Effects of Snake Fungal Disease on Epidermal Microbiome Dynamics

Abstract

Ecological disturbance is a key factor in structuring biotic assemblages. Microbial assemblages are subject to disturbance and react predictably to it. This study aimed to determine if host- and pathogen- associated processes act as perturbations to the microbiome. Snake Fungal Disease (SFD), caused by Ophidiomyces ophiodiicola, is an emerging infectious disease. I hypothesized that shedding and disease would alter the structure and assembly of the snake microbiome. I inoculated 22 Northern Watersnakes (Nerodia sipedon) with O. ophiodiicola to assess the effects of SFD on host microbial assemblages over 82 days. Swabs were taken of each snake/mesocosm weekly and during shedding events. Swabs were utilized for quantitative PCR of O. ophiodiicola (pathogen load) and high-throughput sequencing to characterize microbial assemblages. Infection with SFD generated chronic disturbance of the microbiome; resulting in changes to alpha and beta diversity. Shedding generated acute disturbance of the microbiome; resulting in changes to beta-diversity and assembly processes. This work demonstrates the utility of disturbance ecology in studies of host-pathogen-microbiome interactions.