A new technique to prevent the infection of burn wounds works by preventing the microbes from finding binding sites on host cells may represent a viable method of managing multi-drug-resistant bacteria, according to a paper published in Scientific Reports (Dec. 20, 2016).
“In the United States, there are more than one million burn injuries and 100,000 hospitalizations annually. Up to 75 per cent of the mortality in burn patients is associated with infections, which are particularly common in patients who suffer extensive burns—those that cover 40 per cent or more of the body,” said Dr. Steven Wolf, section chief for burns and professor of surgery at the University of Texas Southwestern Medical Center in Dallas, speaking in a press release from the university.
The research team had previously discovered a widespread group of bacterial adhesions which they call Multivalent Adhesion Molecules (MAMs) which are essential for initial binding of bacteria to host tissues and virulence.
To see if targeting MAM-based adherence could inhibit infection, investigators conducted a study of topical application polymeric microbeads functionalized with the adhesin MAM7 to rat model burn wounds infected with multidrug-resistant Pseudomonas aeruginosa.
They found that the topical treatment substantially decreased the bacterial levels in the wounds in the first 24 hours after administration. As well, it prevented the spread of the infection to adjacent tissue for three more days and both aided wound healing and maintained normal inflammatory responses to the burn.
“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. If bacteria cannot bind, they cannot grow,” said Dr. Wolf, who is also surgery’s vice chair for research and holder of the Golden Charity Guild Charles R. Baxter, M.D. chair.
In the release, co-senior author Dr. Kim Orth, professor of molecular biology and biochemistry at UT Southwestern, said that because the treatment targets the ability of the bacteria to damage the host, rather than attempting to kill the bacteria directly, there is no reason for the microbes to develop resistance to it.
In addition to burns, the study’s third senior author, Dr. Anne-Marie Krachler, said this strategy could work against diabetic ulcers and surgical wounds that can become infected.
“What’s exciting about MAM7 is that the agent is so broad-spectrum. Most bacteria have their own specific type of adhesion molecules. For instance Vibrio uses one kind and Salmonella uses a different one and multidrug-resistant bacteria another, but almost all of them want to park in the same place.
Dr. Krachler is now with the McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth).