Scientists from Purdue University are using Doppler radar to “peek” into cells and monitor metabolic activity in real time, allowing them to test microbes, detect pathogens in different environments and identify potential treatments for antibiotic-resistant bacteria.
Scientists from Purdue University are using Doppler radar to “peek” into cells and monitor metabolic activity in real time, allowing them to test microbes, detect pathogens in different environments and identify potential treatments for antibiotic-resistant bacteria.
In their new study, backed by the National Science Foundation and Purdue’s Discovery Park Big Idea Challenge, researchers from the university exposed immortalized cell lines to known pathogens, including salmonella and Escherichia coli. The investigators then used the Doppler effect to examine how these sentinel cells reacted following exposure using a biodynamic assay.
“First we did biodynamic imaging applied to cancer, and now we’re applying it to other kinds of cells,” said study investigators David Nolte, Purdue’s Edward M. Purcell Distinguished Professor of Physics and Astronomy. “This research is unique. No one else is doing anything like it. That’s why it’s so intriguing.” The strategy used in this study is generally applied in research when scientists want to know if an isolated unknown microbe is pathogenic. These cells often show up in food, water sources and recently melted glaciers.
“This directly measures whether a cell is pathogenic,” added another study researcher Michael Ladisch, Distinguished Professor of Agricultural and Biological Engineering. “If the cells are not pathogenic, the Doppler signal doesn’t change. If they are, the Doppler signal changes quite significantly. Then you can use other methods to identify what the pathogen is. This is a quick way to tell friend from foe.”
According to the researchers, this could help future investigators determine whether a cell is harmful, which could have benefits in quickly establishing mitigation and treatment protocols in situations where people are exposed to a living unknown microorganism.
Another benefit to this Doppler technique, the investigators suggest, could be the ability to swiftly and directly diagnose bacteria that will respond to specific antibiotics. Ultimately, this could help overcome antibiotic resistance, a growing life-threatening issue in hospitals and other healthcare environments.
The new biodynamic assay process used in this study help scientists place a patient’s bacterial samples in petri dishes containing tissue sentinels and treat the samples with different antibiotics. Doppler is subsequently used to examine which samples demonstrate notable metabolic changes. Samples that demonstrate these changes are the ones that react to the antibiotic, which can then inform scientists as to which agent is most appropriate for the patient.
“When we treat with antibiotics, the bacteria don’t have to multiply much before they start to affect the tissue sentinels,” explained Nolte. “There are still too few bacteria to see or to measure directly, but they start to affect how the tissues behave, which we can detect with Doppler.”
The entire process works in less than half the time it takes for a traditional culture and diagnosis protocol, which could improve the chances of a patient’s recovery. Noticing the innovative and promising findings from this study, Purdue researchers have worked with the Purdue Research Foundation Office of Technology Commercialization to both patent and license the studied technologies.
In their statement on the study, the investigators say they plan to conduct future research to see if this Doppler and biodynamic assay method could work for samples exposed to nonliving pathogenic cells or dried spores. The investigators also say they want to method whether the method also works to test and treat viral sepsis.
