Microwave Sensor for Rapid Antibiotic Susceptibility Testing
Researchers at University of British Columbia Okanagan campus have developed an inexpensive and portable microwave sensor that can rapidly detect changes in bacterial growth to assess antibiotic susceptibility. Using a split ring microwave resonator, the device can very sensitively measure bacterial growth in the presence of different concentrations of an antibiotic before any visible changes in growth are present. The technology reduces the time and expense associated with such testing and could pave the way for personalized antibiotic therapy for low-resource or remote regions.
Antibiotics have revolutionized healthcare, permitting routine surgical procedures to proceed without undue fear of devastating infection and putting an end to a huge array of nasty diseases that previously would have spelled death or disability for millions of people every year. However, these advances are slowly but surely being chipped away by antibiotic resistance, which is increasing every year.
“Many types of bacteria are continuously evolving to develop resistance to antibiotics. This is a pressing issue for hospitals around the globe, while sensor and diagnosis technology has been slow to adapt,” said Mohammad Zarifi, a researcher involved in the study, in a press release.
The major issue is inappropriate use of antibiotics, and part of the solution involves choosing the correct antibiotic for each patient. After all, there is little point in prescribing an antibacterial agent for an infection caused by bacteria that are already resistant to that agent. This is where personalized antibiotic therapy comes to the fore, which involves testing a sample of disease-causing bacteria from a specific patient for their antibiotic susceptibility prior to prescribing an appropriate antibiotic.
The problem is that this process is currently time consuming and expensive, often taking as long as 48 hours, which is no joke if you have a serious infection. “Longer wait times can significantly delay the treatments patients receive, which can lead to further medical complications or even fatalities. This method showcases the requirement for a reliable, rapid and cost-effective detection tool,” said Zarifi.
This new technology relies on microwave sensing as a means to monitor bacterial sample growth in the presence of different concentrations of an antibiotic. The system is sensitive enough that it can detect differences in bacterial growth that are invisible to the human eye, and it achieves this using a split ring microwave resonator. The charged substances released by bacterial cells, when they are affected by antibiotics, can assist with the measurement, but in essence, the resonant response of the split ring is affected by the growth of a bacterial sample on agar.
Ultimately, the researchers hope to incorporate an AI element into the technology to aid in sensing and prediction for personalized antibiotic treatment.
“Our ultimate goal is to reduce inappropriate usage of antibiotics and enhance quality of care for the patients,” said Zarifi. “The more quality tools like this that health-care practitioners have at their disposal, the greater their ability to combat bacteria and viruses.”
See a video about the technology below.