Listeria monocytogenes: silage, sandwiches and science

2005 ◽  
Vol 6 (2) ◽  
pp. 211-217 ◽  
Author(s):  
Charles J. Czuprynski
Keyword(s):  
Listeria Monocytogenes ◽  
Murine Model ◽  
Pathogenic Bacteria ◽  
Model Organism ◽  
Intracellular Pathogen ◽  
Innate And Adaptive Immunity ◽  
Potential Vector ◽  
Broad Array ◽  
Common Framework ◽  
Substantial Risk

AbstractListeria monocytogenesis amongst the most intriguing and well studied of the pathogenic bacteria. However, the understanding and perspective one has ofL. monocytogenesdepends to a large extent on the microbiological issues with which one is faced as a part of your professional duties. The focus of the veterinary clinician or investigator is likely to be foremost on the neurologic (circling disease) and reproductive diseasesL. monocytogenescauses. To the food microbiologist, the principal concern is to prevent introduction ofL. monocytogenesinto food products, or to identify its presence and prevent its multiplication to numbers of organisms that are likely to pose a substantial risk to humans who ingest the product. To the cellular immunologist, listeriosis represents a robust murine model that helped to elucidate many important concepts in innate and adaptive immunity, andL. monocytogenesis a potential vector for delivery of novel vaccines. To the student of molecular pathogenesis,L. monocytogenesis a powerful and well-characterized model organism for studying the cellular microbiology of an intracellular pathogen. In this brief overview, I will attempt to highlight some of the classical observations, and contemporary insights, onL. monocytogenesand listeriosis, and integrate these perspectives into a common framework. By so doing, I hope to provide those with one perspective on listeriosis with an appreciation of the broad array of problems and issues faced by those who focus on some other aspect ofL. monocytogenesand its pathogenesis.

scholarly journals Identification of a CD4+ T cell-stimulating antigen of pathogenic bacteria by expression cloning.

1995 ◽  
Vol 182 (6) ◽  
pp. 1751-1757 ◽  
Author(s):  
S Sanderson ◽  
D J Campbell ◽  
N Shastri
Keyword(s):  
T Cells ◽  
Listeria Monocytogenes ◽  
T Cell ◽  
Mhc Class Ii ◽  
T Cell Activation ◽  
Pathogenic Bacteria ◽  
Genomic Library ◽  
Class Ii ◽  
Cd4 T Cell ◽  
Expression Cloning

Identifying the immunogenic proteins that elicit pathogen-specific T cell responses is key to rational vaccine design. While several approaches have succeeded in identifying major histocompatibility complex (MHC) class I bound peptides that stimulate CD8+ T cells, these approaches have been difficult to extend to peptides presented by MHC class II molecules that stimulate CD4+ T cells. We describe here a novel strategy for identifying CD4+ T cell-stimulating antigen genes. Using Listeria monocytogenes-specific, lacZ-inducible T cells as single-cell probes, we screened a Listeria monocytogenes genomic library as recombinant Escherichia coli that were fed to macrophages. The antigen gene was isolated from the E. coli clone that, when ingested by the macrophages, allowed generation of the appropriate peptide/MHC class II complex and T cell activation. We show that the antigenic peptide is derived from a previously unknown listeria gene product with characteristics of a membrane-bound protein.

scholarly journals A Rapid and Sensitive Europium Nanoparticle-Based Lateral Flow Immunoassay Combined with Recombinase Polymerase Amplification for Simultaneous Detection of Three Food-Borne Pathogens

2021 ◽  
Vol 18 (9) ◽  
pp. 4574
Author(s):  
Kai Chen ◽  
Biao Ma ◽  
Jiali Li ◽  
Erjing Chen ◽  
Ying Xu ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Vibrio Parahaemolyticus ◽  
Pathogenic Bacteria ◽  
Simultaneous Detection ◽  
Lateral Flow ◽  
Recombinase Polymerase Amplification ◽  
Quantitative Detection ◽  
Bacterial Strains ◽  
Food Borne Pathogens ◽  
Food Borne

Food-borne pathogens have become an important public threat to human health. There are many kinds of pathogenic bacteria in food consumed daily. A rapid and sensitive testing method for multiple food-borne pathogens is essential. Europium nanoparticles (EuNPs) are used as fluorescent probes in lateral flow immunoassays (LFIAs) to improve sensitivity. Here, recombinase polymerase amplification (RPA) combined with fluorescent LFIA was established for the simultaneous and quantitative detection of Listeria monocytogenes, Vibrio parahaemolyticus, and Escherichia coliO157:H7. In this work, the entire experimental process could be completed in 20 min at 37 °C. The limits of detection (LODs) of EuNP-based LFIA–RPA were 9.0 colony-forming units (CFU)/mL for Listeria monocytogenes, 7.0 CFU/mL for Vibrio parahaemolyticus, and 4.0 CFU/mL for Escherichia coliO157:H7. No cross-reaction could be observed in 22 bacterial strains. The fluorescent LFIA–RPA assay exhibits high sensitivity and good specificity. Moreover, the average recovery of the three food-borne pathogens spiked in food samples was 90.9–114.2%. The experiments indicate the accuracy and reliability of the multiple fluorescent test strips. Our developed EuNP-based LFIA–RPA assay is a promising analytical tool for the rapid and simultaneous detection of multiple low concentrations of food-borne pathogens.

scholarly journals An Effective Counterselection System for Listeria monocytogenes and Its Use To Characterize the Monocin Genomic Region of Strain 10403S

2016 ◽  
Vol 83 (6) ◽  
Author(s):  
Tal Argov ◽  
Lev Rabinovich ◽  
Nadejda Sigal ◽  
Anat A. Herskovits
Keyword(s):  
Listeria Monocytogenes ◽  
Point Mutations ◽  
Model Organism ◽  
Trna Synthetase ◽  
Genomic Region ◽  
Selection Marker ◽  
Content Type ◽  
Allelic Exchange ◽  
Suicide Vector ◽  
Screening Systems

ABSTRACT Construction of Listeria monocytogenes mutants by allelic exchange has been laborious and time-consuming due to lack of proficient selection markers for the final recombination event, that is, a marker conveying substance sensitivity to the bacteria bearing it, enabling the exclusion of merodiploids and selection for plasmid loss. In order to address this issue, we engineered a counterselection marker based on a mutated phenylalanyl-tRNA synthetase gene (pheS*). This mutation renders the phenylalanine-binding site of the enzyme more promiscuous and allows the binding of the toxic p-chloro-phenylalanine analog (p-Cl-phe) as a substrate. When pheS* is introduced into L. monocytogenes and highly expressed under control of a constitutively active promoter, the bacteria become sensitive to p-Cl-phe supplemented in the medium. This enabled us to utilize pheS* as a negative selection marker and generate a novel, efficient suicide vector for allelic exchange in L. monocytogenes. We used this vector to investigate the monocin genomic region in L. monocytogenes strain 10403S by constructing deletion mutants of the region. We have found this region to be active and to cause bacterial lysis upon mitomycin C treatment. The future applications of such an effective counterselection system, which does not require any background genomic alterations, are vast, as it can be modularly used in various selection systems (e.g., genetic screens). We expect this counterselection marker to be a valuable genetic tool in research on L. monocytogenes. IMPORTANCE L. monocytogenes is an opportunistic intracellular pathogen and a widely studied model organism. An efficient counterselection marker is a long-standing need in Listeria research for improving the ability to design and perform various genetic manipulations and screening systems for different purposes. We report the construction and utilization of an efficient suicide vector for allelic exchange which can be conjugated, leaves no marker in the bacterial chromosome, and does not require the use of sometimes leaky inducible promoters. This highly efficient genome editing tool for L. monocytogenes will allow for rapid sequential mutagenesis, introduction of point mutations, and design of screening systems. We anticipate that it will be extensively used by the research community and yield novel insights into the diverse fields studied using this model organism.

scholarly journals Use of multi-locus sequencing typing as identification method for the food-borne pathogen Listeria monocytogenes: a review

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Sonia Lamon ◽  
Domenico Meloni ◽  
Simonetta Gianna Consolati ◽  
Anna Mureddu ◽  
Rina Mazzette
Keyword(s):  
Listeria Monocytogenes ◽  
Detection Methods ◽  
Causative Organism ◽  
Intracellular Pathogen ◽  
Bacterial Strains ◽  
New Approach ◽  
Food Borne ◽  
Global Epidemiology ◽  
Selection Of

<em>Listeria monocytogenes</em> is an ubiquitous, intracellular pathogen which has been implicated within the past decade as the causative organism in several outbreaks of foodborne diseases. In this review, a new approach to molecular typing primarily designed for global epidemiology has been described: multi-<em>locus</em> sequencing typing (MLST). This approach is novel, in that it uses data that allow the unambiguous characterization of bacterial strains via the Internet. Our aim is to present the currently available selection of references on <em>L. monocytogenes</em> MLST detection methods and to discuss its use as <em>gold</em> <em>standard</em> to <em>L. monocytogenes</em> subtyping method.

scholarly journals Antimicrobial activity of the volatile phase of essential oils and their constituents on Legionella pneumophila

2020 ◽  
Vol 14 (1) ◽  
pp. 54-61
Author(s):  
Lucia Bićanić ◽  
Silvestar Mežnarić ◽  
Ivana Gobin
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Legionella Pneumophila ◽  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Model Organism ◽  
Public Health Problem ◽  
Volatile Components ◽  
Atypical Pneumonia ◽  
Pontiac Fever

Abstract Pathogenic bacteria of the genus Legionella cause atypical pneumonia known as Legionnaires’ disease and flu – like disease known as Pontiac fever. As pathogens of the respiratory system, these bacteria represent a public health problem and there is a need for examine new alternative ways to inactivate them. These bacteria live naturally in water and are transmitted by infectious aerosols. To purify the air, essential oils that show antimicrobial properties are widely used. The anti-Legionella activity of five exotic essential oils and five Mediterranean essential oils characteristic for coastal Croatia was examined. Model organism used in experiments was L. pneumophila (strain 130b). This experiment was conducting with modified version of sealed plate method using a BCYE medium. The exotic essential oil with highest anti-Legionella activity was Niaouli essential oil, and the best anti-Legionella activity among Mediterranean essential oils showed Immortelle essential oil. Anti- Legionella activity of four main chemical compounds was examined and compound that show significant highest anti-Legionella activity was α – pinene. Volatile components of essential oils have a great potential as anti-Legionella agents and further research are needed.

scholarly journals The Diversity of Bacteria Associated with the Invasive Gall Wasp Dryocosmus kuriphilus, Its Galls and a Specialist Parasitoid on Chestnuts

Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 86
Author(s):  
Xiaohui Yang ◽  
Yu Hui ◽  
Daohong Zhu ◽  
Yang Zeng ◽  
Lvquan Zhao ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Plant Pathogens ◽  
High Throughput Sequencing ◽  
Bacterial Species ◽  
Gall Wasp ◽  
Potential Vector ◽  
Dryocosmus Kuriphilus ◽  
Torymus Sinensis ◽  
Galling Insects ◽  
First Time

Dryocosmus kuriphilus (Hymenoptera: Cynipidae) induces galls on chestnut trees, which results in massive yield losses worldwide. Torymus sinensis (Hymenoptera: Torymidae) is a host-specific parasitoid that phenologically synchronizes with D. kuriphilus. Bacteria play important roles in the life cycle of galling insects. The aim of this research is to investigate the bacterial communities and predominant bacteria of D. kuriphilus, T. sinensis, D. kuriphilus galls and the galled twigs of Castanea mollissima. We sequenced the V5–V7 region of the bacterial 16S ribosomal RNA in D. kuriphilus, T. sinensis, D. kuriphilus galls and galled twigs using high-throughput sequencing for the first time. We provide the first evidence that D. kuriphilus shares most bacterial species with T. sinensis, D. kuriphilus galls and galled twigs. The predominant bacteria of D. kuriphilus are Serratia sp. and Pseudomonas sp. Furthermore, the bacterial community structures of D. kuriphilus and T. sinensis clearly differ from those of the other groups. Many species of the Serratia and Pseudomonas genera are plant pathogenic bacteria, and we suggest that D. kuriphilus may be a potential vector of plant pathogens. Furthermore, a total of 111 bacteria are common to D. kuriphilus adults, T. sinensis, D. kuriphilus galls and galled twigs, and we suggest that the bacteria may transmit horizontally among D. kuriphilus, T. sinensis, D. kuriphilus galls and galled twigs on the basis of their ecological associations.

scholarly journals Evaluation of sanitary quality of goat milk in dairy industries from the Cariri region, state of Paraíba

2021 ◽  
Vol 10 (12) ◽  
pp. e596101220735
Author(s):  
Iara Nunes de Siqueira ◽  
Aline Antas Cordeiro Cavalcanti ◽  
Joyce Galvão de Souza ◽  
Filipe Jordão Pereira de Medeiros ◽  
João Carlos Taveira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Goat Milk ◽  
Salmonella Spp ◽  
Pasteurized Milk ◽  
Enterococcus Spp ◽  
Bacillus Spp ◽  
Thermotolerant Coliforms ◽  
Staphylococcus Spp

The sanitary evaluation of equipment and hands is fundamental to investigate the presence of pathogens in the dairy industry. Then, this study aims to evaluate the sanitization of equipment, workers’ hands, raw and pasteurized milk in goat milk dairies in the Cariri region, state of Paraíba.  Collected 32 samples of four dairies represented by letters A, B, C, and D. The followings contents were analyzed: mesophiles, total and thermotolerant coliforms, Escherichia coli, Staphylococcus aureus, Samonella spp. and Listeria monocytogenes in the reception tank, pasteurization tank, packing machine, package, wall, workers’ hand, and each dairy’s raw and pasteurized milk. After isolation, 84 colonies were confirmed by MALDI TOF. The indicator microorganisms presented variations for the workers’ hands, while A and B stayed within the patterns. For the equipment, only dairy B was within limits. They were out of the standard for mesophiles, total coliforms, and thermotolerant regarding raw and pasteurized milk. The microorganisms, the Enterobacteriaceae family presented a higher frequency, with 77.38%, and within this family, Escherichia coli, Klebsiella spp., and Enterobacter spp. were the most prevalent. Gram-positive corresponded to 22.62%, Bacillus spp., Staphylococcus spp., Enterococcus spp., and Macrococcus caseolyticus. Listeria monocytogenes and Salmonella spp. were not isolated. These demonstrate failures in goat milk processing with pathogenic bacteria in several dairy plants, indicating the need to adjust the product’s quality control.

scholarly journals Review on Pathogenic Bacteria Listeria monocytogenes, The Detection and The Sequencing Gene Methods Isolated from Meat Products

2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Bhakti Etza Setiani ◽  
Yoyok Budi Pramono ◽  
Lutfi Purwitasari
Keyword(s):  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Meat Product ◽  
Meat Products ◽  
Processed Meat ◽  
Confirmation Test ◽  
Optimum Ph ◽  
Bacterium Species ◽  
Genotypic Identification ◽  
Ph Range

A study was conducted to review on pathogenic bacteria Listeria monocytogenes, the detection and the sequencing gene methods isolated from meat products, compare selected methods that detect the presence of Listeria monocytogenes in selected raw and processed meat products. Results indicate that Listeria monocytogenenes (originally named Bacterium monocytogenes) is a gram-positive, non-sporeforming, highly mobile, rod-type, and facultative anaerobic bacterium species. It can grow under temperatures between -1.5°C to 45°C and at pH range between 4.4 and 9.4, with the optimum pH of 7. Rapid methods (PCR based and VIDAS-LDUO®) detected Listeria monocytogenes faster than the conventional method. It was also gathered that Phenotypic identification and Genotypic identification are two types of confirmation test for Listeria monocytogenes. Listeria monocytogenenes can be found in raw meat and meat product because of environmental contamination, cross contamination or error process.

scholarly journals Identification and Characterization of Di- and Tripeptide Transporter DtpT of Listeria monocytogenes EGD-e

2005 ◽  
Vol 71 (10) ◽  
pp. 5771-5778 ◽  
Author(s):  
Jeroen A. Wouters ◽  
Torsten Hain ◽  
Ajub Darji ◽  
Eric Hüfner ◽  
Henrike Wemekamp-Kamphuis ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Opportunistic Infections ◽  
Essential Amino Acids ◽  
Defined Medium ◽  
Infection Model ◽  
Intracellular Pathogen ◽  
Mouse Infection Model ◽  
Stress Protection ◽  
Identification And Characterization

ABSTRACT Listeria monocytogenes is a gram-positive intracellular pathogen responsible for opportunistic infections in humans and animals. Here we identified and characterized the dtpT gene (lmo0555) of L. monocytogenes EGD-e, encoding the di- and tripeptide transporter, and assessed its role in growth under various environmental conditions as well as in the virulence of L. monocytogenes. Uptake of the dipeptide Pro-[14C]Ala was mediated by the DtpT transporter and was abrogated in a ΔdtpT isogenic deletion mutant. The DtpT transporter was shown to be required for growth when the essential amino acids leucine and valine were supplied as peptides. The protective effect of glycine- and proline-containing peptides during growth in defined medium containing 3% NaCl was noted only in L. monocytogenes EGD-e, not in the ΔdtpT mutant strain, indicating that the DtpT transporter is involved in salt stress protection. Infection studies showed that DtpT contributes to pathogenesis in a mouse infection model but has no role in bacterial growth following infection of J774 macrophages. These studies reveal that DptT may contribute to the virulence of L. monocytogenes.

DIAGNOSTIC PREPARATIONS FOR DETERMINING THE SPECIES OF THE BACTERIA LISTERIA MONOCYTOGENES

2021 ◽  
Author(s):  
V. G. Lobanova ◽  
Keyword(s):  
Listeria Monocytogenes ◽  
Dairy Products ◽  
Pathogenic Bacteria ◽  
Food Products ◽  
Nutrient Media ◽  
Microbiological Study ◽  
Highly Sensitive

This article presents a work on the microbiological study of food products for the presence of pathogenic bacteria Listeria monocytogenes, which can cause listeriosis in humans if sanitary and hygienic rules and regulations are not followed. Highly sensitive and specific nutrient media make it possible to quickly and efficiently test meat, vegetable and dairy products for the detection of Listeria monocytogenes.

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