Health and Medicine Technology

New Device Holds Hope of Earlier Bacterial Infection Diagnosis

pathogen detection

A team of researchers at the Massachusetts General Hospital (or MGH) have recently created a device that may be able to diagnose pathogens that lead to infections in a handful of hours, versus the current wait time of a few days. According to the study, which was published in Science Advances journal, this new technology would lead to point-of-care diagnosis, because it can be used outside of the lab.

Ralph Weissleder, MD, PhD and director of the MGH Center for Systems Biology, Thrall Family Professor of Radiology at Harvard Medical School (or HMS) and co-senior author of the study calls health-care-associated infections a major problem. He says they affect over 600,000 patients every single year. 10% of these cases end in death. These infections cost about $100 billion per year. Weissleder calls this new form of rapid diagnosis a critical beginning step in selecting the best antibiotic regimen. He goes on to explain that the system would offer doctors the information they require in no more than two hours.

What’s so tricky about culture-based diagnosis that is widely used today is that a diagnosis can take days to be reported. On top of that, specialized equipment and trained lab workers are required in order to make a proper diagnosis. This is all very expensive and time consuming. The MGH team’s system, known as PAD (Polarization Anisotropy Diagnosis) offers an accurate testing of genetics without all the fancy equipment. The device uses a small, disposable cartridge to extract bacterial RNA. The RNA is put into a 2-cm plastic cube that looks for specific RNA, which is located via probes that measure responses to light. Optical cubes send data directly to a computer or a smartphone through an electronic base station.

pad diagnostics
A smartphone readout from the Polarization Anisotropy Diagnostics (PAD) system shows the pathogens responsible for an infection and factors such as antibiotic resistance.
Image Credits: Chen-Han Huang, PhD, and Ki Soo Park, PhD, Center for System Biology, Massachusetts General Hospital

For the recent study, with the help of a prototype PAD system containing four optical cubes used for examining clinical samples, the team was able to compare results to the findings from microbiology cultures. The tests were looking for five different bacterial species: E. coli, Eledbsiella, Acinetobacter, Pseudomonas and Staph aureus, as well as both the virulence and antibiotic resistance of varying strains. Both tests shared the exact same results. However, the PAD gave the data in under two hours, while the bacterial culture took between three and five days to pinpoint a diagnosis. As of May 2016, the team has designed probes that are able to diagnose more than 35 bacterial species as well as virulence factors, amazingly at the price of about $2 per test.

Hakho Lee, PhD from the MGH Center of Systems Biology (or CSB), associate professor of Radiology at HMS and co-senior author of the study says there are still improvements needed for the current prototype. The team is working on creating a self-contained system that offers all functions, which should cut the diagnosis time in half. The plan for the device as it stands today is to help in quickly diagnosing infections, locating bacteria that are antibiotic-resistant and pinpointing bacterial contaminations within medical devices or hospital environments.