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• Legionella
  Legionella

  noun

  a genus of rod- or coccus-shaped aerobic Gram-negative bacteria, certain species of which, as L. pneumophila, produce legionnaires' disease.
• legionella
  legionella

  noun

  any Gram-negative rod-shaped bacterium of the genus Legionella, including L. pneumophila, which causes legionnaire's disease

Legionella

American  

[lee-juh-nel-uh] / ˌli dʒəˈnɛl ə /

noun

1. a genus of rod- or coccus-shaped aerobic Gram-negative bacteria, certain species of which, as L. pneumophila, produce legionnaires' disease.

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legionella British  

/ ˌliːdʒəˈnɛlə /

noun

1. any Gram-negative rod-shaped bacterium of the genus Legionella, including L. pneumophila, which causes legionnaire's disease

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Etymology

Origin of Legionella

< New Latin (1979), after legionnaires' disease; see -ella

Example Sentences

Legionnaires' disease is a lung infection most commonly contracted through the inhalation of water droplets containing Legionella bacteria.

From BBC • Jun. 21, 2025

That followed problems, including traces of Legionella bacteria being found in the vessel’s on-board water system, days after the first asylum seekers boarded in August 2023.

From BBC • Oct. 31, 2024

Testing of the hospital’s water has so far been negative for Legionella, the news release said.

From Seattle Times • Nov. 4, 2023

The bacteria do not spread person to person, and most healthy people exposed to Legionella do not get sick.

From Seattle Times • Nov. 4, 2023

Those tests confirmed Legionella was found in restrooms, a break room and shower areas in locker rooms.

From Washington Times • Oct. 18, 2023