New Strategies Emerge in the Fight Against Bacterial Defenses

A pair of recent scientific studies have identified separate mechanisms to counteract bacterial defenses, one targeting antibiotic resistance and another targeting bacterial immunity to viruses. The research, conducted by independent teams, explores new strategies to address the global challenge of antimicrobial resistance.

Study Targets Antibiotic Resistance and Cross-Protection

A study published in the journal eLife describes a mechanism that can disable antibiotic resistance in bacteria and disrupt a process known as cross-protection. Cross-protection occurs when antibiotic-resistant bacteria degrade drugs in their shared environment, allowing nearby susceptible bacteria to survive.

"Targeting this protein-folding system can inactivate both resistance and cross-protection, potentially allowing conventional antibiotics to regain effectiveness." — Nikol Kadeřábková, Lead Author

Research Focus and Methodology

The research focused on synthetic communities of Pseudomonas aeruginosa and Stenotrophomonas maltophilia, bacteria relevant to cystic fibrosis lung infections. S. maltophilia is highly resistant to many antibiotics, including β-lactams, primarily through the production of β-lactamase enzymes.

Researchers targeted a protein-folding system essential for the function of these bacterial resistance enzymes. They employed two strategies:

• Genetic deletion of a protein-folding gene.
• Chemical inhibition of the same system.

Both methods deactivated the resistance enzymes, making the bacteria susceptible to β-lactam antibiotics. Experiments in wax moth larvae and mixed bacterial communities showed that disrupting this system also prevented one bacterial species from protecting another via cross-protection.

Researcher Statements and Support

Lead author Nikol Kadeřábková, a research associate at The University of Texas at Austin, stated that targeting this protein-folding system can inactivate both resistance and cross-protection, potentially allowing conventional antibiotics to regain effectiveness. Co-author Despoina Mavridou noted the work highlights a vulnerability in antibiotic-resistant bacteria and suggests a pathway for developing new adjunct therapies.

The study was led by Kadeřábková and Chris Furniss of Imperial College London. Funding was provided by multiple organizations, including the U.S. National Institute of Allergy and Infectious Diseases and the U.K. Medical Research Council.

Separate Research Identifies Molecule to Counter Bacterial Immunity to Viruses

In a separate line of research, scientists at Indiana University Bloomington's Gerdt Lab are investigating methods to weaken bacterial defenses against viruses, known as bacteriophages. Bacteriophages are viruses that infect and kill bacteria and are considered a potential alternative or complement to antibiotics due to their targeted action.

Research Findings

Former lab member Zhiyu Zang discovered a chemical molecule that, when combined with a bacteriophage, helps the virus overcome a specific bacterial immune system. This discovery was detailed in a paper titled "Chemical inhibition of a bacterial immune system," co-authored by Zang and J.P. Gerdt and published in Cell Host and Microbe.

"This finding could apply to difficult-to-treat infections and in agriculture, where antibiotic overuse is a concern." — J.P. Gerdt, Assistant Professor of Chemistry, IU Bloomington

The identified molecule is reported as the first small molecule capable of inhibiting this type of bacterial immune system. The system is present in approximately 2,000 bacterial species, including antibiotic-resistant pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus.

Potential Applications and Goals

J.P. Gerdt, an assistant professor of chemistry at IU Bloomington, indicated that while antibiotics are expected to remain a primary treatment, this finding could apply to difficult-to-treat infections and in agriculture, where antibiotic overuse is a concern. The lab's long-term objective is to develop a collection of inhibitors for various bacterial immune systems.

Undergraduate students, including Olivia Duncan, contributed to the research. Zang, now a post-doctoral candidate at the Swiss Federal Technology Institute of Lausanne, stated the work enables the development of generalized strategies for targeting pathogenic bacteria with similar immune systems.