Listeria monocytogenes

A set of vocabulary flashcards based on key concepts related to Listeria monocytogenes, its biology, pathogenicity, and public health implications.

Listeria monocytogenes

A gram-positive, rod-shaped bacterium that can cause listeriosis and is known for its ability to survive extreme conditions.

Virulence

The ability of a pathogen to cause disease; in L. monocytogenes, virulence is directly related to its ability to live and spread within cells.

PrfA

A regulator protein that upregulates genes in L. monocytogenes when in the body at 37°C.

Actin Polymerization

The process by which L. monocytogenes uses host cell actin to propel itself into adjacent cells.

Endocytosis

The method by which L. monocytogenes enters phagocytic cells, triggered by internalins InlA and InlB.

Listeriolysin O (LLO)

A major virulence factor that helps L. monocytogenes escape from the phagolysosomes of macrophages.

PC-PLC

Phosphatidylinositol-specific phospholipase C, which contributes to Listeria's escape from the double membrane vacuole.

Facultative Intracellular

An organism that can live both within and outside of host cells; a characteristic of L. monocytogenes.

Incubation period of listeriosis

Typically ranges from 2 to 8 weeks, making it difficult to establish the cause related to infection.

Biofilms

Structured communities of bacteria that attach to surfaces; L. monocytogenes can create biofilms, complicating its elimination in food processing plants.

Zero tolerance policy

The US standard for L. monocytogenes in food products, indicating no permissible presence in ready-to-eat foods.

Tumbling motility

A unique form of motility observed in L. monocytogenes under certain conditions, characterized by a tumbling motion.

Gram-positive rods

Morphological classification of L. monocytogenes, indicating its cell wall structure and staining characteristics.

Environmental sources

Locations where L. monocytogenes can be found, including soil, water, and the feces of healthy animals.

Infection prevention methods

Proper pasteurization, washing, refrigeration, and cooking of foods to prevent L. monocytogenes contamination.

High salt tolerance

Characteristic of L. monocytogenes that allows it to survive in environments with high salt concentrations.

Transmission

Ingestion is the primary method through which L. monocytogenes spreads to cause infection.

Listeria in ready-to-eat foods

Concern arises from products like soft cheeses, hot dogs, and deli meats that may harbor L. monocytogenes due to lack of heating during processing.

CAMP test

A laboratory test used to differentiate L. monocytogenes based on its characteristic hemolytic activity.

Serotyping

Classification of L. monocytogenes based on its flagellar and somatic antigens, crucial for outbreak tracking.