Wasp venom validated to combat antibiotic resistance
*Scientists discover it contains toxin that can completely eradicate deadly bacteria
The fear of being stung by a wasp is a phobia for many. But scientists have discovered the stripey pests may help combat the antibiotic resistance crisis – and not just a pose a threat to your picnic.Researchers adapted the properties of wasp venom in the lab and tested its effect on the deadly, antibiotic-resistant bacteria Pseudomonas aeruginosa.
The team at the Massachusetts Institute of Technology found the venom completely wiped out the bacteria within four days – and caused no pain.The study comes amid growing fears of antibiotic resistance, driven by the unnecessary doling out of the drugs, which has turned once harmless bacteria into superbugs.
The World Health Organization (WHO) has warned if nothing is done the world is heading for a ‘post-antibiotic’ era. In the United States (U.S.) alone, around two million become infected with antibiotic-resistant bacteria every year, resulting in at least 23,000 deaths.Pneumonia, tuberculosis, gonorrhoea, and salmonellosis are among the growing number of infections that are becoming harder to treat. The research was led by the microbiologist and immunologist Dr. Cesar de la Fuente-Nunez and published in the journal Communications Biology.
“We’ve repurposed a toxic molecule into one that is a viable molecule to treat infections,” he said. “By systematically analysing the structure and function of these peptides, we’ve been able to tune their properties and activity.”Peptides are the building blocks of proteins, with virtually all creatures on the planet producing ones that kill microbes by breaking down their cell structure.
The researchers identified one particular peptide in the venom of a South American wasp species, called Polybia paulista, which was previously investigated as a cancer treatment. This peptide is only made up of 12 amino acids – the building blocks of peptides – which makes it easy to manipulate.
“It’s a small enough peptide that you can try to mutate as many amino acid residues as possible to try to figure out how each building block is contributing to antimicrobial activity and toxicity,” Dr. de la Fuente said. The researchers developed a few dozen variations of the peptide, which they tested against seven species of bacteria and two of fungi to see how well they broke the pathogens down.
This enabled the scientists to discover the specific structures and properties of the peptide that were most effective against the microbes, which could then be refined. The refined peptides were then tested for toxicity on lab-grown human kidney cells before they were given to mice infected with P. aeruginosa.
This bacterium can cause pneumonia and urinary tract infections in people with weak immune systems, such as those with cystic fibrosis. Several of the peptides reduced the level of infection but one completely eradicated it. “After four days, that compound can completely clear the infection, and that was quite surprising and exciting”, Dr de la Fuente said.“We don’t typically see that with other experimental antimicrobials or other antibiotics that we’ve tested in the past with this particular mouse model.”
Antibiotics start working immediately after being taken, but most people do not feel better for two-to-three days.The drugs usually need to be taken for one or two weeks, however, this varies depending on the type of treatment and infection. The researchers are investigating if the same level of effectiveness can be achieved with a lower, and therefore likely safer, amount of venom.
A number of drugs are already in development to assess the potential of antimicrobial peptides in treating resistant infections, however, many medications fail to pass clinical trials.However, even if wasp venom ends up being a dead end, the researchers believe their findings can be applied to other antimicrobial proteins to search for a wider range of solutions.