http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/double-dipping-is-germ-warfare/
Does double-dipping really spread germs?
Finding: BUSTED
Explanation: This myth gathered steam after a Seinfeld episode aired in which George was caught in the socially unacceptable act of double-dipping. The theory here is that double-dipping placing a chip in dip, biting off the chip and then placing it again into the dip spreads as much bacteria in the dip as if you'd stuck your whole mouth in the bowl. So, MythBusters Adam Savage and Jamie Hyneman set out on a bacteria-finding mission with somewhat surprising results.
By testing bacterial growth in petri dishes using sterilized chips and a salsa-like substance, they found that double-dipping adds just a small amount of bacteria to the salsa, and definitely not as much as sticking your mouth in the bowl.
The truth is that most dips store-bought or homemade already contain bacteria. Double-dipping adds only a few more microbes than the multitude swimming in your salsa to begin with.
So, if you want your dip to stay totally bacteria-free, it looks like you're out of luck. But if you want to keep your germs to yourself, your best bet is to just eat out of your own private bowl.
How many times was that dip double dipped? Once or a couple dozen or so times? People don’t just double dip once. Have each person double dip a dozen times and put their dirty hands in the chips a couple times throughout the party and then test for germs.
I’m sure this test, not the myth busters test, was done under the right conditions.
EWWWWWWWW!.......................
Interesting, but.
The story says the sour cream is the big culprit in growing the bad stuff.
The Mythbusters test you posted said they used Salsa. No sour cream.
So both reports could be true, since the media are different for the growth.
Salsa has hot peppers in it. Some of them can kill bacteria. Plus the acid in tomatoes is mildly antiseptic. Sour cream, not so much.