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Brennan FP, Alsanius BW, Allende A, Burgess CM, Moreira H, Johannessen GS, Castro PML, Uyttendaele M, Truchado P, Holden NJ. Harnessing agricultural microbiomes for human pathogen control. ISME COMMUNICATIONS 2022; 2:44. [PMID: 37938739 PMCID: PMC9723689 DOI: 10.1038/s43705-022-00127-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 08/24/2023]
Affiliation(s)
- Fiona P Brennan
- Teagasc, Department of Environment, Soils and Landuse, Johnstown Castle, Wexford, Ireland.
| | - Beatrix W Alsanius
- Department of Biosystems and Technology; Microbial Horticulture Unit, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Ana Allende
- Food Safety and Quality Group, CEBAS-CSIC, Campus Universitario de Espinardo, Murcia, Spain
| | - Catherine M Burgess
- Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin, Ireland
| | - Helena Moreira
- Universidade Católica Portuguesa, CBQF-Centro de Biotecnologia e Química Fina-Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - Gro S Johannessen
- Section for Food Safety and Animal Health Research, Norwegian Veterinary Institute, Oslo, Norway
| | - Paula M L Castro
- Universidade Católica Portuguesa, CBQF-Centro de Biotecnologia e Química Fina-Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - Mieke Uyttendaele
- Department of Food Technology, Food Safety and Health, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, Ghent, Belgium
| | - Pilar Truchado
- Food Safety and Quality Group, CEBAS-CSIC, Campus Universitario de Espinardo, Murcia, Spain
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2
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Semenov MV, Krasnov GS, Semenov VM, Ksenofontova N, Zinyakova NB, van Bruggen AHC. Does fresh farmyard manure introduce surviving microbes into soil or activate soil-borne microbiota? JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 294:113018. [PMID: 34144322 DOI: 10.1016/j.jenvman.2021.113018] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/27/2021] [Accepted: 06/03/2021] [Indexed: 06/12/2023]
Abstract
Manure inputs into soil strongly affect soil microbial communities leading to shifts in microbial diversity and activity. It is still not clear whether these effects are caused mainly by the survival of microbes introduced with manure or by activation of the soil-borne microbiome. Here, we investigated how the soil microbiome was changed after the introduction of fresh farmyard cattle manure, and which microorganisms originating from manure survived in soil. Manure addition led to a strong increase in soil microbial biomass, gene copies abundances, respiration activity, and diversity. High-throughput sequencing analysis showed that higher microbial diversity in manured soil was caused mainly by activation of 113 soil-borne microbial genera which were mostly minor taxa in not-fertilized soil. Two weeks after manure input, 78% of the manure-associated genera were not detected anymore. Only 15 of 237 prokaryotic genera that originated from manure survived for 144 days in soil, and only 8 of them (primarily representatives of Clostridia class) were found in manured soil after winter. Thus, an increase in microbial biomass and diversity after manure input is caused mainly by activation of soil-borne microbial communities, while most exogenous microbes from manure do not survive in soil conditions after few months.
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Affiliation(s)
- Mikhail V Semenov
- Department of Soil Biology and Biochemistry, Dokuchaev Soil Science Institute, Moscow, 119017, Russia.
| | - George S Krasnov
- Laboratory of Postgenomic Research, Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Moscow, 119991, Russia
| | - Vyacheslav M Semenov
- Institute of Physicochemical and Biological Problems in Soil Science of RAS, Pushchino, 142290, Moscow Region, Russia; University of Tyumen, Tyumen, 625003, Russia
| | - Natalia Ksenofontova
- Department of Soil Biology and Biochemistry, Dokuchaev Soil Science Institute, Moscow, 119017, Russia
| | - Natalia B Zinyakova
- Institute of Physicochemical and Biological Problems in Soil Science of RAS, Pushchino, 142290, Moscow Region, Russia
| | - Ariena H C van Bruggen
- Department of Plant Pathology and Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32611-0680, USA
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3
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Bozkurt H, Bell T, van Ogtrop F, Phan-Thien KY, McConchie R. Assessment of microbial risk during Australian industrial practices for Escherichia coli O157:H7 in fresh cut-cos lettuce: A stochastic quantitative approach. Food Microbiol 2021; 95:103691. [PMID: 33397620 DOI: 10.1016/j.fm.2020.103691] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 11/21/2022]
Abstract
Escherichia coli O157:H7 risk associated with the consumption of fresh cut-cos lettuce during Australian industrial practices was assessed. A probabilistic risk assessment model was developed and implemented in the @Risk software by using the Monte Carlo simulation technique with 1,000,000 iterations. Australian preharvest practices yielded predicted annual mean E. coli O157:H7 levels from 0.2 to -3.4 log CFU/g and prevalence values ranged from 2 to 6.4%. While exclusion of solar radiation from the baseline model yielded a significant increase in concentration of E. coli O157:H7 (-5.2 -log fold), drip irrigation usage, exclusion of manure amended soil and rainfall reduced E. coli O157:H7 levels by 7.4, 6.5, and 4.3-log fold, respectively. The microbial quality of irrigation water and irrigation type both had a significant effect on E. coli O157:H7 concentrations at harvest (p < 0.05). The probability of illness due to consumption of E. coli O157:H7 contaminated fresh cut-cos lettuce when water washing interventions were introduced into the processing module, was reduced by 1.4-2.7-log fold (p < 0.05). This study provides a robust basis for assessment of risk associated with E. coli O157:H7 contamination on fresh cut-cos lettuce for industrial practices and will assist the leafy green industry and food safety authorities in Australia to identify potential risk management strategies.
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Affiliation(s)
- Hayriye Bozkurt
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia.
| | - Tina Bell
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia
| | - Floris van Ogtrop
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia
| | - Kim-Yen Phan-Thien
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia
| | - Robyn McConchie
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia
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4
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Gekenidis MT, Rigotti S, Hummerjohann J, Walsh F, Drissner D. Long-Term Persistence of blaCTX-M-15 in Soil and Lettuce after Introducing Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli via Manure or Water. Microorganisms 2020; 8:E1646. [PMID: 33114244 PMCID: PMC7690902 DOI: 10.3390/microorganisms8111646] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 01/03/2023] Open
Abstract
The number of environmental antibiotic-resistant bacteria (ARB) has increased dramatically since the start of antibiotic mass production for broad bacterial infection treatment in 1944. Nowadays, ARB and their resistance-determining genes (ARGs) are readily detected in all environments, including the human food chain. A highly relevant food group in this context is fresh produce, frequent raw consumption of which facilitates direct transfer of ARB and ARGs to the consumer. Here, we investigate the persistence of an extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) pEK499 and its clinically most important ARG (blaCTX-M-15), after introduction via irrigation water or manure into a lettuce-growing system. Culturable ESBL-producing E. coli persisted longest in soil and when introduced via manure (until 9 weeks after introduction), while being undetectable on lettuce beyond day 7. In contrast, qPCR detection of blaCTX-M-15 was much more frequent: introduction via water significantly increased blaCTX-M-15 on lettuce until week 4, as opposed to manure, which affected the soil in the long-term (9 weeks) while leading to blaCTX-M-15 detection on lettuce until day 7 only. Our findings demonstrate long-term persistence of undesired ARB and ARG after their introduction via both irrigation and amendment. Such an understanding of the persistence kinetics of an ESBL-producing E. coli and plasmid-encoded blaCTX-M-15 aids the determination of critical actions in order to mitigate their transfer to the consumer.
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Affiliation(s)
| | - Serena Rigotti
- Microbiological Food Safety, Agroscope, 8820 Wädenswil, Switzerland;
| | - Jörg Hummerjohann
- Microbiological Food Safety, Agroscope, 3003 Liebefeld, Switzerland;
| | - Fiona Walsh
- Department of Biology, Maynooth University, W23 F2H6 Maynooth, Co. Kildare, Ireland;
| | - David Drissner
- Department of Life Sciences, Albstadt-Sigmaringen University, 72488 Sigmaringen, Germany;
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5
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Horr T, Pradhan AK. Evaluation of public health risk for Escherichia coli O157:H7 in cilantro. Food Res Int 2020; 136:109545. [PMID: 32846599 DOI: 10.1016/j.foodres.2020.109545] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 07/09/2020] [Accepted: 07/09/2020] [Indexed: 10/23/2022]
Abstract
This study sought to model the growth and die-off of Escherichia coli (E. coli) O157:H7 along the cilantro supply chain from farm-to-fork to investigate its risk to public health. Contributing factors included in the model were on farm contamination from irrigation water and soil, solar radiation, harvesting, and transportation and storage times and temperatures. The developed risk model estimated the microbiological risks associated with E. coli O157:H7 in cilantro and determined the parameters that had the most effect on the estimated number of illnesses per year so future mitigation strategies could be applied. Results showed a similar decrease in the E. coli O157:H7 (median values) concentrations along the supply chain for cilantro grown in both winter and summer weather conditions. With an estimated 0.1% prevalence of E. coli O157:H7 contamination for cilantro post-harvest used for illustration, the model predicted the probability of illness from consuming fresh cilantro as very low with fewer than two illnesses per every one billion servings of cilantro (1.6 × 10-9; 95th percentile). Although rare, 3.7% and 1.6% of scenarios run in this model for summer and winter grown cilantro, respectively, result in over 10 cases per year in the United States. This is reflected in real life where illnesses from cilantro are seen rarely but outbreaks have occurred. Sensitivity analysis and scenario testing demonstrated that ensuring clean and high quality irrigation water and preventing temperature abuse during transportation from farm to retail, are key to reducing overall risk of illness.
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Affiliation(s)
- Taryn Horr
- Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA
| | - Abani K Pradhan
- Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA; Center for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, USA.
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Tran DTQ, Bradbury MI, Ogtrop FFVAN, Bozkurt H, Jones BJ, McCONCHIE R. Environmental Drivers for Persistence of Escherichia coli and Salmonella in Manure-Amended Soils: A Meta-Analysis. J Food Prot 2020; 83:1268-1277. [PMID: 32577760 DOI: 10.4315/0362-028x.jfp-19-460] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 02/04/2020] [Indexed: 11/11/2022]
Abstract
ABSTRACT Application of organic amendments to agricultural land improves soil quality and provides nutrients essential for plant growth; however, they are also a reservoir for zoonotic pathogens whose presence poses a significant risk to public health. The persistence of bacteria in manure-amended soil, and differences in manure handling practices, are important issues from a food safety perspective. The primary objective of this study was to quantitatively summarize the variations in the rate of decline of Escherichia coli and Salmonella spp. in manure-amended soil under laboratory and field conditions, and to assess the impact of environmental factors. Available literature data on persistence of E. coli and Salmonella spp. in manure-amended soil from 42 primary research studies were extracted and statistically analyzed using a mixed-effect regression model. The results indicated that temperature (soil and air combined) was the most prominent factor affecting persistence of both E. coli and Salmonella spp. under laboratory conditions (P < 0.001), and of E. coli under field conditions (P < 0.05). The time required for a log reduction of E. coli under field conditions was significantly higher at low temperature (0 to 10°C) than at high temperature (greater than 20°C) (P < 0.05). In addition, application method was identified as a significant factor, with manure incorporation to soil inducing longer survival compared with surface application by approximately 1.2 times. The significant variation observed among primary research studies of bacterial persistence has highlighted that mitigation strategies associated with the use of manures in fresh produce production need to be improved by addressing factors such as climate, soil management, application method, and initial microbial levels. These findings may be used to support guidelines establishing exclusion periods between manure fertilization and the grazing or harvesting of crops, and may be useful for the generation of quantitative microbial risk models for fresh produce. HIGHLIGHTS
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Affiliation(s)
- Dao T Q Tran
- ARC Training Centre for Food Safety in the Fresh Produce Industry, School of Life and Environmental Sciences, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW 2006, Australia
| | - Mark I Bradbury
- ARC Training Centre for Food Safety in the Fresh Produce Industry, School of Life and Environmental Sciences, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW 2006, Australia
| | - Floris F VAN Ogtrop
- ARC Training Centre for Food Safety in the Fresh Produce Industry, School of Life and Environmental Sciences, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW 2006, Australia
| | - Hayriye Bozkurt
- ARC Training Centre for Food Safety in the Fresh Produce Industry, School of Life and Environmental Sciences, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW 2006, Australia
| | - Brian J Jones
- ARC Training Centre for Food Safety in the Fresh Produce Industry, School of Life and Environmental Sciences, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW 2006, Australia
| | - Robyn McCONCHIE
- ARC Training Centre for Food Safety in the Fresh Produce Industry, School of Life and Environmental Sciences, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW 2006, Australia
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7
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van Overbeek LS, Wichers JH, van Amerongen A, van Roermund HJW, van der Zouwen P, Willemsen PTJ. Circulation of Shiga Toxin-Producing Escherichia coli Phylogenetic Group B1 Strains Between Calve Stable Manure and Pasture Land With Grazing Heifers. Front Microbiol 2020; 11:1355. [PMID: 32714297 PMCID: PMC7340143 DOI: 10.3389/fmicb.2020.01355] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 05/27/2020] [Indexed: 12/31/2022] Open
Abstract
Escherichia coli strains carrying Shiga toxins 1 and 2 (stx1 and stx2), intimin (eae), and hemolysin (ehxA) production genes were found in grass shoot, rhizosphere soil, and stable manure samples from a small-scale cattle farm located at the center of Netherlands, using cultivation-dependent and -independent microbiological detection techniques. Pasture land with grazing heifers in the first year of sampling in 2014 and without grazing cattle in 2015 was physically separated from the stable that housed rose calves during both years. Manure from the stable was applied to pasture via injection into soil once per year in early spring. Among a variety of 35 phylogenetic distinctly related E. coli strains, one large group consisting of 21 closely resembling E. coli O150:H2 (18), O98:H21 (2), and O84:H2 (1) strains, all belonging to phylogenetic group B1 and carrying all screened virulence traits, was found present on grass shoots (10), rhizosphere soil (3), and stable manure (8) in 2014, but not anymore in 2015 when grazing heifers were absent. Presence and absence of these strains, obtained via enrichments, were confirmed via molecular detection using PCR-NALFIA in all ecosystems in both years. We propose that this group of Shiga toxin-producing E. coli phylogenetic group B1 strains was originally introduced via stable manure injection into the pasture. Upon grazing, these potential pathogens proliferated in the intestinal track systems of the heifers resulting in defecation with higher loads of the STEC strain onto the grass cover. The STEC strain was further smeared over the field via the hooves of the heifers resulting in augmentation of the potential pathogen in the pasture in 2014, whereas in 2015, in the absence of heifers, no augmentation occurred and only a more diverse group of potentially mild virulent E. coli phylogenetic group A and B1 strains, indigenous to pasture plants, remained present. Via this model, it was postulated that human pathogens can circulate between plants and farm animals, using the plant as an alternative ecosystem. These data indicate that grazed pasture must be considered as a potential carrier of human pathogenic E. coli strains and possibly also of other pathogens.
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Affiliation(s)
- Leonard S van Overbeek
- Wageningen University and Research (WUR), Wageningen Research (WR), Wageningen, Netherlands
| | - Jan H Wichers
- Wageningen University and Research (WUR), Wageningen Research (WR), Wageningen, Netherlands
| | - Aart van Amerongen
- Wageningen University and Research (WUR), Wageningen Research (WR), Wageningen, Netherlands
| | | | | | - Peter T J Willemsen
- Wageningen University and Research (WUR), Wageningen Research (WR), Wageningen, Netherlands
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Gu G, Strawn LK, Zheng J, Reed EA, Rideout SL. Diversity and Dynamics of Salmonella enterica in Water Sources, Poultry Litters, and Field Soils Amended With Poultry Litter in a Major Agricultural Area of Virginia. Front Microbiol 2019; 10:2868. [PMID: 31956319 PMCID: PMC6951424 DOI: 10.3389/fmicb.2019.02868] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 11/27/2019] [Indexed: 11/13/2022] Open
Abstract
The Eastern Shore of Virginia (ESV) is a major agricultural region in Virginia and in the past has been linked to some tomato-associated outbreaks of salmonellosis. In this study, water samples were collected weekly from irrigation ponds and wells in four representative vegetable farms (Farms A–D, each farm paired with one pond and one well) and a creek as well. In addition, water samples from two sites in the Chesapeake Bay on the ESV were collected monthly. Poultry litter was sampled monthly from three commercial broiler farms. Soil samples were collected monthly after fertilization with poultry litter from 10 farms in 2014 and another 14 farms in 2015. A most probable number method was used to detect Salmonella enterica presence and concentration in collected samples. Presumptive Salmonella colonies were confirmed by the cross-streaking method. Molecular serotyping was carried out to determine the Salmonella serovars. The average prevalence of Salmonella in pond, well, creek, and bay water samples was 19.3, 3.3, 24.2, and 29.2%, respectively. There were significant spatial and temporal differences for Salmonella incidence in various water sources. The prevalence of S. enterica in four tested ponds from farms A, B, C, and D were 16, 12, 22, and 27%, respectively. While the prevalence of S. enterica in irrigation wells was significantly lower, some well water samples tested positive during the study. Salmonella Newport was found to be the predominant serovar isolated from water samples. All poultry houses of the three tested broiler farms were Salmonella-positive at certain sampling points during the study with prevalence ranging from 14.3 to 35.4%. Salmonella was found to be able to survive up to 4 months in poultry litter amended soils from the tested farms in 2014, and up to 6 months in 2015. This research examined the dynamics of S. enterica in relationship to water source, poultry litter, and amended soil in a major agricultural area, and provides useful information for food safety risk assessments.
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Affiliation(s)
- Ganyu Gu
- Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Blacksburg, VA, United States
| | - Laura K Strawn
- Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Blacksburg, VA, United States
| | - Jie Zheng
- Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Elizabeth A Reed
- Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Steven L Rideout
- Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Blacksburg, VA, United States
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Islam MA, Biswas P, Sabuj AAM, Haque ZF, Saha CK, Alam MM, Rahman MT, Saha S. Microbial load in bio-slurry from different biogas plants in Bangladesh. J Adv Vet Anim Res 2019; 6:376-383. [PMID: 31583235 PMCID: PMC6760512 DOI: 10.5455/javar.2019.f357] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 07/12/2019] [Accepted: 07/17/2019] [Indexed: 11/30/2022] Open
Abstract
Objective: The study was aimed to isolate, identify, and characterize common indicator bacteria, including Escherichia coli, Salmonella spp., and Staphylococcus spp. in manure and bio-slurry samples of different livestock farms and biogas plants of Bangladesh. Materials and Methods: A total of 114 samples of manure and bio-slurry were collected from different livestock farms and biogas plants in Bangladesh. The total viable count (TVC), E. coli, Salmonella spp., and Staphylococcus spp. counts were determined by the spread plate technique method. Isolation and identification were performed by colony characteristics, staining, biochemical tests, and, finally, by using PCR. Antibiotic susceptibility test of the isolated bacteria was tested against commonly used antibiotics by using the disk diffusion method. Results: The mean TVC, E. coli, Salmonella spp., and Staphylococcus spp. counts were ranged from 8.19–10.75, 5.2–6.96, 5.81–6.87, 5.68–7.68 in manure samples and 7.26–8.65, 3.82–5.2, 4–5.54, 3.14–5.9 log cfu/gm in bio-slurry, respectively. In anaerobic digester after 30 days digestion, the presence of E. coli, Salmonella spp., and Staphylococcus spp. varied from 0–5.11, 0–4.84, and 0–5.59 log cfu/gm at 25°C, 27°C, 29°C, and 45°C temperature. Above-mentioned bacteria were absent in bio-slurry collected from anaerobic digester after 60 days digestion at environmental temperature. Bacterial counts were reduced significantly in both household slurry pits and experimental anaerobic digester. Antibiotic susceptibility results revealed that multidrug-resistant indicator bacteria were present in the bio-slurry samples. Conclusion: Our findings conclude that the microbial load after treatment of animal manure via anaerobic digestion (Biogas plant) was grossly reduced and the reduction of bacterial pathogen depends on the duration and temperature of digestion.
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Affiliation(s)
- Md Ashraful Islam
- Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
| | - Proteek Biswas
- Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
| | - Abdullah Al Momen Sabuj
- Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
| | - Zobayda Farzana Haque
- Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
| | - Chayan Kumer Saha
- Department of Farm Power and Machinery, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
| | - Md Monjurul Alam
- Department of Farm Power and Machinery, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
| | - Md Tanvir Rahman
- Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
| | - Sukumar Saha
- Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
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10
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Jeamsripong S, Chase JA, Jay-Russell MT, Buchanan RL, Atwill ER. Experimental In-Field Transfer and Survival of Escherichia coli from Animal Feces to Romaine Lettuce in Salinas Valley, California. Microorganisms 2019; 7:microorganisms7100408. [PMID: 31569566 PMCID: PMC6843402 DOI: 10.3390/microorganisms7100408] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/23/2019] [Accepted: 09/26/2019] [Indexed: 11/20/2022] Open
Abstract
This randomized controlled trial characterized the transfer of E. coli from animal feces and/or furrow water onto adjacent heads of lettuce during foliar irrigation, and the subsequent survival of bacteria on the adaxial surface of lettuce leaves. Two experiments were conducted in Salinas Valley, California: (1) to quantify the transfer of indicator E. coli from chicken and rabbit fecal deposits placed in furrows to surrounding lettuce heads on raised beds, and (2) to quantify the survival of inoculated E. coli on Romaine lettuce over 10 days. E. coli was recovered from 97% (174/180) of lettuce heads to a maximal distance of 162.56 cm (5.33 ft) from feces. Distance from sprinklers to feces, cumulative foliar irrigation, and lettuce being located downwind of the fecal deposit were positively associated, while distance from fecal deposit to lettuce was negatively associated with E. coli transference. E. coli exhibited decimal reduction times of 2.2 and 2.5 days when applied on the adaxial surface of leaves within a chicken or rabbit fecal slurry, respectively. Foliar irrigation can transfer E. coli from feces located in a furrow onto adjacent heads of lettuce, likely due to the kinetic energy of irrigation droplets impacting the fecal surface and/or impacting furrow water contaminated with feces, with the magnitude of E. coli enumerated per head of lettuce influenced by the distance between lettuce and the fecal deposit, cumulative application of foliar irrigation, wind aspect of lettuce relative to feces, and time since final irrigation. Extending the time period between foliar irrigation and harvest, along with a 152.4 cm (5 ft) no-harvest buffer zone when animal fecal material is present, may substantially reduce the level of bacterial contamination on harvested lettuce.
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Affiliation(s)
- Saharuetai Jeamsripong
- Western Center for Food Safety, University of California, Davis, CA 95618, USA (M.T.J.-R.)
- Research Unit in Microbial Food Safety and Antimicrobial Resistance, Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Jennifer A. Chase
- Western Center for Food Safety, University of California, Davis, CA 95618, USA (M.T.J.-R.)
| | - Michele T. Jay-Russell
- Western Center for Food Safety, University of California, Davis, CA 95618, USA (M.T.J.-R.)
| | - Robert L. Buchanan
- Center of Food Safety and Security Systems, College of Agricultural and Natural Resources, University of Maryland, MD 20742, USA;
| | - Edward R. Atwill
- Research Unit in Microbial Food Safety and Antimicrobial Resistance, Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
- Correspondence:
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11
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van Bruggen AHC, Goss EM, Havelaar A, van Diepeningen AD, Finckh MR, Morris JG. One Health - Cycling of diverse microbial communities as a connecting force for soil, plant, animal, human and ecosystem health. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 664:927-937. [PMID: 30769316 DOI: 10.1016/j.scitotenv.2019.02.091] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/05/2019] [Accepted: 02/05/2019] [Indexed: 05/06/2023]
Abstract
The One Health concept proposes that there is a connection between human, animal and environmental health. Plants and their health are not explicitly included. In this review, we broaden the One Health concept to include soil, plant, animal and ecosystem health. We argue that the health conditions of all organisms in an ecosystem are interconnected through the cycling of subsets of microbial communities from the environment (in particular the soil) to plants, animals and humans, and back into the environment. After an introduction on health concepts, we present examples of community stability and resilience, diversity and interconnectedness as affected by pollutants, and integrity of nutrient cycles and energy flows. Next, we explain our concept of microbial cycling in relation to ecosystem health, and end with examples of plant and animal disease outbreaks in relation to microbial community composition and diversity. We conclude that we need a better understanding of the role of interconnected microbiomes in promoting plant and animal health and possible ways to stimulate a healthy, diverse microbiome throughout human-dominated ecosystems. We suggest that it is essential to maintain ecosystem and soil health through diversification of plant communities and oligotrophication of managed ecosystems.
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Affiliation(s)
- Ariena H C van Bruggen
- Department of Plant Pathology, University of Florida, Gainesville FL32611, USA; Emerging Pathogens Institute, University of Florida, Gainesville FL32611, USA.
| | - Erica M Goss
- Department of Plant Pathology, University of Florida, Gainesville FL32611, USA; Emerging Pathogens Institute, University of Florida, Gainesville FL32611, USA
| | - Arie Havelaar
- Emerging Pathogens Institute, University of Florida, Gainesville FL32611, USA; Department of Animal Science, University of Florida, Gainesville FL32611, USA
| | - Anne D van Diepeningen
- Business Unit Biointeractions and Plant Health, Wageningen UR, 6708 PB Wageningen, the Netherlands
| | - Maria R Finckh
- Faculty of Organic Agricultural Sciences, Ecological Plant Protection, University of Kassel, 37213 Witzenhausen, Germany
| | - J Glenn Morris
- Emerging Pathogens Institute, University of Florida, Gainesville FL32611, USA; Department of Medicine, School of Medicine, University of Florida, Gainesville FL32611, USA
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12
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Chase JA, Partyka ML, Bond RF, Atwill ER. Environmental inactivation and irrigation-mediated regrowth of Escherichia coli O157:H7 on romaine lettuce when inoculated in a fecal slurry matrix. PeerJ 2019; 7:e6591. [PMID: 30867998 PMCID: PMC6410689 DOI: 10.7717/peerj.6591] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/09/2019] [Indexed: 11/20/2022] Open
Abstract
Field trials were conducted in July-August and October 2012 to quantify the inactivation rate of Escherichia coli O157:H7 when mixed with fecal slurry and applied to romaine lettuce leaves. Lettuce was grown under commercial conditions in Salinas Valley, California. One-half milliliter of rabbit, chicken, or pig fecal slurry, containing an average of 4.05 × 107 CFU E. coli O157:H7 (C0), was inoculated onto the upper (adaxial) surface of a lower leaf on 288 heads of lettuce per trial immediately following a 2.5 h irrigation event. To estimate the bacterial inactivation rate as a function of time, fecal matrix, irrigation and seasonal climate effects, sets of lettuce heads (n = 28) were sampled each day over 10 days and the concentration of E. coli O157:H7 (Ct) determined. E. coli O157:H7 was detected on 100% of heads during the 10-day duration, with concentrations ranging from ≤340 MPN/head (∼5-log reduction) to >3.45 × 1012 MPN/head (∼5-log growth). Relative to C0, on day 10 (Ct = 12) we observed an overall 2.6-log and 3.2-log mean reduction of E. coli O157:H7 in July and October, respectively. However, we observed relative maximum concentrations due to bacterial growth on day 6 (maximum Ct = 8) apparently stimulated by foliar irrigation on day 5. From this maximum there was a mean 5.3-log and 5.1-log reduction by day 10 (Ct = 12) for the July and October trials, respectively. This study provides insight into the inactivation and growth kinetics of E. coli O157:H7 on romaine lettuce leaves under natural field conditions. This study provides evidence that harvesting within 24 h post irrigation has the potential to increase the concentration of E. coli O157:H7 contamination, if present on heads of romaine lettuce; foliar irrigation can temporarily stimulate substantial regrowth of E. coli O157:H7.
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Affiliation(s)
- Jennifer A. Chase
- Western Center for Food Safety, University of California, Davis, Davis, CA, USA
| | - Melissa L. Partyka
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, USA
| | - Ronald F. Bond
- Western Center for Food Safety, University of California, Davis, Davis, CA, USA
| | - Edward R. Atwill
- Western Center for Food Safety, University of California, Davis, Davis, CA, USA
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13
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Gu G, Strawn LK, Oryang DO, Zheng J, Reed EA, Ottesen AR, Bell RL, Chen Y, Duret S, Ingram DT, Reiter MS, Pfuntner R, Brown EW, Rideout SL. Agricultural Practices Influence Salmonella Contamination and Survival in Pre-harvest Tomato Production. Front Microbiol 2018; 9:2451. [PMID: 30386314 PMCID: PMC6198144 DOI: 10.3389/fmicb.2018.02451] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 09/25/2018] [Indexed: 11/13/2022] Open
Abstract
Between 2000 and 2010 the Eastern Shore of Virginia was implicated in four Salmonella outbreaks associated with tomato. Therefore, a multi-year study (2012-2015) was performed to investigate presumptive factors associated with the contamination of Salmonella within tomato fields at Virginia Tech's Eastern Shore Agricultural Research and Extension Center. Factors including irrigation water sources (pond and well), type of soil amendment: fresh poultry litter (PL), PL ash, and a conventional fertilizer (triple superphosphate - TSP), and production practices: staked with plastic mulch (SP), staked without plastic mulch (SW), and non-staked without plastic mulch (NW), were evaluated by split-plot or complete-block design. All field experiments relied on naturally occurring Salmonella contamination, except one follow up experiment (worst-case scenario) which examined the potential for contamination in tomato fruits when Salmonella was applied through drip irrigation. Samples were collected from pond and well water; PL, PL ash, and TSP; and the rhizosphere, leaves, and fruits of tomato plants. Salmonella was quantified using a most probable number method and contamination ratios were calculated for each treatment. Salmonella serovar was determined by molecular serotyping. Salmonella populations varied significantly by year; however, similar trends were evident each year. Findings showed use of untreated pond water and raw PL amendment increased the likelihood of Salmonella detection in tomato plots. Salmonella Newport and Typhimurium were the most frequently detected serovars in pond water and PL amendment samples, respectively. Interestingly, while these factors increased the likelihood of Salmonella detection in tomato plots (rhizosphere and leaves), all tomato fruits sampled (n = 4800) from these plots were Salmonella negative. Contamination of tomato fruits was extremely low (< 1%) even when tomato plots were artificially inoculated with an attenuated Salmonella Newport strain (104 CFU/mL). Furthermore, Salmonella was not detected in tomato plots irrigated using well water and amended with PL ash or TSP. Production practices also influenced the likelihood of Salmonella detection in tomato plots. Salmonella detection was higher in tomato leaf samples for NW plots, compared to SP and SW plots. This study provides evidence that attention to agricultural inputs and production practices may help reduce the likelihood of Salmonella contamination in tomato fields.
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Affiliation(s)
- Ganyu Gu
- Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Painter, VA, United States
| | - Laura K Strawn
- Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Painter, VA, United States
| | - David O Oryang
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Jie Zheng
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Elizabeth A Reed
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Andrea R Ottesen
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Rebecca L Bell
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Yuhuan Chen
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Steven Duret
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - David T Ingram
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Mark S Reiter
- Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Painter, VA, United States
| | - Rachel Pfuntner
- Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Painter, VA, United States
| | - Eric W Brown
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Steven L Rideout
- Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Painter, VA, United States
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14
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Zoellner C, Al-Mamun MA, Grohn Y, Jackson P, Worobo R. Postharvest Supply Chain with Microbial Travelers: a Farm-to-Retail Microbial Simulation and Visualization Framework. Appl Environ Microbiol 2018; 84:e00813-18. [PMID: 29959243 PMCID: PMC6102990 DOI: 10.1128/aem.00813-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/18/2018] [Indexed: 11/20/2022] Open
Abstract
Fresh produce supply chains present variable and diverse conditions that are relevant to food quality and safety because they may favor microbial growth and survival following contamination. This study presents the development of a simulation and visualization framework to model microbial dynamics on fresh produce moving through postharvest supply chain processes. The postharvest supply chain with microbial travelers (PSCMT) tool provides a modular process modeling approach and graphical user interface to visualize microbial populations and evaluate practices specific to any fresh produce supply chain. The resulting modeling tool was validated with empirical data from an observed tomato supply chain from Mexico to the United States, including the packinghouse, distribution center, and supermarket locations, as an illustrative case study. Due to data limitations, a model-fitting exercise was conducted to demonstrate the calibration of model parameter ranges for microbial indicator populations, i.e., mesophilic aerobic microorganisms (quantified by aerobic plate count and here termed APC) and total coliforms (TC). Exploration and analysis of the parameter space refined appropriate parameter ranges and revealed influential parameters for supermarket indicator microorganism levels on tomatoes. Partial rank correlation coefficient analysis determined that APC levels in supermarkets were most influenced by removal due to spray water washing and microbial growth on the tomato surface at postharvest locations, while TC levels were most influenced by growth on the tomato surface at postharvest locations. Overall, this detailed mechanistic dynamic model of microbial behavior is a unique modeling tool that complements empirical data and visualizes how postharvest supply chain practices influence the fate of microbial contamination on fresh produce.IMPORTANCE Preventing the contamination of fresh produce with foodborne pathogens present in the environment during production and postharvest handling is an important food safety goal. Since studying foodborne pathogens in the environment is a complex and costly endeavor, computer simulation models can help to understand and visualize microorganism behavior resulting from supply chain activities. The postharvest supply chain with microbial travelers (PSCMT) model, presented here, provides a unique tool for postharvest supply chain simulations to evaluate microbial contamination. The tool was validated through modeling an observed tomato supply chain. Visualization of dynamic contamination levels from harvest to the supermarket and analysis of the model parameters highlighted critical points where intervention may prevent microbial levels sufficient to cause foodborne illness. The PSCMT model framework and simulation results support ongoing postharvest research and interventions to improve understanding and control of fresh produce contamination.
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Affiliation(s)
- Claire Zoellner
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Mohammad Abdullah Al-Mamun
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Yrjo Grohn
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Peter Jackson
- Department of Operations Research and Information Engineering, Cornell University, Ithaca, New York, USA
| | - Randy Worobo
- Department of Food Science, Cornell University, Ithaca, New York, USA
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15
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Chapman B, Pintar K, Smith BA. Multi-Exposure Pathway Model to Compare Escherichia coli O157 Risks and Interventions. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2018; 38:392-409. [PMID: 28471504 DOI: 10.1111/risa.12826] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 03/09/2017] [Accepted: 03/14/2017] [Indexed: 06/07/2023]
Abstract
The relative contributions of exposure pathways associated with cattle-manure-borne Escherichia coli O157:H7 on public health have yet to be fully characterized. A stochastic, quantitative microbial risk assessment (QMRA) model was developed to describe a hypothetical cattle farm in order to compare the relative importance of five routes of exposure, including aquatic recreation downstream of the farm, consumption of contaminated ground beef processed with limited interventions, consumption of leafy greens, direct animal contact, and the recreational use of a cattle pasture. To accommodate diverse environmental and hydrological pathways, existing QMRAs were integrated with novel and simplistic climate and field-level submodels. The model indicated that direct animal contact presents the greatest risk of illness per exposure event during the high pathogen shedding period. However, when accounting for the frequency of exposure, using a high-risk exposure-receptor profile, consumption of ground beef was associated with the greatest risk of illness. Additionally, the model was used to evaluate the efficacy of hypothetical interventions affecting one or more exposure routes; concurrent evaluation of multiple routes allowed for the assessment of the combined effect of preharvest interventions across exposure pathways-which may have been previously underestimated-as well as the assessment of the effect of additional downstream interventions. This analysis represents a step towards a full evaluation of the risks associated with multiple exposure pathways; future incorporation of variability associated with environmental parameters and human behaviors would allow for a comprehensive assessment of the relative contribution of exposure pathways at the population level.
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Affiliation(s)
- B Chapman
- Public Health Agency of Canada, Guelph, ON, Canada
- University of Guelph, Guelph, ON, Canada
| | - K Pintar
- Public Health Agency of Canada, Guelph, ON, Canada
| | - B A Smith
- Public Health Agency of Canada, Guelph, ON, Canada
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16
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Cox CE, Brandl MT, de Moraes MH, Gunasekera S, Teplitski M. Production of the Plant Hormone Auxin by Salmonella and Its Role in the Interactions with Plants and Animals. Front Microbiol 2018; 8:2668. [PMID: 29375530 PMCID: PMC5770404 DOI: 10.3389/fmicb.2017.02668] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/21/2017] [Indexed: 11/30/2022] Open
Abstract
The ability of human enteric pathogens to colonize plants and use them as alternate hosts is now well established. Salmonella, similarly to phytobacteria, appears to be capable of producing the plant hormone auxin via an indole-3-pyruvate decarboxylase (IpdC), a key enzyme of the IPyA pathway. A deletion of the Salmonella ipdC significantly reduced auxin synthesis in laboratory culture. The Salmonella ipdC gene was expressed on root surfaces of Medicago truncatula. M. truncatula auxin-responsive GH3::GUS reporter was activated by the wild type Salmonella, and not but the ipdC mutant, implying that the bacterially produced IAA (Indole Acetic Acid) was detected by the seedlings. Seedling infections with the wild type Salmonella caused an increase in secondary root formation, which was not observed in the ipdC mutant. The wild type Salmonella cells were detected as aggregates at the sites of lateral root emergence, whereas the ipdC mutant cells were evenly distributed in the rhizosphere. However, both strains appeared to colonize seedlings well in growth pouch experiments. The ipdC mutant was also less virulent in a murine model of infection. When mice were infected by oral gavage, the ipdC mutant was as proficient as the wild type strain in colonization of the intestine, but it was defective in the ability to cross the intestinal barrier. Fewer cells of the ipdC mutant, compared with the wild type strain, were detected in Peyer's patches, spleen and in the liver. Orthologs of ipdC are found in all Salmonella genomes and are distributed among many animal pathogens and plant-associated bacteria of the Enterobacteriaceae, suggesting a broad ecological role of the IpdC-catalyzed pathway.
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Affiliation(s)
- Clayton E Cox
- Department of Soil and Water Science, University of Florida, Gainesville, FL, United States
| | - Maria T Brandl
- Produce Safety and Microbiology Research Unit, United States Department of Agriculture, Agricultural Research Service, Albany, CA, United States
| | - Marcos H de Moraes
- Department of Soil and Water Science, University of Florida, Gainesville, FL, United States
| | | | - Max Teplitski
- Department of Soil and Water Science, University of Florida, Gainesville, FL, United States.,Smithsonian Marine Station, Ft. Pierce, FL, United States
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17
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Weller DL, Kovac J, Roof S, Kent DJ, Tokman JI, Kowalcyk B, Oryang D, Ivanek R, Aceituno A, Sroka C, Wiedmann M. Survival of Escherichia coli on Lettuce under Field Conditions Encountered in the Northeastern United States. J Food Prot 2017; 80:1214-1221. [PMID: 28632416 DOI: 10.4315/0362-028x.jfp-16-419] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although wildlife intrusion and untreated manure have been associated with microbial contamination of produce, relatively few studies have examined the survival of Escherichia coli on produce under field conditions following contamination (e.g., via splash from wildlife feces). This experimental study was performed to estimate the die-off rate of E. coli on preharvest lettuce following contamination with a fecal slurry. During August 2015, field-grown lettuce was inoculated via pipette with a fecal slurry that was spiked with a three-strain cocktail of rifampin-resistant nonpathogenic E. coli. Ten lettuce heads were harvested at each of 13 time points following inoculation (0, 2.5, 5, and 24 h after inoculation and every 24 h thereafter until day 10). The most probable number (MPN) of E. coli on each lettuce head was determined, and die-off rates were estimated. The relationship between sample time and the log MPN of E. coli per head was modeled using a segmented linear model. This model had a breakpoint at 106 h (95% confidence interval = 69, 142 h) after inoculation, with a daily decrease of 0.70 and 0.19 log MPN for 0 to 106 h and 106 to 240 h following inoculation, respectively. These findings are consistent with die-off rates obtained in similar studies that assessed E. coli survival on produce following irrigation. Overall, these findings provide die-off rates for E. coli on lettuce that can be used in future quantitative risk assessments.
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Affiliation(s)
- Daniel L Weller
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - Jasna Kovac
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - Sherry Roof
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - David J Kent
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - Jeffrey I Tokman
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - Barbara Kowalcyk
- 2 RTI International, Research Triangle Park, North Carolina 27709
| | - David Oryang
- 3 U.S. Food and Drug Administration, College Park, Maryland 20740
| | - Renata Ivanek
- 4 Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York 14853
| | - Anna Aceituno
- 2 RTI International, Research Triangle Park, North Carolina 27709
| | - Christopher Sroka
- 5 Department of Economics, Applied Statistics, and International Business, New Mexico State University, Las Cruces, New Mexico 88003, USA
| | - Martin Wiedmann
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
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18
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Allende A, Castro-Ibáñez I, Lindqvist R, Gil MI, Uyttendaele M, Jacxsens L. Quantitative contamination assessment of Escherichia coli in baby spinach primary production in Spain: Effects of weather conditions and agricultural practices. Int J Food Microbiol 2017; 257:238-246. [PMID: 28697385 DOI: 10.1016/j.ijfoodmicro.2017.06.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 04/22/2017] [Accepted: 06/26/2017] [Indexed: 11/16/2022]
Abstract
A quantitative microbial contamination model of Escherichia coli during primary production of baby spinach was developed. The model included only systematic contamination routes (e.g. soil and irrigation water) and it was used to evaluate the potential impact of weather conditions, agricultural practices as well as bacterial fitness in soil on the E. coli levels present in the crop at harvest. The model can be used to estimate E. coli contamination of baby spinach via irrigation water, via soil splashing due to irrigation water or rain events, and also including the inactivation of E. coli on plants due to solar radiation during a variable time of culturing before harvest. Seasonality, solar radiation and rainfall were predicted to have an important impact on the E. coli contamination. Winter conditions increased E. coli prevalence and levels when compared to spring conditions. As regards agricultural practices, both water quality and irrigation system slightly influenced E. coli levels on baby spinach. The good microbiological quality of the irrigation water (average E. coli counts in positive water samples below 1 log/100mL) could have influenced the differences observed among the tested agricultural practices (water treatment and irrigation system). This quantitative microbial contamination model represents a preliminary framework that assesses the potential impact of different factors and intervention strategies affecting E. coli concentrations at field level. Taking into account that E. coli strains may serve as a surrogate organism for enteric bacterial pathogens, obtained results on E. coli levels on baby spinach may be indicative of the potential behaviour of these pathogens under defined conditions.
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Affiliation(s)
- Ana Allende
- Quality, Safety and Bioactivity of Plant Foods, Food Science and Technology, CEBAS-CSIC, PO Box 164, Espinardo, Murcia E-30100, Spain.
| | - Irene Castro-Ibáñez
- Quality, Safety and Bioactivity of Plant Foods, Food Science and Technology, CEBAS-CSIC, PO Box 164, Espinardo, Murcia E-30100, Spain
| | - Roland Lindqvist
- Division of Risk and Benefit Assessment, National Food Agency, SE-75126 Uppsala, Sweden
| | - María Isabel Gil
- Quality, Safety and Bioactivity of Plant Foods, Food Science and Technology, CEBAS-CSIC, PO Box 164, Espinardo, Murcia E-30100, Spain
| | - Mieke Uyttendaele
- Department of Food Safety and Food Quality, Laboratory of Food Preservation and Food Microbiology, Faculty of Bioscience Engineering, Ghent University, Coupure Links, 653, 9000 Ghent, Belgium
| | - Liesbeth Jacxsens
- Department of Food Safety and Food Quality, Laboratory of Food Preservation and Food Microbiology, Faculty of Bioscience Engineering, Ghent University, Coupure Links, 653, 9000 Ghent, Belgium
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19
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Nguyen-The C, Bardin M, Berard A, Berge O, Brillard J, Broussolle V, Carlin F, Renault P, Tchamitchian M, Morris CE. Agrifood systems and the microbial safety of fresh produce: Trade-offs in the wake of increased sustainability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 562:751-759. [PMID: 27110986 DOI: 10.1016/j.scitotenv.2016.03.241] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 06/05/2023]
Abstract
Fresh produce has been a growing cause of food borne outbreaks world-wide prompting the need for safer production practices. Yet fresh produce agrifood systems are diverse and under constraints for more sustainability. We analyze how measures taken to guarantee safety interact with other objectives for sustainability, in light of the diversity of fresh produce agrifood systems. The review is based on the publications at the interface between fresh produce safety and sustainability, with sustainability defined by low environmental impacts, food and nutrition security and healthy life. The paths for more sustainable fresh produce are diverse. They include an increased use of ecosystem services to e.g. favor predators of pests, or to reduce impact of floods, to reduce soil erosion, or to purify run-off waters. In contrast, they also include production systems isolated from the environment. From a socio-economical view, sustainability may imply maintaining small tenures with a higher risk of pathogen contamination. We analyzed the consequences for produce safety by focusing on risks of contamination by water, soil, environment and live stocks. Climate change may increase the constraints and recent knowledge on interactions between produce and human pathogens may bring new solutions. Existing technologies may suffice to resolve some conflicts between ensuring safety of fresh produce and moving towards more sustainability. However, socio-economic constraints of some agri-food systems may prevent their implementation. In addition, current strategies to preserve produce safety are not adapted to systems relying on ecological principles and knowledge is lacking to develop the new risk management approaches that would be needed.
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Affiliation(s)
- Christophe Nguyen-The
- UMR408 SQPOV «Sécurité et Qualité des Produits d'Origine Végétale», INRA, Avignon Université, 84000 Avignon, France.
| | - Marc Bardin
- INRA, UR0407 Plant Pathology, F-84143 Montfavet, France.
| | | | - Odile Berge
- INRA, UR0407 Plant Pathology, F-84143 Montfavet, France.
| | - Julien Brillard
- UMR408 SQPOV «Sécurité et Qualité des Produits d'Origine Végétale», INRA, Avignon Université, 84000 Avignon, France.
| | - Véronique Broussolle
- UMR408 SQPOV «Sécurité et Qualité des Produits d'Origine Végétale», INRA, Avignon Université, 84000 Avignon, France.
| | - Frédéric Carlin
- UMR408 SQPOV «Sécurité et Qualité des Produits d'Origine Végétale», INRA, Avignon Université, 84000 Avignon, France.
| | | | | | - Cindy E Morris
- INRA, UR0407 Plant Pathology, F-84143 Montfavet, France.
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20
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Xu A, Buchanan RL, Micallef SA. Impact of mulches and growing season on indicator bacteria survival during lettuce cultivation. Int J Food Microbiol 2016; 224:28-39. [PMID: 26938806 DOI: 10.1016/j.ijfoodmicro.2016.02.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 11/11/2015] [Accepted: 02/19/2016] [Indexed: 11/22/2022]
Abstract
In fresh produce production, the use of mulches as ground cover to retain moisture and control weeds is a common agricultural practice, but the influence that various mulches have on enteric pathogen survival and dispersal is unknown. The goal of this study was to assess the impact of different mulching methods on the survival of soil and epiphytic fecal indicator bacteria on organically grown lettuce during different growing seasons. Organically managed lettuce, cultivated with various ground covers--polyethylene plastic, corn-based biodegradable plastic, paper and straw mulch--and bare ground as a no-mulch control, was overhead inoculated with manure-contaminated water containing known levels of generic Escherichia coli and Enterococcus spp. Leaves and soil samples were collected at intervals over a two week period on days 0, 1, 3, 5, 7, 10 and 14, and quantitatively assessed for E. coli, fecal coliforms and Enterococcus spp. Data were analyzed using mixed models with repeated measures and an exponential decline with asymptote survival model. Indicator bacterial concentrations in the lettuce phyllosphere decreased over time under all treatments, with more rapid E. coli declines in the fall than in the spring (p<0.01). Persistence of E. coli in spring was correlated with higher maximum and minimum temperatures in this season, and more regular rainfall. The survival model gave very good fits for the progression of E. coli concentrations in the phyllosphere over time (R(2)=0.88 ± 0.12). In the spring season, decline rates of E. coli counts were faster (2013 p=0.18; 2014 p<0.005) for the bare ground-cultivated lettuce compared to mulches. In fall 2014, the E. coli decline rate on paper mulch-grown lettuce was higher (p<0.005). Bacteria fluctuated more, and persisted longer, in soil compared to lettuce phyllosphere, and mulch type was a factor for fecal coliform levels (p<0.05), with higher counts retrieved under plastic mulches in all trials, and higher enterococci levels under straw in fall 2014 (p<0.05). This study demonstrates that mulches used in lettuce production may impact the fate of enteric bacteria in soil or on lettuce, most likely in relation to soil moisture retention, and other weather-related factors, such as temperature and rainfall. The data suggest that the time between exposure to a source of enteric bacteria and harvesting of the crop is season dependent, which has implications for determining best harvest times.
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Affiliation(s)
- Aixia Xu
- Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA
| | - Robert L Buchanan
- Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA; Center for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, USA
| | - Shirley A Micallef
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA; Center for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, USA.
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van Hoek AH, Veenman C, van Overbeek WM, Lynch G, de Roda Husman AM, Blaak H. Prevalence and characterization of ESBL- and AmpC-producing Enterobacteriaceae on retail vegetables. Int J Food Microbiol 2015; 204:1-8. [DOI: 10.1016/j.ijfoodmicro.2015.03.014] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 02/18/2015] [Accepted: 03/13/2015] [Indexed: 12/31/2022]
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Atwill ER, Chase JA, Oryang D, Bond RF, Koike ST, Cahn MD, Anderson M, Mokhtari A, Dennis S. Transfer of Escherichia coli O157:H7 from simulated wildlife scat onto romaine lettuce during foliar irrigation. J Food Prot 2015; 78:240-7. [PMID: 25710137 DOI: 10.4315/0362-028x.jfp-14-277] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A field trial in Salinas Valley, California, was conducted during July 2011 to quantify the microbial load that transfers from wildlife feces onto nearby lettuce during foliar irrigation. Romaine lettuce was grown using standard commercial practices and irrigated using an impact sprinkler design. Five grams of rabbit feces was spiked with 1.29 × 10(8) CFU of Escherichia coli O157:H7 and placed - 3, - 2, and - 1 days and immediately before a 2-h irrigation event. Immediately after irrigation, 168 heads of lettuce ranging from ca. 23 to 69 cm (from 9 to 27 in.) from the fecal deposits were collected, and the concentration of E. coli O157:H7 was determined. Thirty-eight percent of the collected lettuce heads had detectable E. coli O157:H7, ranging from 1 MPN to 2.30 × 10(5) MPN per head and a mean concentration of 7.37 × 10(3) MPN per head. Based on this weighted arithmetic mean concentration of 7.37 × 10(3) MPN of bacteria per positive head, only 0.00573% of the original 5 g of scat with its mean load of 1.29 × 10(8) CFU was transferred to the positive heads of lettuce. Bacterial contamination was limited to the outer leaves of lettuce. In addition, factors associated with the transfer of E. coli O157:H7 from scat to lettuce were distance between the scat and lettuce, age of scat before irrigation, and mean distance between scat and the irrigation sprinkler heads. This study quantified the transfer coefficient between scat and adjacent heads of lettuce as a function of irrigation. The data can be used to populate a quantitative produce risk assessment model for E. coli O157:H7 in romaine lettuce to inform risk management and food safety policies.
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Affiliation(s)
- Edward R Atwill
- Western Center for Food Safety, University of California at Davis, 1477 Drew Avenue, Suite 101, Davis, California 95618, USA.
| | - Jennifer A Chase
- Western Center for Food Safety, University of California at Davis, 1477 Drew Avenue, Suite 101, Davis, California 95618, USA
| | - David Oryang
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, USA
| | - Ronald F Bond
- Western Center for Food Safety, University of California at Davis, 1477 Drew Avenue, Suite 101, Davis, California 95618, USA
| | - Steven T Koike
- University of California Cooperative Extension Monterey County, 1432 Abbott Street, Salinas, California 93901, USA
| | - Michael D Cahn
- University of California Cooperative Extension Monterey County, 1432 Abbott Street, Salinas, California 93901, USA
| | - Maren Anderson
- RTI International, 3040 East Cornwallis Road, Research Triangle Park, North Carolina 27709, USA
| | - Amirhossein Mokhtari
- RTI International, 3040 East Cornwallis Road, Research Triangle Park, North Carolina 27709, USA
| | - Sherri Dennis
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, USA
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24
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Gil MI, Selma MV, Suslow T, Jacxsens L, Uyttendaele M, Allende A. Pre- and Postharvest Preventive Measures and Intervention Strategies to Control Microbial Food Safety Hazards of Fresh Leafy Vegetables. Crit Rev Food Sci Nutr 2014; 55:453-68. [DOI: 10.1080/10408398.2012.657808] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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25
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Park S, Navratil S, Gregory A, Bauer A, Srinath I, Szonyi B, Nightingale K, Anciso J, Jun M, Han D, Lawhon S, Ivanek R. Farm management, environment, and weather factors jointly affect the probability of spinach contamination by generic Escherichia coli at the preharvest stage. Appl Environ Microbiol 2014; 80:2504-15. [PMID: 24509926 PMCID: PMC3993187 DOI: 10.1128/aem.03643-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 02/05/2014] [Indexed: 11/20/2022] Open
Abstract
The National Resources Information (NRI) databases provide underutilized information on the local farm conditions that may predict microbial contamination of leafy greens at preharvest. Our objective was to identify NRI weather and landscape factors affecting spinach contamination with generic Escherichia coli individually and jointly with farm management and environmental factors. For each of the 955 georeferenced spinach samples (including 63 positive samples) collected between 2010 and 2012 on 12 farms in Colorado and Texas, we extracted variables describing the local weather (ambient temperature, precipitation, and wind speed) and landscape (soil characteristics and proximity to roads and water bodies) from NRI databases. Variables describing farm management and environment were obtained from a survey of the enrolled farms. The variables were evaluated using a mixed-effect logistic regression model with random effects for farm and date. The model identified precipitation as a single NRI predictor of spinach contamination with generic E. coli, indicating that the contamination probability increases with an increasing mean amount of rain (mm) in the past 29 days (odds ratio [OR] = 3.5). The model also identified the farm's hygiene practices as a protective factor (OR = 0.06) and manure application (OR = 52.2) and state (OR = 108.1) as risk factors. In cross-validation, the model showed a solid predictive performance, with an area under the receiver operating characteristic (ROC) curve of 81%. Overall, the findings highlighted the utility of NRI precipitation data in predicting contamination and demonstrated that farm management, environment, and weather factors should be considered jointly in development of good agricultural practices and measures to reduce produce contamination.
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Affiliation(s)
- Sangshin Park
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Sarah Navratil
- Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, USA
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Ashley Gregory
- Department of Horticultural Sciences, Texas A&M AgriLife Extension Service, Weslaco, Texas, USA
| | - Arin Bauer
- Department of Horticultural Sciences, Texas A&M AgriLife Extension Service, Weslaco, Texas, USA
| | - Indumathi Srinath
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
- Tarleton State University, Stephenville, Texas, USA
| | - Barbara Szonyi
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Kendra Nightingale
- Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, USA
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Juan Anciso
- Department of Horticultural Sciences, Texas A&M AgriLife Extension Service, Weslaco, Texas, USA
| | - Mikyoung Jun
- Department of Statistics, Texas A&M University, College Station, Texas, USA
| | - Daikwon Han
- Department of Epidemiology and Biostatistics, Texas A&M University, College Station, Texas, USA
| | - Sara Lawhon
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Renata Ivanek
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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Strawn LK, Gröhn YT, Warchocki S, Worobo RW, Bihn EA, Wiedmann M. Risk factors associated with Salmonella and Listeria monocytogenes contamination of produce fields. Appl Environ Microbiol 2013; 79:7618-27. [PMID: 24077713 PMCID: PMC3837806 DOI: 10.1128/aem.02831-13] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 09/24/2013] [Indexed: 11/20/2022] Open
Abstract
Identification of management practices associated with preharvest pathogen contamination of produce fields is crucial to the development of effective Good Agricultural Practices (GAPs). A cross-sectional study was conducted to (i) determine management practices associated with a Salmonella- or Listeria monocytogenes-positive field and (ii) quantify the frequency of these pathogens in irrigation and nonirrigation water sources. Over 5 weeks, 21 produce farms in New York State were visited. Field-level management practices were recorded for 263 fields, and 600 environmental samples (soil, drag swab, and water) were collected and analyzed for Salmonella and L. monocytogenes. Management practices were evaluated for their association with the presence of a pathogen-positive field. Salmonella and L. monocytogenes were detected in 6.1% and 17.5% of fields (n = 263) and 11% and 30% of water samples (n = 74), respectively. The majority of pathogen-positive water samples were from nonirrigation surface water sources. Multivariate analysis showed that manure application within a year increased the odds of a Salmonella-positive field (odds ratio [OR], 16.7), while the presence of a buffer zone had a protective effect (OR, 0.1). Irrigation (within 3 days of sample collection) (OR, 6.0), reported wildlife observation (within 3 days of sample collection) (OR, 6.1), and soil cultivation (within 7 days of sample collection) (OR, 2.9) all increased the likelihood of an L. monocytogenes-positive field. Our findings provide new data that will assist growers with science-based evaluation of their current GAPs and implementation of preventive controls that reduce the risk of preharvest contamination.
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Affiliation(s)
- Laura K. Strawn
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Yrjo T. Gröhn
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, USA
| | - Steven Warchocki
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Randy W. Worobo
- Department of Food Science, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, USA
| | - Elizabeth A. Bihn
- Department of Food Science, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, New York, USA
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Hou Z, Fink RC, Radtke C, Sadowsky MJ, Diez-Gonzalez F. Incidence of naturally internalized bacteria in lettuce leaves. Int J Food Microbiol 2013; 162:260-5. [PMID: 23454817 DOI: 10.1016/j.ijfoodmicro.2013.01.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 01/23/2013] [Accepted: 01/28/2013] [Indexed: 10/27/2022]
Abstract
Lettuce is the fresh leafy vegetable most frequently involved in foodborne disease outbreaks. Human bacterial pathogens may be experimentally internalized into lettuce plants, but the occurrence of natural microflora inside lettuce leaves has not been elucidated. To characterize the endophytic microorganism residing in commercial lettuce leaves, two separate studies were conducted. First, a total of 30 and 25 heads of romaine and red leaf lettuce, respectively, served as the source of individual leaves which were surface sterilized, stomached, enriched in BHI broth for 24h and plated onto BHI agar for non-selective isolation of internalized microorganism. In a separate survey, 80 heads of each of the two types of lettuce were similarly processed, except that GN broth and MacConkey agar (MCA) were used for isolation of Gram negative bacteria. Thirty-eight out of 100 leaves were positive for internalized microorganisms, and Bacillus, Pseudomonas and Pantoea were the genera most frequently found in both types of lettuce. Members of the genus Erwinia were isolated from romaine lettuce only. In the second study, 21 and 60% of romaine and red leaf lettuce heads, respectively, had internalized bacteria capable of growing on MCA. Among the Gram negative strains, Pseudomonas and Pantoea genera were most frequently isolated. Enterobacter isolates were obtained from three red leaf samples. In summary, spore-forming bacteria and traditional epiphytic bacterial genera were frequently detected in surface-sterilized commercial lettuce leaves. Despite the common occurrence of internalized bacteria, only Enterobacter was related to Escherichia coli O157:H7 and Salmonella.
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Affiliation(s)
- Zhe Hou
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, USA
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28
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Liu C, Hofstra N, Franz E. Impacts of climate change on the microbial safety of pre-harvest leafy green vegetables as indicated by Escherichia coli O157 and Salmonella spp. Int J Food Microbiol 2013; 163:119-28. [PMID: 23558195 DOI: 10.1016/j.ijfoodmicro.2013.02.026] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 02/21/2013] [Accepted: 02/26/2013] [Indexed: 12/01/2022]
Abstract
The likelihood of leafy green vegetable (LGV) contamination and the associated pathogen growth and survival are strongly related to climatic conditions. Particularly temperature increase and precipitation pattern changes have a close relationship not only with the fate and transport of enteric bacteria, but also with their growth and survival. Using all relevant literature, this study reviews and synthesises major impacts of climate change (temperature increases and precipitation pattern changes) on contamination sources (manure, soil, surface water, sewage and wildlife) and pathways of foodborne pathogens (focussing on Escherichia coli O157 and Salmonella spp.) on pre-harvested LGVs. Whether climate change increases their prevalence depends not only on the resulting local balance of the positive and negative impacts but also on the selected regional climate change scenarios. However, the contamination risks are likely to increase. This review shows the need for quantitative modelling approaches with scenario analyses and additional laboratory experiments. This study gives an extensive overview of the impacts of climate change on the contamination of pre-harvested LGVs and shows that climate change should not be ignored in food safety management and research.
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Affiliation(s)
- Cheng Liu
- Environmental Systems Analysis Group, Wageningen University, P. O. Box 47, 6700AA Wageningen, The Netherlands.
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29
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Jeon SJ, Elzo M, DiLorenzo N, Lamb GC, Jeong KC. Evaluation of animal genetic and physiological factors that affect the prevalence of Escherichia coli O157 in cattle. PLoS One 2013; 8:e55728. [PMID: 23405204 PMCID: PMC3566006 DOI: 10.1371/journal.pone.0055728] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 12/29/2012] [Indexed: 11/19/2022] Open
Abstract
Controlling the prevalence of Escherichia coli O157 in cattle at the pre-harvest level is critical to reduce outbreaks of this pathogen in humans. Multilayers of factors including the environmental and bacterial factors modulate the colonization and persistence of E. coli O157 in cattle that serve as a reservoir of this pathogen. Here, we report animal factors contributing to the prevalence of E. coli O157 in cattle. We observe the lowest number of E. coli O157 in Brahman breed when compared with other crosses in an Angus-Brahman multibreed herd, and bulls excrete more E. coli O157 than steers in the pens where cattle were housed together. The presence of super-shedders, cattle excreting >10(5) CFU/rectal anal swab, increases the concentration of E. coli O157 in the pens; thereby super-shedders enhance transmission of this pathogen among cattle. Molecular subtyping analysis reveal only one subtype of E. coli O157 in the multibreed herd, indicating the variance in the levels of E. coli O157 in cattle is influenced by animal factors. Furthermore, strain tracking after relocation of the cattle to a commercial feedlot reveals farm-to-farm transmission of E. coli O157, likely via super-shedders. Our results reveal high risk factors in the prevalence of E. coli O157 in cattle whereby animal genetic and physiological factors influence whether this pathogen can persist in cattle at high concentration, providing insights to intervene this pathogen at the pre-harvest level.
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Affiliation(s)
- Soo Jin Jeon
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Mauricio Elzo
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Nicolas DiLorenzo
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America
- North Florida Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Marianna, Florida, United States of America
| | - G. Cliff Lamb
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America
- North Florida Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Marianna, Florida, United States of America
| | - Kwang Cheol Jeong
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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30
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Gu G, Luo Z, Cevallos-Cevallos JM, Adams P, Vellidis G, Wright A, van Bruggen AHC. Factors affecting the occurrence of Escherichia coli O157 contamination in irrigation ponds on produce farms in the Suwannee River Watershed. Can J Microbiol 2012; 59:175-82. [PMID: 23540335 DOI: 10.1139/cjm-2012-0599] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Outbreaks of enteritis caused by Escherichia coli O157 associated with fresh produce have resulted in questions about the safety of irrigation water; however, associated risks have not been systematically evaluated. In this study, the occurrence and distribution of the human pathogen E. coli O157 from vegetable irrigation ponds within the Suwannee River Watershed in Georgia were investigated, and the relationship to environmental factors was analyzed. Surface and subsurface water samples were collected monthly from 10 vegetable irrigation ponds from March 2011 to February 2012. Escherichia coli O157 was isolated from enriched filtrates on CHROMagar and sorbitol MacConkey agar media and confirmed by an agglutination test. Presence of virulence genes stx1, stx2 , and eae was tested by polymerase chain reaction. In addition, 27 environmental variables of the sampled ponds were measured. Denaturing gradient gel electrophoresis was conducted for the analysis of bacterial communities in the water samples. Biserial correlation coefficients were calculated to evaluate the log10 colony-forming unit per millilitre correlations between the environmental factors and the occurrence of E. coli O157. Stepwise and canonical discriminant analyses were used to determine the factors that were associated with the presence and absence of E. coli O157 in water samples. All 10 ponds were positive for E. coli O157 some of the time, mainly in summer and fall of 2011. The temporal distribution of this bacterium differed among the 10 ponds. Temperature, rainfall, populations of fecal coliform, and culturable bacteria were positively correlated with the occurrence of E. coli O157 (P < 0.05), while the total nitrogen concentration, oxidation-reduction potential, and dissolved oxygen concentration were negatively correlated with the occurrence of this pathogen (P < 0.05). Temperature and rainfall were the most important factors contributing to the discrimination between samples with and without E. coli O157, followed by bacterial diversity and culturable bacteria population density. Bacterial numbers and diversity, including fecal coliforms and E. coli O157, increased after rainfall (and possibly runoff from pond margins) in periods with relatively high temperatures, suggesting that prevention of runoff may be important to minimize the risk of enteric pathogens in irrigation ponds.
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Affiliation(s)
- Ganyu Gu
- Emerging Pathogens Institute and Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA.
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31
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Lewis Ivey ML, LeJeune JT, Miller SA. Vegetable producers’ perceptions of food safety hazards in the Midwestern USA. Food Control 2012. [DOI: 10.1016/j.foodcont.2012.01.065] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Cevallos-Cevallos JM, Danyluk MD, Gu G, Vallad GE, van Bruggen AHC. Dispersal of Salmonella Typhimurium by rain splash onto tomato plants. J Food Prot 2012; 75:472-9. [PMID: 22410220 DOI: 10.4315/0362-028x.jfp-11-399] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Outbreaks of Salmonella enterica have increasingly been associated with tomatoes and traced back to production areas, but the spread of Salmonella from a point source onto plants has not been described. Splash dispersal by rain could be one means of dissemination. Green fluorescent protein-labeled, kanamycin-resistant Salmonella enterica sv. Typhimurium dispensed on the surface of plastic mulch, organic mulch, or soil at 10⁸ CFU/cm² was used as the point source in the center of a rain simulator. Tomato plants in soil with and without plastic or organic mulch were placed around the point source, and rain intensities of 60 and 110 mm/h were applied for 5, 10, 20, and 30 min. Dispersal of Salmonella followed a negative exponential model with a half distance of 3 cm at 110 mm/h. Dispersed Salmonella survived for 3 days on tomato leaflets, with a total decline of 5 log and an initial decimal reduction time of 10 h. Recovery of dispersed Salmonella from plants at the maximum observed distance ranged from 3 CFU/g of leaflet after a rain episode of 110 mm/h for 10 min on soil to 117 CFU/g of leaflet on plastic mulch. Dispersal of Salmonella on plants with and without mulch was significantly enhanced by increasing rain duration from 0 to 10 min, but dispersal was reduced when rainfall duration increased from 10 to 30 min. Salmonella may be dispersed by rain to contaminate tomato plants in the field, especially during rain events of 10 min and when plastic mulch is used.
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Affiliation(s)
- Juan M Cevallos-Cevallos
- Emerging Pathogens Institute and Department of Plant Pathology, University of Florida, 2055 Mowry Road, Gainesville, Florida 32611, USA.
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Gu G, Hu J, Cevallos-Cevallos JM, Richardson SM, Bartz JA, van Bruggen AHC. Internal colonization of Salmonella enterica serovar Typhimurium in tomato plants. PLoS One 2011; 6:e27340. [PMID: 22096553 PMCID: PMC3212569 DOI: 10.1371/journal.pone.0027340] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 10/14/2011] [Indexed: 01/04/2023] Open
Abstract
Several Salmonella enterica outbreaks have been traced back to contaminated tomatoes. In this study, the internalization of S. enterica Typhimurium via tomato leaves was investigated as affected by surfactants and bacterial rdar morphotype, which was reported to be important for the environmental persistence and attachment of Salmonella to plants. Surfactants, especially Silwet L-77, promoted ingress and survival of S. enterica Typhimurium in tomato leaves. In each of two experiments, 84 tomato plants were inoculated two to four times before fruiting with GFP-labeled S. enterica Typhimurium strain MAE110 (with rdar morphotype) or MAE119 (without rdar). For each inoculation, single leaflets were dipped in 10(9) CFU/ml Salmonella suspension with Silwet L-77. Inoculated and adjacent leaflets were tested for Salmonella survival for 3 weeks after each inoculation. The surface and pulp of ripe fruits produced on these plants were also examined for Salmonella. Populations of both Salmonella strains in inoculated leaflets decreased during 2 weeks after inoculation but remained unchanged (at about 10(4) CFU/g) in week 3. Populations of MAE110 were significantly higher (P<0.05) than those of MAE119 from day 3 after inoculation. In the first year, nine fruits collected from one of the 42 MAE119 inoculated plants were positive for S. enterica Typhimurium. In the second year, Salmonella was detected in adjacent non-inoculated leaves of eight tomato plants (five inoculated with strain MAE110). The pulp of 12 fruits from two plants inoculated with MAE110 was Salmonella positive (about 10(6) CFU/g). Internalization was confirmed by fluorescence and confocal laser microscopy. For the first time, convincing evidence is presented that S. enterica can move inside tomato plants grown in natural field soil and colonize fruits at high levels without inducing any symptoms, except for a slight reduction in plant growth.
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Affiliation(s)
- Ganyu Gu
- Emerging Pathogens Institute and Department of Plant Pathology, University of Florida, Gainesville, Florida, United States of America.
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Shirron N, Yaron S. Active suppression of early immune response in tobacco by the human pathogen Salmonella Typhimurium. PLoS One 2011; 6:e18855. [PMID: 21541320 PMCID: PMC3082535 DOI: 10.1371/journal.pone.0018855] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Accepted: 03/22/2011] [Indexed: 11/18/2022] Open
Abstract
The persistence of enteric pathogens on plants has been studied extensively, mainly due to the potential hazard of human pathogens such as Salmonella enterica being able to invade and survive in/on plants. Factors involved in the interactions between enteric bacteria and plants have been identified and consequently it was hypothesized that plants may be vectors or alternative hosts for enteric pathogens. To survive, endophytic bacteria have to escape the plant immune systems, which function at different levels through the plant-bacteria interactions. To understand how S. enterica survives endophyticaly we conducted a detailed analysis on its ability to elicit or evade the plant immune response. The models of this study were Nicotiana tabacum plants and cells suspension exposed to S. enterica serovar Typhimurium. The plant immune response was analyzed by looking at tissue damage and by testing oxidative burst and pH changes. It was found that S. Typhimurium did not promote disease symptoms in the contaminated plants. Live S. Typhimurium did not trigger the production of an oxidative burst and pH changes by the plant cells, while heat killed or chloramphenicol treated S. Typhimurium and purified LPS of Salmonella were significant elicitors, indicating that S. Typhimurium actively suppress the plant response. By looking at the plant response to mutants defective in virulence factors we showed that the suppression depends on secreted factors. Deletion of invA reduced the ability of S. Typhimurium to suppress oxidative burst and pH changes, indicating that a functional SPI1 TTSS is required for the suppression. This study demonstrates that plant colonization by S. Typhimurium is indeed an active process. S. Typhimurium utilizes adaptive strategies of altering innate plant perception systems to improve its fitness in the plant habitat. All together these results suggest a complex mechanism for perception of S. Typhimurium by plants.
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Affiliation(s)
- Natali Shirron
- Faculty of Biotechnology and Food Engineering, Technion, Israel Institute of Technology, Haifa, Israel
| | - Sima Yaron
- Faculty of Biotechnology and Food Engineering, Technion, Israel Institute of Technology, Haifa, Israel
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35
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Semenov AM, Kuprianov AA, van Bruggen AHC. Transfer of enteric pathogens to successive habitats as part of microbial cycles. MICROBIAL ECOLOGY 2010; 60:239-49. [PMID: 20397013 DOI: 10.1007/s00248-010-9663-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 03/21/2010] [Indexed: 05/25/2023]
Abstract
Escherichia coli O157:H7 gfp and Salmonella enterica Typhimurium gfp passed through six successive habitats within a microbial cycle. Pathogen cultures were introduced into cow dung or fodder. Microscopically observed cells and CFUs were monitored in fodder, dung, dung-soil mix, rhizosphere and phyllosphere of cress or oat plants grown in infested dung-soil mix, and in excrements of snails or mice fed with contaminated cress or oat shoots. Both methods were sensitive enough to monitor cells and CFUs throughout the chain. There was a positive correlation between cells and CFUs. Both pathogens declined through the successive habitats, but with unexpected increased densities on plants compared to dung-soil mix. Pathogen densities were higher in the phyllosphere than the rhizosphere of cress, but for oat plants this was reverse. Survival in dung was better after passage through the digestive tract of cows than after introduction of cultures into dung. Positive correlations between pathogens and copiotrophic bacteria (CB) and dissolved organic carbon (DOC) were observed in dung and dung-soil mixtures, but at low DOC contents CB densities were higher than pathogen densities. Thus, the pathogens are able to cycle through different habitats, surviving or growing better at high DOC concentrations, but maintaining population densities that are sufficiently high to cause disease in humans.
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Affiliation(s)
- Alexander M Semenov
- Department of Microbiology, Biological Faculty, Moscow State University, Vorob'evy Gory, Moscow, Russia.
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Microbial ecology of foodborne pathogens associated with produce. Curr Opin Biotechnol 2010; 21:125-30. [DOI: 10.1016/j.copbio.2010.01.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 01/02/2010] [Accepted: 01/16/2010] [Indexed: 11/22/2022]
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Semenov AV, Franz E, van Bruggen AH. COLIWAVE a simulation model for survival of E. coli O157:H7 in dairy manure and manure-amended soil. Ecol Modell 2010. [DOI: 10.1016/j.ecolmodel.2009.10.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Kim J, Luo F, Jiang X. Factors impacting the regrowth of Escherichia coli O157:H7 in dairy manure compost. J Food Prot 2009; 72:1576-84. [PMID: 19681288 DOI: 10.4315/0362-028x-72.7.1576] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The environmental variables affecting Escherichia coli O157:H7 regrowth in dairy manure compost were investigated. Factors evaluated were moisture content, strain variation, growth medium of inoculum, level of background microflora and inoculum, different days of composting, and acclimation at room temperature. A mathematical model was applied to describe E. coli O157 regrowth potential in compost. Repopulation occurred in autoclaved compost with a moisture content as low as 20% (water activity of 0.986) in the presence of background microflora of 2.3 to 3.9 log CFU/g. The population of all three E. coli O157 strains increased from ca. 1 to 4.85 log CFU/g in autoclaved compost, with the highest increase in the spinach-outbreak strain. However, E. coli O157 regrowth was suppressed by background microflora at ca. 6.5 log CFU/g. By eliminating acclimation at room temperature and increasing the inoculum level to ca. 3 log CFU/g, E. coli O157:H7 could regrow in the presence of high levels of background microflora. E. coli O157:H7 regrowth in the autoclaved compost collected from the field study was evident at all sampling days, with the population increase ranging from 3.49 to 6.54 log CFU/g. The fate of E. coli O157:H7 in compost was well described by a Whiting and Cygnarowicz-Provost model, with R2 greater than 0.9. The level of background microflora was a significant factor for both growth and death parameters. Our results reveal that a small number of E. coli O157 cells can regrow in compost, and both background microflora and moisture content were major factors affecting E. coli O157:H7 growth.
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Affiliation(s)
- Jinkyung Kim
- Department of Food Science & Human Nutrition, Clemson University, Clemson, South Carolina 29634, USA
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Corrigendum. J Appl Microbiol 2009. [DOI: 10.1111/j.1365-2672.2009.04281.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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