Which of the following are characteristics of Listeria monocytogenes?

Which of the following are characteristics of Listeria monocytogenes?

monocytogenes. Foodborne listeriosis has three main clinical features, namely, meningitis, septicemia, and abortion. In healthy humans it can cause febrile gastroenteritis, but in susceptible persons (children, elderly, immune-compromised and pregnant women) it may lead to septicemia and meningitis [1].

What is the colony morphology of Listeria monocytogenes?

Morphology of Listeria The morphology of the genus Listeria is small, Gram-positive coccobacilli or rod-shaped having a size of 1-3µmX 0.5 µm. They are motile at 25°C showings tumbling motility but are non-motile at37°C. They produce peritrichous flagella optimally at 20-30°C, but they can not produce flagella at all.

What is the difference between Salmonella and Listeria?

The key difference between Listeria and Salmonella is that Listeria is a genus of gram-positive pathogenic bacteria while Salmonella is a genus of gram-negative pathogenic bacteria. Food-borne illnesses are caused by bacteria, viruses, or parasites that contaminate food.

How do you distinguish Listeria?

The identification of Listeria species is based on a limited number of biochemical markers, among which absence or presence of hemolysis and arylamidase are used to differentiate between L. monocytogenes and L. innocua. The CAMP (Christie, Atkins, Munch-Petersen) test must be interpreted with caution.

What makes Listeria unique from other bacteria?

Listeria monocytogenes. L. monocytogenes is one of the most virulent food-borne pathogens. It can flourish with or without oxygen and, unlike many other bacteria, can thrive and reproduce at temperatures as low as 0°C.

What is the shape of Listeria monocytogenes?

-positive rod shaped bacteria
The genus Listeria includes different species of ubiquitary present gram-positive rod shaped bacteria. The species Listeria monocytogenes causes severe diseases like meningitis and meningoencephalitis in humans.

What is Salmonella and Listeria monocytogenes?

Salmonella and Listeria monocytogenes are two bacterial food-borne pathogens that represent a substantial burden to the produce industry. Produce-borne Salmonella outbreaks have been responsible for a considerable number of food-borne illness cases (2–6).

How do Salmonella and shigella infections differ?

Salmonella will not ferment lactose, but produce hydrogen sulfide (H2S) gas. The resulting bacterial colonies will appear colorless with black centers. Shigella do not ferment lactose or produce hydrogen sulfide gas, so the resulting colonies will be colorless.

Does Listeria monocytogenes have a capsule?

Listeria spp. are facultative anaerobic rods of 0.4 by 1 to 1.5 μm that do not form spores, have no capsule, and are motile at 10 to 25°C (98, 552, 579).

What is special about Listeria monocytogenes?

LISTERIA | Listeria monocytogenes In 1981 it was identified as an important and dangerous food-borne disease-causing bacterium, having a fatality rate of 33%. L. monocytogenes is resistant to many environmental challenges and is one of the few food-borne pathogens able to grow at refrigeration temperatures.

Is Listeria monocytogenes a gram-positive rod?

Listeria monocytogenes is a facultative, intracellular, gram-positive rod that is responsible for causing the infection listeriosis. Listeria causes severe infection in the elderly, neonates and the immunocompromised with only a self-limited gastrointestinal infection in the immunocompetent.

Is Listeria monocytogenes Gram-positive or negative?

gram-positive
Listeria monocytogenes is a facultative, intracellular, gram-positive rod that is responsible for causing the infection listeriosis. Listeria causes severe infection in the elderly, neonates and the immunocompromised with only a self-limited gastrointestinal infection in the immunocompetent.

Which of the following is a characteristic of Salmonella?

Salmonellosis is a disease caused by the bacteria Salmonella. It is usually characterized by acute onset of fever, abdominal pain, diarrhoea, nausea and sometimes vomiting. The onset of disease symptoms occurs 6–72 hours (usually 12–36 hours) after ingestion of Salmonella, and illness lasts 2–7 days.

What makes the cell wall of Listeria monocytogenes interesting?

In addition, it also endows the cell with a specific cell shape and provides protection against mechanical stress. As in other noncapsulated gram- positive bacteria, the cell wall of L. monocytogenes is the outermost structure of the cell and acts as a scaffold in which different proteins anchor.

Does Listeria monocytogenes have Pili?

Pili and fimbriae have not been described for L. monocytogenes. In general flagella may be used directly for attachment and colonization as an adhesin, or indirectly to provide movement of the cell to the surface to be colonized.