Micro-organisms, especially bacteria, play essential roles in our bodies, especially in our guts. Some bacteria are beneficial, and some like E.coli are harmful. Another Escherichia strain (in the same genus as E. coli) named Escherichia albertii is also pathogenic to humans, causing diarrhea and food-borne illnesses.  E. albertii was identified for the first time during an illness outbreak in Bangladesh. 

Pathogenic bacteria like E. albertii are very motile, meaning they move around a lot. They are able to do this using hair-like structures called flagella. E. albertii was originally described as non-hairy bacterium and thus far has been considered to be a non-motile pathogenic micro-organism.

A new study led by Tetsuya Ikeda and a team at Hokkaido Institute of Public Health in Japan has found that this may not be true: stressful environments can stimulate E. albertii to make flagella. They showed that, despite the fact of having most of the genes needed for flagella, at normal temperature of 37 degrees Celsius this bacterial strain does not show any motility. But in conditions such as low salt and nutrient concentrations and colder temperatures (20 degrees C), the bacterium's flagellar genes are activated and it becomes motile. More motile cells can survival better under unfavorable conditions, making them more harmful to humans.