plants. The plant itself may be an untapped key to clean produce. This review highlights the life of human pathogens outside an animal host, focusing on the role of plants, and illustrates areas that are ripe for future investigation.
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Affiliation(s)
- Jeri D Barak
- Department of Plant Pathology, University of Wisconsin, Madison, Wisconsin 53706, USA.
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27
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Fedio WM, Jinneman KC, Yoshitomi KJ, Zapata R, Weagant SD. Efficacy of a post enrichment acid treatment for isolation of Escherichia coli O157:H7 from alfalfa sprouts. Food Microbiol 2012; 30:83-90. [DOI: 10.1016/j.fm.2011.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 11/18/2011] [Accepted: 12/01/2011] [Indexed: 11/25/2022]
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28
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Requirement of siderophore biosynthesis for plant colonization by Salmonella enterica. Appl Environ Microbiol 2012; 78:4561-70. [PMID: 22522683 DOI: 10.1128/aem.07867-11] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Contaminated fresh produce has become the number one vector of nontyphoidal salmonellosis to humans. However, Salmonella enterica genes essential for the life cycle of the organism outside the mammalian host are for the most part unknown. Screening deletion mutants led to the discovery that an aroA mutant had a significant root colonization defect due to a failure to replicate. AroA is part of the chorismic acid biosynthesis pathway, a central metabolic node involved in aromatic amino acid and siderophore production. Addition of tryptophan or phenylalanine to alfalfa root exudates did not restore aroA mutant replication. However, addition of ferrous sulfate restored replication of the aroA mutant, as well as alfalfa colonization. Tryptophan and phenylalanine auxotrophs had minor plant colonization defects, suggesting that suboptimal concentrations of these amino acids in root exudates were not major limiting factors for Salmonella replication. An entB mutant defective in siderophore biosynthesis had colonization and growth defects similar to those of the aroA mutant, and the defective phenotype was complemented by the addition of ferrous sulfate. Biosynthetic genes of each Salmonella siderophore, enterobactin and salmochelin, were upregulated in alfalfa root exudates, yet only enterobactin was sufficient for plant survival and persistence. Similar results in lettuce leaves indicate that siderophore biosynthesis is a widespread or perhaps universal plant colonization fitness factor for Salmonella, unlike phytobacterial pathogens, such as Pseudomonas and Xanthomonas.
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29
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Scientific Opinion on the risk posed by Shiga toxin-producingEscherichia coli(STEC) and other pathogenic bacteria in seeds and sprouted seeds. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2424] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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30
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Weagant SD, Jinneman KC, Yoshitomi KJ, Zapata R, Fedio WM. Optimization and evaluation of a modified enrichment procedure combined with immunomagnetic separation for detection of E. coli O157:H7 from artificially contaminated alfalfa sprouts. Int J Food Microbiol 2011; 149:209-17. [DOI: 10.1016/j.ijfoodmicro.2011.06.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 06/11/2011] [Accepted: 06/16/2011] [Indexed: 01/13/2023]
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31
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Urgent advice on the public health risk of Shiga-toxin producingEscherichia coliin fresh vegetables. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2274] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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32
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Abstract
Diseases that cause vomiting, diarrhea, constipation, and gastroenteritis are major problems for populations worldwide. Patients, particularly infants, elderly, and immunocompromised individuals, may present at any point in a wide spectrum of disease states, underscoring the need for the clinician to treat these ailments aggressively. Several promising new treatment modalities, from oral rehydration solutions to antiemetic therapies, have been introduced over the past decade. Future directions include the use of probiotic agents and better tolerated rehydration solutions. Gastrointestinal disease will continue to be a focus worldwide in the search for better ways to cure illnesses associated with vomiting and diarrhea.
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Affiliation(s)
- Leila Getto
- Department of Emergency Medicine, Christiana Care Health System, Newark, DE 19718, USA.
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33
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Colonization of tomato plants by Salmonella enterica is cultivar dependent, and type 1 trichomes are preferred colonization sites. Appl Environ Microbiol 2010; 77:498-504. [PMID: 21075871 DOI: 10.1128/aem.01661-10] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Nontyphoid salmonellosis caused by Salmonella enterica is the most common bacterial food-borne illness in humans, and fresh produce, including tomatoes, is a common vehicle. Accumulating data indicate that human enteric pathogenic bacteria, including S. enterica, interact actively with plants. Tomato plants were inoculated with S. enterica to evaluate plausible contamination routes and to determine if the tomato cultivar affects S. enterica colonization. S. enterica population levels on tomato leaves were cultivar dependent. S. enterica levels on Solanum pimpinellifolium (West Virginia 700 [WVa700]) were lower than on S. lycopersicum cultivars. S. enterica preferentially colonized type 1 trichomes and rarely interacted with stomata, unlike what has been reported for cut lettuce leaves. Early S. enterica leaf colonization led to contamination of all fruit, with levels as high as 10(5) CFU per fruit. Reduced bacterial speck lesion formation correlated with reduced S. enterica populations in the phyllosphere. Tomato pedicels and calyxes also harbored large S. enterica populations following inoculation via contaminated water postharvest. WVa700 green fruit harbored significantly smaller S. enterica populations than did red fruit or S. lycopersicum fruit. We found that plants irrigated with contaminated water had larger S. enterica populations than plants grown from seeds planted in infested soil. However, both routes of contamination resulted in detectable S. enterica populations in the phyllosphere. Phyllosphere S. enterica populations pose a risk of fruit contamination and subsequent human disease. Restricting S. enterica phyllosphere populations may result in reduced fruit contamination. We have identified WVa700 as a tomato cultivar that can restrict S. enterica survival in the phyllosphere.
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Habteselassie MY, Bischoff M, Applegate B, Reuhs B, Turco RF. Understanding the role of agricultural practices in the potential colonization and contamination by Escherichia coli in the rhizospheres of fresh produce. J Food Prot 2010; 73:2001-9. [PMID: 21219711 DOI: 10.4315/0362-028x-73.11.2001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To better protect consumers from exposure to produce contaminated with Escherichia coli, the potential transfer of E. coli from manure or irrigation water to plants must be better understood. We used E. coli strains expressing bioluminescence (E. coli O157:H7 lux) or multiantibiotic resistance (E. coli²(+)) in this study. These marked strains enabled us to visualize in situ rhizosphere colonization and metabolic activity and to track the occurrence and survival of E. coli in soil, rhizosphere, and phyllosphere. When radish and lettuce seeds were treated with E. coli O157:H7 lux and grown in an agar-based growth system, rapid bacterial colonization of the germinating seedlings and high levels of microbial activity were seen. Introduction of E. coli²(+) to soil via manure or via manure in irrigation water showed that E. coli could establish itself in the lettuce rhizosphere. Regardless of introduction method, 15 days subsequent to its establishment in the rhizosphere, E. coli²(+) was detected on the phyllosphere of lettuce at an average number of 2.5 log CFU/g. When E. coli²(+) was introduced 17 and 32 days postseeding to untreated soil (rather than the plant surface) via irrigation, it was detected at low levels (1.4 log CFU/g) on the lettuce phyllosphere 10 days later. While E. coli²(+) persisted in the bulk and rhizosphere soil throughout the study period (day 41), it was not detected on the external portions of the phyllosphere after 27 days. Overall, we find that E. coli is mobile in the plant system and responds to the rhizosphere like other bacteria.
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Affiliation(s)
- Mussie Y Habteselassie
- Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, Georgia 30223, USA.
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35
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Berger CN, Sodha SV, Shaw RK, Griffin PM, Pink D, Hand P, Frankel G. Fresh fruit and vegetables as vehicles for the transmission of human pathogens. Environ Microbiol 2010; 12:2385-97. [DOI: 10.1111/j.1462-2920.2010.02297.x] [Citation(s) in RCA: 581] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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36
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Denno DM, Keene WE, Hutter CM, Koepsell JK, Patnode M, Flodin-Hursh D, Stewart LK, Duchin JS, Rasmussen L, Jones R, Tarr PI. Tri-county comprehensive assessment of risk factors for sporadic reportable bacterial enteric infection in children. J Infect Dis 2009; 199:467-76. [PMID: 19281302 DOI: 10.1086/596555] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The aim of this study was to determine risk factors for childhood sporadic reportable enteric infection (REI) caused by bacteria, specifically Campylobacter, Salmonella, Escherichia coli O157, or Shigella (REI-B). METHODS Matched case-control study. Case patients aged <19 years who were reported to 3 Washington State county health departments and matched control subjects were interviewed from November 2003-November 2005. Matched odds ratios (ORs) were calculated by using conditional logistic regression. Population attributable risk percentages were calculated for exposures associated with infection. RESULTS Two hundred ninety-six case patients were matched to 580 control subjects. Aquatic recreation was the most important factor associated with all REI-Bs studied (beach water exposure [OR for Salmonella infection, 28.3 {CI, 7.2-112.2}; OR for Shigella infection, 14.5 {CI 1.5-141.0} or any recreational water exposure [OR for Campylobacter infection, 2.7 {CI, 1.5-4.8}; OR for Escherichia coli O157 infection, 7.4 {CI, 2.1-26.1}]). Suboptimal kitchen hygiene after preparation of raw meat or chicken (OR, 7.1 [CI, 2.1-24.1]) and consumption of food from restaurants were additional risks for Campylobacter infection. Infection with Salmonella was associated with the use of private wells as sources of drinking water (OR, 6.5 [CI, 1.4-29.7]), and the use of residential septic systems was a risk for both Salmonella (OR, 3.2 [CI, 1.3-7.8]) and E. coli (OR, 5.7 [CI, 1.2-27.2]) O157 infection. CONCLUSIONS Overall, non-food exposures were as important as food-related exposures with regard to their contributions to the proportion of cases. Infection prevention efforts should address kitchen hygiene practices and non-food exposures, such as recreational water exposure, in addition to food-consumption risks.
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Affiliation(s)
- Donna M Denno
- Department of Pediatrics and Global Health, University of Washington, Public Health-Seattle and King County, Seattle, Washington, USA
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Elimination of Escherichia coli O157:H7 from Alfalfa seeds through a combination of high hydrostatic pressure and mild heat. Appl Environ Microbiol 2009; 75:1901-7. [PMID: 19218418 DOI: 10.1128/aem.02531-08] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli O157:H7 has been associated with contaminated seed sprout outbreaks. The majority of these outbreaks have been traced to sprout seeds contaminated with low levels of pathogens. Sanitizing sprout seeds presents a unique challenge in the arena of produce safety in that even a low residual pathogen population remaining on contaminated seed after treatments appears capable of growing to very high levels during sprouting. In this study, the effectiveness of high-pressure treatment in combination with low and elevated temperatures was assessed for its ability to eliminate E. coli O157:H7 on artificially contaminated alfalfa seeds. Inoculated seed samples were treated at 600 MPa for 2 min at 4, 20, 25, 30, 35, 40, 45, and 50 degrees C. The pressure sensitivity of the pathogenic bacteria was strongly dependent on the treatment temperature. At 40 degrees C, the process was adequate in eliminating a 5-log-unit population on the seeds with no adverse effect on seed viability. Three treatments carried out at reduced pressure levels and/or extended treatment time, 550 MPa for 2 min at 40 degrees C, 300 MPa for 2 min at 50 degrees C, and 400 MPa for 5 min at 45 degrees C, were equally lethal to the pathogen. When all three treatments were compared in terms of their impact on seed viability, the process of 550 MPa for 2 min at 40 degrees C was the most desirable, achieving final germination percentages and sprout sizes statistically similar to those of control untreated seeds (P > 0.05).
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A national outbreak of verotoxin-producing Escherichia coli O157 associated with consumption of lemon-and-coriander chicken wraps from a supermarket chain. Epidemiol Infect 2009; 137:375-82. [PMID: 19102799 DOI: 10.1017/s0950268808001702] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
A national outbreak of verotoxin-producing Escherichia coli O157 infection affected five English regions and Wales. Twelve cases were associated with lemon-and-coriander chicken wrap from a single supermarket chain consumed over a 5-day period. An outbreak investigation aimed to identify the source of infection. Descriptive epidemiology and phenotypic and genotypic tests on human isolates indicated a point-source outbreak; a case-control study showed a very strong association between consumption of lemon-and-coriander chicken wrap from the single supermarket chain and being a case (OR 46.40, 95% CI 5.39-infinity, P=0.0002). Testing of raw ingredients, products and faecal samples from staff in the food production unit did not yield any positive results. The outbreak was probably caused by one contaminated batch of an ingredient in the chicken wrap. Even when current best practice is in place, ready-to-eat foods can still be a risk for widespread infection.
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Pedersen TB, Olsen JE, Bisgaard M. Persistence of Salmonella Senftenberg in poultry production environments and investigation of its resistance to desiccation. Avian Pathol 2008; 37:421-7. [PMID: 18622860 DOI: 10.1080/03079450802216561] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Most Salmonella serovars, including Salmonella enterica subsp. enterica serovar Senftenberg (S. Senftenberg), are tolerant to desiccation and able to colonize and persist in feed mills. In addition, they may survive cleaning and disinfection procedures used on poultry farms. The present study was conducted to investigate the survival of S. Senftenberg in broiler parent stock farms and broiler farms. The isolates from one of the parent stock farms investigated only differed by a single band in fluorescent amplified fragment-length polymorphism analysis and had identical pulsed-field gel electrophoresis profiles, indicating that a S. Senftenberg clone had persisted for more than 2 years, despite cleaning, disinfection, desiccation and depopulation, and was subsequently able to infect Salmonella-free layers. Isolates from the same house on a different broiler parent stock farm were found to be identical by amplified fragment-length polymorphism analysis and pulsed-field gel electrophoresis although the farm tested negative for Salmonella 55 times over a period of 18 months between the two positive samplings. An assay was developed to investigate the survival of 34 S. Senftenberg isolates during desiccation at approximately 38% relative humidity. On average, the viability of S. Senftenberg isolates decreased by 1000-fold over 35 days. The persistent clones were no more resistant to desiccation than the other isolates investigated. However, S. Senftenberg was more resistant to desiccation than an isolate of Pantoea agglomerans commonly found on poultry feed-processing lines. This study demonstrates the risk of persistence of feed-associated serovars such as S. Senftenberg.
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Affiliation(s)
- Tina Broennum Pedersen
- Department of Veterinary Pathobiology, Faculty of Life Sciences, University of Copenhagen, Frederiksberg C, Denmark.
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40
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Barak JD, Liang A, Narm KE. Differential attachment to and subsequent contamination of agricultural crops by Salmonella enterica. Appl Environ Microbiol 2008; 74:5568-70. [PMID: 18606796 PMCID: PMC2546622 DOI: 10.1128/aem.01077-08] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 06/25/2008] [Indexed: 11/20/2022] Open
Abstract
U.S. salmonellosis outbreaks have occurred following consumption of tomato and cantaloupe but not lettuce. We report differential contamination among agricultural seedlings by Salmonella enterica via soil. Members of the family Brassicaceae had a higher incidence of outbreak than carrot, lettuce, and tomato. Once they were contaminated, phyllosphere populations were similar, except for tomato. Contamination differences exist among tomato cultivars.
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Affiliation(s)
- Jeri D Barak
- Produce Safety and Microbiology Research Unit, USDA/ARS/WRRC, 800 Buchanan St., Albany, California 94710, USA.
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41
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Food safety evaluation of broccoli and radish sprouts. Food Chem Toxicol 2008; 46:1635-44. [DOI: 10.1016/j.fct.2008.01.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 11/19/2007] [Accepted: 01/02/2008] [Indexed: 11/20/2022]
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42
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PAO S, KALANTARI A, KHALID M. ELIMINATING SALMONELLA ENTERICA IN ALFALFA AND MUNG BEAN SPROUTS BY ORGANIC ACID AND HOT WATER IMMERSIONS. J FOOD PROCESS PRES 2008. [DOI: 10.1111/j.1745-4549.2008.00182.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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43
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Salmonella infections associated with mung bean sprouts: epidemiological and environmental investigations. Epidemiol Infect 2008; 137:357-66. [DOI: 10.1017/s0950268808000411] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SUMMARYWe investigated an outbreak of Salmonella Enteritidis (SE) infections linked to raw mung bean sprouts in 2000 with two case-control studies and reviewed six similar outbreaks that occurred in 2000–2002. All outbreaks were due to unusual phage types (PT) of SE and occurred in the United States (PT 33, 1, and 913), Canada (PT 11b and 913), and The Netherlands (PT 4b). PT 33 was in the spent irrigation water and a drain from one sprout grower. None of the growers disinfected seeds at recommended concentrations. Only two growers tested spent irrigation water; neither discarded the implicated seed lots after receiving a report of Salmonella contamination. We found no difference in the growth of SE and Salmonella Newport on mung beans. Mung bean sprout growers should disinfect seeds, test spent irrigation water, and discontinue the use of implicated seed lots when pathogens are found. Laboratories should report confirmed positive Salmonella results from sprout growers to public health authorities.
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Vidovic S, Block HC, Korber DR. Effect of soil composition, temperature, indigenous microflora, and environmental conditions on the survival of Escherichia coli O157:H7. Can J Microbiol 2008; 53:822-9. [PMID: 17898837 DOI: 10.1139/w07-041] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The survival of Escherichia coli O157:H7 in replicate soil microcosms was quantified in 2 types of silty clay loam soil (high carbon and low carbon) under either sterile or nonsterile conditions. Microcosms were held at -21, 4, and 22 degrees C under constant soil moisture content. Differences existed (P < 0.05) in survival of E. coli O157:H7 in low- and high-carbon soil at all temperatures, indicating an important role of soil composition on the survival of this pathogen. The highest death rate of E. coli O157:H7 in sterile soil occurred in the low-carbon soil at 4 degrees C, whereas in nonsterile soil the highest death rate was observed in the low-carbon soil at 22 degrees C. These results suggest that the most lethal effects on E. coli O157:H7 in the sterile system occurred via the synergy of nutrient limitation and cold stress, whereas in the nonsterile system lethality was owing to inhibition by indigenous soil microorganisms and starvation. Results obtained from an in situ field survival experiment demonstrated the apparent sensitivity of E. coli O157:H7 cells to dehydration, information that may be used to reduce environmental spread of this pathogen as well as formulate appropriate waste management strategies.
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Affiliation(s)
- Sinisa Vidovic
- Applied Microbiology and Food Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada
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Loui C, Grigoryan G, Huang H, Riley LW, Lu S. Bacterial communities associated with retail alfalfa sprouts. J Food Prot 2008; 71:200-4. [PMID: 18236685 DOI: 10.4315/0362-028x-71.1.200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fresh produce, including salad, is increasingly implicated in foodborne outbreaks. Although studies have been carried out to detect specific human pathogens from fresh produce, the total bacterial community associated with fresh produce is poorly understood. In this study, we characterized the bacterial community associated with alfalfa sprouts, using a culture-independent method. Four retail-purchased alfalfa sprout samples were obtained from different producers, and the bacterial community associated with each sample was determined by 16S rDNA profiling. Our results indicate that alfalfa sprouts sampled in our study shared significant similarities in their bacterial communities. Proteobacteria was the dominant phylum detected from all alfalfa sprout samples, with Enterobacteriaceae, Oxalobacteraceae, Moraxellaceae, and Sphingomonadaceae as the most frequently detected families. These results indicate that growth conditions of alfalfa sprouts should be taken into consideration to prevent the proliferation of pathogenic proteobacteria such as Escherichia coli O157 and Salmonella.
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Affiliation(s)
- Cindy Loui
- Program in Infectious Diseases and Immunity, School of Public Health, 140 Warren Hall, University of California, Berkeley, California 94720, USA
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Campbell GA, Uknalis J, Tu SI, Mutharasan R. Detect of Escherichia coli O157:H7 in ground beef samples using piezoelectric excited millimeter-sized cantilever (PEMC) sensors. Biosens Bioelectron 2007; 22:1296-302. [PMID: 16831542 DOI: 10.1016/j.bios.2006.05.028] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2006] [Revised: 05/01/2006] [Accepted: 05/24/2006] [Indexed: 11/20/2022]
Abstract
Piezoelectric-excited millimeter-sized cantilever (PEMC) sensors consisting of a piezoelectric and a borosilicate glass layer with a sensing area of 4 mm2 were fabricated. An antibody specific to Escherichia coli (anti-E. coli) O157:H7 was immobilized on PEMC sensors, and exposed to samples containing E. coli O157:H7 (EC) prepared in various matrices: (1) broth, broth plus raw ground beef, and broth plus sterile ground beef without inoculation of E. coli O157:H7 served as controls, (2) 100 mL of broth inoculated with 25 EC cells, (3) 100 mL of broth containing 25 g of raw ground beef and (4) 100 mL of broth with 25 g of sterile ground beef inoculated with 25 EC cells. The total resonant frequency change obtained for the broth plus EC samples were 16+/-2 Hz (n=2), 30 Hz (n=1), and 54+/-2 Hz (n=2) corresponding to 2, 4, and 6h growth at 37 degrees C, respectively. The response to the broth plus 25 g of sterile ground beef plus EC cells were 21+/-2 Hz (n=2), 37 Hz (n=1), and 70+/-2 Hz (n=2) corresponding to 2, 4, and 6 h, respectively. In all cases, the three different control samples yielded a frequency change of 0+/-2 Hz (n=6). The E. coli O157:H7 concentration in each broth and beef samples was determined by both plating and by pathogen modeling program. The results indicate that the PEMC sensor detects E. coli O157:H7 reliably at 50-100 cells/mL with a 3 mL sample.
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Affiliation(s)
- Gossett A Campbell
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, United States
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Hora R, Kumar M, Kostrzynska M, Dixon MA, Warriner K. Inactivation of Escherichia coli O157:H7 and Salmonella on artificially or naturally contaminated mung beans (Vigna radiata L) using a stabilized oxychloro-based sanitizer. Lett Appl Microbiol 2007; 44:188-93. [PMID: 17257259 DOI: 10.1111/j.1472-765x.2006.02049.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To evaluate the efficacy of a stabilized oxychloro-based (SOC) sanitizer to decontaminate mung beans artificially or naturally contaminated with Escherichia coli O157:H7 or Salmonella. METHODS AND RESULTS Naturally contaminated beans were produced by introducing a five-strain cocktail of E. coli O157:H7 or Salmonella onto the flowers of growing mung bean plants. Escherichia coli O157:H7 was only sporadically recovered from sprout lots (three testing positive from 10 tested) derived from harvested beans. In contrast, Salmonella was recovered from 18 of 20 lots screened. Pathogens present on naturally contaminated seed could be successfully inactivated with SOC applied at 200 ppm for 24 h at 28 degrees C. SOC treatment could also decontaminate artificially inoculated mung bean batches containing different levels of contaminated seed. SOC inactivated E. coli O157:H7, but not Salmonella introduced onto damaged (scarified) beans. CONCLUSIONS SOC sanitizer could inactivate Salmonella or E. coli O157:H7 naturally or artificially introduced onto mung beans. However, the SOC treatment failed to inactivate Salmonella introduced onto damaged mung beans. SIGNIFICANCE AND IMPACT OF THE STUDY SOC sanitizer represents an effective method for decontaminating undamaged mung beans.
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Affiliation(s)
- R Hora
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada
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48
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Solid phase microextraction/gas chromatography/mass spectrometry integrated with chemometrics for detection of Salmonella typhimurium contamination in a packaged fresh vegetable. Anal Chim Acta 2007; 581:63-70. [DOI: 10.1016/j.aca.2006.08.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Revised: 08/06/2006] [Accepted: 08/08/2006] [Indexed: 11/24/2022]
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49
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Werber D, Kramer MH, Buchholz U, Koch J, Weise E, Bockemühl J, Huppertz HI, Karch H, Zimmerhackl LB, Pulz M, Wildner M, Tschäpe H, Ammon A. [Surveillance of infectious foodborne diseases after enactment of the German Protection against Infection Act in 2001. Potentials and requirements]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2006; 49:1020-6. [PMID: 16927031 DOI: 10.1007/s00103-006-0026-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The epidemiology of infectious foodborne diseases has changed. Outbreaks more frequently occur geographically dispersed or protractedly over longer periods of time, and they often appear as a scatter of seemingly sporadic cases. This hampers and delays the identification of their epidemiological link. The surveillance of infectious foodborne diseases has to be refined accordingly to be able to detect these diffuse outbreaks. The German Protection against Infection Act, enacted in 2001, offers the potential of increased sensitivity due to timely electronic reporting of individual cases and detailed data accompanying each report. In addition to a timely and comprehensive reporting system, subtyping of pathogens has become an invaluable tool in identifying epidemiologically linked cases, i.e. outbreaks. Still, the sensitivity of foodborne disease surveillance still hinges on the willingness of physicians to order stool testing for enteric pathogens (and to report suspected outbreaks to local health departments). Without the active participation of physicians, the chance of detecting outbreaks and successfully investigating them is markedly reduced. Consequently, the general preventive strategy would be jeopardised, namely to understand the (often new) mechanisms by which contamination and disease transmission occur well enough to interrupt them.
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Affiliation(s)
- D Werber
- European Programme for Intervention, Epidemiology Training, Robert Koch-Institut, Abteilung für Infektionsepidemiologie, Postfach 650261, 13302 Berlin, BRD.
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50
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Siripatrawan U, Linz JE, Harte BR. Detection of Escherichia coli in packaged alfalfa sprouts with an electronic nose and an artificial neural network. J Food Prot 2006; 69:1844-50. [PMID: 16924908 DOI: 10.4315/0362-028x-69.8.1844] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A rapid method for the detection of Escherichia coli (ATCC 25922) in packaged alfalfa sprouts was developed. Volatile compounds from the headspace of packaged alfalfa sprouts, inoculated with E. coli and incubated at 10 degrees C for 1, 2, and 3 days, were collected and analyzed. Uninoculated sprouts were used as control samples. An electronic nose with 12 metal oxide electronic sensors was used to monitor changes in the composition of the gas phase of the package headspace with respect to volatile metabolites produced by E. coli. The electronic nose was able to differentiate between samples with and without E. coli. To predict the number of E. coli in packaged alfalfa sprouts, an artificial neural network was used, which included an input layer, a hidden layer, and an output layer, with a hyperbolic tangent sigmoidal transfer function in the hidden layer and a linear transfer function in the output layer. The network was shown to be capable of correlating voltametric responses with the number of E. coli. A good prediction was possible, as measured by a regression coefficient (R2 = 0.903) between the actual and predicted data. In conjunction with the artificial neural network, the electronic nose proved to have the ability to detect E. coli in packaged alfalfa sprouts.
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Affiliation(s)
- Ubonrat Siripatrawan
- Department of Food Technology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
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