Bacteria may be frogs’ and toads’ best hope in their fight against a devastating fungus

Chytrids are some of the oldest fungi on Earth, and until recently nobody minded as they fed on dead or rotting material. In 1999 however, a species of chytrid was discovered that was passing the usual menu of dead tissue, instead targeting living frogs, salamanders and other amphibians. This species, named Batrachochytrium dendrobatidis, has since turned out to be terrifyingly successful as a parasite, and is thought to be responsible for the collapse or extinction of at least 200 species of amphibians from around the world. Ecologists are now racing to protect the surviving animals, with one of the most promising ideas involving a potentially inoculating bath in bacteria.

Not-so-secret weapon

The bacteria, called Janthinobacterium lividum aka J-liv, is actually incredibly common. The benign microbe can be found on just about every continent, riding on the bodies of everything from birds to, yes, amphibians. It hasn’t been the subject of extensive research up to this point, largely because it didn’t seem to do much. No animal was clearly doing better or worse in its presence, and so it seemed like just another species of bacteria simply along for the ride.

The key factor that has pulled J-liv into this microbial battle is that an ingredient in the bacteria’s metabolism can slow or block fungal growth. Combined with its natural prevalence around the world, it seems that J-liv may be a good way to stop the spread of chytrids. It’s been successful in laboratory settings, but now scientists are trying to use it in the field, hopefully preventing more frogs and toads from their likely extinction.

Bacterial baths

A current project in Colorado is focusing on young boreal toads (Bufo boreas boreas). The toads are most vulnerable when transitioning from tadpoles to adult frogs, as the process requires enormous amounts of energy, leaving their metabolisms without a lot of strength to fight infections. So researchers are looking for these young toads and basting them in a J-liv-rich solution. While some ponds seem to have a natural supply of J-liv, other bodies of water mysteriously lack the bacteria, and so they’re getting extra attention to head off fungal infections.

If spreading J-liv proves successful, humans might not want to pat ourselves on the back too much. Nothing is conclusive at this point, but there’s evidence to suggest that water quality plays a big role in why some ponds are J-liv deficient, putting amphibians at risk. That shift in quality is most pronounced near human development, meaning we may need to look at more than microbes to really figure out how we can help the world’s frogs and toads survive.

Source: Soaking A Bunch Of Toads In Their Own Bacteria Could Save Their Lives by Krista Langlois, FiveThirtyEight