A team of researchers from MIT discovered that the venom of insects—like bees and wasps—contains lots of compounds that can kill bacteria. Unfortunately, these compounds—found in insect venom—are also toxic to humans, at least when the toxins are administered in their natural state. What the team at MIT has discovered, however, is that some variants of the particular peptide in the South American wasps venom that is potent to bacteria also happens to be nontoxic to humans.
The MIT researchers studied the antimicrobial properties of this toxin by administering the toxin to mice and published their findings in the journal Nature Communications Biology. The researchers say that the strongest peptide could eliminate entirely the Pseudomonas aeruginosa bacterial strain; this strain causes respiratory infections and other infections that are resistant to most available antibiotics.
According to co-lead author of the paper, MIT post-doctorate student Cesar de la Fuente-Nunez, systematically analyzing the structure and the function of these particular peptides allows them to repurpose a toxic molecule into a molecule that can be used to treat infections. MIT associate professor of electrical engineering and computer science and associate professor of biological engineering, Timothy Lu; and Federal University of ABC (Brazil) associate professor Vani Oliveira are the other senior co-authors. Former visiting MIT student, Marcelo Der Torossian Torres is the paper’s lead author.
De La Fuente-Nunez and his colleagues focused on a peptide from the Polybia paulista wasp. They say they chose this particular peptide because it is very small: only 12 amino acids. This size, they describe, is easy to work with and such would be more feasible as a means to create several variants which they could then test for potency against microbes and against human cells.
The research team then took the most promising compounds to form this peptide and tested it in mice that had been infected with Pseudomonas aeruginosa. This is a common source for respiratory and urinary tract infection, and they found that one of the peptide compounds—when administered in high doses—could actually completely eliminate the infection within as little as four days!
De la Fuente-Nunez comments, too, that this research has not only helped to develop new antibiotics but could lay a foundation for more research. Obviously, they could apply the technique to other peptides and test those reactions to different environments, but it also lays the way for exploring helicity and hydrophobicity within this type of research.