Antibiotics are essential in treating bacterial infections. However, bacteria have evolved mechanisms to protect themselves from these life-saving drugs. In particular, some bacteria can halt growth and enter a dormant state, reducing their metabolism and antibiotic sensitivity, helping them survive antibiotic treatments.
To fully cure a bacterial infection and avoid the development of resistance, it is essential to understand how long the pathogen can persist in such dormant states. However, methods to measure how long bacteria can resist different drugs are complex and can take several days to provide a result.
Now, researchers at EPFL have developed a new method that rapidly quantifies how long bacteria can survive antibiotic treatment. The new method is based on measuring the bacterial cell size and requires a simple device that can be easily built in any lab.
The method, named QUIPS-q (QUantitative Imaging of Persistence and Survival for quantifying bacterial persistence and quantifying bacterial survival), allows researchers to measure the size distribution of bacterial cells in a given environment. By tracking how the cell size distribution changes over time, QUIPS-q reveals how long bacteria can persist under antimicrobial treatment.
The EPFL team tested their new method on two bacterial species that commonly cause infections in humans: Escherichia coli and Pseudomonas aeruginosa. They found that the bacteria could survive antibiotic treatment for several hours to days, depending on the antibiotic used.
The researchers also tested QUIPS-q on bacteria that were previously exposed to antibiotics. They found that bacteria that were previously exposed to antibiotics could survive longer under antibiotic treatment, indicating that the bacteria had developed resistance.
The new method provides a simple and rapid way to measure how long bacteria can survive antibiotic treatment and can be used to investigate bacterial persistence as well as antimicrobial resistance.
