I believe E Coli is also found in human excrement. When it has been linked to vegetables (as it has over the past few years), it was discovered a couple of times that the cause was due to the farmhands urinating and defecating right in the fields they were harvesting.
I’m not saying that’s how it got in the flour. But it could have gotten there if a patch of the wheat field was an area frequented by wildlife for urinating/defecating. It gets on the wheat. They harvest and process it. It is not irradiated or cooked, and the E Coli is alive in the flour.
The article doesn’t specify the strain of E. coli involved.
E. coli lives in everyone’s guts. It is also a common little laboratory “workhorse” (in that scientists use it for all kinds of experiments).
As I said, E. coli is found in mammalian excrement. (Actually all warm-blooded animals.) Humans are mammals and all of us carry E. coli. In fact, it is essential to human life. Produces vitamins for us, and many of the presently popular probiotic treatments involve consumption of E. coli.
The particular strains that cause serious human disease are more likely to be carried by herbivores than by other humans.
The fact that contamination by feces of water sources is usually measured by the E. coli concentration misleads a lot of people into thinking it’s the E. coli that is particularly dangerous. In actual fact, it’s just easy to measure and provides an excellent tracer organism. There are lots of other bacteria in human feces that are more likely to cause serious illness in people.
BTW, E. coli is such an extremely diverse species that it should probably have many of its “strains” reclassified as separate species.