Emergence of cryptic species and clades of species complex exhibiting limited susceptibility to antifungals in patients with candidemia.

Members of the species complex are able to cause superficial and life-threatening systemic infections with low susceptibility to azoles and echinocandins. We tested 130 bloodstream complex isolates collected from eight Latin American medical centers over 18 years (period 1 = 2000-2008 and period 2 = 2009-2018) to investigate trends in species distribution and antifungal resistance. The isolates were identified by rDNA ITS region sequencing, and antifungal susceptibility tests were performed against fluconazole, voriconazole, anidulafungin, and amphotericin B using the CLSI microbroth method. (s.s.; = 116) was the most prevalent species, followed by ( = 12) and ( = 2). Based on rDNA ITS identification, three clades within were characterized (clade 1 = 94; clade 2 = 19; and clade 3 = 3). In the second period of study, we found a substantial increment in the isolation of (3.4% versus 13.8%; = 0.06) and clade 2 s.s. exhibiting lower susceptibility to one or more triazoles. IMPORTANCE Yeast-invasive infections play a relevant role in human health, and there is a concern with the emergence of non- pathogens causing disease worldwide. There is a lack of studies addressing the prevalence and antifungal susceptibility of different species within the complex that cause invasive infections. We evaluated 130 episodes of species complex candidemia documented in eight medical centers over 18 years. We detected the emergence of less common species within the complex causing candidemia and described a new clade of with limited susceptibility to triazoles. These results support the relevance of continued global surveillance efforts to early detect, characterize, and report emergent fungal pathogens exhibiting limited susceptibility to antifungals.