Could we instantly I.D. pathogens by their glow?

A new method to identify pathogens relies on spectroscopy, determining an object's identity through the type of light it emits. (Credit: Gadgee Fadgee/Flickr)

There are plenty of ways in the lab to determine which bug is bugging you when you’re sick. But most of them are complicated and can take days.

“You can do a swab and culture the bacterium or fungi, but that takes days,” says Xinyu Liu, an assistant professor of chemistry at the University of Pittsburgh. “You can examine the DNA, but that takes another day or two. It’s a pretty tedious process.

“So, before the identity of the pathogen can be determined, doctors give infected people a broad-spectrum antibiotic that kills everything.”

It would be better for the patient, then, to correctly identify the pathogen in question as soon as possible and treat it with a specific antibiotic aimed directly at the offending bug.

The light they emit

Liu and colleagues have developed a method of identifying pathogens that relies on spectroscopy, determining an object’s identity through the type of light it emits. Their work appears in the journal Angewandte Chemie International Edition.

They developed a protein hydrogel that interacts with carbohydrates on the surface of a fungus named Candida albicans, which is responsible for oral thrush and skin yeast infection and can be life-threatening for some people.

[this mobile phone microscope finds parasites in blood]

When the protein hydrogel interacts with the carbohydrates on the surface of C. ablicans, it shrinks the 2D photonic crystals the hydrogel resides on, emitting a specific light signature that can be recognized by the naked eye or a spectroscope. This happens almost immediately.

The researchers say the broader implications are big.

“You can imagine that if we try to extend this work, we can use differing antibodies to make hydrogels tailored for specific pathogens such as staph, E. coli, etc,” the researchers report. “And people living in rural areas or underdeveloped countries might be able to use this method to see if their food or water is contaminated or their kids are infected with deadly pathogens.”

Source: University of Pittsburgh