What are the virulence factors of Listeria monocytogenes?

Several virulence factors of Listeria monocytogenes have been identified and extensively characterized at the molecular and cell biologic levels, including the hemolysin (listeriolysin O), two distinct phospholipases, a protein (ActA), several internalins, and others.

What is Listeria virulence?

The gram-positive pathogenic bacterium Listeria monocytogenes is widely spread in the nature. L. Listeriolysin O (LLO) is a L. monocytogenes major virulence factor. In the course of infection in mammals, LLO is required for intracellular survival and apoptosis induction in lymphocytes.

What are microbial virulence factors?

Microbial virulence factors encompass a wide range of molecules produced by pathogenic microorganisms, enhancing their ability to evade their host defenses and cause disease.

What makes Listeria pathogenic?

Pathogenic Listeria organisms pass directly from cell to cell by a mechanism involving host cell actin polymerization (see below). Therefore, regardless of the mechanism of entry used, the bacteria that penetrate the intestinal wall might then invade neighboring enterocytes by basolateral spread, leading to enteritis.

What are symptoms of listeriosis?

Symptoms of listeriosis vary depending on the form and can come on suddenly. Symptoms may include fever, muscle aches, severe headache, nausea, vomiting, stiff neck, confusion, loss of balance, and convulsions.

What is the incubation period for listeria?

This form of disease is characterized by severe symptoms and a high mortality rate (20%–30%). The symptoms include fever, myalgia (muscle pain), septicemia, meningitis. The incubation period is usually one to two weeks but can vary between a few days and up to 90 days.

What is the incubation period for Listeria?

What is Listeria most commonly found in?

Listeria bacteria can be found in soil, water and animal feces. People can get infected by eating the following: Raw vegetables that have been contaminated from the soil or from contaminated manure used as fertilizer.

EVs purified from Gram-positive bacteria are implicated in virulence, toxin release, and transference to host cells, eliciting immune responses, and spread of antibiotic resistance. Listeria monocytogenesis a Gram-positive bacterium that causes listeriosis.

How does Listeria escape from the phagosome?

When epithelial cells internalize this pathogen for phagocytosis, it can escape from the phagosome, multiplies in the cytosol, and spreads directly to adjacent cells. It secretes several proteins that have been shown to contribute to its intracellular adaptation.

How does Listeria spread from cell to cell?

Actin tails enable Listeria to be actively motile and spread directly from cell to cell. Once within the cytoplasm of the host cell, ActA protein released by Listeria causes the polymerization of actin filaments at the end of the bacterium.