http://news.nationalpost.com/2011/01...?__federated=1

15 Monate, ohne Waschen.

But when Le and assistant human ecology professor Rachel McQueen swabbed the inside of the jeans and tested them for bacteria in December 2010, they found levels pretty normal. And after Le washed the jeans, then wore them for 13 days before re-testing them, bacteria levels were nearly identical.
“I was pleasantly surprised,” said McQueen. “What I found was just normal skin flora. The counts were really, really similar. The bacteria load from the swabbed areas were pretty much the same.”
This means wearing raw denim for months without washing is likely safe for a normal, healthy person, said McQueen, adding the caution that this is just one unpublished study with one person’s jeans.