Horse Dung Fungus: Bizarre Help vs Antibiotic Resistance

Antimicrobial resistant (AMR) bacteria pose a very real threat to the world, one that a highly concerned World Health Organization (WHO) has kept in its radar for years. Now a team of researchers has identified a new natural antibiotic in horse dung-dwelling fungus, offering up secrets that might help us avoid or at least understand an encroaching AMR world crisis.

The Threat of Apocalypse

Antibiotic (antimicrobial) resistance is not exactly a new concept. The WHO and national organizations like the US Centers for Disease Control and Prevention (CDC) have been struggling with AMR strains of bacterial infections for decades, pumping considerable amounts of money and effort into the development of new and effective antibiotics.

However, the increased prevalence of multiple-drug-resistant bacteria across the globe is now noticeably outpacing antibiotic development. The CDC warned earlier this year how this is largely due to rampant overuse of drugs, in which concerned parents and livestock owners alike are exposing their charges to antibiotics even when there is no serious bacterial infection to fix.

The result is that microbial communities are given numerous chances to resist and adapt, becoming immune to the things that once killed them - much like a cockroach. (Scroll to read on...)

The WHO then warned back in April that an ever-increasing range of infections caused by bacteria, parasites and fungi are becoming AMR, with a multi-drug-resistant form of tuberculosis becoming a leading problem in undeveloped countries.

"A post-antibiotic era - in which common infections and minor injuries can kill - far from being an apocalyptic fantasy, is instead a very real possibility for the 21st Century," the organization reported.

International investigators added that primary treatments for a number of life-threatening bacterial infections are already not effective in at least 50 percent of the world's patients.

Horse Dung Savior?

Now, a new study published in The Journal of Biological Chemistry has discovered a peculiar natural antibiotic that could give us a sliver of hope.

The common inky cap mushroom Coprinopsis cinerea can be found growing straight out of ignored piles of horse dung, and has been the subject of research for some time, as it boasts a genetic history that is fascinating to scientists.

In fact, this latest study actually began with researchers investigating how this fungus and various bacteria affect each other's growth. Interestingly, in the course of the work, it was found that the fungus was actually killing off certain types of bacteria, and researchers wanted to know how. (Scroll to read on...)

It was quickly revealed that the mushroom produces a protein called copsin that has the same effect as traditional antibiotics, but belongs to a different class of biochemical substances.

"Copsin is an exceptionally stable protein," lead author Andreas Essig said in a statement, explaining how the agent not only survives incredible circumstances (such as superheated temperatures) but also slips into bacteria to halt the production of cell walls.

"Building the cell wall is the Achilles heel of bacteria," Essig added.

He and his colleagues have already seen the protein work its magic to kill pathogens like Listeria - a bacterium that causes food poisoning that is infamously difficult to treat.

All About Control

Still, the main focus of Essig and his colleagues at the Swiss Federal Institute of Technology (ETH) in Zurich and the University of Bonn, in Germany, was to understand how this agent worked in the fungus.

"Whether copsin will one day be used as an antibiotic in medicine remains to be seen," said Markus Aebi, who led the research team. "This is by no means certain, but it cannot be ruled out either."

Aebi adds that copsin has likely been used by Coprinopsis cinerea as a first line of defense against bacteria for countless generations - even millions of years. So how is it that bacteria haven't adapted?

"Fungi have internal instructions on how to use these substances without resulting in selection of resistant bacteria," Aebi explained.

Copsin, it turned out, was no miracle drug. Just one only used when absolutely necessary, and never at any other time - a lesson from nature that humanity would do well to remember.