Definition

Noun: 1. A type of bacteria: Legionella is a genus of motile, aerobic, rod-shaped, Gram-negative bacteria. It is known for thriving in warm water environments, particularly in human-made water systems like cooling towers, air conditioning units, hot water tanks, and large plumbing systems. 2. The causative agent of disease: This bacterium is the pathogen responsible for causing Legionnaires' disease, a severe form of pneumonia, and Pontiac fever, a milder flu-like illness.

Usage Examples

• Noun:
  • The outbreak was traced to legionella contamination in the hotel's cooling tower.
  • Water treatment is essential to control the growth of legionella in industrial systems.
  • Legionella bacteria are not spread from person to person but are inhaled through contaminated water droplets or mist.

Advanced Usage

• Scientific/Medical Context: The term is often used in its plural form, , when referring to multiple bacteria of this genus. It is frequently modified by the species name, most commonly .
  • The lab confirmed the presence of Legionella pneumophila in the samples.

Variants and Related Words

• Legionellosis (n): The collective term for the diseases caused by bacteria, encompassing both Legionnaires' disease and Pontiac fever.
• Legionnaires' disease (n): The severe, potentially fatal pneumonia caused by infection with bacteria.

Synonyms

• Pathogen: A general term for a bacterium, virus, or other microorganism that can cause disease.
• Bacterium: A single-celled microorganism. ( is a specific type of bacterium.)

Notes on Meaning

The word legionella is almost exclusively used in scientific, medical, and public health contexts to refer specifically to this genus of bacteria and the diseases it causes. It is not used in general conversation.

Noun

1. the motile aerobic rod-shaped Gram-negative bacterium that thrives in central heating and air conditioning systems and can cause Legionnaires' disease