What can we learn from ants to resolve Antibiotic weakness?

The world is facing an antibiotics crisis. Due to overuse, many of powerful drugs are now useless against certain strains of serious bacterial infections. S scientists are on the hunt for new ways to attack harmful microbes.

One possibility is to investigate how other species have evolved ways to defend themselves. A new study highlights how most ants, even from small colonies, produce antimicrobial chemicals in their bodily secretions. It also suggests those ants that don’t make these substances are likely to have some other method of controlling bacteria that could be investigated.

Scientists have found that ants use a number of tricks to limit disease. Many species have efficient waste removal systems, ensuring diseased waste (including dead ants) is removed from the nest or contained in special chambers. They also regularly clean themselves and each other, and group together to disinfect contaminated ants.

For example, some ants, when infected, eat toxins such as hydrogen peroxide to fight disease. Others collect conifer resin, which they incorporate into their nests as a preventative measure. Some species of ant are able to produce formic acid, which combines with the resin to form a potent antimicrobial agent.

In a new study published in the journal Royal Society Open Science, researchers from Arizona State University investigated the antimicrobial activity of 20 ant species in the US living in nests with between 80 and 220,000 inhabitants.

Testing external secretions against Staphylococcus epidermidis, a common bacterium not known to cause disease, showed that 60% of the ant species produced secretions with antimicrobial activity. But, surprisingly, 40% didn’t produce an antimicrobial that could kill the bacterium.

What’s more, species in larger colonies were no more likely to have antimicrobial activity than small colonies. This is surprising as it is generally thought that disease is more likely to be spread in larger colonies. The authors suggest that the 40% of ants without antimicrobial activity have other methods of controlling the spread of bacteria. But we also don’t know if these 40% produce antimicrobial agents that work against other microbes.

But the more we learn about the strategies ants use to fight disease, the more likely we are to uncover new ways to deal with the threat of resistant bacteria and disease.