By Stephanie Lachapelle for Wounds1A new study published in the journal Molecular Cell claims that exposure to low levels of antibiotics makes the creation of drug resistant strains of E. Coli and Staphylococcus more likely.
With the present over-use of antibiotics in the United States and other countries, antibiotic resistance has moved to the top of the list of concerns of public health officials. Officials are concerned about poor prescription practices among doctors and patients who don’t take all of their prescribed antibiotics.
An antibiotic is a drug prescribed to kill bacteria. Although mechanisms of action of these drugs vary, their collective goal is to target and inhibit or breakdown some part of the cell so the bacteria can no longer live or reproduce. Bozena Korczak, Vice President Drug Development at Radnor, PA-based PolyMedix Inc., explains, "Like anything in nature, bacteria have ways to fight its opponents, and do so either by pumping antibiotics out of themselves through a process called efflux, or by rapidly mutating and changing the shape of the target of attack of the antibiotic drug. They can do this, even with large doses of antibiotics, it's their innate way to try to survive. The best approach to preventing this phenomenon is by directly attacking the bacteria's cell membrane, rendering them destroyed and dead in a way that there is little chance of resistance. They cannot live to fight another day."
Researchers have found that low levels of antibiotics, like the low levels that occur when a patient doesn’t finish a bottle of antibiotics, may not kill the bacteria in an infection, but stresses the bacteria, causing them to mutate quicker. This increases the chance of developing a new, antibiotic resistant strain of bacteria. Researchers suggest that low levels of antibiotics may even make bacteria grow and mutate faster.
PolyMedix, Inc., has developed an investigational antibiotic agent called PMX-30063, which has a mechanism of action different than the typical commercially available antibiotics. The drug imitates the natural human immune system and mimics the activity of host defense proteins responsible for reacting to an infection. Because this action mimics that of the natural immune system, researchers suggest that this drug may create a lower risk for bacteria in an infection to develop a resistance to the immune system. In one PolyMedix study of PMX-30063, multiple serial passages of the drug did not produce resistance.
Data from two Phase I studies show that PMX-30063 is safe and well-tolerated in single and multiple doses, and have a therapeutic effect. PMX-30063 has been effective against MRSA.
PMX-30063 should enter Phase 2 clinical trials for the treatment of pan-Staphylococcal infections by the end of this year.
