bacterium
Americannoun
noun
plural
bacteria-
Any of a large group of one-celled organisms that lack a cell nucleus, reproduce by fission or by forming spores, and in some cases cause disease. They are the most abundant lifeforms on Earth, and are found in all living things and in all of the Earth's environments. Bacteria usually live off other organisms. Bacteria make up most of the kingdom of prokaryotes (Monera or Prokaryota), with one group (the archaea) sometimes classified as a separate kingdom.
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See also archaeon prokaryote
Usage
It is important to remember that bacteria is the plural of bacterium, and that saying a bacteria is incorrect. It is correct to say The soil sample contains millions of bacteria, and Tetanus is caused by a bacterium.
Etymology
Origin of bacterium
1840–50; < New Latin < Greek baktḗrion, diminutive of baktēría staff; akin to báktron stick, Latin baculum, bacillum
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The researchers discovered higher levels of Streptococcus mutans -- a common oral bacterium known for causing dental caries -- in the gut microbiomes of people with Parkinson's.
From Science Daily
This gene was linked to higher levels of Paraprevotella, a bacterium believed to feed on these sugars.
From Science Daily
By contrast, it takes ingesting thousands of salmonella particles to get sick from that bacterium.
From Los Angeles Times
In response, Italian city states began bringing in grain from the Black Sea region, and those shipments may have carried the plague bacterium, Yersinia pestis.
From Science Daily
The disease was caused by a bacterium known as Yersinia pestis spread by wild rodents, such as rats, and fleas.
From BBC
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
