# What is the hardest bacteria to kill?

**URL:** <https://boards.straightdope.com/t/what-is-the-hardest-bacteria-to-kill/436053>\
**Category:** Factual Questions\
**Created:** [February 3, 2008, 3:02am UTC](https://boards.straightdope.com/t/what-is-the-hardest-bacteria-to-kill/436053 "2008-02-03T03:02:53Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\
**Post date:** [February 3, 2008, 3:02am UTC](https://boards.straightdope.com/t/what-is-the-hardest-bacteria-to-kill/436053/1 "2008-02-03T03:02:53Z")

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What bacteria wins the prize re ability to withstand temperature extremes, chemical assaults etc.? What bacteria wins the Toughest Unicellular Microorganism competition?

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**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\
**Post date:** [February 3, 2008, 3:08am UTC](https://boards.straightdope.com/t/what-is-the-hardest-bacteria-to-kill/436053/2 "2008-02-03T03:08:22Z")

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_Deinococcus radiodurans_ would have to be in the running…

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**Author:** ![WoodenTaco](https://avatars.discourse-cdn.com/v4/letter/w/45deac/32.png) [@WoodenTaco](https://boards.straightdope.com/u/WoodenTaco)\
**Post date:** [February 3, 2008, 3:27am UTC](https://boards.straightdope.com/t/what-is-the-hardest-bacteria-to-kill/436053/3 "2008-02-03T03:27:54Z")

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Clearly, this depends on your method of extermination.

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**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\
**Post date:** [February 3, 2008, 5:54am UTC](https://boards.straightdope.com/t/what-is-the-hardest-bacteria-to-kill/436053/4 "2008-02-03T05:54:40Z")

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As far as common human pathogens, the botulism spore is the standard. Clostridium botulinum forms incredibly tough spores when it’s stressed. They’re used all over to test if sterilization procedures are working properly - you put a vial of them through whatever process you’re testing and see if they can grow. If it kills the spores, it’ll kill anything else.

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**Author:** ![Walloon](https://avatars.discourse-cdn.com/v4/letter/w/fbc32d/32.png) [@Walloon](https://boards.straightdope.com/u/Walloon)\
**Post date:** [February 3, 2008, 6:03am UTC](https://boards.straightdope.com/t/what-is-the-hardest-bacteria-to-kill/436053/5 "2008-02-03T06:03:18Z")

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Bacteria are notoriously differentiated in their survival ability. As **beowulff** mentioned above, _Deinococcus radiodurans_ is the most radiation-resistant bacterium. This microbe and its close relatives survive immense doses of x-rays and gamma-rays.

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**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\
**Post date:** [February 3, 2008, 6:24am UTC](https://boards.straightdope.com/t/what-is-the-hardest-bacteria-to-kill/436053/6 "2008-02-03T06:24:08Z")

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[QUOTE=WoodenTaco]  
Clearly, this depends on your method of extermination.  
[/QUOTE]

This needs to be repeated, often. It depends entirely and totally on your method of extermination. Those bacteria resisatnt to radiation aren’t very resistant to bleach. Those bacteria that can survive high bleach concentrations don’t handle high temperatures, those that can withstand high temepratures are UV sensitive, those that are UV resistant don’t handle dessication and so on and so forth.

There simply isn’t one most retsistant species. There is a separate and distinct species that are most resistant to each and every bactericidal treatment you can think of.