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SSMF-funded postdoctoral researcher Gabriel Torrens (pictured) and Professor Felipe Cava have shown that resistant bacteria depend on the lipid molecule undecaprenyl phosphate to transport building blocks needed to construct the cell wall. Disrupting this transport significantly weakened the bacteria's resistance.
Photo Credit: Mattias Pettersson
Scientific Frontline: Extended "At a Glance" Summary: Vulnerability in Antibiotic-Resistant Bacteria
The Core Concept: Antibiotic-resistant bacteria possess a critical vulnerability within their cell wall transport systems that, when disrupted, drastically reduces their resistance. This discovery reveals an evolutionary trade-off where the genetic mechanisms bacteria use to survive antibiotic exposure can simultaneously be exploited to make them susceptible to existing treatments.
Key Distinction/Mechanism: Unlike traditional approaches that seek entirely new classes of drugs, this mechanism targets a specific lipid molecule, undecaprenyl phosphate, which functions as a conveyor belt for cell wall building blocks. Disrupting this lipid carrier stresses the bacteria, effectively blocking the evolutionary pathways that enable resistance to β-lactam antibiotics and causing resistant strains to grow more slowly and become less infectious.
Major Frameworks/Components:
- Undecaprenyl Phosphate: A vital small lipid molecule required to transport essential building blocks for bacterial cell wall construction.
- β-Lactam Antibiotics: A widely used class of drugs, including penicillins, that target the bacterial cell wall and to which many pathogens have developed severe resistance.
- Evolutionary Trade-Offs: The biological phenomenon where genetic mutations conferring antibiotic resistance simultaneously impose a physiological cost, such as stunted growth and reduced infectivity.
- Gram-Positive Bacteria Applicability: The conserved vulnerability affects a broad group of Gram-positive pathogens, most notably methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pneumoniae.
Branch of Science: Molecular Biology, Microbiology, Bacteriology, and Evolutionary Biology.
Future Application: This mechanism opens new therapeutic avenues designed to block cell wall transport, thereby restoring the efficacy of existing β-lactam antibiotics. The commercial and clinical potential of this strategy has already prompted a patent application for targeted treatments.
Why It Matters: With antimicrobial resistance posing an escalating global health crisis, extending the lifespan and utility of current antibiotics is critical. Pushing resistant bacteria into an evolutionary dead end offers a powerful, alternative strategy to combat increasingly untreatable and lethal infections without relying solely on the discovery of novel drugs.
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| Felipe Cava is Professor of Molecular Biology at Umeå University. His research focuses on uncovering new insights into one of the most remarkable bacterial structures: the cell wall. Photo Credit: Mattias Pettersson, simon ohman jonsson inhousebyran |
Even highly antibiotic-resistant bacteria become more vulnerable when their cell-wall transport system is disrupted, according to a new study from Umeå University. The discovery reveals a previously overlooked weakness that could help researchers develop new strategies to combat antibiotic resistance.
“The search for new antibiotics remains crucial, but we also need smarter ways to extend the lifespan of the antibiotics we already have. We wanted to find out whether resistant bacteria could be pushed into an evolutionary dead end, where the very mechanisms that help them survive instead make them vulnerable to existing antibiotics,” says Felipe Cava, professor at the Department of Molecular Biology at Umeå University.
Antibiotic resistance is a growing global health challenge. As bacteria evolve resistance to medicines, infections become increasingly difficult to treat, raising the risk of severe illness and death. Now, researchers at Umeå University have identified an unexpected vulnerability in certain resistant bacteria that could potentially be exploited to make them susceptible to antibiotics once again.
The study, published in Nature Communications, was led by Felipe Cava's research group at Umeå University in collaboration with researchers from the Spanish National Research Council (CSIC) and Umeå University Hospital.
Bacteria are protected by robust cell walls that help them survive in harsh environments. The cell wall is also the target of β-lactam antibiotics, a class of drugs that includes penicillins and remains among the most widely used treatments for bacterial infections. Some bacteria, however, have evolved the ability to continue building their cell walls despite antibiotic treatment, making them resistant.
A well-known example is methicillin-resistant Staphylococcus aureus (MRSA), which causes difficult-to-treat infections worldwide. Over time, these bacteria can acquire additional mutations that further strengthen their resistance.
The researchers found that resistant bacteria depend on a small lipid molecule called undecaprenyl phosphate, which acts as a conveyor belt for the building blocks needed to construct the cell wall. When this transport system was disrupted, it became considerably more difficult for the bacteria to maintain their resistance.
In the study, the researchers tracked how MRSA evolved during antibiotic treatment. They identified genetic changes that enabled the bacteria to regain resistance. However, when the transport of cell-wall building blocks was disrupted, this evolutionary route was effectively blocked.
The researchers also found that bacteria carrying new resistance mutations often grew more slowly and were less capable of causing infection.
“What surprised us was that some mutations that help bacteria survive antibiotic treatment simultaneously create new vulnerabilities. Rather than becoming stronger in every respect, the bacteria appear to be forced into a trade-off,” says Gabriel Torrens, first author of the study and postdoctoral fellow at the Department of Molecular Biology at Umeå University.
The phenomenon was observed not only in MRSA but also in Streptococcus pneumoniae, a bacterium that commonly causes diseases such as pneumonia. This suggests that the same vulnerability may exist across many antibiotic-resistant Gram-positive bacteria, a group that includes staphylococci and pneumococci.
The researchers believe the discovery opens a new avenue for future therapies aimed at restoring the effectiveness of existing antibiotics. Its potential to lead to new treatments has already resulted in the filing of a patent application.
Funding: The study was funded by the Swedish Research Council (research environment grant within infection and antibiotics), the Knut and Alice Wallenberg Foundation, and the Kempe Foundations. Gabriel Torrens was recruited to Umeå University through the "Excellence by Choice" postdoctoral program and is currently funded by the Swedish Society for Medical Research (SSMF).
Published in journal: Nature Communications
Authors: Gabriel Torrens, Sean W. Bisset, Maria López-Bravo, Anders F. Johansson, Daniel Lopez, and Felipe Cava
Source/Credit: Umeå University | Ingrid Söderbergh
Edited by: Scientific Frontline
Reference Number: mbio091026_01
