Tiny sensors can tell if antibiotics are working
“Some of our most effective antibiotics are like termites eating away at the walls of a wooden house—they attack bacterial cell walls so they eventually collapse,” says Matthew A. Cooper, professor in University of Queensland’s Institute for Molecular Bioscience.
“But competing molecules in the blood can bind to antibiotics and prevent them from working, meaning there are less molecules free to exert force on bacterial cell walls.”
The researchers used nano-sized levers as sensors to measure the concentration of active antibiotics in blood. “The sensor we developed, one billionth of a meter in size, can detect the bending that occurs in a cell wall when it is assaulted by antibiotics.
“This enables us to measure how many antibiotic molecules are free in the blood to attack bacteria and treat the infection based upon how much force they exert onto the wall.”
Customized dosageThe amount of free antibiotics in the blood will vary between people, meaning this method could be used to determine the best antibiotic dosages for different individuals and different infections.
“Understanding the way antibiotics use physical force against bacteria could also provide researchers with a new angle on the design of better drugs to fight superbugs, which often have thicker, stronger cell walls,” Cooper says.
The researchers tested the method on two antibiotics: vancomycin, used to treat multi-drug resistant infections such as Methicillin-resistant Staphylococcus aureus, and oritavacin, a new antibiotic still in clinical trials designed to combat bacteria that are resistant to vancomycin.
Details of the method were published in the journal Nature Nanotechnology in a study led by Joseph Ndieyira from the London Centre for Nanotechnology (LCN) at University College London. It also involved researchers from the University of Cambridge and Jomo Kenyatta University of Agriculture and Technology in Kenya.
An Australia Fellowship from the National Health and Medical Research Council helped support the research.
Source: University of Queensland