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Applied and Environmental Microbiology Nov 2021In this study, we addressed different aspects regarding the implementation of quasimetagenomic sequencing as a hybrid surveillance method in combination with enrichment...
In this study, we addressed different aspects regarding the implementation of quasimetagenomic sequencing as a hybrid surveillance method in combination with enrichment for early detection of Listeria monocytogenes in the food industry. Different experimental enrichment cultures were used, comprising seven L. monocytogenes strains of different sequence types (STs), with and without a background microbiota community. To assess whether the proportions of the different STs changed over time during enrichment, the growth and population dynamics were assessed using colony sequencing and and 16S rRNA amplicon sequencing. There was a tendency of some STs to have a higher relative abundance during the late stage of enrichment when L. monocytogenes was enriched without background microbiota. When coenriched with background microbiota, the population dynamics of the different STs was more consistent over time. To evaluate the earliest possible time point during enrichment that allows the detection of L. monocytogenes and at the same time the generation of genetic information that enables an estimation regarding the strain diversity in a sample, quasimetagenomic sequencing was performed early during enrichment in the presence of the background microbiota using Oxford Nanopore Technologies Flongle and Illumina MiSeq sequencing. The application of multiple displacement amplification (MDA) enabled detection of L. monocytogenes (and the background microbiota) after only 4 h of enrichment using both applied sequencing approaches. The MiSeq sequencing data additionally enabled the prediction of cooccurring L. monocytogenes strains in the samples. We showed that a combination of a short primary enrichment combined with MDA and Nanopore sequencing can accelerate the traditional process of cultivation and identification of L. monocytogenes. The use of Illumina MiSeq sequencing additionally allowed us to predict the presence of cooccurring L. monocytogenes strains. Our results suggest quasimetagenomic sequencing is a valuable and promising hybrid surveillance tool for the food industry that enables faster identification of L. monocytogenes during early enrichment. Routine application of this approach could lead to more efficient and proactive actions in the food industry that prevent contamination and subsequent product recalls and food destruction, economic and reputational losses, and human listeriosis cases.
Topics: Food Microbiology; Genes, Bacterial; Listeria monocytogenes; Metagenomics; Microbiota; Population Dynamics; RNA, Ribosomal, 16S
PubMed: 34613762
DOI: 10.1128/AEM.01774-21 -
Cellular Microbiology Apr 2020Decades of breakthroughs resulting from cross feeding of microbiological research and technological innovation have promoted Listeria monocytogenes to the rank of model... (Review)
Review
Decades of breakthroughs resulting from cross feeding of microbiological research and technological innovation have promoted Listeria monocytogenes to the rank of model microorganism to study host-pathogen interactions. The extraordinary capacity of this bacterium to interfere with a vast array of host cellular processes uncovered new concepts in microbiology, cell biology and infection biology. Here, we review technological advances that revealed how bacteria and host interact in space and time at the molecular, cellular, tissue and whole body scales, ultimately revolutionising our understanding of Listeria pathogenesis. With the current bloom of multidisciplinary integrative approaches, Listeria entered a new microbiology era.
Topics: Animals; Bacterial Proteins; Biotechnology; Gene Expression Regulation, Bacterial; Host-Pathogen Interactions; Humans; Listeria monocytogenes; Listeriosis; Mice; Virulence; Virulence Factors
PubMed: 32185895
DOI: 10.1111/cmi.13183 -
Food and Chemical Toxicology : An... Nov 2020Listeria monocytogenes is a well-known pathogen responsible for the severe foodborne disease listeriosis. The control of L. monocytogenes occurrence in seafood products... (Review)
Review
Listeria monocytogenes is a well-known pathogen responsible for the severe foodborne disease listeriosis. The control of L. monocytogenes occurrence in seafood products and seafood processing environments is an important challenge for the seafood industry and the public health sector. However, bacteriophage biocontrol shows great potential to be used as safety control measure in seafood. This review provides an update on Listeria-specific bacteriophages, focusing on their application as a safe and natural strategy to prevent L. monocytogenes contamination and growth in seafood products and seafood processing environments. Furthermore, the main properties required from bacteriophages intended to be used as biocontrol tools are summarized and emerging strategies to overcome the current limitations are considered. Also, major aspects relevant for bacteriophage production at industrial scale, their access to the market, as well as the current regulatory status of bacteriophage-based solutions for Listeria biocontrol are discussed.
Topics: Animals; Bacteriophages; Disease Outbreaks; Food Contamination; Foodborne Diseases; Humans; Listeria monocytogenes; Listeriosis; Seafood
PubMed: 32805341
DOI: 10.1016/j.fct.2020.111682 -
Applied and Environmental Microbiology Jun 2024The foodborne pathogen is differentiated into four distinct lineages which differ in their virulence. It remains unknown, however, whether the four lineages also differ...
The foodborne pathogen is differentiated into four distinct lineages which differ in their virulence. It remains unknown, however, whether the four lineages also differ with respect to their ability to persist in food processing facilities, their resistance to high pressure, a preservation method that is used commercially for control on ready-to-eat meats, and their ability to form biofilms. This study aimed to determine differences in the pressure resistance and biofilm formation of 59 isolates of representing lineages I and II. Furthermore, the genetic similarity of 9 isolates of that were obtained from a meat processing facility over a period of 1 year and of 20 isolates of from food processing facilities was analyzed to assess whether the ability of the lineages of to persist in these facilities differs. Analysis of 386 genomes with respect to the source of isolation revealed that genomes of lineage II are over-represented in meat isolates when compared with clinical isolates. Of the 38 strains of that persisted in food processing facilities (this study or published studies), 31 were assigned to lineage II. Isolates of lineage I were more resistant to treatments at 400 to 600 MPa. The thickness of biofilms did not differ between lineages. In conclusion, strains of lineage II are more likely to persist in food processing facilities while strains of lineage I are more resistant to high pressure.IMPORTANCE substantially contributes to the mortality of foodborne disease in developed countries. The virulence of strains of four lineages of differs, indicating that risks associated with the presence of are lineage specific. Our study extends the current knowledge by documentation that the lineage-level phylogeny of plays a role in the source of isolation, in the persistence in food processing facilities, and in the resistance to pathogen intervention technologies. In short, the control of risks associated with the presence of in food is also lineage specific. Understanding the route of contamination is an important factor to consider when designing improved control measures.
Topics: Listeria monocytogenes; Phylogeny; Food Microbiology; Food Handling; Biofilms; Food-Processing Industry; Meat Products
PubMed: 38809044
DOI: 10.1128/aem.00861-24 -
Food Microbiology Oct 2021Genomic diversity of Listeria monocytogenes isolates from the deboning and slicing areas of three dry-cured ham processing plants was analysed. L. monocytogenes was...
Genomic diversity of Listeria monocytogenes isolates from the deboning and slicing areas of three dry-cured ham processing plants was analysed. L. monocytogenes was detected in 58 out of 491 samples from the environment and equipment surfaces, all from the deboning area, with differences in prevalence among facilities. The most frequent PCR-serogroup was IIa (74.1%) followed by IIb and IIc, and only one isolate was serogroup IVb. Twenty different pulsotypes and 11 sequence types (STs) grouped into 10 clonal complexes (CCs) were determined. ST121 (CC121) and ST9 (CC9) were the most abundant. Premature stop codons (PMSC6 and PMSC19) associated with attenuated virulence were found in the inlA sequence in 7 out of 12 selected strains. CC121 strains were strong biofilm formers and some harboured the transposon Tn6188, related with increased tolerance to quaternary ammonium compounds. L. monocytogenes clones considered hypovirulent resulted predominant in the deboning areas. The clonal structure and potential virulence of the isolates could help to establish adequate control measures and cleaning protocols for the comprehensive elimination of the pathogen in dry-cured ham processing environment.
Topics: Animals; Bacterial Proteins; Bacterial Typing Techniques; Biofilms; Equipment Contamination; Equipment and Supplies; Food Handling; Food Microbiology; Genetic Variation; Genomics; Listeria monocytogenes; Meat Products; Pork Meat; Swine
PubMed: 34119091
DOI: 10.1016/j.fm.2021.103779 -
Angewandte Chemie (International Ed. in... Jul 2019Detection of Salmonella and L. monocytogenes in food samples by current diagnostic methods requires relatively long time to results (2-6 days). Furthermore, the... (Review)
Review
Detection of Salmonella and L. monocytogenes in food samples by current diagnostic methods requires relatively long time to results (2-6 days). Furthermore, the ability to perform environmental monitoring at the factory site for these pathogens is limited due to the need for laboratory facilities. Herein, we report new chemiluminescence probes for the ultrasensitive direct detection of viable pathogenic bacteria. The probes are composed of a bright phenoxy-dioxetane luminophore masked by triggering group, which is activated by a specific bacterial enzyme, and could detect their corresponding bacteria with an LOD value of about 600-fold lower than that of fluorescent probes. Moreover, we were able to detect a minimum of 10 Salmonella cells within 6 h incubation. The assay allows for bacterial enrichment and detection in one test tube without further sample preparation. We anticipate that this design strategy will be used to prepare analogous chemiluminescence probes for other enzymes relevant to specific bacteria detection and point-of-care diagnostics.
Topics: Food Microbiology; Listeria monocytogenes; Luminescent Measurements; Salmonella
PubMed: 31233265
DOI: 10.1002/anie.201904719 -
Microbiology and Molecular Biology... Nov 2019The foodborne pathogen can modulate its transcriptome and proteome to ensure its survival during transmission through vastly differing environmental conditions. While... (Review)
Review
The foodborne pathogen can modulate its transcriptome and proteome to ensure its survival during transmission through vastly differing environmental conditions. While utilizes a large array of regulators to achieve survival and growth in different intra- and extrahost environments, the alternative sigma factor σ and the transcriptional activator of virulence genes protein PrfA are two key transcriptional regulators essential for responding to environmental stress conditions and for host infection. Importantly, emerging evidence suggests that the shift from extrahost environments to the host gastrointestinal tract and, subsequently, to intracellular environments requires regulatory interplay between σ and PrfA at transcriptional, posttranscriptional, and protein activity levels. Here, we review the current evidence for cross talk and interplay between σ and PrfA and their respective regulons and highlight the plasticity of σ and PrfA cross talk and the role of this cross talk in facilitating successful transition of from diverse extrahost to diverse extra- and intracellular host environments.
Topics: Bacterial Proteins; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Humans; Listeria monocytogenes; Peptide Termination Factors; Sigma Factor; Signal Transduction; Stress, Physiological; Virulence
PubMed: 31484692
DOI: 10.1128/MMBR.00034-19 -
Cellular Microbiology Apr 2020By modifying the host cell transcription programme, pathogenic bacteria disrupt a wide range of cellular processes and take control of the host's immune system.... (Review)
Review
By modifying the host cell transcription programme, pathogenic bacteria disrupt a wide range of cellular processes and take control of the host's immune system. Conversely, by mobilising a network of defence genes, the host cells trigger various responses that allow them to tolerate or eliminate invaders. The study of the molecular basis of this crosstalk is crucial to the understanding of infectious diseases. Although research has long focused on the targeting of eukaryotic DNA-binding transcription factors, more recently, another powerful way by which bacteria modify the expression of host genes has emerged: chromatin modifications in the cell nucleus. One of the most prolific bacterial models in this area has been Listeria monocytogenes, a facultative intracellular bacterium responsible for serious food-borne infections. Here, we aim to highlight the contribution of this model to the field of bacteria-mediated chromatin modifications. We will first recall the general principles of epigenetic regulation and then illustrate five mechanisms that mobilise the epigenetic machinery in response to Listeria factors, either through bacterial molecular patterns, a toxin, an invasion protein, or nucleomodulins. Strategies used by Listeria to control the expression of host genes at the chromatin level, by activation of cytosolic signalling pathways or direct targeting of epifactors in the nucleus, have contributed to the emergence of a new discipline combining cellular microbiology and epigenetics: "patho-epigenetics."
Topics: Animals; Bacterial Proteins; Chromatin; Epigenesis, Genetic; Host-Pathogen Interactions; Humans; Listeria monocytogenes; Listeriosis; Mice; Protein Binding; Protein Processing, Post-Translational; Virulence Factors
PubMed: 32185898
DOI: 10.1111/cmi.13169 -
International Journal of Food... Oct 2021Among pathogens, L. monocytogenes has the capability to persist on Food Processing Environment (FPE), first of all posing safety issues, then economic impact on...
Among pathogens, L. monocytogenes has the capability to persist on Food Processing Environment (FPE), first of all posing safety issues, then economic impact on productivity. The aim of this work was to determine the influence of biofilm forming-ability and molecular features on the persistence of 19 Listeria monocytogenes isolates obtained from FPE, raw and processed products of a cold-smoked salmon processing plant. To verify the phenotypic and genomic correlations among the isolates, different analyses were employed: serotyping, Clonal Complex (CC), core genome Multi-Locus Sequence Typing (cgMLST) and Single Nucleotide Polymorphisms (SNPs) clustering, and evaluation of the presence of virulence- and persistence-associated genes. From our results, the biofilm formation was significantly higher (*P < 0.05) at 37 °C, compared to 30 and 12 °C, suggesting a temperature-dependent behaviour. Moreover, the biofilm-forming ability showed a strain-specific trend, not correlated with CC or with strains persistence. Instead, the presence of internalin (inL), Stress Survival Islet (SSI) and resistance to erythromycin (ermC) genes was correlated with the ability to produce biofilms. Our data demonstrate that the genetic profile influences the adhesion capacity and persistence of L. monocytogenes in food processing plants and could be the result of environmental adaptation in response to the external selective pressure.
Topics: Animals; Biofilms; Food Handling; Food Industry; Food Microbiology; Listeria monocytogenes; Multilocus Sequence Typing; Salmon
PubMed: 34411997
DOI: 10.1016/j.ijfoodmicro.2021.109353 -
Biochemical and Biophysical Research... Oct 20214-Hydroxyphenylacetic acid (4-HPCA) is the major intestinal metabolite of kaempferol and polymeric proanthocyanidins whereas the effect of 4-HPCA on Listeria...
4-Hydroxyphenylacetic acid (4-HPCA) is the major intestinal metabolite of kaempferol and polymeric proanthocyanidins whereas the effect of 4-HPCA on Listeria monocytogenes remains unknown. In this study, we investigated the effect and mechanism of action of 4-HPCA on the highly lethal foodborne pathogen Listeria monocytogenes. Our results indicated that 4-HPCA inhibited L. monocytogenes growth and proliferation in a dose-dependent manner. In particular, L. monocytogenes displayed negligible growth or proliferation after 4-HPCA treatment (15.61 mM) for 24 h. The impact of 4-HPCA on cell membrane structure and function was investigated in terms of fluorometric cell membrane integrity, zeta potential and relative electrical conductivity. We observed an approximately 15 % fluorescence reduction in the cell membrane after MIC treatment. The zeta potential of the bacteria shifted significantly from -49.74 to -43.70 mV, -36.65 mV and -37.97 mV after treatment with 4-HPCA at the MIC for 0 h, 3 h and 12 h, respectively. The absolute value of the relative electrical conductivities increased significantly following 3 h, 6 h, 9 h and 15 h of 4-HPCA treatment at the MIC level. The results of scanning electron microscopy (SEM) showed that cells treated with 4-HPCA displayed a wrinkled morphology and irregular shapes. Moreover, 4-HPCA obviously decreased the expression of three virulence genes (hlyA, prfA, and inlA) in L. monocytogenes after 12 h of treatment. All these results verified that 4-HPCA, as an effective antibacterial compound against L. monocytogenes, could cause cell death through cell membrane damage and decrease the expression of three virulence factors.
Topics: Anti-Bacterial Agents; Bacterial Outer Membrane; Listeria monocytogenes; Microbial Sensitivity Tests; Phenylacetates
PubMed: 34364294
DOI: 10.1016/j.bbrc.2021.07.096