Researchers have developed a device with the potential of shortening the time required to rapidly diagnose bacterial infections from days to a couple of hours.The system could also allow point-of-care diagnosis, as it does not require the facilities and expertise available only in hospital laboratories, the study said. "Health-care-associated infections are a major problem that affects more than 600,000 patients each year, more than 10 percent of whom will die, and incurs more $100 billion in related costs," said co-senior author of the study Ralph Weissleder from Massachusetts General Hospital (MGH) in Boston, US."Rapid and efficient diagnosis of the pathogen is a critical first step in choosing the appropriate antibiotic regimen, and this system could provide that information in a physician's office in less than two hours," Weissleder noted.The system developed by the MGH team, dubbed PAD for Polarization Anisotropy Diagnostics, allows for accurate genetic testing in a simple device. In this study, the team used a prototype PAD system to test clinical samples from nine patients and compared the results with those acquired by conventional microbiology cultures.
Testing for the presence of five important bacterial species -- E. coli, Klebsiella, Acinetobacter, Pseudomonas, and Staph aureus -- and for factors indicating the virulence and antibiotic resistance of specific strains produced identical results with both procedures. But while PAD provided results in less than two hours, the bacterial culture process took three to five days. The findings were reported in the journal Science Advances."We can see three immediate applications for a system that can provide such rapid and accurate results - quickly diagnosing a patient's infection, determining whether antibiotic-resistant bacteria are present in a group of patients, and detecting bacterial contamination of medical devices or patient environments," co-senior author Hakho Lee, associate professor of radiology at Harvard Medical School, pointed out.