my·​co·​bac·​te·​ri·​um ˌmī-kō-bak-ˈtir-ē-əm How to pronounce mycobacterium (audio)
: any of a genus (Mycobacterium) of nonmotile aerobic acid-fast bacteria that include numerous saprophytes and the pathogens causing tuberculosis and leprosy
mycobacterial adjective

Example Sentences

Recent Examples on the Web Serious pathogens commonly found in plumbing include mycobacterium avium complex (MAC), which can lead to turberculois, and pseudomonas aeruginosa, which causes a wide variety of diseases including respiratory and gastrointestinal infections. Elena Bruess, San Antonio Express-News, 25 June 2021 Indeed, this infection, caused by a cousin of tuberculosis, mycobacterium marinum (M.M.), is sometimes called fish handlers’ disease. New York Times, 16 Dec. 2020 In 2012, for example, Dávalos used shotgun proteomics —a type of protein analysis common in cancer medicine—to help Corthals identify a previously unsequenced mycobacterium in a 500-year-old Andean Inca mummy. Eleanor Cummins, Science, 4 Dec. 2020 Tuberculosis is a disease of the lungs caused by a mycobacterium. Joseph Osmundson, The New Republic, 30 July 2020 The vaccine is named after its inventors, Dr. Albert Calmette and Dr. Camille Guerin, who developed it in the early 1900s from mycobacterium bovis, a form of tuberculosis that infects cattle. Roni Caryn Rabin, New York Times, 3 Apr. 2020 Davies says the clay has also demonstrated the ability to combat mycobacterium ulcerans, a debilitating skin infection. Smithsonian, 19 Dec. 2019 In 2017, Zhu graduated with a Ph.D. and a fascination with the basic biology of the mycobacterium that is the causative agent of TB. Jeffrey Mervis, Science | AAAS, 11 Sep. 2019 In many American homes, water is treated with chlorine and chloramine, which kill pathogens but not mycobacteria, a genus that includes the cause of tuberculosis. Lisa Margonelli, WSJ, 28 Nov. 2018 See More

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

Word History


New Latin

First Known Use

1909, in the meaning defined above

Time Traveler
The first known use of mycobacterium was in 1909

Dictionary Entries Near mycobacterium

Cite this Entry

“Mycobacterium.” Dictionary, Merriam-Webster, Accessed 21 Mar. 2023.

Medical Definition


my·​co·​bac·​te·​ri·​um -ˈtir-ē-əm How to pronounce mycobacterium (audio)
capitalized : a genus of nonmotile acid-fast aerobic bacteria of the family Mycobacteriaceae that are usually slender and difficult to stain and that include the causative agents of tuberculosis (M. tuberculosis) and leprosy (M. leprae) as well as numerous purely saprophytic forms
plural mycobacteria -ē-ə How to pronounce mycobacterium (audio) : any bacterium of the genus Mycobacterium or a closely related genus
mycobacterial adjective

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