A team of researchers has discovered that some antibiotics can still kill antibiotic-resistant bacteria through brute force. Antibiotics must bind to bacteria in order to destroy them and enhancing binding mechanisms can literally tear bacteria apart. The team is using their findings to develop stronger antibiotics. The details were just published in the journal Scientific Reports.
Antibiotic resistance occurs when bacteria develop mutations that grant them immunity to a specific antibiotic drug. Most of these mutations cause molecular changes on the surface of the bacterial cell, destroying or preventing the antibiotics from getting inside. Normally, antibiotics are shaped in a way that lets them latch onto a bacterial site. Bacteria with protective mutations, however, change the shape of this site—making it impossible for the antibiotics to attach. When a bacterial infection is unaffected by all modern antibiotics, treatment becomes very difficult. Approximately 23,000 people die every year from these types of infections in the United States alone.
Scientists from University College London studied the mechanical aspects of antibiotic treatments on bacteria in an attempt to create more potent drugs. The team compared the mechanisms of action for a few different antibiotics, including vancomycin and oritavancin. Oritavancin is a modified, stronger version of vancomycin. The team discovered that it kills bacteria with a different method that works within 15 minutes, compared to vancomycin, which sometimes doesn’t work for up to 24 hours. Oritavancin molecules easily form clusters that burrow into the surface of bacterial cells. When there are multiple clusters, they end up pushing away from each other. This forms tears in the bacterial surface, essentially ripping the bacteria apart. This explains why oritavancin kills bacteria so rapidly, making the drug more effective than its vancomycin cousin. If researchers can use this mechanism to improve other existing drugs, antibiotics as a whole could become stronger.
The research team’s findings could lead to improved antibiotics and new, more effective medications. By designing forceful antibiotics that use similar mechanisms to oritavancin, scientists may be able to come up with new solutions for the growing problem of antibiotic resistance.
Ndieyira et al. Surface mediated cooperative interactions of drugs enhance mechanical forces for antibiotic action. Scientific Reports (2017).