Molecular Epidemiology of Blastomyces gilchristii Clusters, Minnesota, USA

Abstract

We characterized 2 clusters of blastomycosis cases in Minnesota, USA, using whole-genome sequencing and single-nucleotide polymorphism analyses. Blastomyces gilchristii was confirmed as the cause of infection. Genomic analyses corresponded with epidemiologic findings for cases of B. gilchristii infections, demonstrating the utility of genomic methods for future blastomycosis outbreak investigations.

Keywords: Blastomyces gilchristii; Minnesota; United States; blastomycosis; fungi; respiratory infections; whole-genome sequencing.

Figure

Genetic relationships and molecular epidemiology of Blastomyces gilchristii clusters, Minnesota, USA. We performed whole-genome sequencing of isolates from 4 patients in Minnesota who had Blastomyces gilchristii infections and compared the sequences with 3 publicly available B. dermatitidis isolates (National Center for Biotechnology Information run nos. SRR11849827, SRR11849828, SRR11849829). We analyzed single-nucleotide polymorphisms (SNPs) using the MycoSNP version 0.19 analytical workflow (https://github.com/CDCgov/mycosnp). We used the genome assembly data for B. gilchristii strain SLH14081 from GenBank (accession no. GCA_000003855.2) as a reference. Neighbor-joining tree shows the genetic relationships between cluster A and B, which each comprised isolates from 2 patients, the B. gilchristii reference strain, and B. dermatitidis isolates. Numbers represent the SNPs for each strain. Ref., reference.