Identification of Genes Induced in Listeria monocytogenes during Growth and Attachment to Cut Cabbage, Using Differential Display

ABSTRACT The food-borne pathogen Listeria monocytogenes is a ubiquitous soil bacterium with the potential to contaminate fresh produce during cultivation and postharvest processing. In order to identify potential mechanisms by which L. monocytogenes may successfully attach to and colonize fresh produce, gene expression in L. monocytogenes cells inoculated onto fresh-cut cabbage was compared to gene expression in cells grown under control conditions. Differential display of reverse transcriptase PCR fragments amplified with a set of 81 arbitrary primers allowed the isolation and identification of 32 L. monocytogenes gene fragments that were observed to be more highly expressed under cabbage-associated conditions. Genes involved in carbohydrate, amino acid, and nucleic acid metabolism, motility and cell division, and transport were identified, as were a number of open reading frames (ORFs) encoding putative proteins with no known functions. Site-directed mutations in two ORFs encoding potential cell surface-associated proteins and a third ORF encoding a putative regulatory protein had no effect on the mutants' capacity to attach to fresh-cut cabbage. Although this study did not show clearly the impact of the differentially expressed genes on growth on cabbage, it is a first step in identifying some of the genetic factors that are potentially involved.

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Pathogenic Biohacking: Induction, Modulation and Subversion of Host Transcriptional Responses by Listeria monocytogenes

Toxins ◽

10.3390/toxins12050294 ◽

2020 ◽

Vol 12 (5) ◽

pp. 294

Author(s):

Matthew J. G. Eldridge ◽

Pascale Cossart ◽

Mélanie A. Hamon

Keyword(s):

Gene Expression ◽

Listeria Monocytogenes ◽

Virulence Factors ◽

Bacterial Pathogen ◽

Typical Feature ◽

Host Gene ◽

Host Cells ◽

Host Gene Expression ◽

Transcriptional Responses ◽

The Impact

During infection, the foodborne bacterial pathogen Listeria monocytogenes dynamically influences the gene expression profile of host cells. Infection-induced transcriptional changes are a typical feature of the host-response to bacteria and contribute to the activation of protective genes such as inflammatory cytokines. However, by using specialized virulence factors, bacterial pathogens can target signaling pathways, transcription factors, and epigenetic mechanisms to alter host gene expression, thereby reprogramming the response to infection. Therefore, the transcriptional profile that is established in the host is delicately balanced between antibacterial responses and pathogenesis, where any change in host gene expression might significantly influence the outcome of infection. In this review, we discuss the known transcriptional and epigenetic processes that are engaged during Listeria monocytogenes infection, the virulence factors that can remodel them, and the impact these processes have on the outcome of infection.

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Assessment of Environmental Factors on Listeria monocytogenes Scott A inlA Gene Expression by Relative Quantitative Taqman Real-Time Reverse Transcriptase PCR

Journal of Food Protection ◽

10.4315/0362-028x-69.11.2754 ◽

2006 ◽

Vol 69 (11) ◽

pp. 2754-2757 ◽

Cited By ~ 6

Author(s):

SCOTT E. HANNA ◽

HUA H. WANG

Keyword(s):

Gene Expression ◽

Listeria Monocytogenes ◽

Environmental Factors ◽

Reverse Transcriptase ◽

Real Time ◽

Virulence Factors ◽

Virulence Factor ◽

Internal Standard ◽

Reverse Transcriptase Pcr ◽

The Impact

Several virulence factors are involved in Listeria monocytogenes pathogenicity. L. monocytogenes internalins, particularly internalin A, are required for bacterial adhesion to and invasion of human intestinal epithelial cells. The expression of inter-nalins is thus related to virulence. Identification of conditions involved in regulating the expression of L. monocytogenes virulence factors is essential for developing targeted strategies to control listeriosis incidence and improving therapeutic approaches. The primary aim of this study was to develop a quantitative real-time reverse transcriptase PCR platform to study the impact of environmental factors on L. monocytogenes Scott A virulence factor expression, particularly in potentially complex ecosystems. A Taqman PCR–based, rapid quantitative gene expression evaluation method was established with the L. monocytogenes ribosomal protein L4 encoding gene used as an internal standard. Our data suggest that inlA expression is influenced by food composition and temperature, indicating that certain food processing or storage conditions, such as the use of lactic and acetic acids at common storage temperatures, could affect the expression of L. monocytogenes virulence factor.

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Growth of Salmonella enterica and Listeria monocytogenes on Fresh-Cut Cantaloupe under Different Temperature Abuse Scenarios

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-468 ◽

2015 ◽

Vol 78 (6) ◽

pp. 1125-1131 ◽

Cited By ~ 15

Author(s):

JINGWEI HUANG ◽

YAGUANG LUO ◽

XIANGWU NOU

Keyword(s):

Listeria Monocytogenes ◽

Salmonella Enterica ◽

Room Temperature ◽

Storage Temperature ◽

Cold Chain ◽

Significant Deterioration ◽

Tissue Integrity ◽

Cell Counts ◽

Fresh Cut ◽

The Impact

Effective cold chain management is a critical component of food safety practice. In this study, we examined the impact of commonly encountered temperature abuse scenarios on the proliferation of Salmonella enterica and Listeria monocytogenes on fresh-cut cantaloupe. Inoculated fresh-cut cantaloupe cubes were subjected to various temperature abuse conditions, and the growth of S. enterica and L. monocytogenes was determined. During 1 week of storage, Salmonella cell counts on fresh-cut cantaloupe increased by −0.26, 1.39, and 2.23 log units at 4°C (control), 8°C, and 12°C (chronic temperature abuse), respectively, whereas that of L. monocytogenes increased by 0.75, 2.86, and 4.17 log units. Under intermittent temperature abuse conditions, where storage temperature fluctuated twice daily to room temperature for 30 min, Salmonella cell count increased by 2.18 log units, whereas that of L. monocytogenes increased by 1.86 log units. In contrast, terminal acute temperature abuses for 2 to 4 h resulted in upwards to 0.6 log unit for Salmonella, whereas the effect on L. monocytogenes was less significant compared with L. monocytogenes on cut cantaloupe stored at 4°C. Significant deterioration of produce visual quality and tissue integrity, as reflected by electrolyte leakage, was also observed under various temperature abuse conditions.

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Photomorphogenesis in Phycomyces: differential display of gene expression by PCR with arbitrary primers

Molecular Genetics and Genomics ◽

10.1007/s00438-002-0680-7 ◽

2002 ◽

Vol 267 (3) ◽

pp. 424-428 ◽

Cited By ~ 14

Author(s):

L. Corrochano

Keyword(s):

Gene Expression ◽

Differential Display ◽

Arbitrary Primers

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Effect of Enterocins A and B on the Viability and Virulence Gene Expression of Listeria monocytogenes in Sliced Dry-Cured Ham

Applied Microbiology ◽

10.3390/applmicrobiol2010001 ◽

2021 ◽

Vol 2 (1) ◽

pp. 1-11

Author(s):

Aida Pérez-Baltar ◽

Margarita Medina ◽

Raquel Montiel

Keyword(s):

Gene Expression ◽

Listeria Monocytogenes ◽

Expression Patterns ◽

Meat Products ◽

Virulence Gene ◽

Virulence Gene Expression ◽

Industrial Processing ◽

Dry Cured Ham ◽

Serotype 4B ◽

The Impact

Dry-cured ham can be contaminated with Listeria monocytogenes during its industrial processing. The use of bacteriocins could ensure the safety of such meat products, but their effect on pathogen physiology is unknown. Therefore, the impact of enterocins A and B on the L. monocytogenes population, and the expression patterns of five genes (inlA, inlB, clpC, fbpA and prfA) related to adhesion/invasion and virulence regulation have been monitored in sliced dry-cured ham during 30 d of storage in refrigeration (4 °C) and temperature-abuse conditions (20 °C). L. monocytogenes strains S2 (serotype 1/2a) and S7-2 (serotype 4b) counts were reduced by 0.5 and 0.6 log units immediately after the application of enterocins A and B, a decrease lower than previously reported. Differences in gene expression were found between the two strains. For strain S2, expression tended to increase for almost all genes up to day seven of storage, whereas this increase was observed immediately after application for strain S7-2; however, overall gene expression was repressed from day one onwards, mainly under temperature-abuse conditions. L. monocytogenes strains investigated in the present work exhibited a mild sensitivity to enterocins A and B in sliced dry-cured ham. Bacteriocins caused changes in the expression patterns of virulence genes associated with adhesion and invasion, although the potential virulence of surviving cells was not enhanced.

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Kitchen-scale Treatments for Reduction of Listeria monocytogenes in Prepared Produce

Journal of Food Protection ◽

10.4315/jfp-21-019 ◽

2021 ◽

Author(s):

Carly Blair Gomez ◽

Elliot T. Ryser ◽

Bradley Marks

Keyword(s):

Listeria Monocytogenes ◽

Mortality Rate ◽

Untreated Control ◽

Tap Water ◽

Fresh Produce ◽

Foodborne Illness ◽

Different Types ◽

Low Incidence ◽

The Impact ◽

Water Rinse

Listeriosis, a foodborne illness caused by Listeria monocytogenes , has relatively low incidence, but a substantial mortality rate, particularly in immunocompromised populations. Because of the known risk of L. monocytogenes and other pathogens in produce, immunocompromised individuals are often placed on neutropenic diets that exclude fresh produce. Therefore, this study aimed to evaluate several kitchen-scale treatments as potential interventions to reduce L. monocytogenes in prepared produce. Cucumbers, apples, and celery were dip inoculated with a three-strain cocktail of L. monocytogenes and dried for 24 h. Inoculated products were subjected to the following treatments as applicable: commercial sanitizer soak (90 s, with agitation), tap water rinse (15 s), tap water soak (90 s, with agitation), surface blanching (25 s), tap water rinse (15 s) followed by peeling, and surface blanching (25 s) followed by peeling. Additionally, inoculum uptake in celery and the impact of two different types of peelers (mechanical crank and manual) were assessed. Treated samples were plated on differential media and incubated for 48 h at 37°C. L. monocytogenes populations were then enumerated and compared to the untreated control (log CFU/g). All treatments lacked efficacy for celery, with reductions significantly less ( P < 0.05) than in other products, likely due to inoculum internalization. The sanitizer soak, tap water rinse, and tap water soak did not differ in efficacy ( P > 0.05), which was low for cucumbers (< 1.5 log CFU/g), apples (< 1.3 log CFU/g), and celery (< 0.7 log CFU/g). The two types of apple peelers did not differ in efficacy ( P > 0.05). Surface blanching and surface blanching followed by peeling were the most effective treatments in both cucumbers and apples ( P < 0.05), with average reductions of 4.2 to 5.1 and 3.5 to 5.9 log CFU/g, respectively.

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