Listeria monocytogenes Essay - 1007 Words

Listeria monocytogenes Introduction Listeria monocytogenes, a motile, gram-positive rod, is an opportunistic food-borne pathogen capable of causing listeriosis in humans. Listeriosis includes manifestations of septicemia, meningitis, pneumonia, and encephalitis. L. monocytogenes is also implicated in miscarriages, stillbirth, and premature birth for pregnant women. L. monocytogenes is a tough bacterium resistant to freezing, drying, and heat; most strains have been shown to be pathogenic. It is hypothesized that 1-10% of humans are intestinal carriers of L. monocytogenes. Over 37 mammalian species, including wild and domestic animals, are capable of L. monocytogenes infection and transmission. Extensive environmental reservoirs for L.†¦show more content†¦Pathogenic L. monocytogenes go through an intracellular life cycle involving early escape from the phagocytic vacuole, rapid intracytoplasmic multiplication, bacterially induced actin-based motility, and direct spread to neighboring cells, in which they reini tiate the cycle. The bacterium is first phagocytosed by these cells and secretes a pore-forming toxin called listeriolysin, which allows the bacterium to escape from the phagosome. All virulent strains of L. monocytogenes synthesize and secrete listeriolysin. Phospholipase A and B are other virulence factors that facilitate escape of L. monocytogenes from the phagosome. Once out of the phagosome L. monocytogenes is capable of rapid division in the cytoplasm, evading the immune response and moving throughout the cytoplasm from cell to cell. L. monocytogenes is well known for its ability to propel itself like a rocket through the cell cytoplasm. This is the result of the bacterium’s ability to polymerize actin filaments at its tail end. Actin is arranged in subunits to form microfilaments that are capable of directing cell movement. L. monocytogenes accomplishes cell motility through a virulence factor called ActA that takes advantage of normal actin polymerization going on in the cell. The ActA protein shares sequence homology with a protein called WASP that is found in virtually all eukaryotic cells. WASP is responsible for recognizing andShow MoreRelatedListeria Monocytogenes2714 Words   |  11 PagesDescription Listeria monocytogenes is a gram-positive motile facultative anaerobe that inhabits a variety of environments. Using selective media it can be readily isolated from soil, water, vegetation and processed products, including ready-to-eat products designated for human consumption (Graves et al., 1992). The bacterium was named monocytogenes because one distinguish characteristic of infection in rabbits, which was the production of monocytosis in blood (Shuin et al., 1982). L. monocytogenes is phychrophilicRead MoreListeria Monocytogenes Essay examples660 Words   |  3 PagesListeria monocytogenes can cause a food borne illness called Listeriosis. (Murano 2003) This bacterium can be found in soil and water. (Murano 2003) Unlike many other germs, it can grow in cold temperatures such as the refrigerator. Listeria monocytogenes can be killed by pasteurization and cooking. (Murano 2003) Some foods that are typically contaminate by Listeria monocytogenes are a variety of raw foods, processed foods and foods made from unpasteurized milk. Vegetables can become contaminatedRead MoreA Dairy Problem : Listeria Monocytogenes1612 Words   |  7 PagesA Dairy Problem: Listeria monocytogenes I. History One of the earliest detections of Listeria was in 1924 by E.G.D. Murray from rabbits. He isolated Gram-positive rods from a rabbit’s blood in the laboratory. He was unable to classify it with other bacterial genus, thus he decided to call this new species Bacterium monocytogenes. However, only after 1940 that this bacterium was given the genus name Listeria by J.H.H. Pirie. He was able to classify it due to its catalase-positive, Gram-positive rodRead MoreThe Outbreak Of Salmonella Heidelberg1806 Words   |  8 Pagesfoods, proper hygiene, as well as sanitary supplies and work space/place. (b) Similar to the Salmonella outbreak, in 2011 there was another, unrelated, multistate outbreak of Listeria monocytogenes infections (Listeriosis). There were a total of 147 affected persons; this includes all 5 of the associated subtypes of Listeria. The affected persons were found in 28 states. Furthermore, there were a total of 33 related deaths, one spontaneous abortion, and 10 additional deaths resulting from an infectionRead MoreEssay on Listeria Monocytogenus1293 Words   |  6 Pages Introduction: The purpose of this Literature review is to gain a broader insight into the food borne pathogen known as Listeria and its traits .In This review I will discuss in detail the different types of Listeria Species which can be isolated from various types of food samples and determining their overall antibiotic resistance, the illness associated with each and the incidences and outbreaks worldwide. I will then compare my overall findings, due to the word count I will not be discussing theRead MoreFoodborne Pathogens And Effects Of Biofilms1035 Words   |  5 PagesThe potential of foodborne pathogens and spoilage organisms to form biofilms has raised issues in food industries. A wide range of micro-organisms such as Listeria monocytogenes, Bacillus cereus, Escherichia coli O157:H7, Salmonella spp., Pseudomonas spp., Staphylococcus aureus, have been documented to cause biofilm formation on food and food contact surfaces (Dewanti Wong, 1995; Sharma Anand, 2002). Apart from bacteriaâ€⠄¢s intrinsic capability to initiate attachment, extrinsic factors such asRead MoreThe Effects Of Listeria Monovytogenes On Healthy Population908 Words   |  4 PagesIntroduction: Listeria Monovytogenes is a soil opptunistic bacterium that at same time is a food borne pathogen. Though its existence in nature can be as high as 20% in soil-plant sample, the infection occurs in healthy population is rare. However, to population that have immature or compromised immune systems, it is a dangerous pathogen; its infection has a mortality rate as high as 30%. The first record of L. Monovytogenes discovery was in 1926, when Department of Pathology of the University ofRead MoreAntimicrobial Activity Of The Essential Oil1607 Words   |  7 Pagesrelative percentages of 34.39, ‎†15.17†Ã¢â‚¬Å½, ‎†6.54†Ã¢â‚¬Å½, ‎†5.81†Ã¢â‚¬Å½, ‎†5.14†Ã¢â‚¬Å½ ‎and 5.06 %, respectively. Z. clinopodioides essential oil exhibited varied ‎antibacterial activity against all examined strains. Among the examined bacterial ‎species, Listeria monocytogenes was the most sensitive while Pseudomonas ‎aerogi nosa was the most resistant to the essential oil, using both qualitative and ‎quantitative assays. Z. clinopodioides essential oil could, however, be ‎recommended for further applications asRead MoreConsiderations of Food Safety1128 Words   |  4 Pagescompound that controls microbial activity of certain pathogenic bacteria species (Riley and Wertz, 2002). The gram-positive bacterium, Listeria monocytogenes, is a pathogen present in the environment that could resist drastic conditions. Bower (1995) revealed that this organism is the primary cause of Listeriosis, a name for general group of disorders caused by L. monocytogenes that could result in intrauterine infection, or worse, spontaneous abortion or stillbirth to pregnant women. However, the said bacteriaRead MoreTypes Of The Immune System1445 Words   |  6 Pagespatterns (PAMPs) derived from pathogens could be a suitable agent. Our earlier research has shown that protein components derived from Listeria monocytogenes can induce mouse and human DC maturation [12, 13]. Recently, we figure out that one characterized protein fraction (F2HIC; fraction 2 obtained by hydrophobic interaction chromatography) derived from Listeria monocytogenes is able to activate human DC maturation [14]. We identifies 109 different proteins in this fraction. Based on that study we found