WHAT DRIVES BSAL SUSCEPTIBILITY IN NEWTS?

Batrachochytrium salamandrivorans (Bsal) is a major threat to salamanders of the world. Interestingly, some individuals of the same species can respond very differently to this pathogen. Our GLOSSI research project investigates the mechanisms underlying this variation, in order to find solutions for amphibian conservation. In our latest publication, we characterized the relation between individual variation in susceptibility to Bsal and the skin microbiome of Iberian ribbed newt (Pleurodeles waltl).

Iberian ribbed newt, Pleurodeles Waltl (© Eduardo Fernández Meléndez)

Does the skin microbiome protect against Bsal?

Diverse bacteria live on the amphibian skin, forming their “skin microbiome”. Some beneficial bacteria in the microbiome defend their hosts against various diseases. Here, we tested whether differences in microbiome could explain why some newts become sicker than others. We found that:

• Newts from different origins have distinct skin microbiome, even when raised in identical conditions.

• Microbiome does not predict individual susceptibility to Bsal, but host origin does.

So what explains susceptibility? Our results point to host origin -not microbiota - as a key factor shaping how Iberian ribbed newts respond to Bsal, suggesting that genetic or early-life factors may play a key role in disease susceptibility.

Why does it matter?

Understanding the factors underlying disease susceptibility is crucial for conservation. While microbiome-based strategies are promising against other pathogens, they may be less effective for Bsal. Identifying the host traits that drive susceptibility will be important as we work to protect amphibians - the world’s most endangered class of vertebrates.

For more information about this study, you can read the full scientific article here, and for more information about the project, you can visit the GLOSSI’s tab.