- Solenopsis molesta, also known as the thief ant was
the ant species found to produce the most powerful antimicrobial agents.
- While sixty percent of ant species
tested produced antimicrobial agents against the bacteria used, the
remaining did not produce any at all.
- Ants that produce antibiotics
could be the source of new antibiotics that could help fight human
Studying twenty different ant
species, researchers discovered that only sixty percent of them produce
antibiotics contrary to the popular belief that all ants are capable of
producing at least one type of antimicrobial. Like humans, ants also use
antibiotics to fight invading bacteria. The current study revealed certain
antibiotic-producing ant species that can be useful treatment sources to help
fight human diseases.
The study conducted by North Carolina State
University scientists tested the antimicrobial properties of twenty different
- First, a solvent was used to
remove all substances from the surface of the ant's body.
- This solution was then introduced
to a bacterial slurry.
- Growth of bacteria in the slurry
was then compared to the growth of bacteria in a control group that did
not contain the ant's surface substances.
If bacteria in the slurry that contained the
ant solution grew less than the control, it meant that there was some
antimicrobial property in that slurry that prevented bacterial growth. That
would mean that the ant species in that slurry produced its antibiotic kill
- Twelve of the twenty ant species
(sixty percent) tested had antimicrobial agents on their exoskeletons.
- The other eight ant species did
not make antibiotics against the bacteria that were used in the study.
- An ant species called Solenopsis molesta also known as
the thief ant had the most powerful antibiotic properties. This study was
also the first to report antimicrobials in few ant species including the
"Finding a species that carries a
powerful antimicrobial agent is good news for those interested in finding new
agents that can help humans," Adrian
Smith, co-author of the paper says. "But the fact that so many ant species
appear to have little or no chemical defense against microbial pathogens is
While it is widespread belief that most ant
species carry at least one type of antimicrobial, this study shows that only sixty
percent of the ant species tested had antimicrobial properties. The other forty
percent did not produce antimicrobials.
‘Antimicrobial agents found in exoskeletons of certain ant species could be used as antibiotics to help fight human diseases.’
"We thought every ant species would
produce at least some type of antimicrobial," says Clint Penick, an
assistant research professor at Arizona State University says. "Instead,
it seems like many species have found alternative ways to prevent infection
that does not rely on antimicrobial chemicals."
The study suggests that instead of looking
for antibiotics in all species of ants, it is better to refine the search for
species that hold promise.
The study only takes into account 20 ant
species when there are over 12,000 different species in the world. Moreover,
the antimicrobial activity was tested for only a particular bacteria. It is
highly possible that the ant species that did not produce any antimicrobial
agents against the bacteria used in the study produce antimicrobials against
other bacterial strains.
"Next steps include testing ant species
against other bacteria; determining what substances are producing the
antibiotic effects - and whether ants produce them or obtain them elsewhere;
and exploring what alternative strategies ants use to defend against bacterial
pathogens," Smith says.
- Clint A. Penick, Omar Halawani, Bria Pearson and Adrian A. Smith, Stephanie Mathews, Campbell University; Margarita López-Uribe, and Robert R. Dunn. "External immunity in ant societies: sociality and colony size do not predict investment in antimicrobials" Royal Society Open Science DOI: 10.1098/rsos.171332