Testing Antibiotics Against Bacteria Faster With New Chip
TORONTO, May 26 (UPI) — A new chip could make it easier for doctors to prescribe the correct antibiotic, if one is even needed at all, by quickly analyzing the effectiveness of the antibiotic on bacteria collected from patient samples.
Patient samples are flowed through the chip and samples collect at the bottom of well-like structures where bacteria mix with the antibiotic to be tested and a signal molecule called resazurin. If the antibiotic is not successful, the bacteria will metabolize resazurin into resorufin, changing the electrochemical signature of the sample. If nothing happens, the antibiotic will have successfully killed the bacteria.
The speed of testing bacteria with the new chip is key to its usefulness because previously bacteria samples would need to be sent to a lab for analysis, which can take two to three days, leaving doctors to prescribe a more powerful – and possibly ineffective – antibiotic until they know what they’re dealing with. The chip could help doctors to make the right choice more quickly.
“Guessing can lead to resistance to these broad-spectrum antibiotics, and in the case of serious infections, to much worse outcomes for the patient,” Justin Besant, a researcher at the University of Toronto, said in a press release. “We wanted to determine whether bacteria are susceptible to a particular antibiotic, on a time scale of hours, not days.”
Amid growing concerns that antibiotics are losing their effectiveness because of overuse that has led to bacteria and viruses evolving for survival against them – 2 million people in the United States contract antibiotic resistant bugs each year – selecting the right drug to fight these infections is important.
“The electronics for our electrochemical readout can easily fit in a very small benchtop instrument, and this is something you could see in a doctor’s office, for example,” Besant said. “The next step would be to create a device that would allow you to test many different antibiotics at many different concentrations, but we’re not there yet.”
The study is published in Lab on a Chip.
