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Myintzaw P, Pennone V, McAuliffe O, Begley M, Callanan M. Association of Virulence, Biofilm, and Antimicrobial Resistance Genes with Specific Clonal Complex Types of Listeria monocytogenes. Microorganisms 2023; 11:1603. [PMID: 37375105 DOI: 10.3390/microorganisms11061603] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Precise classification of foodborne pathogen Listeria monocytogenes is a necessity in efficient foodborne disease surveillance, outbreak detection, and source tracking throughout the food chain. In this study, a total of 150 L. monocytogenes isolates from various food products, food processing environments, and clinical sources were investigated for variations in virulence, biofilm formation, and the presence of antimicrobial resistance genes based on their Whole-Genome Sequences. Clonal complex (CC) determination based on Multi-Locus Sequence Typing (MLST) revealed twenty-eight CC-types including eight isolates representing novel CC-types. The eight isolates comprising the novel CC-types share the majority of the known (cold and acid) stress tolerance genes and are all genetic lineage II, serogroup 1/2a-3a. Pan-genome-wide association analysis by Scoary using Fisher's exact test identified eleven genes specifically associated with clinical isolates. Screening for the presence of antimicrobial and virulence genes using the ABRicate tool uncovered variations in the presence of Listeria Pathogenicity Islands (LIPIs) and other known virulence genes. Specifically, the distributions of actA, ecbA, inlF, inlJ, lapB, LIPI-3, and vip genes across isolates were found to be significantly CC-dependent while the presence of ami, inlF, inlJ, and LIPI-3 was associated with clinical isolates specifically. In addition, Roary-derived phylogenetic grouping based on Antimicrobial-Resistant Genes (AMRs) revealed that the thiol transferase (FosX) gene was present in all lineage I isolates, and the presence of the lincomycin resistance ABC-F-type ribosomal protection protein (lmo0919_fam) was also genetic-lineage-dependent. More importantly, the genes found to be specific to CC-type were consistent when a validation analysis was performed with fully assembled, high-quality complete L. monocytogenes genome sequences (n = 247) extracted from the National Centre for Biotechnology Information (NCBI) microbial genomes database. This work highlights the usefulness of MLST-based CC typing using the Whole-Genome Sequence as a tool in classifying isolates.
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Affiliation(s)
- Peter Myintzaw
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland
| | - Vincenzo Pennone
- Teagasc Food Research Centre, Moorepark, Fermoy, Co., P61 C996 Cork, Ireland
| | - Olivia McAuliffe
- Teagasc Food Research Centre, Moorepark, Fermoy, Co., P61 C996 Cork, Ireland
| | - Máire Begley
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland
| | - Michael Callanan
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland
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Zoz F, Guyot S, Grandvalet C, Ragon M, Lesniewska E, Dupont S, Firmesse O, Carpentier B, Beney L. Management of Listeria monocytogenes on Surfaces via Relative Air Humidity: Key Role of Cell Envelope. Foods 2021; 10:foods10092002. [PMID: 34574112 PMCID: PMC8468791 DOI: 10.3390/foods10092002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/20/2021] [Accepted: 08/24/2021] [Indexed: 12/25/2022] Open
Abstract
Although relative air humidity (RH) strongly influences microbial survival, its use for fighting surface pathogens in the food industry has been inadequately considered. We asked whether RH control could destroy Listeria monocytogenes EGDe by envelope damage. The impact of dehydration in phosphate-buffered saline (PBS) at 75%, 68%, 43% and 11% RH on the bacterial envelope was investigated using flow cytometry and atomic force microscopy. Changes after rehydration in the protein secondary structure and peptidoglycan were investigated by infrared spectroscopy. Complementary cultivability measurements were performed by running dehydration–rehydration with combinations of NaCl (3–0.01%), distilled water, city water and PBS. The main results show that cell membrane permeability and cell envelope were greatly altered during dehydration in PBS at 68% RH followed by rapid rehydration. This damage led cells to recover only 67% of their initial volume after rehydration. Moreover, the most efficient way to destroy cells was dehydration and rehydration in city water. Our study indicates that rehydration of dried, sullied foods on surfaces may improve current cleaning procedures in the food industry.
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Affiliation(s)
- Fiona Zoz
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France; (F.Z.); (C.G.); (M.R.); (S.D.); (L.B.)
- Mérieux NutriSciences–70 Mail Marcel Cachin, F-38600 Fontaine, France
| | - Stéphane Guyot
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France; (F.Z.); (C.G.); (M.R.); (S.D.); (L.B.)
- Correspondence: ; Tel.: +33-3-8077-2387
| | - Cosette Grandvalet
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France; (F.Z.); (C.G.); (M.R.); (S.D.); (L.B.)
| | - Mélanie Ragon
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France; (F.Z.); (C.G.); (M.R.); (S.D.); (L.B.)
| | - Eric Lesniewska
- ICB UMR CNRS 6303, Université de Bourgogne Franche-Comté, F-21078 Dijon, France;
| | - Sébastien Dupont
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France; (F.Z.); (C.G.); (M.R.); (S.D.); (L.B.)
| | - Olivier Firmesse
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, F-94700 Maisons-Alfort, France; (O.F.); (B.C.)
| | - Brigitte Carpentier
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, F-94700 Maisons-Alfort, France; (O.F.); (B.C.)
| | - Laurent Beney
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France; (F.Z.); (C.G.); (M.R.); (S.D.); (L.B.)
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Poimenidou SV, Chatzithoma DN, Nychas GJ, Skandamis PN. Adaptive Response of Listeria monocytogenes to Heat, Salinity and Low pH, after Habituation on Cherry Tomatoes and Lettuce Leaves. PLoS One 2016; 11:e0165746. [PMID: 27798688 PMCID: PMC5087945 DOI: 10.1371/journal.pone.0165746] [Citation(s) in RCA: 24] [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: 06/10/2016] [Accepted: 10/16/2016] [Indexed: 11/18/2022] Open
Abstract
Pathogens found on fresh produce may encounter low temperatures, high acidity and limited nutrient availability. The aim of this study was to evaluate the effect of habituation of Listeria monocytogenes on cherry tomatoes or lettuce leaves on its subsequent response to inhibitory levels of acid, osmotic and heat stress. Habituation was performed by inoculating lettuce coupons, whole cherry tomatoes or tryptic soy broth (TSB) with a three-strains composite of L. monocytogenes, which were further incubated at 5°C for 24 hours or 5 days. Additionally, cells grown overnight in TSB supplemented with 0.6% yeast extract (TSBYE) at 30°C were used as control cells. Following habituation, L. monocytogenes cells were harvested and exposed to: (i) pH 3.5 adjusted with lactic acid, acetic acid or hydrochloric acid (HCl), and pH 1.5 (HCl) for 6 h; (ii) 20% NaCl and (iii) 60°C for 150 s. Results showed that tomato-habituated L. monocytogenes cells were more tolerant (P < 0.05) to acid or osmotic stress than those habituated on lettuce, and habituation on both foods resulted in more stress resistant cells than prior growth in TSB. On the contrary, the highest resistance to heat stress (P < 0.05) was exhibited by the lettuce-habituated L. monocytogenes cells followed by TSB-grown cells at 5°C for 24 h, whereas tomato-habituated cells were highly sensitized. Prolonged starvation on fresh produce (5 days vs. 24 h) increased resistance to osmotic and acid stress, but reduced thermotolerance, regardless of the pre-exposure environment (i.e., tomatoes, lettuce or TSB). These results indicate that L. monocytogenes cells habituated on fresh produce at low temperatures might acquire resistance to subsequent antimicrobial treatments raising important food safety implications.
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Affiliation(s)
- Sofia V. Poimenidou
- Laboratory of Food Quality Control and Hygiene, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece
- Laboratory of Food Microbiology and Biotechnology, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece
| | - Danai-Natalia Chatzithoma
- Laboratory of Food Quality Control and Hygiene, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece
| | - George-John Nychas
- Laboratory of Food Microbiology and Biotechnology, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece
| | - Panagiotis N. Skandamis
- Laboratory of Food Quality Control and Hygiene, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece
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The response of foodborne pathogens to osmotic and desiccation stresses in the food chain. Int J Food Microbiol 2016; 221:37-53. [PMID: 26803272 DOI: 10.1016/j.ijfoodmicro.2015.12.014] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 12/22/2015] [Accepted: 12/30/2015] [Indexed: 12/24/2022]
Abstract
In combination with other strategies, hyperosmolarity and desiccation are frequently used by the food processing industry as a means to prevent bacterial proliferation, and particularly that of foodborne pathogens, in food products. However, it is increasingly observed that bacteria, including human pathogens, encode mechanisms to survive and withstand these stresses. This review provides an overview of the mechanisms employed by Salmonella spp., Shiga toxin producing E. coli, Cronobacter spp., Listeria monocytogenes and Campylobacter spp. to tolerate osmotic and desiccation stresses and identifies gaps in knowledge which need to be addressed to ensure the safety of low water activity and desiccated food products.
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Abstract
The review centers on the human gastrointestinal tract; focusing first on the bacterial stress responses needed to overcome the physiochemical defenses of the host, specifically how these stress survival strategies can be used as targets for alternative infection control strategies. The concluding section focuses on recent developments in molecular diagnostics; centring on the shifting paradigm from culture to molecular based diagnostics.
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Affiliation(s)
- Roy D Sleator
- a Department of Biological Sciences ; Cork Institute of Technology ; Bishopstown , Cork , Ireland
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Sleator RD. Designer probiotics: Development and applications in gastrointestinal health. World J Gastrointest Pathophysiol 2015; 6:73-78. [PMID: 26301121 PMCID: PMC4540709 DOI: 10.4291/wjgp.v6.i3.73] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 04/23/2015] [Accepted: 07/14/2015] [Indexed: 02/06/2023] Open
Abstract
Given the increasing commercial and clinical relevance of probiotics, improving their stress tolerance profile and ability to overcome the physiochemical defences of the host is an important biological goal. Herein, I review the current state of the art in the design of engineered probiotic cultures, with a specific focus on their utility as therapeutics for the developing world; from the treatment of chronic and acute enteric infections, and their associated diarrhoeal complexes, to targeting HIV and application as novel mucosal vaccine delivery vehicles.
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Role of sigB and osmolytes in desiccation survival of Listeria monocytogenes in simulated food soils on the surface of food grade stainless steel. Food Microbiol 2015; 46:443-451. [DOI: 10.1016/j.fm.2014.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/05/2014] [Accepted: 09/12/2014] [Indexed: 11/24/2022]
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Feeney A, Kropp KA, O’Connor R, Sleator RD. Cronobacter sakazakii: stress survival and virulence potential in an opportunistic foodborne pathogen. Gut Microbes 2015; 5:711-8. [PMID: 25562731 PMCID: PMC4615781 DOI: 10.4161/19490976.2014.983774] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A characteristic feature of the opportunistic foodborne pathogen Cronobacter sakazakii is its ability to survive in extremely arid environments, such as powdered infant formula, making it a dangerous opportunistic pathogen of individuals of all age groups, especially infants and neonates. Herein, we provide a brief overview of the pathogen; clinical manifestations, environmental reservoirs and our current understanding of stress response mechanisms and virulence factors which allow it to cause disease.
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Affiliation(s)
- Audrey Feeney
- Department of Biological Sciences; Cork Institute of Technology; Bishopstown, Cork, Ireland
| | - Kai A Kropp
- Department of Biological Sciences; Cork Institute of Technology; Bishopstown, Cork, Ireland
| | - Roxana O’Connor
- Department of Biological Sciences; Cork Institute of Technology; Bishopstown, Cork, Ireland
| | - Roy D Sleator
- Department of Biological Sciences; Cork Institute of Technology; Bishopstown, Cork, Ireland,Correspondence to: Roy D Sleator;
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Daneshvar Alavi HE, Truelstrup Hansen L. Kinetics of biofilm formation and desiccation survival of Listeria monocytogenes in single and dual species biofilms with Pseudomonas fluorescens, Serratia proteamaculans or Shewanella baltica on food-grade stainless steel surfaces. BIOFOULING 2013; 29:1253-1268. [PMID: 24102145 DOI: 10.1080/08927014.2013.835805] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This study investigated the dynamics of static biofilm formation (100% RH, 15 °C, 48-72 h) and desiccation survival (43% RH, 15 °C, 21 days) of Listeria monocytogenes, in dual species biofilms with the common spoilage bacteria, Pseudomonas fluorescens, Serratia proteamaculans and Shewanella baltica, on the surface of food grade stainless steel. The Gram-negative bacteria reduced the maximum biofilm population of L. monocytogenes in dual species biofilms and increased its inactivation during desiccation. However, due to the higher desiccation resistance of Listeria relative to P. fluorescens and S. baltica, the pathogen survived in greater final numbers. In contrast, S. proteamaculans outcompeted the pathogen during the biofilm formation and exhibited similar desiccation survival, causing the N21 days of Serratia to be ca 3 Log10(CFU cm(-2)) greater than that of Listeria in the dual species biofilm. Microscopy revealed biofilm morphologies with variable amounts of exopolymeric substance and the presence of separate microcolonies. Under these simulated food plant conditions, the fate of L. monocytogenes during formation of mixed biofilms and desiccation depended on the implicit characteristics of the co-cultured bacterium.
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Affiliation(s)
- Hessam Edin Daneshvar Alavi
- a Food Science Program, Faculty of Engineering, Department of Process Engineering and Applied Science , Dalhousie University , Halifax , Canada
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Abstract
The accumulation of osmolytes like glycinebetaine (GB) in cell is known to protect organisms against abiotic stresses via osmoregulation or osmoprotection. Transgenic plants engineered to produce GB accumulate very low concentration of GB, which might not be sufficient for osmoregulation. Therefore, other roles of GB like cellular macromolecule protection and ROS detoxification have been suggested as mechanisms responsible for abiotic stress tolerance in transgenic plants. In addition, GB influences expression of several endogenous genes in transgenic plants. The new insights gained about the mechanism of stress tolerance in GB accumulating transgenic plants are discussed.
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Affiliation(s)
- Jitender Giri
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India.
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11
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Desiccation of adhering and biofilm Listeria monocytogenes on stainless steel: Survival and transfer to salmon products. Int J Food Microbiol 2011; 146:88-93. [DOI: 10.1016/j.ijfoodmicro.2011.01.032] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 12/19/2010] [Accepted: 01/23/2011] [Indexed: 11/18/2022]
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Beattie GA. Water relations in the interaction of foliar bacterial pathogens with plants. ANNUAL REVIEW OF PHYTOPATHOLOGY 2011; 49:533-55. [PMID: 21438680 DOI: 10.1146/annurev-phyto-073009-114436] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
This review examines the many ways in which water influences the relations between foliar bacterial pathogens and plants. As a limited resource in aerial plant tissues, water is subject to manipulation by both plants and pathogens. A model is emerging that suggests that plants actively promote localized desiccation at the infection site and thus restrict pathogen growth as one component of defense. Similarly, many foliar pathogens manipulate water relations as one component of pathogenesis. Nonvascular pathogens do this using effectors and other molecules to alter hormonal responses and enhance intercellular watersoaking, whereas vascular pathogens use many mechanisms to cause wilt. Because of water limitations on phyllosphere surfaces, bacterial colonists, including pathogens, benefit from the protective effects of cellular aggregation, synthesis of hygroscopic polymers, and uptake and production of osmoprotective compounds. Moreover, these bacteria employ tactics for scavenging and distributing water to overcome water-driven barriers to nutrient acquisition, movement, and signal exchange on plant surfaces.
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Affiliation(s)
- Gwyn A Beattie
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011-3211, USA.
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Sleator RD, Hill C. Compatible solutes: the key to Listeria's success as a versatile gastrointestinal pathogen? Gut Pathog 2010; 2:20. [PMID: 21143981 PMCID: PMC3006354 DOI: 10.1186/1757-4749-2-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 12/10/2010] [Indexed: 01/05/2023] Open
Abstract
Recently we reported a role for compatible solute uptake in mediating bile tolerance and increased gastrointestinal persistence in the foodborne pathogen Listeria monocytogenes[1]. Herein, we review the evolution in our understanding of how these low molecular weight molecules contribute to growth and survival of the pathogen both inside and outside the body, and how this stress survival mechanism may ultimately be used to target and kill the pathogen.
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Affiliation(s)
- Roy D Sleator
- Department of Biological Sciences, Cork Institute of Technology, Rossa Avenue, Bishopstown, Cork, Ireland.
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The survival of Listeria monocytogenes during long term desiccation is facilitated by sodium chloride and organic material. Int J Food Microbiol 2010; 140:192-200. [DOI: 10.1016/j.ijfoodmicro.2010.03.035] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Revised: 03/17/2010] [Accepted: 03/20/2010] [Indexed: 11/17/2022]
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Sleator RD, Hill C. Compatible solutes: A listerial passe-partout? Gut Microbes 2010; 1:77-79. [PMID: 21326913 PMCID: PMC3023583 DOI: 10.4161/gmic.1.2.10968] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 12/17/2009] [Accepted: 12/17/2009] [Indexed: 02/03/2023] Open
Abstract
Recently we reported a role for compatible solute uptake in mediating bile tolerance and increased gastrointestinal persistence in the foodborne pathogen Listeria monocytogenes.1 Herein, we review the evolution in our understanding of how these low molecular weight molecules contribute to growth and survival of the pathogen both inside and outside the body, and how this stress survival mechanism may ultimately be used to target and kill the pathogen.
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Affiliation(s)
- Roy D Sleator
- Department of Biological Sciences; Cork Institute of Technology; Cork, Ireland,Alimentary Pharmabiotic Centre; University College Cork; Cork, Ireland
| | - Colin Hill
- Alimentary Pharmabiotic Centre; University College Cork; Cork, Ireland
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Rieu A, Guzzo J, Piveteau P. Sensitivity to acetic acid, ability to colonize abiotic surfaces and virulence potential of Listeria monocytogenes EGD-e after incubation on parsley leaves. J Appl Microbiol 2009; 108:560-70. [PMID: 19778346 DOI: 10.1111/j.1365-2672.2009.04463.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To investigate how the survival of Listeria monocytogenes on parsley leaves may affect its ability to sustain process-related harsh conditions and its virulence. METHODS AND RESULTS Parsley seedlings were spot inoculated with stationary phase cells of L. monocytogenes EGD-e and incubated for 15 days. Each day, bacterial cells were harvested and enumerated, and their ability to survive acetic acid challenge (90 min, pH 4.0), to colonize abiotic surfaces and to grow as biofilms was assessed. After a 3-log decrease over the first 48 h, the population stabilized to about 10(6) CFU g(-1) until the sixth day. After the sixth day, L. monocytogenes was no longer detected, even after specific enrichment. Incubation on parsley leaves affected the ability of L. monocytogenes to survive acetic acid challenge (90 min, pH 4.0) and to adhere to stainless steel although the ability to grow as biofilm was preserved. To further investigate these physiological alterations, the mRNA levels of six target genes (bsh, clpC, groEL, inlA, opuC, prfA) was quantified using reverse transcription qPCR after 5 h of incubation on parsley leaves. A decrease was observed in all but one (bsh) target, including groEL and clpC which are involved in resistance to salt and acid. Moreover, the decrease in the levels of inlA, prfA and opuC transcripts after incubation on parsley suggested a repression of some genes involved in pathogenicity. In vitro assessment of mammalian cell adherence and invasion using Caco-2 cells confirmed the repression of the virulence factor InlA; however, the virulence potential in vivo in the chick embryo model was not affected. CONCLUSION Listeria monocytogenes did undergo rapid changes to adapt its physiology to the phyllosphere. SIGNIFICANCE AND IMPACT OF THE STUDY This study highlights the physiological changes undergone by L. monocytogenes during/after survival on parsley leaves.
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Affiliation(s)
- A Rieu
- Laboratoire de Recherche En Vigne et Vin REVV, Université de Bourgogne, IUVV, Dijon, France
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Sleator RD, Banville N, Hill C. Carnitine enhances the growth of Listeria monocytogenes in infant formula at 7 degrees C. J Food Prot 2009; 72:1293-5. [PMID: 19610343 DOI: 10.4315/0362-028x-72.6.1293] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Carnitine has beneficial vitamin-like qualities and functions as a compatible solute. The presence of L-carnitine in infant formula significantly promoted the growth of Listeria monocytogenes at 7 degrees C, whereas disruption of the genes for carnitine and glycine betaine uptake compromised growth of the L. monocytogenes mutant in formula containing carnitine that was stored at 7 degrees C. Thus, addition of carnitine to baby formula may pose a potential food safety risk.
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Affiliation(s)
- Roy D Sleator
- Alimentary Pharmabiotic Centre, University College Cork, College Road, Cork, Ireland.
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Dinu LD, Delaquis P, Bach S. Nonculturable response of animal enteropathogens in the agricultural environment and implications for food safety. J Food Prot 2009; 72:1342-54. [PMID: 19610353 DOI: 10.4315/0362-028x-72.6.1342] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Concerns about animal enteropathogen contamination of fresh horticultural products have,increased worldwide and are mainly due to the ability of bacteria to survive under stress conditions in the agricultural environment and during raw-vegetable processing. This review challenges the idea that the viable but nonculturable phenomenon that has been proven to occur in plant-associated environments contributes to human pathogen survival and might be correlated with foodborne infection. Factors associated with the nonculturable response of bacteria in the field and during postharvest processing and distribution are discussed, specifically for the most common animal enteropathogens linked with the consumption of raw products: Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and Shigella spp. The accurate detection of live bacterial populations is essential for pathogen screening in food and environmental safety control and in epidemiological analysis and may have to be considered for identification of critical control points at the time of food inspection.
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Affiliation(s)
- Laura-Dorina Dinu
- Agriculture and Agri-Food Canada, Pacific Agri-Food Research Centre, 4200 Highway 97 South, Summerland, British Columbia, Canada
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