In an effort to communicate a more complete understanding of E. coli bacteria, the American Academy of Microbiology (AAM) released a colloquium report titled “E. coli: Good, Bad & Deadly” on Tuesday. Focusing on the fact that deadly, Shiga toxin-producing strains account for a small minority of E. coli types, the report presents the full picture of E. coli’s relationship to human health and food.


The 13-page report is the end product of a September 2011 AAM meeting between microbiologists, food safety experts and bacteriologists who set out to set the record straight — or well-rounded — on E. coli. It reads as an introductory crash-course, simple enough for casual readers to gain a more complete understanding of the complex nature of the single-celled bacterium.

Some strains of E. coli can cause serious harm — or even death — to humans, while many others live peacefully in human intestines, aiding in digestion and even defending its host against harmful microbes. Research on some strains has led to scientific breakthroughs and useful chemical compounds.

The report details E. coli’s contributions to science — studies on the organism have resulted in a record-setting 11 Nobel Prizes — and gives readers a sense of how beneficial strains of E. coli fit into the ecosystem of microorganisms the human digestive tract. At the opposite end of the spectrum, it also details how pathogenic E. coli invades intestines and causes severe illness using traits especially adapted for survival in humans.

Getting more technical, the report explains the processes behind E. coli reproduction that breed new strains with potentially harmful genes. For example, E. coli O104:H4, the strain that caused the massive European E. coli outbreak of summer 2011 was the result of a pervasive-yet-harmless E. coli strain eventually acquiring the genes for Shiga toxin production. It describes bacteriophages, too — viruses that target bacteria and can exchange genes from other types of bacteria.

By also exploring how food becomes contaminated with pathogenic E. coli — “It all starts with poop” — and how food can be kept safe from harmful bacteria, the report presents a rounded, fact-heavy primer on E. coli and, to a more general extent, the intricate world of microbiology. 

“E. coli has accompanied humans and larger animals for millennia,” the report’s final page reads. “It has become an important part of our gut and, much more recently, a remarkable tool for scientific study. We cannot preduct how E. coli will impact mankind in the future, but we know that it will always be with us.”

A PDF version of the report is available here.