Almost 3 million people a year in the U.S. alone are infected with bacteria deemed resistant to antibiotics, according to the CDC. While there are many reasons bacteria have become resistant to antibiotics, one of the chief reasons involves the overuse and over prescription of antibiotics to treat infections, which has allowed bacteria to evolve to a point where antibiotics no longer work on them. As a result, even common infections are becoming harder to treat. The World Health Organization has even labeled antibiotic resistance as one of the chief health problems the world is facing.
Researchers at the Washington University School of Medicine have developed a type of ultrashort pulsed (USP) laser to destroy bacteria cells that resist antibiotics without causing harm to human cells, specifically for the bacteria that contaminates wounds. A description of the laser and the results of a study showing how the laser works on certain drug-resistant bacteria are published in the Journal of Biophotonics.
The laser works by breaking up protein structures in bacteria cells. This causes bacteria cells to break apart and become a jumbled mess of internal structures that are no longer able to function, ultimately leading to cell death. The laser was tested on several strains of different resistant bacteria: Staphylococcus aureus (MRSA) and extended spectrum beta-lactamase (ESBL)-producing Escherichia coli. The laser was shown to reduce bacteria cultures by 99.9%.
Researchers believe their laser may have a range of medicinal uses, particularly below the skin where strategies like bleach or heat (which can help with decontamination at the surface of a wound) do not work.
Shaw-Wei Tsen, the study’s lead researcher, highlighted the potential uses of their laser technology: “I can see this technology being used soon to disinfect biological products in vitro, and even to treat bloodstream infections in the future by putting patients on dialysis and passing the blood through a laser treatment device.”