Scientists have found out how electrochemical energy in bacteria makes them resistant to antibiotics

By Dr Graham Beards at en.wikipedia, CC BY-SA 4.0,

The threat posed by antibiotic-resistant microorganisms to world health is growing. Each year, millions of people die as a result of bacterial infections that acquire genetic resistance to antibiotics. However, one of the many ways that bacteria might resist antibiotics is through genetic resistance.

Texas A&M University researchers are looking at how bacteria might become resistant to drugs without gaining new genes or changing their already existing ones. To comprehend how bacteria adapt to antibiotics, the researches focused on differences in the electrochemical energy that drive bacterial development. These energies are powerful: The electric field that contributes to them can be greater in a single bacteria than in a lightning bolts.

In order to live in harsh environments, bacteria have evolved a variety of adaption tactics over billions of years, according to Dr. Pushkar Lele, an associate professor in Texas A&M’s Artie McFerrin Department of Chemical Engineering. The majority of adaptive processes are still poorly known.

The team’s research was published in a paper titled “Heterogeneous Distribution of Proton-Motive Force in Nonheritable Antibiotic Resistance” in the journal mBio.

Eight times as much antibiotics are needed annually to keep animals healthy for human consumption as compared to the 3 million pounds used annually in human treatment. Unfortunately, overuse and careless application of antibiotics can foster an environment that encourages the growth of bacterial antibiotic resistance.

Individual bacterial cells with insufficient energy commonly withstand deadly dosages of antibiotics, according to earlier investigations. It’s possible that these inactive cells lack the genes necessary to develop antibiotic resistance. They instead sleep throughout the antibiotic treatment.

Antibiotics destroy bacteria that are actively developing, often by targeting on important cellular functions, according to Lele. High energy levels, in fact, are thought to be harmful to their chances of survival in dormant bacteria since those activities may be halted there, rendering antibiotics useless.

Therefore, the team was shocked when they saw Escherichia coli survivors swimming fast for several hours in the presence of antibiotics. Flagella, which are revolving, thin appendages, are used by bacteria to swim. Strong electric fields that are applied across the cell membrane cause the flagella to rotate several hundred times per second. Thus, the studies revealed that survivors maintain high electrochemical energy, which goes against what is often believed.

The researchers gave cells several antibiotic combinations in order to examine the relationship between cell energy and antibiotic tolerance. They kept track of the electrochemical energy levels in the surviving cells using fluorescent dyes and sensitive photon detection methods. The cells were in a growth arrest yet unexpectedly showed a great range of energies.

The next step was to predict how the survivors would react if the antibiotic treatment was interrupted. Working at the level of a single cell, they found that high energy cells grew right away when the antibiotic threat was removed, highlighting the dangers of partial antibiotic treatments.

The finding suggest that certain bacteria, even those that are neither resistant nor dormant, can survive the antibiotic treatment. The capacity of these bacteria to swim out of dangerous areas and spread quickly is alarming. Additionally, they are able to respond differently to the antibiotics due to their high energy retention.

According to Lele, the energy source in E. coli that fuels motility also powers numerous transporters, commonly referred to as efflux pumps. The swimming cells they saw may have evolved via this method, as these transporters may pump antibiotics out of the cell to decrease the toxicity.

If an infected patient doesn’t improve after receiving a first antibiotic intervention, medical therapy frequently requires changing to a new antibiotic. The intriguing finding, in Lele’s opinion, is that cells with high energy survive more frequently when antibiotics are changed than when only one antibiotic is used.

In spite of sharing the same genetic makeup, cells in a population may and do use a variety of ways to adapt to antibiotic stress, according to Lele’s research. If treatment plans took into consideration this variation, the results would be better.


Lee, A. H., Gupta, R., Nguyen, H. N., Schmitz, I. R., Siegele, D. A., & Lele, P. P. (2023). Heterogeneous Distribution of Proton Motive Force in Nonheritable Antibiotic Resistance. mBio, e0238422. Advance online publication.

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