Researchers at Binghamton University, State University of New York, give a trick to improve chronic wound care-just listen to bacterial conversations.
Led by Alex Rickard, assistant professor of biological sciences, the researchers could identify specific types of chronic wound bacteria and to test their ability to produce cell-cell signalling molecules.
"Bacteria, often viewed as simplistic creatures, are in fact very sociable units of life. They can physically and chemically interact with one another and are quite selective about who they hang out with. How bacteria might communicate in chronic wounds, however, was somewhat of a mystery," said Rickard.
Using partial gene sequencing, the team identified 46 chronic wound strains belonging to nine genera.
Further research inferred that close to 70 percent of those chronic wound strains produce a specific type of communication molecule - autoinducer-2 (AI-2). A smaller percentage - around 20 percent - produce a different type of communication molecules that are called acyl-homoserine-lactones (AHLs).
Scientists already know that structurally different bacterial cell-cell signalling molecules are able to mediate cell-cell communication, including A1-2 and AHLs.
"Based on our findings, we think that most resident species - the 'good' bacteria that live on us and don't cause disease - produce AI-2 while the pathogenic species typically produce AHLs. And it didn't seem to matter what kind of chronic wound we looked at - diabetic ulcers, vascular ulcers or environmentally induced chronic wounds. They all indicated a presence of possible AHLs or AI-2s," said Katelynn Manton.
For Randy Wolcott, director of the Southwest Regional Wound Care Center, a clearer understanding of how these bacteria function is particularly important.
Rickard and his team said that the typically pathogenic bacteria communicate in one language, the 'good' bacteria in another.
The big question now is whether any of them are bilingual and can listen in on one another's 'conversations.'
They said if they could interpret - or perhaps even guide - these cell-cell signals, it could do be vital in how wound development could be influenced.
"Can we steer pathogenic bacteria away from what is, in essence, a 'mob' mentality and prevent them from communicating. Or can we tell the mob to do one thing when they should in fact be doing something completely different?" said Rickard.
Manipulation of cell-cell signaling has the potential to be an effective strategy for wound healing, particularly in influencing 'bad' bacteria -which are particularly resistant to antimicrobials.
"When bacteria form biofilms, as they do in chronic wounds, they become protected from killing by antimicrobial agents. Topical antiseptics, systemic antibiotics, and the body's own defenses are unable to clear these infections. We need alternative strategies - such as jamming bacterial communication - to help weaken the biofilm defenses. Listening in on the bacterial signals may also provide a way to diagnose the state of a chronic wound," said Phil Stewart, director of the Center for Biofilm Engineering at Montana State University.
The findings have been published in the Journal of Applied Microbiology.