Finally, Something to Like about Wasps
Written by Kacey Zimmerman
Edited by Madeleine Lu
Jan 31, 2021
Edited by Madeleine Lu
Jan 31, 2021
Though wasps technically do provide pollination and insect control, they are most popularly known as the unfortunate cousins to bees for their aggressive behavior and painful sting. Surprisingly, there is an upside to their venom: scientists have been able to isolate toxins and develop them into antimicrobial molecules!
Antibiotics are one of the most revolutionary advances in modern medicine and are responsible for the treatment of many previously lethal diseases. However, their increased use has brought about another issue entirely: the rise of antibiotic resistant bacteria. Antibiotic resistance occurs when antibiotic drugs are used on a population of bacteria, which naturally have a few members with antibiotic resistance. Resistant members will survive, reproduce, and even pass the gene to other bacteria, creating a strain that will not respond to any antibiotics. This becomes especially dangerous when bacteria have gained resistance to multiple antibiotics, drastically reducing treatment options. According to the Centers for Disease Control and Prevention (CDC), antibiotic resistant microbes infect nearly 3 million Americans a year, causing around 35,000 deaths. Tuberculosis and sepsis are two diseases with high levels of antibiotic resistant bacterial infection. Sepsis, a potentially lethal immune response to infection, is thought to cause roughly ⅕ of all deaths on a global scale. Thus, scientists are interested in venoms as a new source of antibiotic material.
The molecule of interest in this study was a small toxic protein derived from the Korean yellow-jacket wasp, also known as Vespula lewisii. Researchers then engineered the molecule, called Mastoparan-L (mast-L), to remain highly toxic to bacterial cells while having less of an effect on human cells. To do this, they used an antimicrobial database to find a small region shown to be effective against bacteria and used it to replace the segment of mast-L most associated with toxicity in humans. This new molecule was called mast-MO.
Next, researchers used mice to test mast-MO’s ability to stop infection. Mice were introduced to sepsis-inducing strains of deadly bacteria, either E. coli or Staphylococcus aureus. After a couple hours, some mice were treated with mast-MO and others with mast-L. The trial was successful, with 80% of the mice treated with the antimicrobial molecule surviving. Moreover, mast-MO was shown to be less toxic to the mice over mast-L, which showed severe side effects at higher concentrations. Thus, the changes the scientists made to the protein’s sequence was effective in reducing toxicity.
Mast-MO was shown to kill bacteria by increasing the permeability of the outer membrane, which would increase the effect of other co-delivered antibiotics. The researchers hope to eventually develop this molecule into antibiotics available for human use. Overall, natural occurring substances like wasp venom are promising sources for new antibiotics to combat the rise of increased resistance to current antibiotics on the market.
Works Cited
University of Pennsylvania School of Medicine. “Scientists engineer bacteria-killing molecules from wasp venom: Potential new antibiotics work by disrupting bacterial membrane and summoning immune cells in animal models.” ScienceDaily. ScienceDaily, 12 October 2020. <www.sciencedaily.com/releases/2020/10/201012164223.htm>.