FIG 1 Culture of A. calidoustus on Sabouraud dextrose agar showing curved conidiophores with characteristic echinulated conidia in lactophenol preparation (magnification, ×100) (A) and clusters of Hülle cells of various sizes and shapes with brown-colored hyphae in lactophenol cotton blue preparation (magnification, ×40) (B).

FIG 2 Grocott's methenamine silver-stained sections obtained 10 days postinfection with A. calidoustus showing characteristic branched fungal hyphae with numerous dormant conidia in kidney tissue (magnification, ×40) (A) and nongerminated/dormant conidial structures in a kidney tubule (magnification, ×100) (B) and in liver parenchyma (magnification, ×100) (C).

FIG 3 Neighbor-joining phylogenetic tree based on combined β-tubulin, calmodulin, and ITS regions of rRNA gene sequence data for clinical and environmental A. calidoustus isolates from Kuwait together with reference A. calidoustus strain CBS 113228. A. ustus CBS 261.67 was used as an outgroup, and numbers on the node branches are bootstrap frequencies.