Know your ennemy

Light source identifies a key protein interaction during E. coli infection

Escherichia coli is a common source for contaminated water and food products, causing the condition known as gastroenteritis with symptoms that include diarrhea, vomiting, fever, loss of energy, and dehydration. In fact, for children or individuals with weakened immune systems, this bacterial infection in the gut can be life-threatening.

One of the microbes responsible for gastroenteritis, known formally as enteropathogenic E. coli (EPEC), causes infections by directing a pointed, needle-like projection into the human intestinal tract, releasing toxins that make people sick.

“Enteropathogenic E. coli can fire toxic proteins from inside the bacterium right into the cells of your gut lining,” says Dustin Little, a post-doctoral researcher in the Brian Coombes lab at McMaster University’s Department of Biochemistry and Biomedical Sciences.

>Read more on the Canadian Light Source website

Image: Dustin Little and Brian Coombes in the lab.
Credit: Dustin Little. 

Infrared beams show cell types in a different light

Berkeley Lab scientists developing new system to identify cell differences.

By shining highly focused infrared light on living cells, scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) hope to unmask individual cell identities, and to diagnose whether the cells are diseased or healthy.
They will use their technique to produce detailed, color-based maps of individual cells and collections of cells – in microscopic and eventually nanoscale detail – that will be analyzed using machine-learning techniques to automatically sort out cell characteristics.

Using microscopic color maps to unlock cell identity

Their focus is on developing a rapid way to easily identify cell types, and features within cells, to aid in biological and medical research by providing a way to probe living cells in their native environment without harming the cells or requiring obtrusive cell-labeling techniques.
“This is totally noninvasive,” said Cynthia McMurray, a biochemist and senior scientist in Berkeley Lab’s Molecular Biophysics and Integrated Bioimaging (MBIB) Division who is leading this new imaging effort with Michael Martin, a physicist and senior staff scientist at Berkeley Lab’s Advanced Light Source (ALS).
The ALS has dozens of beamlines that produce beams of intensely focused light, from infrared to X-rays, for a broad range of experiments.

>Read more on the Advanced Light Source website

Image: From left to right: Aris Polyzos, Edward Barnard, and Lila Lovergne, pictured here at Berkeley Lab’s Advanced Light Source, are part of a research team that is developing a cell-identification technique based on infrared imaging and machine learning.
Credit: Marilyn Chung/Berkeley Lab