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NMR-based metabolomic investigation on antimicrobial mechanism of Salmonella on cucumber slices treated with organic acids. Food Control 2022. [DOI: 10.1016/j.foodcont.2022.108973] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Luu P, Chhetri VS, Janes ME, King JM, Adhikari A. Efficacy of gaseous chlorine dioxide in reducing Salmonella enterica, E. coli O157:H7, and Listeria monocytogenes on strawberries and blueberries. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.110906] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Comparative transcriptomic study of Escherichia coli O157:H7 in response to ohmic heating and conventional heating. Food Res Int 2021; 140:109989. [PMID: 33648224 DOI: 10.1016/j.foodres.2020.109989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 05/29/2020] [Accepted: 12/08/2020] [Indexed: 11/22/2022]
Abstract
In this study, the high-throughput Illumina HiSeq 2000 mRNA sequencing technique was used to investigate the transcriptome response of Escherichia coli O157:H7 exposed to ohmic heating (OH) and water bath heating (WB). Compared to untreated samples, a total of 293, 516, and 498 genes showed differential expression after HVOH (high voltage short time ohmic heating), LVOH (low voltage long time ohmic heating), and WB, respectively. Therefore, LVOH had the potential to cause comparable effects on the transcriptome of E. coli O157:H7 as compared to WB, but not HVOH. These results indicated that additional non-thermal effects were not reflected on transcriptome of E. coli O157:H7 using both HVOH and LVOH, in particular the HVOH. Most of differentially expressed genes involved in information storage and processing, and cellular processes and signaling showed up-regulation whereas most of genes related to the metabolism were down-regulated after HVOH, LVOH, and WB. In addition, more attention needs to be paid to the up-regulation of a large number of virulence genes, which might increase the ability of surviving E. coli O157:H7 to infect host cells after HVOH, LVOH, and WB. This transcriptomic study on the response of E. coli O157:H7 to OH protomes the understanding of inactivation mechanism of OH on the molecular level and opens the door to future studies for OH.
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Luu P, Chhetri VS, Janes ME, King JM, Adhikari A. Effectiveness of Aqueous Chlorine Dioxide in Minimizing Food Safety Risk Associated with Salmonella, E. coli O157:H7, and Listeria monocytogenes on Sweet Potatoes. Foods 2020; 9:foods9091259. [PMID: 32911767 PMCID: PMC7554816 DOI: 10.3390/foods9091259] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/01/2020] [Accepted: 09/05/2020] [Indexed: 11/28/2022] Open
Abstract
Sodium hypochlorite (NaOCl) is a commonly used sanitizer in the produce industry despite its limited effectiveness against contaminated human pathogens in fresh produce. Aqueous chlorine dioxide (ClO2) is an alternative sanitizer offering a greater oxidizing potency with greater efficacy in reducing a large number of microorganisms. We investigated the effect of aqueous chlorine dioxide treatment against human pathogens, Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes seeded on sweet potatoes. Sweet potatoes were spot inoculated (4.2 to 5.7 log CFU/cm2) with multi-strain cocktails of Salmonella spp., E. coli O157:H7, and L. monocytogenes and treated for 10–30 min with 5 ppm aqueous ClO2 or water. Aqueous ClO2 treatment was significantly (p < 0.05) effective in reducing Salmonella with a reduction of 2.14 log CFU/cm2 within 20 min compared to 1.44 log CFU/cm2 for water treatment. Similar results were observed for L. monocytogenes with a 1.98 log CFU/cm2 reduction compared to 0.49 log CFU/cm2 reduction observed after 30 min treatment with aqueous ClO2 the water respectively. The maximum reduction in E. coli O157: H7 reached 2.1 Log CFU/cm2 after 20 min of treatment with aqueous ClO2. The level of the pathogens in ClO2 wash solutions, after the treatment, was below the detectable limit. While in the water wash solutions, the pathogens’ populations ranged from 3.47 to 4.63 log CFU/mL. Our study indicates that aqueous ClO2 is highly effective in controlling cross-contamination during postharvest washing of sweet potatoes.
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Bezanson G, Mader D, Fillmore S, Bach S, Delaquis P. Reaction of Surrogate Escherichia coli Serotype O157:H7 and Non-O157 Strains to Nutrient Starvation: Variation in Phenotype and Transcription of Stress Response Genes and Behavior on Lettuce Plants in the Field. J Food Prot 2019; 82:1988-2000. [PMID: 31644333 DOI: 10.4315/0362-028x.jfp-19-072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Preharvest contamination with bacteria borne by irrigation water may result in leafy vegetables serving as vehicles for transmission of Shiga toxin-producing Escherichia coli (STEC) to humans. The influence of starvation-associated stress on the behavior of non-toxin-producing strains of E. coli serotype O157:H7 and serotypes O26, O103, O111, and O145 was examined subsequent to their introduction to the phyllosphere of field-grown romaine lettuce as inocula simulating starved (96 h in sterile deionized water) and nutrient-depleted (24 h broth culture) cells. As with E. coli O157:H7, leaf populations of the non-O157 strains declined rapidly during the first 72 h postinoculation, displaying the biphasic decay curve typical of serotype O157:H7 isolates. Preinoculation treatment appeared not to influence decay rates greatly (P > 0.5), but strain-specific differences (persistence period and attachment proficiency) indicated that serotype O103:H2 strain PARC445 was a better survivor. Also assessed was the impact of preinoculation treatment on phenotypes key to leaf colonization and survival and the expression of starvation stress-associated genes. The 96-h starvation period enhanced biofilm formation in one strain but reduced motility and autoinducer 2 formation in all five study strains relative to those characteristics in stationary-phase cells. Transcription of rpoS, dps, uspA, and gapA was reduced significantly (P < 0.05) in starvation-stressed cells relative to that for exponential- and stationary-phase cultures. Strain-specific differences were observed; serotype O103:H2 PARC445 had greater downturns than did serotype O157:H7 and other non-O157 strains. Within this particular cohort, the behavior of the representative serotype O157:H7 strain, PARC443 (ATCC 700728), was not predictive of behavior of non-O157 members of this STEC group.
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Affiliation(s)
- Greg Bezanson
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, 32 Main Street, Kentville, Nova Scotia, Canada B4N 1J
| | - David Mader
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, 32 Main Street, Kentville, Nova Scotia, Canada B4N 1J
| | - Sherry Fillmore
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, 32 Main Street, Kentville, Nova Scotia, Canada B4N 1J
| | - Susan Bach
- Agriculture and Agri-Food Canada, Brandon Research and Development Centre, 2701 Grand Valley Road, Brandon, Manitoba, Canada R7A 5Y3
| | - Pascal Delaquis
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, 4200 Highway 97, Summerland, British Columbia, Canada V0H 1Z0
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Chhetri VS, Janes ME, King JM, Doerrler W, Adhikari A. Effect of residual chlorine and organic acids on survival and attachment of Escherichia coli O157: H7 and Listeria monocytogenes on spinach leaves during storage. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.02.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Guo X, Xie C, Wang L, Li Q, Wang Y. Biodegradation of persistent environmental pollutants by Arthrobacter sp. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:8429-8443. [PMID: 30706270 DOI: 10.1007/s11356-019-04358-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 01/23/2019] [Indexed: 05/17/2023]
Abstract
Persistent environmental pollutants are a growing problem around the world. The effective control of the pollutants is of great significance for human health. Some microbes, especially Arthrobacter, can degrade pollutants into nontoxic substances in various ways. Here, we review the biological properties of Arthrobacter adapting to a variety of environmental stresses, including starvation, hypertonic and hypotonic condition, oxidative stress, heavy metal stress, and low-temperature stress. Furthermore, we categorized the Arthrobacter species that can degrade triazines, organophosphorus, alkaloids, benzene, and its derivatives. Metabolic pathways behind the various biodegradation processes are further discussed. This review will be a helpful reference for comprehensive utilization of Arthrobacter species to tackle environmental pollutants.
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Affiliation(s)
- Xiaohong Guo
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Chengyun Xie
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Lijuan Wang
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Qinfan Li
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Yan Wang
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China.
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Chhetri VS, Fontenot K, Strahan R, Yemmireddy VK, Cason C, Kharel K, Adhikari A. Attachment strength and on-farm die-off rate of Escherichia coli on watermelon surfaces. PLoS One 2019; 14:e0210115. [PMID: 30620744 PMCID: PMC6324798 DOI: 10.1371/journal.pone.0210115] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 12/17/2018] [Indexed: 01/10/2023] Open
Abstract
Pre-harvest contamination of produce has been a major food safety focus. Insight into the behavior of enteric pathogens on produce in pre-harvest conditions will aid in developing pre-harvest and post-harvest risk management strategies. In this study, the attachment strength (SR) and die-off rate of E. coli on the surface of watermelon fruits and the efficacy of aqueous chlorine treatment against strongly attached E. coli population were investigated. Watermelon seedlings were transplanted into eighteen plots. Prior to harvesting, a cocktail of generic E. coli (ATCC 23716, 25922 and 11775) was inoculated on the surface of the watermelon fruits (n = 162) and the attachment strength (SR) values and the daily die-off rates were examined up to 6 days by attachment assay. After 120 h, watermelon samples were treated with aqueous chlorine (150 ppm free chlorine for 3 min). The SR value of the E. coli cells on watermelon surfaces significantly increased (P<0.05) from 0.04 to 0.99 in the first 24 h, which was primarily due to the decrease in loosely attached population, given that the population of strongly attached cells was constant. Thereafter, there was no significant change in SR values, up to 120 h. The daily die-off rate of E. coli ranged from -0.12 to 1.3 log CFU/cm2. The chlorine treatment reduced the E. coli level by 4.2 log CFU/cm2 (initial level 5.6 log CFU/cm2) and 0.62 log CFU/cm2 (initial level 1.8 log CFU/cm2), on the watermelons that had an attachment time of 30 min and 120 h respectively. Overall, our findings revealed that the population of E. coli on watermelon surfaces declined over time in an agricultural environment. Microbial contamination during pre-harvest stages may promote the formation of strongly attached cells on the produce surfaces, which could influence the efficacy of post-harvest washing and sanitation techniques.
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Affiliation(s)
- Vijay Singh Chhetri
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Kathryn Fontenot
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Ronald Strahan
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Veerachandra K. Yemmireddy
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Cameron Cason
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Karuna Kharel
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Achyut Adhikari
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
- * E-mail:
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Pesciaroli M, Chardon JE, Evers EG. Modelling of inactivation through heating for quantitative microbiological risk assessment (QMRA). EFSA J 2018; 16:e16089. [PMID: 32626060 PMCID: PMC7015491 DOI: 10.2903/j.efsa.2018.e16089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
EFSA regards the household as a stage in the food chain that is important for the final number of food‐borne infections. The fate of a pathogen in the private kitchen largely depends on consumer hygiene during preparation of food and on its proper cooking, especially in the case of meat. Unfortunately, detailed information on the microbiological survival in meat products after heating in the consumer kitchen is lacking. The aim of the study was to improve the estimation of the inactivating effect on pathogens by heating meat or a meat product by the consumer in the kitchen. On that account, artificially contaminated meat and meat products were cooked according to several degrees of doneness and simulating real world conditions, and bacterial survival was measured. Heat camera pictures and button temperature loggers inserted into the food matrix served to record time and the temperature of heating. Temperature, time and the microbial survival ratio observed served to inform a mathematical model able to explain the thermal inactivation of meat or a meat product in home settings. The results of the study would help to improve microbiological comparative exposure assessments of pathogens in food, as an attribution tool and as a supportive tool for risk‐based sampling in monitoring and surveillance.
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