Researchers at the University of California, San Diego (UCSD) used MALDI-TOF imaging mass spectrometry to observe the effects of multiple microbial signals in an interspecies interaction. This revealed that chemical "conversations" between bacteria involve many signals that function simultaneously. The study appears in the November 8 issue of Nature Chemical Biology.
Microbial interactions such as signaling have generally been considered by scientists in terms of an individual, predominant chemical activity. A single bacterial species, however, is capable of producing many bioactive compounds that can alter neighboring organisms.
“Scientists tend to study the metabolic exchange of bacteria, for example, penicillin, one molecule at a time,” says Pieter C. Dorrestein, Ph.D., assistant professor, UCSD Skaggs School of Pharmacy and Pharmaceutical Sciences. “Actually, such exchanges by microbes are much more complex, involving 10, 20, or even 50 molecules at one time. Now scientists can capture that complexity.” Dr. Dorrestein and colleagues’ approach to describe how bacteria interface with other bacteria in a laboratory setting utilizes natural product MALDI-TOF imaging mass spectrometry.
The researchers anticipate that this tool will enable development of a “bacterial dictionary” that translates the output signals. The team is currently mapping hundreds of bacterial interactions and signals. Their hope is that this method will also enable them to translate bacterial-mediated mechanisms in the future.
“Our ability to translate the metabolic output of microbes is becoming more important, as they outnumber other cells in our body by a 10 to one margin,” Dr. Dorrestein explains. “We want to begin to understand how those bacteria interact with our cells. This is a powerful tool that may ultimately aid in understanding these interactions.”
Understanding the means by which microorganism cells talk to one another will facilitate therapeutic discovery, according to Dr. Dorrestein. For instance, knowing how microbes interact with human immune cells could lead to discovery of novel immune-system modulators, and how these molecules control bacterial growth may lead to new anti-infectives.