The Centers for Disease Control and Prevention (CDC) report that more than 2 million people in the United States become infected with an antibiotic-resistant strain of bacteria resulting in at least 23,000 deaths annually. Antibiotic resistance is of growing concern with the increase in resistant bacterial strains and the emergence of multi-drug resistant bacteria. The CDC has categorized antibiotic-resistant bacteria based on level of concern. Many of the bacteria that fall within the urgent and serious categories are multi-drug resistant and resistant to the antibiotic vancomycin, which is often used to treat severe bacterial infections. To address the growing problem of antibiotic resistance, researchers at The Scripps Research Institute have developed a new vancomycin that is more efficacious than previous versions of the antibiotic. Their findings were published in the Proceedings of the National Academy of Sciences.
Vancomycin is a glycopeptide that binds to bacterial cell wall precursors and subsequently prevents cell wall synthesis. Bacteria that are resistant to vancomycin treatment have mutated to utilize different cell wall precursors to evade vancomycin binding. This type of resistance is common in enterococci, a type of bacteria that live in the intestinal tract, and Staphylococcus aureus, a common culprit in skin infections and bacteremia. Both types of bacteria pose significant risk to people who are hospitalized or have a weakened immune system. Dr. Dale Boger and his colleagues at Scripps were able to improve the potency and efficacy of vancomycin by introducing new modifications that use three different modes of action to limit acquired resistance. The new modifications induce cell wall permeability that acts to complement the current mechanism of cell wall synthesis inhibition. This modified version of vancomycin resulted in a 200-fold improvement in antimicrobial potency against vancomycin-resistant enterococci.
This modified vancomycin has yet to be studied for safety and efficacy in whole animal models and humans, but these early studies indicate great potential for its use in medicine, not only to treat vancomycin-resistant bacteria but also as a strategy to improve other types of antibiotics.