# Using smell to help ID bacteria **URL:** \ **Category:** Factual Questions\ **Created:** [February 14, 2006, 10:54pm UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550 "2006-02-14T22:54:23Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Antigen](https://avatars.discourse-cdn.com/v4/letter/a/848f3c/32.png) [@Antigen](https://boards.straightdope.com/u/Antigen)\ **Post date:** [February 14, 2006, 10:54pm UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/1 "2006-02-14T22:54:23Z")
I’ve noticed that the veteran techs in the micro lab have the ability to open up a plate and say “oh, that’s a staph aureus” just from the smell as the lid is lifted. My clinical instructor used to have a printout about characteristic bacterial smells, but now she can’t find it, and I’d like to help her put a new one together. The only problem is, because this isn’t really an ID method, I’m having a tough time finding any information about bacterial odors in textbooks or online. Can any Straight Dope microbiologists, techs, or weirdos who culture bacteria in their spare time, help me make a list of characteristic odors? Feel free to use any sort of descriptors for the smells. The ones I’ve got so far: \* Pseudomonas aeruginosa\*: grape (like kool-aid) _Eikenella corrodens_: bleach ---
**Author:** ![picunurse](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@picunurse](https://boards.straightdope.com/u/picunurse)\ **Post date:** [February 15, 2006, 12:15am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/2 "2006-02-15T00:15:23Z")
> [@Antigen](#): > > I’ve noticed that the veteran techs in the micro lab have the ability to open up a plate and say “oh, that’s a staph aureus” just from the smell as the lid is lifted. My clinical instructor used to have a printout about characteristic bacterial smells, but now she can’t find it, and I’d like to help her put a new one together. The only problem is, because this isn’t really an ID method, I’m having a tough time finding any information about bacterial odors in textbooks or online. > > Can any Straight Dope microbiologists, techs, or weirdos who culture bacteria in their spare time, help me make a list of characteristic odors? Feel free to use any sort of descriptors for the smells. > > The ones I’ve got so far: > \* > Pseudomonas aeruginosa\*: grape (like kool-aid) > _Eikenella corrodens_: bleach I have no idea how you came up with grape koolaid for_Pseudomonas aeruginosa_, but I can tell you from many nights in various burn units, it doesn’t smell like anything I’d ingest. It smells like rotting flesh to me. ickky ---
**Author:** ![edwino](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@edwino](https://boards.straightdope.com/u/edwino)\ **Post date:** [February 15, 2006, 12:21am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/3 "2006-02-15T00:21:24Z")
_Pseudomonas_ does have a characteristic grape-y odor, but I think it is usually too covered up by other human smells. _C. difficile_ stools have a very characteristic odor, though. Smell that once and you won’t forget it. I know the smell of a culture of _E. coli_ from all my years doing molecular biology, it smells somewhere between vomit and melting styrofoam. Kind of tart, sweet, pungent, chemical. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [February 15, 2006, 12:35am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/4 "2006-02-15T00:35:59Z")
Trichomonas vaginitis has quite the characteristic odor, and I was often very successful in diagnosing it presumptively before looking at the wet prep. I won’t describe the odor other than observe that its not nice. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [February 15, 2006, 12:53am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/5 "2006-02-15T00:53:40Z")
> [@Qadgop the Mercotan](#): > > Trichomonas vaginitis has quite the characteristic odor, and I was often very successful in diagnosing it presumptively before looking at the wet prep. I won’t describe the odor other than observe that its not nice. What’s the one responsible for dental caries/gingivitis? It’s very specific, I can only describe the smell as “black”. It just makes me feel like wilting whenever it gets breathed on me (usually while riding the train). There’s many kinds of bad breath but only one black cloud of decay. ---
**Author:** ![Tamerlane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tamerlane/32/7602_2.png) [@Tamerlane](https://boards.straightdope.com/u/Tamerlane)\ **Post date:** [February 15, 2006, 1:00am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/6 "2006-02-15T01:00:59Z")
> [@edwino](#): > > I know the smell of a culture of _E. coli_ from all my years doing molecular biology, it smells somewhere between vomit and melting styrofoam. Kind of tart, sweet, pungent, chemical. I’m not squeamish at all most stuff, but that is one of the few odors that almost instantly makes me want to heave. Good description, by the way. - Tamerlane ---
**Author:** ![Br\_er\_Lapin](https://avatars.discourse-cdn.com/v4/letter/b/e79b87/32.png) [@Br\_er\_Lapin](https://boards.straightdope.com/u/Br_er_Lapin)\ **Post date:** [February 15, 2006, 1:26am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/7 "2006-02-15T01:26:21Z")
> [@picunurse](#): > > I have no idea how you came up with grape koolaid for_Pseudomonas aeruginosa_, but I can tell you from many nights in various burn units, it doesn’t smell like anything I’d ingest. It smells like rotting flesh to me. ickky It always reminded me of really dirty socks. Unfortunately, that’s the only one whose smell I can distinctly recall. ---
**Author:** ![Antigen](https://avatars.discourse-cdn.com/v4/letter/a/848f3c/32.png) [@Antigen](https://boards.straightdope.com/u/Antigen)\ **Post date:** [February 15, 2006, 1:48am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/8 "2006-02-15T01:48:42Z")
> [@edwino](#): > > _C. difficile_ stools have a very characteristic odor, though. Smell that once and you won’t forget it. It’s noticeable in the stool specimens, definitely, but when you open up an anaerobic jar that’s got a C diff. plate in it… my textbook calls it a “horse stable odor” but I say it smells like the anaerobic jar’s been shat in. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [February 15, 2006, 3:13am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/9 "2006-02-15T03:13:00Z")
> [@Brain Wreck](#): > > What’s the one responsible for dental caries/gingivitis? It’s very specific, I can only describe the smell as “black”. It just makes me feel like wilting whenever it gets breathed on me (usually while riding the train). There’s many kinds of bad breath but only one black cloud of decay. Dammit Brain, I’m a doctor, not a dentist! 😉 Probably some nasty anaerobe or something. I’ll ask a dentist colleague if I remember. ---
**Author:** ![edwino](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@edwino](https://boards.straightdope.com/u/edwino)\ **Post date:** [February 15, 2006, 7:03am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/10 "2006-02-15T07:03:01Z")
> [@Qadgop the Mercotan](#): > > Trichomonas vaginitis has quite the characteristic odor, and I was often very successful in diagnosing it presumptively before looking at the wet prep. I won’t describe the odor other than observe that its not nice. Google ad reads “Fishy Vaginal Odor?” I’m on OB/Gyn for the next two weeks. The “whiff test” makes me nearly retch, every time. And I do three or four of them a day. ---
**Author:** ![edwino](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@edwino](https://boards.straightdope.com/u/edwino)\ **Post date:** [February 15, 2006, 7:05am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/11 "2006-02-15T07:05:40Z")
> [@Qadgop the Mercotan](#): > > Dammit Brain, I’m a doctor, not a dentist! 😉 > > Probably some nasty anaerobe or something. I’ll ask a dentist colleague if I remember. The most common mouth anaerobes that we tend to get is _Fusobacterium_, _Strep mutans_, or _Peptostreptococcus_. I’d bet it is one of those. Did I mention I’m thinking about doing a fellowship in Infectious Disease? ---
**Author:** ![irishgirl](https://avatars.discourse-cdn.com/v4/letter/i/8edcca/32.png) [@irishgirl](https://boards.straightdope.com/u/irishgirl)\ **Post date:** [February 15, 2006, 9:13am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/12 "2006-02-15T09:13:33Z")
Perhaps we’ve got a new variant on “see one, do one teach one”? See one, smell one, know one. Staph. Aureus just smells like…Staph. Aureus, it’s the one I remember most, a horrible yeasty pus smell. Yuck. What’s worse than the “whiff test” is when you can diagnose TV or BV the second the patient walks into the room. I love everything about OB/Gyn except those particular smells. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [February 15, 2006, 1:51pm UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/13 "2006-02-15T13:51:38Z")
> [@edwino](#): > > Did I mention I’m thinking about doing a fellowship in Infectious Disease? Cool! Who’s your attending? I had John Bartlett when I took ID. 🆒 I doubt I left any significant impression on _him_, tho. ---
**Author:** ![August\_West](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/august_west/32/18069_2.png) [@August\_West](https://boards.straightdope.com/u/August_West)\ **Post date:** [February 15, 2006, 2:24pm UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/14 "2006-02-15T14:24:10Z")
I am not in medicine, but I do microbiological plating of beer and can usually tell by smell if it’s a wild yeast or a bacteria. Several beer spoiling bacteria have characteristic aromas _Pectinatus_ has a sort of vomity, butyric aroma _Lactobacillis_ is a sharp sour milk smell And of course _Acetobacter_ is vinegary ---
**Author:** ![edwino](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@edwino](https://boards.straightdope.com/u/edwino)\ **Post date:** [February 15, 2006, 2:36pm UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/15 "2006-02-15T14:36:00Z")
> [@Qadgop the Mercotan](#): > > Cool! Who’s your attending? I had John Bartlett when I took ID. 🆒 > > I doubt I left any significant impression on _him_, tho. Right now, I’m finishing medical school (2 months, 1 week, 2 days left). Match day is in one month and one day, then my fate will be sealed. Intern year starts in July, and I’ll have a little while to decide between ID, endocrine, and critical care. My friend, who’s trying to convince me to come to Hopkins, emailed me a few months ago when John Bartlett was his attending. So apparently, still going strong over at Hopkins… ---
**Author:** ![edwino](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@edwino](https://boards.straightdope.com/u/edwino)\ **Post date:** [February 15, 2006, 2:44pm UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/16 "2006-02-15T14:44:05Z")
> [@edwino](#): > > Right now, I’m finishing medical school (2 months, 1 week, 2 days left). Match day is in one month and one day, then my fate will be sealed. > > Intern year starts in July, and I’ll have a little while to decide between ID, endocrine, and critical care. > > My friend, who’s trying to convince me to come to Hopkins, emailed me a few months ago when John Bartlett was his attending. So apparently, still going strong over at Hopkins… But I have to name drop, I’m reasonably close with Dan Musher, who wrote the Harrison’s chapter on Pneumococcus. I’ve never worked directly under him, but we’ve consulted him a bunch, I know his son pretty well, I’ve eaten dinner with him a few times, etc. But that’s it in terms of ID around here. Some good attendings, but nobody really leading the field. ---
**Author:** ![Bewildebeest](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@Bewildebeest](https://boards.straightdope.com/u/Bewildebeest)\ **Post date:** [February 15, 2006, 7:48pm UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/17 "2006-02-15T19:48:40Z")
Scratch-N-Sniff for dangerous pathogens! There’s a concept for you. ---
**Author:** ![tsarina](https://avatars.discourse-cdn.com/v4/letter/t/f4b2a3/32.png) [@tsarina](https://boards.straightdope.com/u/tsarina)\ **Post date:** [February 15, 2006, 11:26pm UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/18 "2006-02-15T23:26:20Z")
There’s a Neisseria species (I think it may be N. cinerea, but don’t quote me on it) that vaguely smells like chocolate cake. Campylobacter jejuni always reminded me of a cross between rotting tomatoes and rotting flesh. Yum! ---
**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\ **Post date:** [February 16, 2006, 11:44am UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/19 "2006-02-16T11:44:29Z")
Cant help the OP but there are many laboratories developing diagnostic tests that will essentially sniff for the odours of infections, and use a GC/MS system to analyze it. It could be used for quick diagnosis say of TB or MRSA ---
**Author:** ![monied406](https://avatars.discourse-cdn.com/v4/letter/m/7ab992/32.png) [@monied406](https://boards.straightdope.com/u/monied406)\ **Post date:** [May 3, 2014, 6:36pm UTC](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550/20 "2014-05-03T18:36:47Z")
I believe smell (even a slight waft of the colonies) can help with identification of bacteria. I see and smell (much to my dismay sometimes) the microorganisms everyday. Staphyloccocus aureus: smells like a strong skin like smell with a secondary smell of bread. Pseudomonas aeruginosa: initial smell of grapes with a secondary smell of tortillas Eikenella corrodens: bleach Group F Beta Hemolytic Streptococcus: has a strong buttery smell Alpha hemolytic Streptococcus Viridans group: also has a strong buttery smell Proteus sp: strong putrid and sour smell E. coli: starts out sweet then goes into a sour smell 🙂 [Next page](https://boards.straightdope.com/t/using-smell-to-help-id-bacteria/344550.md?page=2)