Plural word for bacteria Bacteria is the plural form of the singular bacterium. Because microscopic bacterium is most often found in multiples, the plural form bacteria is more commonly used. The plurals of several other singular words ending in -um are also formed this way, such as memorandum/memoranda and curriculum/curricula. The irregular noun bacterium’s plural derives directly from its original pluralization in Latin and Greek. Bacteria is sometimes treated as a singular collective noun. However, this is not standard in English, and bacteria should be treated as a plural form.
Some bacteria are beneficial to humans (for example, those that live in the stomach and aid digestion), and some are harmful (for example, those that cause disease).
First recorded in 1860–65; from New Latin, from Greek baktḗria, plural of baktḗrion, diminutive of baktēría “staff, cane”; see origin at bacterium
First recorded in 1860–65; from New Latin; see origin at bacteria ( def. )
Bacteria are microscopic living organisms, usually one-celled, that can be found everywhere. They can be dangerous, such as when they cause infection, or beneficial, as in the process of fermentation (such as in wine) and that of decomposition. In 1676, Anton Van Leeuwenhoek first observed bacteria through a microscope and called them “animalcules.” In 1838, the German Naturalist Christian Gottfried Ehrenberg called them bacteria, from the Greek baktḗria, meaning "little stick." An apt word, as the first observed bacteria were shaped like rods, although bacteria can also be spiral or spherical in shape. A grammar note: The word bacteria is the plural form of "bacterium" and so should be written as plural, as in "Many bacteria are harmless."
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Preservatives are added to foods for several reasons, including preventing the growth of bacteria and mold, slowing spoilage, and helping products maintain their color, flavor, or freshness for longer.
From Science Daily ● Sep. 20, 2026
His team investigated urolithin A, or UroA, a naturally occurring microbial metabolite produced by gut bacteria after the digestion of foods including pomegranates, walnuts and berries.
From Science Daily ● Sep. 17, 2026
The amount Abbott Laboratories has agreed to pay to settle allegations related to its management of a baby formula facility where deadly bacteria was suspected of causing infant deaths, according to the Justice Department.
From The Wall Street Journal ● Sep. 15, 2026
Anthrax is caused by a bacteria called Bacillus anthracis, which largely survives as spores that hide away in soil for years before entering an animal through inhalation or a cut or wound.
From BBC ● Sep. 14, 2026
The highly contagious illness is caused by bacteria growing in the body, usually the lungs, and is spread through the air when people cough, sneeze, or spit.
From "At Last She Stood" by Erin Entrada Kelly
Bacteria in treated trees have dropped by at least 90%.
From The Wall Street Journal ● Sep. 19, 2026
Bacteria then transform those compounds into organic acids, primarily acetic acid and gluconic acid.
From Science Daily ● Jun. 23, 2026
Bacteria can also infect wounds where screwworm maggots are present and may cause an infection that can lead to symptoms like fever or chills.
From Los Angeles Times ● Jun. 6, 2026
Bacteria such as E. coli and Salmonella, or parasites like Cryptosporidium and Giardia, also cause severe diarrhea that can lead to dangerous levels of dehydration.
From Salon ● Jan. 27, 2025
Bacteria, fungi, and algae are the principal agents of decay, reducing plant and animal residues to their component minerals.
From "Silent Spring" by Rachel Carson
By analyzing DNA from the plague bacterium preserved in archaeological human remains, scientists were able to reconstruct how the disease spread, evolved, and repeatedly reappeared long after the Black Death.
From Science Daily ● Sep. 20, 2026
It uses a harmless bacterium to insert DNA into the rootstock exactly where it is needed to give the tree resistance.
From The Wall Street Journal ● Sep. 19, 2026
Infection with this bacterium is a known risk factor for gastric cancer.
From Science Daily ● Sep. 10, 2026
For these components, the researchers used Pantoea agglomerans, a bacterium that commonly grows on surfaces, including plants.
From Science Daily ● Sep. 4, 2026
Bruno Latour maintained that the fact that the bacterium that causes tuberculosis has been discovered in the lungs of an ancient Egyptian pharaoh, Ramses II, did not mean that Ramses died of tuberculosis.
From "The Invention of Science" by David Wootton
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.
