"Blinded" superbugs can't infect what they can't see
The rise of drug-resistant bacteria, or superbugs, is a serious issue. A UK government report estimates that they could kill up to 10 million people a year by 2050 – one person every three seconds. With overprescription of antibiotics one of the key drivers of this trend, scientists are exploring others ways for us to stave off infection, among which is a new molecule that essentially blinds bacteria before they can latch onto healthy cells and grow.
"Antibiotics are amazing drugs, and they have saved countless lives since their discovery more than 80 years ago," says Dr. Anne-Marie Krachler, from the University of Texas Health Science Center and senior author on the new study. "But there is a challenge – the challenge of antibiotic resistance that has made many antibiotics ineffective. A material that targets virulence instead of killing bacteria could be a way to treat infections that are resistant to antibiotics."
The researchers may have found such a material in the form of a newly developed adhesion inhibitor molecule called Multivalent Adhesion Molecule 7 (MAM7). It works by hampering the activity of adhesive molecules that certain types of bacteria use to bind to cells and kickstart infections.
Krachler and her colleagues carried out a study designed to test the effectiveness of MAM7 on burn injuries. The researchers say that there are more than one million burn injuries each year in the US, and that 75 percent of the mortalities experienced by burn patients are associated with infections. So coming up with new ways to prevent them taking hold (that don't involve antibiotics) could have a huge say in patient recovery rates.
The study was carried out on rats and focused on a particularly lethal pathogen called Pseudomonas aeruginosa, which is found in around 33 percent of all burn cases and 59 percent of extensive burns. The team found that the topical application of MAM7 substantially reduced bacterial levels in wounds within the first 24 hours and stopped infections spreading to adjacent tissue for three days. Furthermore, it actually helped the wound heal, and a regular inflammatory response to the burn was observed.
"Rather than killing the bacteria, we blinded them so they could not find the places where they normally stick to the host (body's) cells," explains Dr. Steven Wolf, one of the senior authors of the study. "If bacteria cannot bind, they cannot grow."
Beyond burns, the researchers say that MAM7 could also work against surgical wounds and are now taking steps to explore this possibility, along with its potential use in treating diabetic ulcers. Further down the track, they hope to use the approach on patients, where it would avoid contributing to the development of drug-resistant bacteria by working in a similar way to a full parking lot.
"Our approach doesn't target bacterial survival; rather it targets the microbes' ability to damage the host – its virulence," says co-senior author Dr. Kim Orth. "There is no reason for the bacteria to become resistant to this approach. Being unable to bind to wounded tissue is an inconvenience, and the bacteria move on. If all the parking spaces are filled, then the bacteria have no place to park."
The research was published in the journal Scientific Reports.
Source: University of Texas