Whoa....slow down folks. Before we all get panicky...
The E. coli scare with spinach was contaminated surface water from cattle production running into a field. E. coli is usually water born and is usually a surface contaminant. This was a function of some bad field design, a sloppy rancher for a neighbor, and some bad luck. Most forms of E.coli are harmless (you have a gut load right now as you read this) and even most of the Shiga Toxin E. coli (STECs) will run a course of 5-7 days with most people surviving...These superbugs are byproducts of our cattle raising programs that focus on grains, making bovine digestion overly acidic and creating strains that survive human stomach acids. Grass feeding raises the Omega 3 ratio compared to the Omega 6 heavy regimen from grain feeding (like your doctor is always telling you you need Omega 3 fatty acids; it's because they are not as acidic as the O6 variety...we should stop feeding cattle grain and start feeding grass and a lot of good things would happen (those global warming causing cow f**ts would be reduced along with higher Omega 3 in beef and less deadly E.coli due to lower stomach acidities)
Bacteria are simply food in a healthy soil biology. Protozoa eat 10,000 bacteria in a day, and there are tens of thousands of protozoa in a teaspoon
of soil. Fungal structure holds the soil open and keeps it airy, and as long as we have the right moisture, air, and food in the soil the protozoa will predate on bacteria, keeping the numbers very low and allowing for no dominant culture to emerge. In the eating of the bacteria the protozoa release the nitrogen to the soil, feeding the plant...in other words organics is just a protozoa eat bacteria world...
E.coli is a facultative anarobe, meaning it is able to survive in air, but it is happiest without. In biologically dead soils, like ones whose structure is so compacted that air cannot get in, E. coli stands a better chance to thrive than the aerated organic soil, thriving with predators. Silty wet soils are far more likely to be an issue, as organic soil tends to clump (we call it microaggeregation and macroaggregation) creating porosity and therefore air. Chemically treated soils are far more likely to be [url=https://en.wikipedia.org/wiki/Anaerobic]anaerobic[/url]. Treating soils with Effective Microbes (EM), another selection of facultative anarobes, could certainly limit E. coli by out-competing it (These microbes have been used to eat old paint, oil slicks and just about anything you feed it so it's tougher than E.coli) Japanese bokashi is a centuries old way of making EM; this is not new technology. There is also evidence that worms may well play a key role in mitigating E.coli and fecal coliforms, considerable reducing the CFU (colony forming units). I have seen this myself with manure composts drastically reduced in CFU counts by vermicomposting.
I would certainly eat tomaotes grown over a septic tank, as long as it was organic. If you wish to avoid E. coli, climb in the bubble today and take your antibiotics and hook up to the IV, because you are loaded with it as you need E.coli to digest your food, just like most other living things with a stomach. Therefore it is a completely common bacteria, found everywhere throughout the planet. Our best defense against being overrun is protozoas, which we get in good compost, the best compost having a manure component, so there will be some E.coli and coliforms
See the dilemma here? See why chemical companies might try to convince people that E. coli is going to killl us all? Without compost, organics just doesn't work that well (organic fertilizers need the biological action to release the nutrients) and the chemical guys would love to start a stampede away from organics because of this issue. But you won't find too many germaphobes among soil people; we know what's in there and out there and the chemicals are a lot more dangerous in the long run. There is some growing evidence that prion contamination from humanure may have ill effects, including a newly found link to Alzheimers, but that is another topic.
E. coli through the soil, picked up by a plants roots and transmitted to its fruit, and then to a human? I'd like to see that white paper.