Where There’s E. Coli, There’s Poop!

A large and dead­ly out­break of food poi­son­ing in Europe has been linked to a “super-tox­ic” new strain of Escherichia coli bac­te­ria. The out­break seems to be linked to the con­sump­tion of fresh veg­eta­bles. Yet when­ev­er I hear of an out­break of E. coli, I won­der, “Where’s the poop?”

The nat­ur­al habi­tat of E. coli is inside the intestines of warm-blood­ed ani­mals. Since veg­eta­bles are not warm-blood­ed, and they have no intestines, how can they be a source of E. coli? The answer, of course, is that E. coli can sur­vive out­side of their host for a short time. That’s how they can spread from one host to anoth­er. It’s also why “col­iform bac­te­ria counts” are used to eval­u­ate how bad­ly a body of water has been con­t­a­m­i­nat­ed with raw sewage. If veg­eta­bles are spread­ing E. coli, it’s because they’ve been con­t­a­m­i­nat­ed by the drop­pings of a warm-blood­ed ani­mal.

Some strains of E. coli are nor­mal inhab­i­tants of the human intesti­nal tract. How­ev­er, if you find ordi­nary E. coli you might also find oth­er, more dan­ger­ous bac­te­ria and virus­es that can spread from one per­son to anoth­er by the “fecal-oral route,” which is when peo­ple swal­low some­thing that has been con­t­a­m­i­nat­ed by some­one else’s poop.

The E. coli strains that are com­mon­ly found inside human intestines have learned to live inside a human host with­out caus­ing any trou­ble under nor­mal cir­cum­stances. Unfor­tu­nate­ly, the E. coli that nor­mal­ly live in the intestines of oth­er kinds of ani­mals, such as cat­tle, can make peo­ple real­ly sick. Even more unfor­tu­nate­ly, E. coli bac­te­ria can swap genes with oth­er strains of E. coli, and even with unre­lat­ed bac­te­ria. Thus, bac­te­ria can learn bad habits from each oth­er. They may learn how to make a dead­ly new tox­in, or how to resist antibi­otics.

If his­to­ry is any guide, this out­break of dead­ly E. coli food poi­son­ing result­ed from the use of fresh ani­mal manure to fer­til­ize veg­eta­bles. Fresh manure is unsan­i­tary. It should nev­er be allowed any­where near food that will be eat­en raw!


Update, 6/6: At first, health offi­cials sus­pect­ed that the E. coli out­break result­ed from raw veg­eta­bles from Spain. Then, sus­pi­cion shift­ed to raw sprouts from an organ­ic farm in Ger­many. Bean and alfal­fa sprouts are a com­mon source of Sal­mo­nel­la and E. coli food poi­son­ing. That’s because they are often grown in moist con­di­tions at a tem­per­a­ture that approx­i­mates human body tem­per­a­ture. How­ev­er, sprouts aren’t fer­til­ized and there­fore should not have come into con­tact with cow manure. The E. coli would there­fore have had to come from con­t­a­m­i­nat­ed seeds, from con­t­a­m­i­nat­ed water, or from one of the work­ers. The own­er of the Ger­man sprout farm insists that there were no ani­mals or ani­mal prod­ucts on site. It’s pos­si­ble, but some­what unlike­ly, for one of the work­ers to be car­ry­ing a dan­ger­ous bovine strain of E. coli. So far, health author­i­ties have been unable to find any evi­dence of the E. coli strain in the sprouts or at the sprout producer’s premis­es. Of course, those tests can’t prove that the E. coli strain was nev­er there. It’s pos­si­ble that the source of the out­break may nev­er be known for sure.

Pho­to by Randy Heinitz