Listeriosis: Difference between revisions
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===Epidemiology=== | ===Epidemiology=== | ||
===Virulence factors=== | ===Virulence factors=== | ||
1. Adhesion to the surface of mammalian cells. Close interaction between host cells and <i> L. monocytogenes </i> makes invasion possible. Numerous surface adhesion factors allow the pathogen to connect to host cells | 1. Adhesion to the surface of mammalian cells. Close interaction between host cells and <i> L. monocytogenes </i> makes invasion possible. Numerous surface adhesion factors allow the pathogen to connect to host cells such as: <br> | ||
<ul> | <ul> | ||
<li> Lap adhesion protein uses an alcohol acetaldehyde dehydrogenase interaction with the host cell receptor, Hsp60, to adhere to intestinal cells. This Lap protein is required for full virulence. </li> | <li> Lap adhesion protein uses an alcohol acetaldehyde dehydrogenase interaction with the host cell receptor, Hsp60, to adhere to intestinal cells. This Lap protein is required for full virulence. </li> | ||
<li>Ami protein associates to the bacterial surface via its C-terminal cell wall-anchoring (CWA) domain. The CWA allow adhesion to host epithelial cells. </li> | <li>Ami protein associates to the bacterial surface via its C-terminal cell wall-anchoring (CWA) domain. The CWA allow adhesion to host epithelial cells. </li> | ||
<li> The gene segment <i> dltA </i> integrates D-alanine-polyphosphoribitol into lipoteichoic acids (LTAs)which contributes to cell adhesion.</li> | <li> The gene segment <i> dltA </i> integrates D-alanine-polyphosphoribitol into lipoteichoic acids (LTAs)which contributes to cell adhesion.</li> | ||
<li> FbpA is expressed on the bacterial surface and binds to stationary host fibronectin. FbpA also helps expression of LLO and InlB (other virulence factor proteins). </li> | |||
<li>The C-terminus of InlJ has an LPXTG segment which bonds LPXTG-containing proteins to the cell membrane of the host. </li> | |||
</ul> | |||
==Clinical features== | ==Clinical features== | ||
Revision as of 09:38, 14 July 2013
Etiology/Bacteriology
Taxonomy
Domain: Bacteria
Kingdom: Bacteria
Phylum: Firmicutes
Class: Bacilli
Order: Bacillales
Family: Listeriaceae
Genus: Listeria
Species: monocytogenes
Description
Listeria are gram positive facultative anaerobes observed to be bacilli in short chains. If a direct sample is observed under the microscope, Listeria can resemble cocci shapes and can be mistaken for streptococci. All species produce flagella at room temperature but do not express it at 37 degrees Celsius. These non-spore forming, catalase positive bacteria are found in soil, sewage, stream water and animal carriers.
Pathogenesis
Transmission
Infectious dose, incubation, and colonization
Epidemiology
Virulence factors
1. Adhesion to the surface of mammalian cells. Close interaction between host cells and L. monocytogenes makes invasion possible. Numerous surface adhesion factors allow the pathogen to connect to host cells such as:
- Lap adhesion protein uses an alcohol acetaldehyde dehydrogenase interaction with the host cell receptor, Hsp60, to adhere to intestinal cells. This Lap protein is required for full virulence.
- Ami protein associates to the bacterial surface via its C-terminal cell wall-anchoring (CWA) domain. The CWA allow adhesion to host epithelial cells.
- The gene segment dltA integrates D-alanine-polyphosphoribitol into lipoteichoic acids (LTAs)which contributes to cell adhesion.
- FbpA is expressed on the bacterial surface and binds to stationary host fibronectin. FbpA also helps expression of LLO and InlB (other virulence factor proteins).
- The C-terminus of InlJ has an LPXTG segment which bonds LPXTG-containing proteins to the cell membrane of the host.
Clinical features
Diagnosis
Treatment
Prevention
Host Immune Response
References
1. Conway, Tyrrell. “Genus conway”. “Microbe Wiki” 2013. Volume 1. p. 1-2.
2. http://www.cdc.gov/listeria/
3. D Cabanes, et al. "The Arsenal Of Virulence Factors Deployed By Listeria Monocytogenes To Promote Its Cell Infection Cycle." Virulence 2.5 (n.d.): 379-394. Science Citation Index. Web. 14 July 2013.
4. Burkholder KM, Kim KP, Mishra KK, Medina S,
Hahm BK, Kim H, et al. Expression of LAP, a
SecA2-dependent secretory protein, is induced under
anaerobic environment. Microbes Infect 2009; 11:859-
67; PMID:19454322; http://dx.doi.org/10.1016/j.
micinf.2009.05.006.
Created by Danielle Vinnedge, Naomi Quillin, Jennifer Gallup, students of Tyrrell Conway at the University of Oklahoma.
