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Anthony C, Pearson K, Callaby R, Allison L, Jenkins C, Smith-Palmer A, James M. Reasons for difficulties in isolating the causative organism during food-borne outbreak investigations using STEC as a model pathogen: a systematic review, 2000 to 2019. Euro Surveill 2024; 29. [PMID: 39639814 DOI: 10.2807/1560-7917.es.2024.29.49.2400193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2024] Open
Abstract
IntroductionFood-borne disease outbreak investigations use epidemiological, microbiological and food chain evidence to identify the implicated food and inform risk management actions.AimsWe used Shiga toxin-producing Escherichia coli (STEC) as a model pathogen to investigate the success of outbreak strain isolation from food or environmental samples during outbreak investigations, and examined the factors influencing the chance of isolation.MethodsWe searched for reports of food-borne STEC outbreak investigations worldwide in peer-reviewed and grey literature in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.ResultsWe found a total of 223 outbreaks suitable for inclusion. Food and/or environmental samples were available for testing in 137 investigations, and the outbreak strain was isolated in 94 (42%) of investigations. We found no significant effect of STEC serovar or size of outbreak on likelihood of successful outbreak strain isolation. Isolation success ranged across different implicated commodities from 86% for beef-related outbreaks to 50% for salads and leafy greens. In 20% of outbreaks with samples available for testing, an additional STEC strain was isolated alongside the outbreak strain and in 6.6%, only an alternative STEC strain was isolated. Risk management action was taken on epidemiological evidence alone in 21 incidents.ConclusionThe principal reasons why the outbreak strain was not isolated were lack of sample availability and methodological issues concerned with laboratory isolation. We recommend strategies that could improve the likelihood of isolation including the rapid collection of samples based on epidemiological intelligence.
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Affiliation(s)
| | | | | | - Lesley Allison
- Scottish E. coli O157/STEC Reference Laboratory, Edinburgh, United Kingdom
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White AE, Smith KE, Booth H, Medus C, Tauxe RV, Gieraltowski L, Scallan Walter E. Hypothesis Generation During Foodborne-Illness Outbreak Investigations. Am J Epidemiol 2021; 190:2188-2197. [PMID: 33878169 DOI: 10.1093/aje/kwab118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 12/24/2022] Open
Abstract
Hypothesis generation is a critical, but challenging, step in a foodborne outbreak investigation. The pathogens that contaminate food have many diverse reservoirs, resulting in seemingly limitless potential vehicles. Identifying a vehicle is particularly challenging for clusters detected through national pathogen-specific surveillance, because cases can be geographically dispersed and lack an obvious epidemiologic link. Moreover, state and local health departments could have limited resources to dedicate to cluster and outbreak investigations. These challenges underscore the importance of hypothesis generation during an outbreak investigation. In this review, we present a framework for hypothesis generation focusing on 3 primary sources of information, typically used in combination: 1) known sources of the pathogen causing illness; 2) person, place, and time characteristics of cases associated with the outbreak (descriptive data); and 3) case exposure assessment. Hypothesis generation can narrow the list of potential food vehicles and focus subsequent epidemiologic, laboratory, environmental, and traceback efforts, ensuring that time and resources are used more efficiently and increasing the likelihood of rapidly and conclusively implicating the contaminated food vehicle.
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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: 26] [Impact Index Per Article: 6.5] [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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Stanton E, Wahlig TA, Park D, Kaspar CW. Chronological set of E. coli O157:H7 bovine strains establishes a role for repeat sequences and mobile genetic elements in genome diversification. BMC Genomics 2020; 21:562. [PMID: 32807088 PMCID: PMC7430833 DOI: 10.1186/s12864-020-06943-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/23/2020] [Indexed: 11/21/2022] Open
Abstract
Background Enterohemorrhagic Escherichia coli O157:H7 (EHEC) is a significant foodborne pathogen that resides asymptomatically within cattle and other ruminants. The EHEC genome harbors an extensive collection of mobile genetic elements (MGE), including multiple prophage, prophage-like elements, plasmids, and insertion sequence (IS) elements. Results A chronological collection of EHEC strains (FRIK804, FRIK1275, and FRIK1625) isolated from a Wisconsin dairy farm (farm X) comprised a closely related clade genetically differentiated by structural alterations to the chromosome. Comparison of the FRIK804 genome with a reference EHEC strain Sakai found a unique prophage like element (PLE, indel 1) and an inversion (1.15 Mb) situated symmetrically with respect to the terminus region. Detailed analysis determined the inversion was due to homologous recombination between repeat sequences in prophage. The three farm X strains were distinguished by the presence or absence of indel 3 (61 kbp) and indel 4 (48 kbp); FRIK804 contained both of these regions, FRIK1275 lacked indel 4, and indels 3 and 4 were both absent in FRIK1625. Indel 3 was the stx2 prophage and indel 4 involved a deletion between two adjacent prophage with shared repeat sequences. Both FRIK804 and FRIK1275 produced functional phage while FRIK1625 did not, which is consistent with indel 3. Due to their involvement in recombination events, direct and inverted repeat sequences were identified, and their locations mapped to the chromosome. FRIK804 had a greater number and overall length of repeat sequences than E. coli K12 strain MG1655. Repeat sequences were most commonly associated with MGE. Conclusions This research demonstrated that three EHEC strains from a Wisconsin dairy farm were closely related and distinguished by variability within prophage regions and other MGE. Chromosome alterations were associated with recombination events between repeat sequences. An inventory of direct and inverted repeat sequences found a greater abundance and total length of repeat sequences in the EHEC strains compared to E. coli strain MG1655. The locations of the repeat sequences were biased towards MGE. The findings from this study expand our understanding of the precise molecular events and elements that contributed to genetic diversification of wild-type EHEC in the bovine and farm environments.
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Affiliation(s)
- Eliot Stanton
- Department of Bacteriology, University of Wisconsin-Madison, Microbial Sciences Building, 1550 Linden Drive, Madison, WI, 53706, USA
| | - Taylor A Wahlig
- Department of Bacteriology, University of Wisconsin-Madison, Microbial Sciences Building, 1550 Linden Drive, Madison, WI, 53706, USA.,University of Utah, School of Medicine, 30 N 1900 E, Salt Lake City, UT, 84132, USA
| | - Dongjin Park
- Food Science and Technology Department, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Charles W Kaspar
- Department of Bacteriology, University of Wisconsin-Madison, Microbial Sciences Building, 1550 Linden Drive, Madison, WI, 53706, USA. .,Food Research Institute, University of Wisconsin-Madison, Microbial Sciences Building, 1550 Linden Drive, Madison, WI, 53706, USA.
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Awofisayo-Okuyelu A, Brainard J, Hall I, McCarthy N. Incubation Period of Shiga Toxin-Producing Escherichia coli. Epidemiol Rev 2020; 41:121-129. [PMID: 31616910 PMCID: PMC7108491 DOI: 10.1093/epirev/mxz001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 03/20/2019] [Accepted: 05/08/2019] [Indexed: 01/21/2023] Open
Abstract
Shiga toxin–producing Escherichia coli are pathogenic bacteria found in the gastrointestinal tract of humans. Severe infections could lead to life-threatening complications, especially in young children and the elderly. Understanding the distribution of the incubation period, which is currently inconsistent and ambiguous, can help in controlling the burden of disease. We conducted a systematic review of outbreak investigation reports, extracted individual incubation data and summary estimates, tested for heterogeneity, classified studies into subgroups with limited heterogeneity, and undertook a meta-analysis to identify factors that may contribute to the distribution of the pathogen’s incubation period. Twenty-eight studies were identified for inclusion in the review (1 of which included information on 2 outbreaks), and the resulting I2 value was 77%, indicating high heterogeneity. Studies were classified into 5 subgroups, with the mean incubation period ranging from 3.5 to 8.1 days. The length of the incubation period increased with patient age and decreased by 7.2 hours with every 10% increase in attack rate.
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Affiliation(s)
- Adedoyin Awofisayo-Okuyelu
- Correspondence to Adedoyin Awofisayo-Okuyelu, Department of Zoology, University of Oxford, Peter Medawar Building for Pathogen Research, South Parks Road, Oxford, United Kingdom OX1 3SY ()
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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: 4.8] [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: 119] [Impact Index Per Article: 19.8] [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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Liu D, Cui Y, Walcott R, Chen J. Fate of Salmonella enterica and Enterohemorrhagic Escherichia coli Cells Artificially Internalized into Vegetable Seeds during Germination. Appl Environ Microbiol 2018; 84:e01888-17. [PMID: 29079622 PMCID: PMC5734032 DOI: 10.1128/aem.01888-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 10/24/2017] [Indexed: 11/20/2022] Open
Abstract
Vegetable seeds contaminated with bacterial pathogens have been linked to fresh-produce-associated outbreaks of gastrointestinal infections. This study was undertaken to observe the physiological behavior of Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) cells artificially internalized into vegetable seeds during the germination process. Surface-decontaminated seeds of alfalfa, fenugreek, lettuce, and tomato were vacuum-infiltrated with four individual strains of Salmonella or EHEC. Contaminated seeds were germinated at 25°C for 9 days, and different sprout/seedling tissues were microbiologically analyzed every other day. The internalization of Salmonella and EHEC cells into vegetable seeds was confirmed by the absence of pathogens in seed-rinsing water and the presence of pathogens in seed homogenates after postinternalization seed surface decontamination. Results show that 317 (62%) and 343 (67%) of the 512 collected sprout/seedling tissue samples were positive for Salmonella and EHEC, respectively. The average Salmonella populations were significantly larger (P < 0.05) than the EHEC populations. Significantly larger Salmonella populations were recovered from the cotyledon and seed coat tissues, followed by the root tissues, but the mean EHEC populations from all sampled tissue sections were statistically similar, except in pregerminated seeds. Three Salmonella and two EHEC strains had significantly larger cell populations on sprout/seedling tissues than other strains used in the study. Salmonella and EHEC populations from fenugreek and alfalfa tissues were significantly larger than those from tomato and lettuce tissues. The study showed the fate of internalized human pathogens on germinating vegetable seeds and sprout/seedling tissues and emphasized the importance of using pathogen-free seeds for sprout production.IMPORTANCE The internalization of microorganisms into vegetable seeds could occur naturally and represents a possible pathway of vegetable seed contamination by human pathogens. The present study investigated the ability of two important bacterial pathogens, Salmonella and enterohemorrhagic Escherichia coli (EHEC), when artificially internalized into vegetable seeds, to grow and disseminate along vegetable sprouts/seedlings during germination. The data from the study revealed that the pathogen cells artificially internalized into vegetable seeds caused the contamination of different tissues of sprouts/seedlings and that pathogen growth on germinating seeds is bacterial species and vegetable seed-type dependent. These results further stress the necessity of using pathogen-free vegetable seeds for edible sprout production.
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Affiliation(s)
- Da Liu
- Department of Food Science and Technology, The University of Georgia, Griffin, Georgia, USA
| | - 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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Shah MS, Eppinger M, Ahmed S, Shah AA, Hameed A, Hasan F. Flooding adds pathogenic Escherichia coli strains to the water sources in southern Khyber Pakhtunkhwa, Pakistan. Indian J Med Microbiol 2016; 34:483-488. [PMID: 27934827 DOI: 10.4103/0255-0857.195350] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
PURPOSE Seasonal rains in Pakistan result in heavy floods across the country, whereby faecal contaminants will be added to the water bodies and cause numerous food-borne outbreaks. The present study was aimed to determine the prevalence of diarrheagenic Escherichia coli (DEC) strains in the water sources. MATERIALS AND METHODS Two hundred water samples collected during (2011-2012) were processed for the isolation of E. coli (EC) strains. EC strains were further analysed for antibiotic susceptibility patterns, and pathogroups-specific virulence factors stx1, stx2, stx2c, eae, tir, hlyA, bfpA, estA and eltA were detected using multiplex polymerase chain reaction. RESULTS Thirty-three percent of the water samples were contaminated with EC pathotypes. Fifty percent (33/66) of the DEC pathotypes were identified as enterotoxigenic EC (ETEC). Seventy-two percent (13/18) of the enteropathogenic EC (EPEC) strains were identified as typical EPEC and 28% (5/18) as atypical EPEC. Eleven percent (7/66) of the Shiga toxin EC (STEC) isolates carried a combination of stx1 and stx2 genes. Summer was found as a peak season with 47% (31/66) for EC pathogroups' activities. Eighty-nine percent of the strains showed resistance against tetracycline. CONCLUSION ETEC and EPEC are the primary causes of water contamination in southern regions of Khyber Pakhtunkhwa province, Pakistan. Firm adherence to the prescribed drugs can decrease trends in antibiotic resistance.
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Affiliation(s)
- M S Shah
- Department of Microbiology, Quaid-i-Azam University, Islamabad, Pakistan; Department of Biology, University of Texas at San Antonio, San Antonio, Texas, USA
| | - M Eppinger
- Department of Biology, University of Texas at San Antonio, San Antonio, Texas, USA
| | - S Ahmed
- Department of Microbiology, Quaid-i-Azam University, Islamabad, Pakistan
| | - A A Shah
- Department of Microbiology, Quaid-i-Azam University, Islamabad, Pakistan
| | - A Hameed
- Department of Microbiology, Quaid-i-Azam University, Islamabad, Pakistan
| | - F Hasan
- Department of Microbiology, Quaid-i-Azam University, Islamabad, Pakistan
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Dechet AM, Herman KM, Chen Parker C, Taormina P, Johanson J, Tauxe RV, Mahon BE. Outbreaks caused by sprouts, United States, 1998-2010: lessons learned and solutions needed. Foodborne Pathog Dis 2015; 11:635-44. [PMID: 25076040 DOI: 10.1089/fpd.2013.1705] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
After a series of outbreaks associated with sprouts in the mid-1990s, the U.S. Food and Drug Administration (FDA) published guidelines in 1999 for sprouts producers to reduce the risk of contamination. The recommendations included treating seeds with an antimicrobial agent such as calcium hypochlorite solution and testing spent irrigation water for pathogens. From 1998 through 2010, 33 outbreaks from seed and bean sprouts were documented in the United States, affecting 1330 reported persons. Twenty-eight outbreaks were caused by Salmonella, four by Shiga toxin-producing Escherichia coli, and one by Listeria. In 15 of the 18 outbreaks with information available, growers had not followed key FDA guidelines. In three outbreaks, however, the implicated sprouts were produced by firms that appeared to have implemented key FDA guidelines. Although seed chlorination, if consistently applied, reduces pathogen burden on sprouts, it does not eliminate the risk of human infection. Further seed and sprouts disinfection technologies, some recently developed, will be needed to enhance sprouts safety and reduce human disease. Improved seed production practices could also decrease pathogen burden but, because seeds are a globally distributed commodity, will require international cooperation.
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Affiliation(s)
- Amy M Dechet
- 1 Medical Education, Portland Providence Medical Center , Portland, Oregon
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Abstract
Shiga toxin-producing Escherichia coli (STEC) is among the common causes of foodborne gastroenteritis. STEC is defined by the production of specific toxins, but within this pathotype there is a diverse group of organisms. This diversity has important consequences for understanding the pathogenesis of the organism, as well as for selecting the optimum strategy for diagnostic testing in the clinical laboratory. This review includes discussions of the mechanisms of pathogenesis, the range of manifestations of infection, and the several different methods of laboratory detection of Shiga toxin-producing E coli.
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Multidrug-resistant diarrheagenic E. coli pathotypes are associated with ready-to-eat salad and vegetables in Pakistan. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13765-015-0019-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Salvadori M, Bertoni E. Update on hemolytic uremic syndrome: Diagnostic and therapeutic recommendations. World J Nephrol 2013. [PMID: 24255888 DOI: 10.5527/wjn.v2.i3.56)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Hemolytic uremic syndrome (HUS) is a rare disease. In this work the authors review the recent findings on HUS, considering the different etiologic and pathogenetic classifications. New findings in genetics and, in particular, mutations of genes that encode the complement-regulatory proteins have improved our understanding of atypical HUS. Similarly, the complement proteins are clearly involved in all types of thrombotic microangiopathy: typical HUS, atypical HUS and thrombotic thrombocytopenic purpura (TTP). Furthermore, several secondary HUS appear to be related to abnormalities in complement genes in predisposed patients. The authors highlight the therapeutic aspects of this rare disease, examining both "traditional therapy" (including plasma therapy, kidney and kidney-liver transplantation) and "new therapies". The latter include anti-Shiga-toxin antibodies and anti-C5 monoclonal antibody "eculizumab". Eculizumab has been recently launched for the treatment of the atypical HUS, but it appears to be effective in the treatment of typical HUS and in TTP. Future therapies are in phases I and II. They include anti-C5 antibodies, which are more purified, less immunogenic and absorbed orally and, anti-C3 antibodies, which are more powerful, but potentially less safe. Additionally, infusions of recombinant complement-regulatory proteins are a potential future therapy.
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Affiliation(s)
- Maurizio Salvadori
- Maurizio Salvadori, Elisabetta Bertoni, Renal Unit, Careggi Hospital, Careggi University, Florence 50139, Italy
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Salvadori M, Bertoni E. Update on hemolytic uremic syndrome: Diagnostic and therapeutic recommendations. World J Nephrol 2013; 2:56-76. [PMID: 24255888 PMCID: PMC3832913 DOI: 10.5527/wjn.v2.i3.56] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 06/26/2013] [Accepted: 08/13/2013] [Indexed: 02/06/2023] Open
Abstract
Hemolytic uremic syndrome (HUS) is a rare disease. In this work the authors review the recent findings on HUS, considering the different etiologic and pathogenetic classifications. New findings in genetics and, in particular, mutations of genes that encode the complement-regulatory proteins have improved our understanding of atypical HUS. Similarly, the complement proteins are clearly involved in all types of thrombotic microangiopathy: typical HUS, atypical HUS and thrombotic thrombocytopenic purpura (TTP). Furthermore, several secondary HUS appear to be related to abnormalities in complement genes in predisposed patients. The authors highlight the therapeutic aspects of this rare disease, examining both “traditional therapy” (including plasma therapy, kidney and kidney-liver transplantation) and “new therapies”. The latter include anti-Shiga-toxin antibodies and anti-C5 monoclonal antibody “eculizumab”. Eculizumab has been recently launched for the treatment of the atypical HUS, but it appears to be effective in the treatment of typical HUS and in TTP. Future therapies are in phases I and II. They include anti-C5 antibodies, which are more purified, less immunogenic and absorbed orally and, anti-C3 antibodies, which are more powerful, but potentially less safe. Additionally, infusions of recombinant complement-regulatory proteins are a potential future therapy.
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15
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McLean SK, Dunn LA, Palombo EA. Phage inhibition of Escherichia coli in ultrahigh-temperature-treated and raw milk. Foodborne Pathog Dis 2013; 10:956-62. [PMID: 23909774 DOI: 10.1089/fpd.2012.1473] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Escherichia coli can contaminate raw milk during the milking process or via environmental contamination in milk-processing facilities. Three bacteriophages, designated EC6, EC9, and EC11, were investigated for their ability to inhibit the growth of three strains of E. coli in ultrahigh-temperature (UHT) treated and raw bovine milk. A cocktail of the three phages completely inhibited E. coli ATCC 25922 and E. coli O127:H6 in UHT milk at 25 °C and under refrigeration temperatures (5-9 °C). The phage cocktail produced similar results in raw milk; however, E. coli ATCC 25922 and O127:H6 in raw milk controls also declined to below the level of detection at both temperatures. This observation indicated that competition by the raw milk microbiota might have contributed to the decline in viable E. coli cells. A cocktail containing EC6 and EC9 completely inhibited E. coli O5:H-, an enterohemorrhagic strain, in UHT milk at both temperatures. In raw milk, the phage cocktail initially inhibited growth of E. coli O5:H- but regrowth occurred following incubation for 9 h at 25 °C and 144 h at 5-9 °C. In contrast to the other E. coli strains, O5:H- was not inhibited in the raw milk controls. This study demonstrates that bacteriophages are effective biocontrol agents against E. coli host strains in UHT and raw bovine milk at various storage temperatures.
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Affiliation(s)
- Sarah K McLean
- Environment and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology , Victoria, Australia
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Weiser AA, Gross S, Schielke A, Wigger JF, Ernert A, Adolphs J, Fetsch A, Müller-Graf C, Käsbohrer A, Mosbach-Schulz O, Appel B, Greiner M. Trace-back and trace-forward tools developed ad hoc and used during the STEC O104:H4 outbreak 2011 in Germany and generic concepts for future outbreak situations. Foodborne Pathog Dis 2013; 10:263-9. [PMID: 23268760 PMCID: PMC3698685 DOI: 10.1089/fpd.2012.1296] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The Shiga toxin-producing Escherichia coli O104:H4 outbreak in Germany in 2011 required the development of appropriate tools in real-time for tracing suspicious foods along the supply chain, namely salad ingredients, sprouts, and seeds. Food commodities consumed at locations identified as most probable site of infection (outbreak clusters) were traced back in order to identify connections between different disease clusters via the supply chain of the foods. A newly developed relational database with integrated consistency and plausibility checks was used to collate these data for further analysis. Connections between suppliers, distributors, and producers were visualized in network graphs and geographic projections. Finally, this trace-back and trace-forward analysis led to the identification of sprouts produced by a horticultural farm in Lower Saxony as vehicle for the pathogen, and a specific lot of fenugreek seeds imported from Egypt as the most likely source of contamination. Network graphs have proven to be a powerful tool for summarizing and communicating complex trade relationships to various stake holders. The present article gives a detailed description of the newly developed tracing tools and recommendations for necessary requirements and improvements for future foodborne outbreak investigations.
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Escherichia coli O104:H4 outbreak from sprouted seeds. Int J Hyg Environ Health 2012; 216:346-54. [PMID: 22898546 DOI: 10.1016/j.ijheh.2012.07.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 06/13/2012] [Accepted: 07/26/2012] [Indexed: 11/21/2022]
Abstract
From May to July 2011, one of the largest reported outbreaks of haemolytic uraemic syndrome (HUS) and bloody diarrhoea caused by the Shiga toxin-producing Escherichia coli (STEC) O104:H4 occurred in Germany and France. The hypothetical origin of the outbreak strain was a combined enteroaggregative E. coli and an enterohaemorrhagic E. coli with the ability to resist multi-antibiotics and produce Shiga-toxin 2. The combination of aggregative ability, antibiotic resistance and the production of Shiga-toxin 2 significantly affected the severity of the symptoms presented. Since humans may be the primary reservoir, it is likely that contamination could have occurred through contact with infected individuals. Farm food safety management, and hand hygiene training programmes are crucial to primary production to prevent or reduce risks of contamination.
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Barak JD. The Biggest Food Safety Threat from the Tiniest of Crops. CEREAL FOOD WORLD 2012. [DOI: 10.1094/cfw-57-3-0123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- J. D. Barak
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, U.S.A
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Castro-Rosas J, Cerna-Cortés JF, Méndez-Reyes E, Lopez-Hernandez D, Gómez-Aldapa CA, Estrada-Garcia T. Presence of faecal coliforms, Escherichia coli and diarrheagenic E. coli pathotypes in ready-to-eat salads, from an area where crops are irrigated with untreated sewage water. Int J Food Microbiol 2012; 156:176-80. [PMID: 22507628 DOI: 10.1016/j.ijfoodmicro.2012.03.025] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 03/22/2012] [Accepted: 03/22/2012] [Indexed: 11/26/2022]
Abstract
Consumption of ready-to-eat (RTE) salads has increased worldwide. Consequently, the number of outbreaks caused by food-borne pathogens, including diarrheagenic E. coli pathotypes (DEPs), associated with the consumption of RTE-salads has increased. DEPs include enterotoxigenic (ETEC), typical and atypical enteropathogenic (tEPEC, aEPEC), enteroinvasive (EIEC), enteroaggregative (EAEC), diffuse adherent (DAEC) and Shiga toxin-producing (STEC) E. coli. In less-developed areas of the world, fresh crops continue to be irrigated with untreated sewage water. The aims of this study were to evaluate the microbiological quality and prevalence of DEPs in RTE-salads of raw vegetables, purchased from restaurants at Pachuca-City, Hidalgo, Mexico, where most locally consumed vegetables are irrigated with untreated sewage water. A total of 130 salads were purchased from restaurants of three categories: A) national chain restaurants and B) local restaurants, both with the H distinctive (a recognition that the Secretary of Tourism grants to restaurants that manage supplies with high levels of hygiene); and C) local small inexpensive restaurants without H distinctive. A total of 6 restaurants were included, 2 per category (A(1-2), B(1-2), C(1-2)). Each sample was tested for the presence of faecal coliforms (FC) and E. coli by standard procedures. E. coli strains were further characterized for the presence of DEPs loci by two multiplex polymerase chain reactions. Among the 130 salad samples 99% (129) were contaminated with FC; 85% (110/129) harboured E. coli and 7% (8/110) DEPs. The amount of positive salad samples for FC and E. coli was similar between restaurants and categories. The FC mean (571 FC/g) of all samples was significantly higher (p<0.001) than the E. coli mean (63 E. coli/g). A weak correlation of 7.7% (r(2)=0.077, p=0.003) between median FC and E. coli MPN (most probable number) per sample was found. Of the 8 salad samples contaminated with DEPs, 2 were spinach salads from restaurant A(2) and 3 were (Mixed salad) samples from each C restaurant. Three samples harboured non-O157 STEC strains, 2 EIEC, 1 ETEC and 2 samples had non-O157 STEC and EIEC strains, simultaneously. A significant difference (p=0.008) between the prevalence of E. coli vs. DEPs was observed. Independently of the restaurants' overall hygienic status, most RTE-salads had a poor microbiological quality and some harboured DEPs that have been associated with illness in Mexico. Health authorities should focus on implementing DEPs screening in raw vegetables and enforcing the legislation that forbids irrigation with untreated sewage water of both root and leafy vegetables.
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Affiliation(s)
- Javier Castro-Rosas
- Centro de Investigaciones Químicas, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Centro Universitario, Carretera Pachuca-Tulancingo km 4.5, Mineral de la Reforma, Hidalgo, C.P. 42183, México
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Vally H, Hall G, Dyda A, Raupach J, Knope K, Combs B, Desmarchelier P. Epidemiology of Shiga toxin producing Escherichia coli in Australia, 2000-2010. BMC Public Health 2012; 12:63. [PMID: 22264221 PMCID: PMC3398300 DOI: 10.1186/1471-2458-12-63] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 01/21/2012] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Shiga toxin-producing Escherichia coli (STEC) are an important cause of gastroenteritis in Australia and worldwide and can also result in serious sequelae such as haemolytic uraemic syndrome (HUS). In this paper we describe the epidemiology of STEC in Australia using the latest available data. METHODS National and state notifications data, as well as data on serotypes, hospitalizations, mortality and outbreaks were examined. RESULTS For the 11 year period 2000 to 2010, the overall annual Australian rate of all notified STEC illness was 0.4 cases per 100,000 per year. In total, there were 822 STEC infections notified in Australia over this period, with a low of 1 notification in the Australian Capital Territory (corresponding to a rate of 0.03 cases per 100,000/year) and a high of 413 notifications in South Australia (corresponding to a rate of 2.4 cases per 100,000/year), the state with the most comprehensive surveillance for STEC infection in the country. Nationally, 71.2% (504/708) of STEC infections underwent serotype testing between 2001 and 2009, and of these, 58.0% (225/388) were found to be O157 strains, with O111 (13.7%) and O26 (11.1%) strains also commonly associated with STEC infections. The notification rate for STEC O157 infections Australia wide between 2001-2009 was 0.12 cases per 100,000 per year. Over the same 9 year period there were 11 outbreaks caused by STEC, with these outbreaks generally being small in size and caused by a variety of serogroups. The overall annual rate of notified HUS in Australia between 2000 and 2010 was 0.07 cases per 100,000 per year. Both STEC infections and HUS cases showed a similar seasonal distribution, with a larger proportion of reported cases occurring in the summer months of December to February. CONCLUSIONS STEC infections in Australia have remained fairly steady over the past 11 years. Overall, the incidence and burden of disease due to STEC and HUS in Australia appears comparable or lower than similar developed countries.
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Affiliation(s)
- Hassan Vally
- National Centre for Epidemiology and Population Health, ANU College of Medicine, Biology and Environment, The Australian National University, Canberra, Australia
- School of Public Health and Human Biosciences, La Trobe University, Melbourne, Australia
| | - Gillian Hall
- Medical School, ANU College of Medicine, Biology and Environment, The Australian National University, Canberra, Australia
| | - Amalie Dyda
- South Australian Department of Health, Government of South Australia, Canberra, Australia
| | - Jane Raupach
- South Australian Department of Health, Government of South Australia, Canberra, Australia
| | - Katrina Knope
- OzFoodNet, Australian Department of Health and Ageing, Canberra, Australia
| | - Barry Combs
- OzFoodNet, Western Australian Department of Health, Canberra, Australia
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Nagar V, Hajare SN, Saroj SD, Bandekar JR. Radiation processing of minimally processed sprouts (dew gram and chick pea): effect on sensory, nutritional and microbiological quality. Int J Food Sci Technol 2011. [DOI: 10.1111/j.1365-2621.2011.02885.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Neil KP, Biggerstaff G, MacDonald JK, Trees E, Medus C, Musser KA, Stroika SG, Zink D, Sotir MJ. A Novel Vehicle for Transmission of Escherichia coli O157:H7 to Humans: Multistate Outbreak of E. coli O157:H7 Infections Associated With Consumption of Ready-to-Bake Commercial Prepackaged Cookie Dough--United States, 2009. Clin Infect Dis 2011; 54:511-8. [DOI: 10.1093/cid/cir831] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Dynamics of Escherichia coli O157:H7 outbreak detection and investigation, Minnesota 2000-2008. Epidemiol Infect 2011; 140:1430-8. [PMID: 22093879 DOI: 10.1017/s0950268811002330] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We determined characteristics of Escherichia coli O157:H7 pulsed-field gel electrophoresis clusters that predict their being solved (i.e. that result in identification of a confirmed outbreak). Clusters were investigated by the Minnesota Department of Health (MDH) using a dynamic iterative model. During 2000-2008, 19 (23%) of 84 clusters were solved. Clusters of ≥3 isolates were more likely to be solved than clusters of two isolates. Clusters in which the first two case isolates were received at MDH on the same day were more likely to be solved than were clusters in which the first two case isolates were received over ≥8 days. Investigation of clusters of ≥3 E. coli O157:H7 cases increased the success of cluster investigations.
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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: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Kirk MD. The German Escherichia coli outbreak — could it happen here? Med J Aust 2011; 195:325-6. [DOI: 10.5694/mja11.10816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 08/09/2011] [Indexed: 11/17/2022]
Affiliation(s)
- Martyn D Kirk
- Medical School and National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT
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27
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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: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Yamazaki A, Li J, Hutchins WC, Wang L, Ma J, Ibekwe AM, Yang CH. Commensal effect of pectate lyases secreted from Dickeya dadantii on proliferation of Escherichia coli O157:H7 EDL933 on lettuce leaves. Appl Environ Microbiol 2011; 77:156-62. [PMID: 21075884 PMCID: PMC3019694 DOI: 10.1128/aem.01079-10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 10/31/2010] [Indexed: 11/20/2022] Open
Abstract
The outbreaks caused by enterohemorrhagic Escherichia coli O157:H7 on leafy greens have raised serious and immediate food safety concerns. It has been suggested that several phytopathogens aid in the persistence and proliferation of the human enteropathogens in the phyllosphere. In this work, we examined the influence of virulence mechanisms of Dickeya dadantii 3937, a broad-host-range phytopathogen, on the proliferation of the human pathogen E. coli O157:H7 EDL933 (EDL933) on postharvest lettuce by coinoculation of EDL933 with D. dadantii 3937 derivatives that have mutations in virulence-related genes. A type II secretion system (T2SS)-deficient mutant of D. dadantii 3937, A1919 (ΔoutC), lost the capability to promote the multiplication of EDL933, whereas Ech159 (ΔrpoS), a stress-responsive σ factor RpoS-deficient mutant, increased EDL933 proliferation on lettuce leaves. A spectrophotometric enzyme activity assay revealed that A1919 (ΔoutC) was completely deficient in the secretion of pectate lyases (Pels), which play a major role in plant tissue maceration. In contrast to A1919 (ΔoutC), Ech159 (ΔrpoS) showed more than 2-fold-greater Pel activity than the wild-type D. dadantii 3937. Increased expression of pelD (encodes an endo-pectate lyase) was observed in Ech159 (ΔrpoS) in planta. These results suggest that the pectinolytic activity of D. dadantii 3937 is the dominant determinant of enhanced EDL933 proliferation on the lettuce leaves. In addition, RpoS, the general stress response σ factor involved in cell survival in suboptimal conditions, plays a role in EDL933 proliferation by controlling the production of pectate lyases in D. dadantii 3937.
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Affiliation(s)
- Akihiro Yamazaki
- Department of Biological Sciences, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, Department of Civil Engineering and Mechanics, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, USDA-ARS U.S. Salinity Laboratory, Riverside, California 92507
| | - Jin Li
- Department of Biological Sciences, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, Department of Civil Engineering and Mechanics, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, USDA-ARS U.S. Salinity Laboratory, Riverside, California 92507
| | - William C. Hutchins
- Department of Biological Sciences, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, Department of Civil Engineering and Mechanics, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, USDA-ARS U.S. Salinity Laboratory, Riverside, California 92507
| | - Lixia Wang
- Department of Biological Sciences, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, Department of Civil Engineering and Mechanics, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, USDA-ARS U.S. Salinity Laboratory, Riverside, California 92507
| | - Jincai Ma
- Department of Biological Sciences, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, Department of Civil Engineering and Mechanics, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, USDA-ARS U.S. Salinity Laboratory, Riverside, California 92507
| | - A. Mark Ibekwe
- Department of Biological Sciences, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, Department of Civil Engineering and Mechanics, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, USDA-ARS U.S. Salinity Laboratory, Riverside, California 92507
| | - Ching-Hong Yang
- Department of Biological Sciences, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, Department of Civil Engineering and Mechanics, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, USDA-ARS U.S. Salinity Laboratory, Riverside, California 92507
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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: 38.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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YE JIANXIONG, KOSTRZYNSKA MAGDALAENA, DUNFIELD KARI, WARRINER KEITH. Control of Salmonella on Sprouting Mung Bean and Alfalfa Seeds by Using a Biocontrol Preparation Based on Antagonistic Bacteria and Lytic Bacteriophages. J Food Prot 2010; 73:9-17. [DOI: 10.4315/0362-028x-73.1.9] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The following reports on the application of a combination of antagonistic bacteria and lytic bacteriophages to control the growth of Salmonella on sprouting mung beans and alfalfa seeds. Antagonistic bacteria were isolated from mung bean sprouts and tomatoes by using the deferred plate assay to assess anti-Salmonella activity. From the isolates screened, an Enterobacter asburiae strain (labeled “JX1”) exhibited stable antagonistic activity against a broad range of Salmonella serovars (Agona, Berta, Enteritidis, Hadar, Heidelberg, Javiana, Montevideo, Muenchen, Newport, Saint Paul, and Typhimurium). Lytic bacteriophages against Salmonella were isolated from pig or cattle manure effluent. A bacteriophage cocktail prepared from six isolates was coinoculated with E. asburiae JX1 along with Salmonella in broth culture. The combination of E. asburiae JX1 and bacteriophage cocktail reduced the levels of Salmonella by 5.7 to 6.4 log CFU/ml. Mung beans inoculated with Salmonella and sprouted over a 4-day period attained levels of 6.72 ± 0.78 log CFU/g. In contrast, levels of Salmonella were reduced to 3.31 ± 2.48 or 1.16 ± 2.14 log CFU/g when the pathogen was coinoculated with bacteriophages or E. asburiae JX1, respectively. However, by using a combination of E. asburiae JX1and bacteriophages, the levels of Salmonella associated with mung bean sprouts were only detected by enrichment. The biocontrol preparation was effective at controlling the growth of Salmonella under a range of sprouting temperatures (20 to 30°C) and was equally effective at suppressing the growth of Salmonella on sprouting alfalfa seeds. The combination of E. asburiae JX1 and bacteriophages represents a promising, chemical-free approach for controlling the growth of Salmonella on sprouting seeds.
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Affiliation(s)
- JIANXIONG YE
- 1Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | - MAGDALAENA KOSTRZYNSKA
- 2Food Program, Agriculture & Agri-Food Canada, 93 Stone Road West, Guelph, Ontario, Canada N1G 5C9
| | - KARI DUNFIELD
- 3Land Resource Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | - KEITH WARRINER
- 1Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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Neetoo H, Ye M, Chen H. Factors affecting the efficacy of pressure inactivation of Escherichia coli O157:H7 on alfalfa seeds and seed viability. Int J Food Microbiol 2009; 131:218-23. [DOI: 10.1016/j.ijfoodmicro.2009.02.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2008] [Revised: 02/19/2009] [Accepted: 02/28/2009] [Indexed: 10/21/2022]
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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: 1.8] [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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La Ragione RM, Best A, Woodward MJ, Wales AD. Escherichia coli O157:H7 colonization in small domestic ruminants. FEMS Microbiol Rev 2008; 33:394-410. [PMID: 19207740 DOI: 10.1111/j.1574-6976.2008.00138.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Enterohaemorrhagic Escherichia coli O157:H7 was first implicated in human disease in the early 1980s, with ruminants cited as the primary reservoirs. Preliminary studies indicated cattle to be the sole source of E. coli O157:H7 outbreaks in humans; however, further epidemiological studies soon demonstrated that E. coli O157:H7 was widespread in other food sources and that a number of transmission routes existed. More recently, small domestic ruminants (sheep and goats) have emerged as important sources of E. coli O157:H7 human infection, particularly with the widespread popularity of petting farms and the increased use of sheep and goat food products, including unpasteurized cheeses. Although the colonization and persistence characteristics of E. coli O157:H7 in the bovine host have been studied intensively, this is not the case for small ruminants. Despite many similarities to the bovine host, the pathobiology of E. coli O157:H7 in small domestic ruminants does appear to differ significantly from that described in cattle. This review aims to critically review the current knowledge regarding colonization and persistence of E. coli O157:H7 in small domestic ruminants, including comparisons with the bovine host where appropriate.
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Affiliation(s)
- Roberto M La Ragione
- Department of Food and Environmental Safety, Veterinary Laboratories Agency, Addlestone, Surrey, UK.
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34
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Kirk M, McKay I, Hall G, Dalton C, Stafford R, Unicomb L, Gregory J. Food Safety: Foodborne Disease in Australia: The OzFoodNet Experience. Clin Infect Dis 2008; 47:392-400. [DOI: 10.1086/589861] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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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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Denno DM, Klein EJ, Young VB, Fox JG, Wang D, Tarr PI. Explaining unexplained diarrhea and associating risks and infections. Anim Health Res Rev 2007; 8:69-80. [PMID: 17692144 DOI: 10.1017/s1466252307001302] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Gastrointestinal illnesses are common afflictions. However, knowledge of their etiology is often lacking. Moreover, most cases of infections with reportable enteric pathogens (Campylobacter jejuni, Escherichia coli O157:H7, Salmonella, Shigella, Yersinia, Cryptosporidia and Giardia) have sporadic modes of acquisition, yet control measures are often biased towards mitigation of risks discerned by outbreak analysis. To determine the etiology of unexplained diarrhea it is important to study populations that can be matched to appropriate controls and to couple thorough classic microbiologic evaluation on receipt of specimens with archiving and outgrowth capabilities. Research evaluations should address the potential roles of a broad panel of candidate bacterial pathogens including diarrheagenic E. coli, Listeria monocytogenes, Helicobacters and jejuni Campylobacters, and also apply novel massively parallel sequencing and nucleic acid detection technologies that allow the detection of viral pathogens. To fill voids in our knowledge regarding sources of known enteric pathogens it will be critical to extend case-control studies to assess risk factors and exposures to patients with non-epidemic illnesses and to appropriate controls. By filling these gaps in our knowledge it should be possible to formulate rational prevention mechanisms for human gastrointestinal illnesses.
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Affiliation(s)
- Donna M Denno
- Department of Health Services, University of Washington School of Medicine, Seattle, WA, USA
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Nou X, Arthur TM, Bosilevac JM, Brichta-Harhay DM, Guerini MN, Kalchayanand N, Koohmaraie M. Improvement of immunomagnetic separation for Escherichia coli O157:H7 detection by the PickPen magnetic particle separation device. J Food Prot 2006; 69:2870-4. [PMID: 17186652 DOI: 10.4315/0362-028x-69.12.2870] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Conventional immunomagnetic separation (IMS) procedures, which use an external magnetic source to capture magnetic particles against the side of a test tube, are labor-intensive and can have poor sensitivity for the target organism because of high background microflora that is not effectively washed away during the IMS process. This report compares the conventional IMS procedure to a new IMS procedure with an intrasolution magnetic particle transfer device, the PickPen. The IMS target for the majority of these studies is Escherichia coli O157:H7 in various types of samples, including cattle feces, hides, carcasses, and ground beef. Comparison of the two IMS methods showed a significant difference (P < 0.05) in the efficiency of detecting E. coli O157:H7 from cattle carcass surface, cattle hide, and cattle fecal samples. No significant improvement (P > 0.05) in E. coli O157:H7 detection was observed when the PickPen IMS procedure was used to isolate this pathogen from ground beef samples. Use of the PickPen IMS greatly increases the throughput of the IMS procedure and may be more compatible with various emerging technologies for pathogen detection. In addition, the efficacy of sequential IMS for multiple pathogens is reported herein.
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Affiliation(s)
- Xiangwu Nou
- U.S. Department of Agriculture, Agricultural Research Service, Roman L. Hruska U.S. Meat Animal Research Center, Spur 18-D, P.O. Box 166, Clay Center, Nebraska 68933-0166, USA
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Saroj SD, Shashidhar R, Pandey M, Dhokane V, Hajare S, Sharma A, Bandekar JR. Effectiveness of radiation processing in elimination of Salmonella typhimurium and Listeria monocytogenes from sprouts. J Food Prot 2006; 69:1858-64. [PMID: 16924910 DOI: 10.4315/0362-028x-69.8.1858] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The effectiveness of radiation treatment in eliminating Salmonella Typhimurium and Listeria monocytogenes on laboratory inoculated ready-to-eat sprouts was studied. Decimal reduction doses (D10-values) for Salmonella Typhimurium and L. monocytogenes in dry seeds of mung (green gram), matki (dew gram), chana (chick pea), and vatana (garden pea) ranged from 0.189 to 0.303 kGy and 0.294 to 0.344 kGy, respectively. In sprouts made from these seeds, the D10-values ranged from 0.192 to 0.208 kGy for Salmonella Typhimurium and from 0.526 to 0.588 kGy for L. monocytogenes. Radiation treatment with a 2-kGy dose resulted in complete elimination of 10(4) CFU/g of Salmonella Typhimurium and 10(3) CFU/g of L. monocytogenes from all the four varieties of sprouts. No recovery of Salmonella Typhimurium and L. monocytogenes was observed in the radiation treated samples stored at 4 and 8 degrees C up to 12 days. Radiation treatment with 1 kGy and 2 kGy resulted in a reduction of aerobic plate counts and coliform counts by 2 and 4 log CFU/g, respectively; the yeast and mold counts and staphylococci counts decreased by 1 and 2 log CFU/g, respectively. However, during postirradiation storage at 4 and 8 degrees C, aerobic plate counts, coliform counts, yeast and mold counts, and staphylococci counts remained constant throughout the incubation period. This study demonstrates that a 2-kGy dose of irradiation could be an effective method of processing to ensure microbial safety of sprouts.
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Affiliation(s)
- Sunil D Saroj
- Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
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Hedberg CW, Besser JM. Commentary: cluster evaluation, PulseNet, and public health practice. Foodborne Pathog Dis 2006; 3:32-5. [PMID: 16602977 DOI: 10.1089/fpd.2006.3.32] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Craig W Hedberg
- School of Public Health, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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Bielaszewska M, Prager R, Zhang W, Friedrich AW, Mellmann A, Tschäpe H, Karch H. Chromosomal dynamism in progeny of outbreak-related sorbitol-fermenting enterohemorrhagic Escherichia coli O157:NM. Appl Environ Microbiol 2006; 72:1900-9. [PMID: 16517637 PMCID: PMC1393231 DOI: 10.1128/aem.72.3.1900-1909.2006] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157:NM (nonmotile) is a unique clone that causes outbreaks of hemorrhagic colitis and hemolytic-uremic syndrome. In well-defined clusters of cases, we have observed significant variability in pulsed-field gel electrophoresis (PFGE) patterns which could indicate coinfection by different strains. An analysis of randomly selected progeny colonies of an outbreak strain after subcultivation demonstrated that they displayed either the cognate PFGE outbreak pattern or one of four additional patterns and were <89% similar. These profound alterations were associated with changes in the genomic position of one of two Shiga toxin 2-encoding genes (stx2) in the outbreak strain or with the loss of this gene. The two stx2 alleles in the outbreak strain were identical but were flanked with phage-related sequences with only 77% sequence identity. Neither of these phages produced plaques, but one lysogenized E. coli K-12 and integrated in yecE in the lysogens and the wild-type strain. The presence of two stx2 genes which correlated with increased production of Stx2 in vitro but not with the clinical outcome of infection was also found in 14 (21%) of 67 SF EHEC O157:NM isolates from sporadic cases of human disease. The variability of PFGE patterns for the progeny of a single colony must be considered when interpreting PFGE patterns in SF EHEC O157-associated outbreaks.
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Affiliation(s)
- Martina Bielaszewska
- Institut für Hygiene, Universität Münster, Robert Koch Str. 41, 48149 Münster, Germany.
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