Re: [DIYbio] Re: Something is Rotten in Denmark

First of all, whenever you isolate an unknown organism from an environmental sample, you really should be doing that in a BioSafety Level 2 lab...

On the other hand, fermenting grapes to make wine, or making sauerkraut (beware, wild lactobacilli!) is also culturing unknown organisms from environmental sample... Yes, using a sample from humans makes it orders of magnitude more dangerous, but still, I would be very surprised if something bad happened. Yoghurt is not a good environment for typical pathogens.

Still, of course, not lege artis.

Jakub Friedl

On Tue, Jun 30, 2015 at 10:53 AM, Patrik D'haeseleer <patrikd@gmail.com> wrote:
Yes, this is definitely a really bad idea. Not that you couldn't do what they claim to be doing. But the way they're doing it isn't even close to safe. At least, it sounds like nobody is actually going to *eat* this vaghurt, since the program ends with "Visual inspection" and "Inactivating the biomaterials".

First of all, whenever you isolate an unknown organism from an environmental sample, you really should be doing that in a BioSafety Level 2 lab, because there is always some chance you'll be isolating (and greatly amplifying!) a pathogen instead. Check out the answer to my question to ask.diybio.org on this issue:

Secondly, the fact that they're starting from a human sample increases the odds of isolating a pathogen by orders of magnitude. Sure, by culturing in milk they will be selecting for the more harmless lactobacilli. But they're only doing a single day of culturing, and they're not even picking colonies. So there's no chance in hell they'll get rid of anything that may be dangerous. Remember: one person's commensal bacteria is another's pathogens! Nice cup of Candida or STD yoghurt, anyone? 

And even if they were able to select a single Lactobacillus strain (which they can't - not with the procedure they described), that's still not a guarantee it would be harmless. We tend to equate Lactobacilli with yoghurt, cheese and other fermented dairy products, but there's plenty of pathogenic ones as well:

Pathogenic potential of lactobacilli.
Pathogenic relevance of Lactobacillus: a retrospective review of over 200 cases.


You want to do this safely? You do the isolation in a BSL-2 lab, or at least a biosafety cabinet. You isolate colonies and subculture a couple times until you're confident they're axenic. They you use 16S sequencing to figure out what you have, and whether it's closely related to any pathogens. Then you try it *yourself* first, before you start exposing anyone else.

Good thing they're not actually planning on eating this...


On Monday, June 29, 2015 at 9:33:31 PM UTC-7, Roninlaw wrote:


VAGHURT - DIY Vagina Yoghurt - Check the event and sign-up http://biologigaragen.org/2015/124


Seems like you could easily culture a pathogen.  Michael Douglas would not approve. Anyone want to weigh in on the safety aspects?  Today is the day they were supposed to eat it.  I would urge you not to.

Dan


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