A microbe-derived treatment to help inhibit white-nose syndrome in hibernating North American bats

Abstract

<i>Pseudogymnoascus destructans</i> (<i>P. destructans</i>) is known to be the causative agent of White-Nose Syndrome in hibernating North American bats. To date, this disease has caused largescale mortality in bat populations present in 25 US states and 5 Canadian provinces. White Nose Syndrome is associated with a decrease in fat reserves and a substantial loss in water and electrolytes. This disturbance in normal metabolism leads to frequent arousal periods during hibernation. While fighting against the disease, exhaustion of compensatory mechanisms leads to mortality.<br> Probiotics and microbe-derived treatments are the likely solution for managing White Nose Syndrome since introducing foreign antifungals can affect an already sensitive cave environment. This study examines the inhibitory effect of one <i>Penicillium spp</i>. isolate on <i>P. destructans</i>. Sanger sequencing and NCBI BLAST confirmed the identity of the <i>Penicillium spp</i>. The isolate was identified to be <i>Penicillium herquei</i>. Using pairwise testing plates, the fungus has been shown to inhibit the growth of <i>P. destructans</i> over the course of two weeks. The growth curve of the isolate was tracked by measuring the dry mass and the absorbance of different liquid cultures over 10 days. The inhibition could either be due to resource or interference competition. The cell-free liquid culture was added to fresh media to make up plates that were subsequently inoculated with <i>P. destructans</i>. These plates had no to little growth which showed that the presence of the <i>P. herquei</i> is not crucial to the inhibition and that there is no resource competition between the two fungi. This indicates that the isolate probably secretes an inhibitory compound. Plates inoculated with the isolate were extracted with solvents of different polarities and then analyzed using a quadrupole time-of-flight mass spectrometer to determine the mass-to-charge ratio and the retention time of the inhibitory compound.