plural E. coli
: an enterobacterium (Escherichia coli) that is used in public health as an indicator of fecal pollution (as of water or food) and in medicine and genetics as a research organism and that occurs in various strains that may live as harmless inhabitants of the human lower intestine or may produce a toxin causing intestinal illness see enterobacterium illustration

Examples of E. coli in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Five separate recalls have been issued involving Whole Foods Market products so far in 2025, with issues ranging from undeclared allergens to potential E. coli contamination. Nuri Kino, MSNBC Newsweek, 20 June 2025 In lab tests, Petri dishes containing Penicillin-PPG-doped agar were inoculated with E. coli bacteria, then half of each dish was covered with a light-blocking aluminum sticker. Ben Coxworth, New Atlas, 13 June 2025 What are possible consequences of salmonella and E. coli infections? Katia Hetter, CNN Money, 13 June 2025 For example, Escherichia coli K-12 bacteria can’t survive among the E. coli that live in the human gut, so they’re considered low risk for biological research. Eva Amsen, JSTOR Daily, 11 June 2025 See All Example Sentences for E. coli

Word History

First Known Use

1925, in the meaning defined above

Time Traveler
The first known use of E. coli was in 1925

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Cite this Entry

“E. coli.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/E.%20coli. Accessed 3 Jul. 2025.

Kids Definition

E. coli

noun
plural E. coli
: a bacterium in the shape of a short rod that may cause intestinal illness
Etymology

short for Escherichia coli, the taxonomic name in biology

Medical Definition

E. coli

noun
ˌē-ˈkō-ˌlī
plural E. coli also E. colis
: a straight rod-shaped gram-negative bacterium (Escherichia coli of the family Enterobacteriaceae) that is used in public health as an indicator of fecal pollution (as of water or food) and in medicine and genetics as a research organism and that occurs in various strains that may live as harmless inhabitants of the human lower intestine or may produce a toxin causing intestinal illness marked especially by diarrhea
one million acid-resistant E. coli per gram of fecesJohn Schwartz
this E. coli can survive … longer than all the other E. colisEd Geldreich
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