This particular e.coli variation is a member of the O104 strain, and O104 strains are almost never (normally) resistant to antibiotics. In order for them to acquire this resistance, they must be repeatedly exposed to antibiotics in order to provide the "mutation pressure" that nudges them toward complete drug immunity.
So if you're curious about the origins of such a strain, you can essentially reverse engineer the genetic code of the e.coli and determine fairly accurately which antibiotics it was exposed to during its development. This step has now been done (see below), and when you look at the genetic decoding of this O104 strain now threatening food consumers across the EU, a fascinating picture emerges of how it must have come into existence.
So how, exactly, does a bacterial strain come into existence that's resistant to over a dozen antibiotics in eight different drug classes and features two deadly gene mutations plus ESBL enzyme capabilities?