poly·​myx·​in ˌpä-lē-ˈmik-sən How to pronounce polymyxin (audio)
: any of several toxic antibiotics obtained from a soil bacterium (Bacillus polymyxa) and active against gram-negative bacteria

Examples of polymyxin in a Sentence

Recent Examples on the Web The foreign bodies were removed from the nasal region of the right cornea using Jewelers forceps, and the patient was prescribed a combination neomycin, polymyxin B, and dexamethasone ointment (Maxitrol(®)), given 4 times per day. Seriously Science, Discover Magazine, 23 Oct. 2013 In a study published last month in The Lancet, the scientists describe the emergence of a new gene, MCR-1, that grants E. coli bacteria immunity to a class of antibiotics called colistin, also referred to as polymyxin. Nathaniel Scharping, Discover Magazine, 12 Dec. 2015 After 30 days of exposure, the bacteria could tolerate doses of polymyxin B that were 256 times higher than the original amount, but the SCUBs remained effective at the same dose. Max G. Levy, Wired, 30 Nov. 2021 Instead, antibiotics commonly used in flu vaccine manufacturing include neomycin, kanamycin, polymyxin B and gentamicin. Anne P. Kim, The Conversation, 13 Nov. 2020

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'polymyxin.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary, from New Latin polymyxa, from poly- + Greek myxa mucus — more at mucus

First Known Use

1947, in the meaning defined above

Time Traveler
The first known use of polymyxin was in 1947

Dictionary Entries Near polymyxin

Cite this Entry

“Polymyxin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/polymyxin. Accessed 19 Jun. 2024.

Medical Definition


poly·​myx·​in ˌpäl-i-ˈmik-sən How to pronounce polymyxin (audio)
: any of several toxic antibiotics obtained from a soil bacterium of the genus Bacillus (B. polymyxa) and active against gram-negative bacteria

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