Case Study 4NGS reveals a Coccidioides immitis cluster in three organ transplant patients (90)

Whole-genome sequence typing (WGST) is an application of NGS that was used in this case to identify multiple donor transplant-related cocccidioidomycosis events that occurred in patients who resided in an area of the United States where Coccidioides immitis (C. immitis) was endemic. In regions of endemicity, it can be diffi-cult to distinguish between donor-derived primary infections with Coccidioides and latent infections with this pathogenic fungus. Whole-genome sequencing and single-nucleotide polymorphism (SNP) analysis showed that the three C. immitis isolates collected from the organ recipient patients were nearly genetically identical, with only three SNP differences among them. Postmortem analysis of the donor's serum was positive for IgM antibodies to Coccidioides spp., therefore making the donor the common source for this cluster of transplant-related infections. WGST demonstrated the genotypic and epidemiologic relatedness of C. immitis clinical isolates among organ recipients and their donor.