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Trends in Microbiology Sep 2021Listeria monocytogenes is a foodborne pathogen responsible for listeriosis, an infection that can manifest in humans as bacteremia, meningoencephalitis in... (Review)
Review
Listeria monocytogenes is a foodborne pathogen responsible for listeriosis, an infection that can manifest in humans as bacteremia, meningoencephalitis in immunocompromised patients and the elderly, and fetal-placental infection in pregnant women. Reference strains from this facultative intracellular bacterium have been instrumental in the investigation of basic mechanisms in microbiology, immunology, and cell biology. The integration of bacterial population genomics with environmental, epidemiological, and clinical data allowed the uncovering of new factors involved in the virulence of L. monocytogenes and its adaptation to different environments. This review illustrates how these investigations have led to a better understanding of the bacterium's virulence and the driving forces that shaped it.
Topics: Adaptation, Physiological; Animals; Biodiversity; Humans; Listeria monocytogenes; Listeriosis; Virulence
PubMed: 33583696
DOI: 10.1016/j.tim.2021.01.008 -
Microbiological Reviews Sep 1991The gram-positive bacterium Listeria monocytogenes is an ubiquitous, intracellular pathogen which has been implicated within the past decade as the causative organism in... (Review)
Review
The gram-positive bacterium Listeria monocytogenes is an ubiquitous, intracellular pathogen which has been implicated within the past decade as the causative organism in several outbreaks of foodborne disease. Listeriosis, with a mortality rate of about 24%, is found mainly among pregnant women, their fetuses, and immunocompromised persons, with symptoms of abortion, neonatal death, septicemia, and meningitis. Epidemiological investigations can make use of strain-typing procedures such as DNA restriction enzyme analysis or electrophoretic enzyme typing. The organism has a multifactorial virulence system, with the thiol-activated hemolysin, listeriolysin O, being identified as playing a crucial role in the organism's ability to multiply within host phagocytic cells and to spread from cell to cell. The organism occurs widely in food, with the highest incidences being found in meat, poultry, and seafood products. Improved methods for detecting and enumerating the organism in foodstuffs are now available, including those based on the use of monoclonal antibodies, DNA probes, or the polymerase chain reaction. As knowledge of the molecular and applied biology of L. monocytogenes increases, progress can be made in the prevention and control of human infection.
Topics: Animals; Food Microbiology; Humans; Listeria monocytogenes; Listeriosis; Virulence
PubMed: 1943998
DOI: 10.1128/mr.55.3.476-511.1991 -
Microbiology Spectrum Jul 2019Bacterial metabolism represents the biochemical space that bacteria can manipulate to produce energy, reducing equivalents and building blocks for replication.... (Review)
Review
Bacterial metabolism represents the biochemical space that bacteria can manipulate to produce energy, reducing equivalents and building blocks for replication. Gram-positive pathogens, such as , show remarkable flexibility, which allows for exploitation of diverse biological niches from the soil to the intracytosolic space. Although the human host represents a potentially rich source for nutrient acquisition, competition for nutrients with the host and hostile host defenses can constrain bacterial metabolism by various mechanisms, including nutrient sequestration. Here, we review metabolism in the model Gram-positive bacterium, , and highlight pathways that enable the replication, survival, and virulence of this bacterial pathogen.
Topics: Animals; Bacterial Proteins; Gene Expression Regulation, Bacterial; Humans; Listeria monocytogenes; Listeriosis; Virulence
PubMed: 31418407
DOI: 10.1128/microbiolspec.GPP3-0066-2019 -
Microbiology Spectrum Jul 2019Whereas obligate human and animal bacterial pathogens may be able to depend upon the warmth and relative stability of their chosen replication niche, environmental... (Review)
Review
Whereas obligate human and animal bacterial pathogens may be able to depend upon the warmth and relative stability of their chosen replication niche, environmental bacteria such as that harbor the ability to replicate both within animal cells and in the outside environment must maintain the capability to manage life under a variety of disparate conditions. Bacterial life in the outside environment requires adaptation to wide ranges of temperature, available nutrients, and physical stresses such as changes in pH and osmolarity as well as desiccation. Following ingestion by a susceptible animal host, the bacterium must adapt to similar changes during transit through the gastrointestinal tract and overcome a variety of barriers associated with host innate immune responses. Rapid alteration of patterns of gene expression and protein synthesis represent one strategy for quickly adapting to a dynamic host landscape. Here, we provide an overview of the impressive variety of strategies employed by the soil-dwelling, foodborne, mammalian pathogen to straddle diverse environments and optimize bacterial fitness both inside and outside host cells.
Topics: Animals; Bacterial Proteins; Gene Expression Regulation, Bacterial; Humans; Immunity, Innate; Listeria monocytogenes; Listeriosis; Osmolar Concentration; Virulence
PubMed: 31441398
DOI: 10.1128/microbiolspec.GPP3-0064-2019 -
Journal of Applied Microbiology Oct 2018Listeria monocytogenes is an intracellular human pathogen which enters the body through contaminated food stuffs and is known to contaminate fresh leafy produce such as... (Review)
Review
Listeria monocytogenes is an intracellular human pathogen which enters the body through contaminated food stuffs and is known to contaminate fresh leafy produce such as spinach, lettuce and rocket. Routinely, fresh leafy produce is grown and processed on a large scale before reaching the consumer through various products such as sandwiches and prepared salads. From farm to fork, the fresh leafy produce supply chain (FLPSC) is complex and contains a diverse range of environments where L. monocytogenes is sporadically detected during routine sampling of produce and processing areas. This review describes sources of the bacteria in the FLPSC and outlines the physiological and molecular mechanisms behind its survival in the different environments associated with growing and processing fresh produce. Finally, current methods of source tracking the bacteria in the context of the food supply chain are discussed with emphasis on how these methods can provide additional, valuable information on the risk that L. monocytogenes isolates pose to the consumer.
Topics: Colony Count, Microbial; Food Contamination; Food Handling; Humans; Listeria monocytogenes; Plant Leaves; Vegetables
PubMed: 30039586
DOI: 10.1111/jam.14025 -
Cellular Microbiology Oct 2017Listeria monocytogenes, the causative agent of listeriosis, is an intracellular pathogen that is exquisitely evolved to survive and replicate in the cytosol of... (Review)
Review
Listeria monocytogenes, the causative agent of listeriosis, is an intracellular pathogen that is exquisitely evolved to survive and replicate in the cytosol of eukaryotic cells. Eukaryotic cells typically restrict bacteria from colonising the cytosol, likely through a combination of cell autonomous defences, nutritional immunity, and innate immune responses including induction of programmed cell death. This suggests that L. monocytogenes and other professional cytosolic pathogens possess unique metabolic adaptations, not only to support replication but also to facilitate resistance to host-derived stresses/defences and avoidance of innate immune activation. In this review, we outline our current understanding of L. monocytogenes metabolism in the host cytosol and highlight major metabolic processes which promote intracellular replication and survival.
Topics: Cytosol; Immunity, Innate; Listeria monocytogenes; Virulence
PubMed: 28656691
DOI: 10.1111/cmi.12762 -
Current Opinion in Microbiology Feb 2019Listeria monocytogenes (Lm) is a Gram-positive bacterium that thrives in nature as a saprophyte and in the mammalian host as an intracellular pathogen. Both environments... (Review)
Review
Listeria monocytogenes (Lm) is a Gram-positive bacterium that thrives in nature as a saprophyte and in the mammalian host as an intracellular pathogen. Both environments pose potential danger in the form of redox stress. In addition, endogenous reactive oxygen species (ROS) are continuously generated as by-products of aerobic metabolism. Redox stress from ROS can damage proteins, lipids, and DNA, making it highly advantageous for bacteria to evolve mechanisms to sense and detoxify ROS. This review focuses on the five redox-responsive regulators in Lm: OhrR (to sense organic hydroperoxides), PerR (peroxides), Rex (NAD/NADH homeostasis), SpxA1/2 (disulfide stress), and PrfA (redox stress during infection).
Topics: Gene Expression Regulation, Bacterial; Listeria monocytogenes; Metabolic Networks and Pathways; Oxidation-Reduction; Reactive Oxygen Species
PubMed: 30412828
DOI: 10.1016/j.mib.2018.10.006 -
Applied Microbiology and Biotechnology Jun 2016The genus Listeria is currently comprised of 17 species, including 9 Listeria species newly described since 2009. Genomic and phenotypic data clearly define a distinct... (Review)
Review
The genus Listeria is currently comprised of 17 species, including 9 Listeria species newly described since 2009. Genomic and phenotypic data clearly define a distinct group of six species (Listeria sensu strictu) that share common phenotypic characteristics (e.g., ability to grow at low temperature, flagellar motility); this group includes the pathogen Listeria monocytogenes. The other 11 species (Listeria sensu lato) represent three distinct monophyletic groups, which may warrant recognition as separate genera. These three proposed genera do not contain pathogens, are non-motile (except for Listeria grayi), are able to reduce nitrate (except for Listeria floridensis), and are negative for the Voges-Proskauer test (except for L. grayi). Unlike all other Listeria species, species in the proposed new genus Mesolisteria are not able to grow below 7 °C. While most new Listeria species have only been identified in a few countries, the availability of molecular tools for rapid characterization of putative Listeria isolates will likely lead to future identification of isolates representing these new species from different sources. Identification of Listeria sensu lato isolates has not only allowed for a better understanding of the evolution of Listeria and virulence characteristics in Listeria but also has practical implications as detection of Listeria species is often used by the food industry as a marker to detect conditions that allow for presence, growth, and persistence of L. monocytogenes. This review will provide a comprehensive critical summary of our current understanding of the characteristics and distribution of the new Listeria species with a focus on Listeria sensu lato.
Topics: Biological Evolution; Genome, Bacterial; Listeria; Listeria monocytogenes; Phylogeny; Species Specificity; Virulence
PubMed: 27129530
DOI: 10.1007/s00253-016-7552-2 -
Molecular Microbiology Dec 2021Listeria monocytogenes is a food-borne bacterium that causes gastroenteritis, meningitis, or abortion. L. monocytogenes induces its internalization (entry) into human... (Review)
Review
Listeria monocytogenes is a food-borne bacterium that causes gastroenteritis, meningitis, or abortion. L. monocytogenes induces its internalization (entry) into human cells and either spreads laterally in tissues or transcytoses to traverse anatomical barriers. In this review, we discuss mechanisms by which five structurally related proteins of the "internalin" family of L. monocytogenes (InlA, InlB, InlC, InlF, and InlP) interact with distinct host receptors to promote infection of human cells and/or crossing of the intestinal, blood-brain, or placental barriers. We focus on recent results demonstrating that the internalin proteins InlA, InlB, and InlC exploit exocytic pathways to stimulate transcytosis, entry, or cell-to-cell spread, respectively. We also discuss evidence that InlA-mediated transcytosis contributes to traversal of the intestinal barrier, whereas InlF promotes entry into endothelial cells to breach the blood-brain barrier. InlB also facilitates the crossing of the blood-brain barrier, but does so by extending the longevity of infected monocytes that may subsequently act as a "Trojan horse" to transfer bacteria to the brain. InlA, InlB, and InlP each contribute to fetoplacental infection by targeting syncytiotrophoblast or cytotrophoblast layers of the placenta. This work highlights the diverse functions of internalins and the complex mechanisms by which these structurally related proteins contribute to disease.
Topics: Animals; Bacterial Proteins; Humans; Listeria monocytogenes; Listeriosis; Membrane Proteins; Transcytosis
PubMed: 34704304
DOI: 10.1111/mmi.14836 -
BMC Microbiology May 2020Listeria monocytogenes (L. monocytogenes) is a global opportunistic intracellular pathogen that can cause many infections, including meningitis and abortion in humans...
BACKGROUND
Listeria monocytogenes (L. monocytogenes) is a global opportunistic intracellular pathogen that can cause many infections, including meningitis and abortion in humans and animals; thus, L. monocytogenes poses a great threat to public safety and the development of the aquaculture industry. The isolation rate of Listeria monocytogenes in fishery products has always been high. And the pore-forming toxin listeriolysin O (LLO) is one of the most important virulence factors of L. monocytogenes. LLO can promote cytosolic bacterial proliferation and help the pathogen evade attacks from the host immune system. In addition, L. monocytogenes infection can trigger a series of severe inflammatory reactions.
RESULTS
Here, we further confirmed that morin lacking anti-Listeria activity could inhibit LLO oligomerization. We also found that morin can effectively alleviate the inflammation induced by Listeria in vivo and in vitro and exerted an obvious protective effect on infected cells and mice.
CONCLUSIONS
Morin does not possess anti-Listeria activity, neither does it interfere with secretion of LLO. However, morin inhibits oligomerisation of LLO and morin does reduce the inflammation caused during Listeria infection.
Topics: Animals; Bacterial Toxins; Cell Line; Disease Models, Animal; Flavonoids; Gene Expression Regulation, Bacterial; Heat-Shock Proteins; Hemolysin Proteins; Humans; Listeria monocytogenes; Listeriosis; Mice; Protein Multimerization; Virulence
PubMed: 32398085
DOI: 10.1186/s12866-020-01807-6