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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In other words, changes in gut bacteria appeared to increase intestinal pyruvate, a compound involved in energy metabolism.
From Science Daily ● Oct. 27, 2026
Scientists have uncovered a surprising connection between the bacteria living in the human gut and the speed at which the body ages.
From Science Daily ● Oct. 27, 2026
To investigate the relationship between gut bacteria and aging, researchers examined stool and blood samples collected from 123 adults across a wide range of ages.
From Science Daily ● Oct. 27, 2026
This weakening of immune protection could make it easier for an infection to develop, similar to how bacteria can enter through a cut on the foot and cause illness.
From Science Daily ● Oct. 25, 2026
Chicago’s water teemed with bacteria, thanks mainly to the Chicago River.
From "The Devil in the White City" by Erik Larson
Bacteria in treated trees have dropped by at least 90%.
From The Wall Street Journal ● Sep. 19, 2026
Bacteria found in soil and water are essential parts of natural ecosystems, and some species are capable of processing substances that can be harmful to humans and other organisms.
From Science Daily ● Aug. 9, 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 and viruses can survive inside amoebae, shielded from disinfection processes that would normally eliminate them.
From Science Daily ● Jan. 25, 2026
Bacteria feeding on sugars should grow in smooth arcs.
From "The Gene" by Siddhartha Mukherjee
Plague is a disease caused by the Yersinia pestis bacterium, the same pathogen that killed millions of people in Europe during the Middle Ages.
From Barron's ● Oct. 7, 2026
The bacterium that causes the plague, Yersinia pestis, found among rodents such as marmots in the area.
From BBC ● Oct. 7, 2026
The bacterium Yersinia pestis, which can cause pneumonic and bubonic plagues, has been identified from time to time in Siberia, linked to exposure to vermin.
From The Wall Street Journal ● Oct. 5, 2026
Studies of modern plague systems have shown that changes in climate can strongly affect outbreaks among wild rodents, which act as natural hosts for the bacterium.
From Science Daily ● Sep. 20, 2026
Grown on either sugar alone, the bacterium begins to divide rapidly, doubling in number every twenty minutes or so.
From "The Gene" by Siddhartha Mukherjee
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