RESEARCH ARTICLE Direct Detection of Fungal Siderophores on Bats with White-Nose Syndrome via

White-nose syndrome (WNS) caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat spe-cies. Little is known about the molecular interplay between pathogen and host in this dis-ease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were de-tected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and high-lights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection