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 forPseudomonas 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
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.
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.
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.
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?
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.
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
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.
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
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
