Andrew Loudon

Andy gives each hellbender a bath to remove foreign bacteria before swabbing its skin.

Institution: James Madison University

My job: Salamander Slime Collector

Real title: Graduate Student

Education:  Mount Union College, B.S., 2011. James Madison University, M.S., 2013

How I help save sallies: In the laboratory of Dr. Reid Harris, we study the microbial communities living on amphibians’ skin and how they protect against the amphibian fungal disease, chytridiomycosis… Some microbes produce anti-fungal metabolites that work synergistically with host skin secretions to inhibit the pathogen and act as extensions of the host defenses.  We are studying hellbender microbial defenses at three levels. First, we are determining which microbial species make up the microbial communities on hellbenders and if community structure is similar among different hellbender populations. Second, in collaboration with the Dr. Kevin Minbiole at Villanova University, we are examining which bacterially-produced metabolites are found on hellbender skins. These chemicals are vital since they can inhibit the pathogen and provide a defensive function. Once we know the structure of microbial communities and structure of chemical communities on hellbenders we can determine if microbial community structure is correlated with chemical community structure. We can then determine how these communities change when faced with climate change and if metabolites associated with disease defense are reduced. Third, to measure the defensive function produced by the chemicals on hellbenders we have developed a bioassay where the fungal pathogen, Batrachochytrium dendrobatidis (Bd), is challenged by total chemicals collected off of hellbenders’ skin. This assay tells us the quantity of hellbender skin chemicals that are needed to inhibit the pathogen.  This assay tests the synergistic effect of chemicals produced by bacteria and by hellbenders, such as antimicrobial peptides. We hypothesize that hellbenders in climate change treatments to will have reduced defensive function and will be more susceptible to chytridiomycosis and other diseases.  By using all of these approaches we will learn how climate change affects the microbial defenses of hellbenders and will use this information to optimize repatriation programs.  For example, it may be important to repatriate hellbenders to cooler streams where hellbender defenses are not compromised.  Lastly, it is possible to apply beneficial bacteria to amphibians as a probiotic to boost defenses against diseases. This approach has been successful in field trials with the frog species, Rana muscosa, and is a promising strategy to aid hellbenders affected by climate change and other anthropogenic stressors.

Best salamander story:  While working with the Ohio Hellbender Partners this past fall we found three hellbender nests. This was a success since only two hellbender nests had previously been found in Ohio.


Leave a Reply

Your email address will not be published. Required fields are marked *