A new study has identified a promising strategy to tackle antimicrobial resistance by making multidrug-resistant bacteria more vulnerable to existing antibiotics, potentially allowing doctors to treat life-threatening infections with lower and safer drug doses.
The research, led by Professor Kwang-sun Kim of the Department of Chemistry and the Chemistry Institute for Functional Materials at Pusan National University in South Korea, introduces a bacteria-control-centric approach that manipulates the biology of bacteria rather than relying solely on developing new antibiotics.
Antimicrobial resistance has become one of the world’s most serious public health threats, with multidrug-resistant (MDR) gram-negative bacteria increasingly rendering even last-resort antibiotics ineffective. Among the few remaining treatment options are polymyxins, which are used against severe infections caused by resistant Escherichia coli. However, their clinical use is limited because they can cause severe kidney and nerve damage.
To address this challenge, the findings published in Drug Resistance Updates on July 1, 2026, identified a naturally occurring bacterial peptide known as TimP, encoded by the small non-coding RNA (sRNA) RyfA.
Instead of killing bacteria directly, TimP reprograms multidrug-resistant E. coli by reorganizing the bacteria’s outer membrane, creating openings that allow polymyxin antibiotics to penetrate more effectively.
The team screened 91 bacterial sRNAs before identifying RyfA as capable of increasing bacterial sensitivity to polymyxins. Further structural prediction and laboratory validation showed that TimP binds to an outer membrane protein called LamB, triggering changes that increase membrane permeability, boost the production of reactive oxygen species and promote the release of extracellular vesicles.
Building on this discovery, the researchers engineered extracellular vesicles carrying both TimP and polymyxin B, creating a targeted drug delivery platform known as PMB@TimP EVs. Described as a “Trojan-horse drug delivery system,” the vesicles deliver the antibiotic directly to bacteria while simultaneously making the bacterial membrane easier for the drug to penetrate.
Laboratory tests showed the engineered vesicles enhanced bacterial killing, remained stable across a broader range of pH conditions and caused significantly less toxicity to mammalian cells than polymyxin B alone.
The platform also produced encouraging results in animal studies. In a mouse model of sepsis caused by multidrug-resistant E. coli, PMB@TimP EVs improved survival at antibiotic doses that failed to protect animals treated with free polymyxin B.
Additional safety studies found no abnormal accumulation of the treatment in major organs, while inflammatory markers and liver enzymes remained within normal physiological ranges.
Treading a wide range of multidrug-resistant bacterial infections
The researchers also discovered that LamB, the bacterial protein required for TimP’s activity, is conserved in Salmonella Typhimurium. This suggests the platform could eventually be adapted to treat a broader range of multidrug-resistant gram-negative bacterial infections beyond E. coli.
“With the development of new antibiotics failing to keep pace with bacterial evolution, maximizing the efficacy of existing resources will become the primary strategy to bridge the therapeutic gap in clinical settings,” Prof. Kim said.
He added that “PMB@TimP EVs can serve as a potent adjuvant therapy for patients suffering from sepsis, pneumonia, or urinary tract infections caused by MDR gram-negative bacteria, significantly improving recovery rates.”
Despite the promising findings, the researchers cautioned that the work has so far been demonstrated only in murine models. They said further research is needed before the platform can enter human clinical trials, including studies on long-term safety, manufacturing and effectiveness against a wider range of drug-resistant bacterial infections.
Prof. Kim said the researchers are optimistic about the technology’s future potential.
“Within 5-10 years, this platform could be integrated into standards for combating MDR pathogens. This will ultimately reduce the over-prescription of antibiotics and contribute to a more sustainable healthcare system,” he said.
If future clinical studies confirm the findings, the platform could help extend the useful lifespan of existing antibiotics, reduce reliance on high-dose polymyxin treatment and provide clinicians with a new strategy for treating severe infections caused by multidrug-resistant gram-negative bacteria.
This version follows a conventional news structure with a strong lead, clear background, balanced reporting of the findings, and all key quotes while accurately noting that the research has so far been demonstrated only in mice.
