Jennifer L. Anderson
Matthew C. Fisher
Daniel A. Henk
Brian L. Sloss
Kurt D. Reed
Jennifer K. Meece
2011
<p><span id="named-content-2" class="named-content genus-species">Blastomyces dermatitidis</span><span>, a thermally dimorphic fungus, is the etiologic agent of North American blastomycosis. Clinical presentation is varied, ranging from silent infections to fulminant respiratory disease and dissemination to skin and other sites. Exploration of the population genetic structure of </span><span id="named-content-3" class="named-content genus-species">B. dermatitidis</span><span> would improve our knowledge regarding variation in virulence phenotypes, geographic distribution, and difference in host specificity. The objective of this study was to develop and test a panel of microsatellite markers to delineate the population genetic structure within a group of clinical and environmental isolates of </span><span id="named-content-4" class="named-content genus-species">B. dermatitidis</span><span>. We developed 27 microsatellite markers and genotyped </span><span id="named-content-5" class="named-content genus-species">B. dermatitidis</span><span> isolates from various hosts and environmental sources (</span><i>n</i><span>=112). Assembly of a neighbor-joining tree of allele-sharing distance revealed two genetically distinct groups, separated by a deep node. Bayesian admixture analysis showed that two populations were statistically supported. Principal coordinate analysis also reinforced support for two genetic groups, with the primary axis explaining 61.41% of the genetic variability. Group 1 isolates average 1.8 alleles/locus, whereas group 2 isolates are highly polymorphic, averaging 8.2 alleles/locus. In this data set, alleles at three loci are unshared between the two groups and appear diagnostic. The mating type of individual isolates was determined by PCR. Both mating type-specific genes, the HMG and α-box domains, were represented in each of the genetic groups, with slightly more isolates having the HMG allele. One interpretation of this study is that the species currently designated </span><span id="named-content-6" class="named-content genus-species">B. dermatitidis</span><span> includes a cryptic subspecies or perhaps a separate species.</span></p>
application/pdf
10.1128/AEM.00258-11
en
American Society for Microbiology
Population genetic structure of clinical and environmental isolates of Blastomyces dermatitidis based on 27 polymorphic microsatellite markers
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