New antiseptic kills antibiotic-resistant bacteria
CAGE kills bacteria at the cellular level
Ask any young athlete about MRSA (short for the ominous-sounding methicillin-resistant Staphylococcus aureus) and they might have a story to tell about their terrible experience with the disease. Easily spread in contact sports such as football and wrestling, MRSA is a skin infection that starts off as a painful, swollen bump that looks like a bloated spider bite or a pimple gone wrong. If not aggressively treated, this bacterial infection can invade the bloodstream or attack internal organs such as the heart and lungs, sometimes becoming life-threatening.
But athletes aren’t the only group that should worry about MRSA. Many MRSA infections also develop in people in hospitals or other healthcare settings such as nursing homes and dialysis centers. According to the journal U.S. Pharmacist, each year, more than 1.2 million people acquire MRSA while in a hospital and, on average, one in 20 inpatients acquires a MRSA infection during hospital care.
MRSA is just one example of skin infections that have evolved resistance to conventional treatments with such antibiotics as penicillin or methicillin. Antibiotics do not necessarily destroy every germ they target and, over time, some bacteria that survive an antibiotic treatment quickly “learn” through evolution to easily resist subsequent treatments, making them in effect super-resilient bacteria.
To battle super-resilient bacteria, scientists at Los Alamos National Laboratory have developed a new topical ointment designed to kill what were once considered “unkillable” bacteria. Collaborating with Northern Arizona University and Dixie State University, Los Alamos scientists discovered what they have dubbed CAGE, a variation of something called a choline capable of penetrating the deepest skin layers to deliver antibiotics. Choline helps the body improve memory and cognition, protect the heart and boost metabolism, among other things.
To test the effectiveness of CAGE, Los Alamos scientists developed a skin ointment and applied it on 11 clinically isolated bacteria known to be strongly resistant to topical treatment. In as little as two hours, CAGE destroyed the infections with little to no irritation to a subject’s skin. In battling the bacteria that causes MRSA, CAGE destroyed the germs in less than 30 seconds.
CAGE destroys bacteria at the cellular level by thinning a cell’s membrane, which protects a cell from its surroundings. Thinning the membrane destabilizes the cell’s lipid bilayer, which is made of two layers of fat cells and serves as a barrier marking the boundaries of a cell. Destabilizing the membranes results in cellular death, which in turn kills the bacteria.
Having acquired a patent for CAGE, the collaborators are in discussions with possible industrial partners to refine the choline variant into a topical ointment to battle superresistant bacterial infections such as MRSA. Another possible application of CAGE is decontaminating medical devices and sports equipment, thus minimizing the possibility of getting an infection while in hospital, other treatment centers, or on sports equipment that is not quickly cleaned after a game or workout.
David T. Fox works for the Actinide Analytical Chemistry group at Los Alamos National Laboratory, where he researches the metabolic engineering of bacteria that use sunlight as food, isoprenoid (an example would be camphor, which is used in some medications), commodity chemicals (chemicals regularly produced for global markets) and therapeutics.