Scientists from Rockefeller University, US, have shown that a natural enzyme derived from tiny viruses that live inside bacteria can successfully target and kill disease bacteria, including those that are resistant to drugs.
This approach may be used to prevent infections and, when used in combination with antibiotics, may provide a more efficient strategy for attacking bacterial invaders.
"A nasal spray containing this enzyme would prevent infections before they start," says Vincent Fischetti, co-head of the Laboratory of Bacterial Pathogenesis at Rockefeller University. "We would no longer have to wait for an infection to arise in order to treat it."
Resistance to antibiotics is rapidly becoming a serious public health concern. These enzymes offer an alternative method for combating resistant pathogens," he adds.
Traditional antibiotics primarily attack bacteria that reside inside cells, while the recently discovered bacteriophage enzymes only kill disease bacteria that lie on the surface of cells. In this study, Fischetti and his colleagues used these enzymes to eliminate Streptococcus pneumoniae present in the nasopharynx, an area between the back of the nose and throat, of mice. In addition, the researchers demonstrated that these enzymes can kill penicillin-resistant strains of this bacterium in a test tube.
S. pneumoniae normally lives on mucous membranes in the nose and throat of humans. It is from here that they strike out and cause infections, including ear infections, pneumonia and bacterial meningitis. According to the Centers for Disease Control and Prevention, this pathogen is among the leading causes worldwide of illness and death in young children, persons with underlying medical conditions and the elderly. It is a special concern in nursing homes and day-care centers, where drug-resistant strains thrive.
However, it is important to note that these enzymes, which seem to excel at preventing infections, are unlikely to cure full-blown infections. On the other hand, these enzymes are better at killing infectious bacteria that lie on the surface of the cells, or mucous membranes, where antibiotics are less effective. Consequently, a combination of these two strategies might prove to be a powerful weapon against infectious bacteria and, additionally, may reduce the amount of traditional antibiotics a person is required to take.
