A team studying the antimicrobial properties of several ant species has found the industrious insects could help scientists develop new antibiotics to join the fight against human diseases. The research also revealed several ant species that have no chemical antimicrobial defense against bacteria, offering exciting alternative pathways for scientists to study.

In this new study, the antimicrobial properties of 20 different ant species were evaluated by stripping away all the substances on the surface of their bodies with a solvent. This solution, generated from the elements gathered from the ants' bodies, was then added to a bacterial slurry to see if any of the compounds contained antibiotic properties. After bacterial growth was compared to the rate of growth in a control slurry, 60 percent of the ant species were found to have some kind of antimicrobial element on their bodies.

"One species we looked at, the thief ant (Solenopsis molesta), had the most powerful antibiotic effect of any species we tested – and until now, no one had even shown that they made use of antimicrobials," says Adrian Smith, co-author on the study.

Perhaps even more interesting than the ants found to produce their own antibiotics were those discovered to have almost no antimicrobial properties. Before the research was conducted it was assumed that virtually all ant species must carry some kind of antimicrobial agent, but this study unexpectedly revealed eight out of the 20 species examined held almost no antibiotic agent.

"We thought every ant species would produce at least some type of antimicrobial," says Clint Penick, lead author on the study. "Instead, it seems like many species have found alternative ways to prevent infection that do not rely on antimicrobial chemicals."

These "alternative ways" the ants have developed to fight off pathogens present intriguing new mysteries to be solved by future research. Further study will initially home in on what specific compounds are generating these antimicrobial effects and how broad the effects actually are, as a major limitation of this study is that only a single bacterial agent was used in the experiments.

The study was published in the journal Royal Society Open Science.