Resistant bacteria complicate antibiotic treatment.

The fight against bacterial diseases is a constant arms race between new medical treatments and disease-causing bacteria that are constantly changing in order to survive even when they come into contact with antibiotics.

When antibacterial treatment is started, the high concentration of antibiotics causes most bacteria to die or stop growing almost immediately – and we often feel better a few days after starting treatment. But now a group of researchers in Uppsala can show that a small fraction of bacteria continue to grow, sometimes up to ten generations.

These bacteria are not resistant. Their ability to continue dividing – despite being exposed to a relatively high concentration of antibiotics – is a result of natural variation in the bacterial strain.

increases the risk of resistance

But each cell division gives the bacteria a chance to genetically change in a way that eventually makes the bacteria resistant. However, it rarely happens – and if you keep going through your antibiotic regimen to the last pill, you have a good chance of getting rid of the infection for good.

– This is a new concept that we call bacterial persistence or persistence. Perseverance describes how a small group of bacteria with random conditions to continue growing can accumulate a lot of mutations. If they are lucky, and the patient is unlucky, one of these mutations makes them able to tolerate the antibiotic, says Gerrit Brandis, a researcher at Uppsala University.

Individual bacteria are studied in the laboratory

Often when you study bacteria, you look at how bacteria interact as a community, i.e. you’re looking at a very large number of bacteria at the same time.

Because there are so few resistant bacteria, they have flown a bit under the radar.

In a laboratory at Uppsala University, the researchers specialized in studying individual bacteria and how they interact with various stimuli, such as antibiotics. Using microfluidic culture chambers and AI-based algorithms for image analysis, they can follow the individual growth of tens of thousands of bacteria at once.

– It’s a very powerful tool. It shows the importance of not grouping everyone together, even when it comes to bacteria, says Johan Elf, a professor in the Department of Cell and Molecular Biology at Uppsala University.

Scientific study:

Antibiotic persistence increases the risk of developing resistanceBanas.

stopper:

Johan Elf, Professor, Department of Cell and Molecular Biology, Uppsala University, [email protected]