In a University of Sydney lab, honey from Australia’s tiny Tetragonula carbonaria bees stopped the growth of every bacterium researchers tested—including two that can be difficult to treat in hospitals. The result points to a possible new source of clues in the search for ways to fight infections as antimicrobial resistance makes some medicines less effective.
Antimicrobial resistance happens when germs change so that drugs no longer work as well against them. Researchers are looking for new substances that could help treat infections. Yet most scientific work on medicinal honey has focused on European honey bees, even though Australia’s native stingless bees, also known as sugarbag bees, have a long history of use in Indigenous medicine.
In a study published in the journal PLOS One, Ph.D. candidate Jasmin Li and colleagues tested honey and propolis from Tetragonula carbonaria against 16 bacterial and fungal pathogens. Propolis is a mix of plant resin and beeswax that bees use to build their nests. The honey stopped the growth of all bacteria in the tests, including Pseudomonas aeruginosa and Klebsiella pneumoniae, hospital-associated bacteria that can be hard to treat.
The honey’s strength was comparable to medical-grade Manuka and Jarrah honeys, according to the researchers. It also acted against fungi that cause ringworm and athlete’s foot. Propolis showed high potency too, but its effects were selective: it worked against some targets more than others, in a pattern unlike propolis from honey bees.
One of the most striking findings is that the known compounds researchers usually look for did not explain the activity of either product. That suggests the stingless bee honey and propolis may contain antimicrobial substances that have not yet been identified. The study does not show that these products can treat infections in people, but the unknown substances could give scientists new leads for drug research.
“Now that we’ve shown how powerful sugarbag honey is, the next step is finding out what makes it so effective, because those compounds could offer new ways to tackle difficult infections,” said co-author Dr. Kenya Fernandes, who supervised the work at the university’s Faculty of Science.
The findings add scientific evidence to interest in a native bee product that has been used in Indigenous medicine, while raising questions for researchers to investigate next. They will need to identify the active compounds and test what they can safely and effectively do. For now, the study offers a promising starting point: a small Australian bee has produced honey with a broad effect in laboratory tests, and its chemistry may hold clues worth following as drug-resistant infections remain a serious challenge.