Israeli Researchers Uncover How Bacteria Rapidly Develop Antibiotic Resistance

Researchers at the Technion in Israel have identified a hidden mechanism that enables bacteria to quickly adapt to antibiotic treatments by producing multiple copies of specific genes, thereby increasing their resistance. The study, led by Dr. Idan Yelin and Prof. Roy Kishony from the Technion's Faculty of Biology, was published in Nature Microbiology and supported by the National Science Foundation and the EU's Horizon Europe program. Using a new computational tool called AmpliFinder, the team analyzed over 10,000 bacterial samples evolved under laboratory conditions.

The discovered mechanism involves an unconventional gene duplication process where a single DNA segment connects distant genome regions, allowing bacteria to rapidly generate dozens of gene copies related to antibiotic resistance. This accelerated evolutionary process enhances bacterial survival against antibiotics more effectively than previously known duplication methods. The research focused on Escherichia coli and Acinetobacter baumannii bacteria exposed to chloramphenicol, showing that duplication of the mdfA gene segment not only increased resistance but also enabled adaptation to rising drug levels.

Dr. Yelin explained that this mechanism is not limited to chloramphenicol but applies broadly to many antibiotics, including ampicillin and trimethoprim, commonly used to treat various infections. The gene duplication persists only while bacteria are exposed to antibiotics and reverses when the drug is removed. Although the study was conducted on laboratory strains related to hospital pathogens, the researchers believe the mechanism likely operates in clinical resistant bacteria as well.

The genetic elements involved can transfer between bacteria, suggesting that multiple infectious bacteria could develop resistance through this pathway. Future research aims to determine the prevalence of this mechanism in hospital strains and explore its role in "hidden resistance" that appears only after antibiotic exposure. The team also proposes developing drugs that inhibit this gene duplication process to be used alongside antibiotics, potentially preventing rapid resistance development.

Currently, the findings do not alter clinical treatment protocols or antibiotic dosing recommendations. Additionally, the mechanism may provide bacteria advantages beyond antibiotic resistance, such as defense against bacteriophages and environmental stresses, highlighting its broader biological significance.