bacteria

noun
bac·​te·​ria | \bak-ˈtir-ē-ə \
plural bacteria also bacterias

Definition of bacteria 

: bacterium not usually used technically

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Is bacteria singular or plural?: Usage Guide

Bacteria is regularly a plural in scientific and pedagogical use; in speech and in journalism it is also used as a singular, and it is sometimes pluralized as bacterias. caused by a bacteria borne by certain tiny ticks Wall Street Journal more resistant to chlorine and elevated water temperatures than other bacterias — Allan Bruckheim, M.D., Chicago Tribune These journalistic uses are found in British as well as American sources.

Did You Know?

Microscopic single-celled organisms lacking a distinct nucleus are known as bacteria. They may be shaped like spheres, rods, or spirals. They inhabit virtually all environments, including soil, water, organic matter, and the bodies of animals. Many bacteria swim by means of long whip-like structures called flagella. The DNA of most bacteria is found in a single, circular chromosome, and is distributed throughout the cytoplasm rather than contained within a membrane-enclosed nucleus. Though some bacteria can cause food poisoning and infectious diseases in humans, most are harmless and many are beneficial. They are used in various industrial processes, especially in the food industry (for example, in the production of yogurt, cheeses, and pickles).

Examples of bacteria in a Sentence

Recent Examples on the Web

And there were some bacteria that hadn’t been detected before the treatment but appeared in the samples afterward. Cathleen O'grady, Ars Technica, "Gut bacteria recover from antibiotics, but they may take six months," 28 Oct. 2018 To top it off, it can be washed in hot water so it's game-over for killing germs and bacteria. Caroline Picard, Good Housekeeping, "How to Build Your Best Bed Ever," 26 Oct. 2018 This can help wash away any bacteria that can upset the hair follicle. Kara Wahlgren, Seventeen, "5 Things You Need to Know About Butt Pimples," 13 Sep. 2018 It’s hard to spread bacteria in such a dry environment. Rachel Becker, The Verge, "What happens on plane full of sick passengers? An aerospace medicine expert explains," 6 Sep. 2018 Disinfect by using: Unscented household chlorine bleach or iodine (useful against most, but not all, harmful viruses or bacteria). Gary Robbins, sandiegouniontribune.com, "Disaster preparedness: How do you make drinking water safe," 8 July 2018 Tuberculosis is an airborne bacteria spread through the air. Brett Molina, USA TODAY, "Tuberculosis scare forces evacuations at Johns Hopkins Hospital," 6 July 2018 Components of bacteria then seem to sneak past immune cells in the underlying intestinal tissue and make their way to the bloodstream and liver, prompting inflammation. Kelly Servick, Science | AAAS, "What’s really behind ‘gluten sensitivity’?," 23 May 2018 Symptoms of salmonella—a bacteria that can cause infections within the body—most commonly include nausea, vomiting, abdominal cramps, diarrhea, fever, chills, headache, and blood in your stool. Devon Elizabeth, SELF, "Update: There Are Now 100 Salmonella Cases Linked to Recalled Honey Smacks Cereal," 13 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'bacteria.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of bacteria

1864, in the meaning defined above

History and Etymology for bacteria

plural of bacterium

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Statistics for bacteria

Last Updated

13 Nov 2018

Look-up Popularity

Time Traveler for bacteria

The first known use of bacteria was in 1864

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More Definitions for bacteria

bacteria

Medical Definition of bacteria 

(Entry 1 of 2)

plural of bacterium

bacteria

noun
bac·​te·​ria | \bak-ˈtir-ē-ə \

Medical Definition of bacteria (Entry 2 of 2)

1 : bacterium not usually used technically caused by a bacteria borne by certain tiny ticksWall Street Journal a single bacteria—there are roughly 200 in each cough—apparently can infect a person— Cheryl Clark

2  plural capitalized : a domain in the system of classification dividing all organisms into three major domains of life that includes the prokaryotes that are bacteria but not those that are archaebacteria or archaea — compare eubacteria

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