Centennial Honors College
Western Illinois University
Undergraduate Research Day 2014
Poster Presentation
Phylogenetic Relationship Between Human Opportunistic Pathogens and the
Causative Agent of White Nose Syndrome in Bats
Shiloh Lueschow
Faculty Mentor: Andrea Porras-Alfaro
Biological Sciences
Geomyces pannorum is a common soil fungus that has been isolated as an
opportunistic human pathogen causing nail and skin infections. In addition to
Geomyces pannorum, in the last years the genus Geomyces has acquired great
importance due to the large mortality of bats caused by the fungus Pseudogymnoascus
destructans (previously described as a Geomyces species). P. destructans is
responsible for White Nose Syndrome (WNS). The phylogenetic placement of
pathogenic Geomyces species in humans with respect to P. destructans is unclear.
The goal of this research was to characterize and determine the phylogenetic
relationships between various Geomyces strains, isolated from humans, bats, and from
the environment with respect to the bat pathogen P. destructans using microscopy,
culturing methods and two gene markers, the ITS rDNA and MCM7 regions. A
collection of 44 different isolates, 36 of which were isolated from bat wings, four from
human hosts, and four from environmental samples were characterized. All of the
isolates were psychrotolerant, including the human pathogens, while only P.
destructans was a true psychrophile. Phylogenetic analysis showed that bat swab
cultures from Illinois are closely related to multiple Pseudogymnoascus clades as well
as the Geomyces clade. Human opportunistic and environmental isolates considered to
be Geomyces pannorum cluster in the Pseudogymnoascus clade. All of the isolates
cluster with well-defined groups with the exception of three cultures isolated from bats
and one from the environment. These isolates could represent four potential new
groups for the highly diverse Pseudogymnoascus genus.