277. Identification and Antifungal Susceptibility of Candida Species Isolated from Bloodstream Infections Over a 14-Year Period

Abstract

BackgroundInvasive infections caused by Candida species are associated with significant morbidity and mortality. Historically, C. albicans has been the predominant species recovered from patients with candidemia. However, the changing epidemiology of invasive candidiasis now includes more non-C. albicans species, which may exhibit intrinsic resistance or reduced susceptibility to antifungal agents used for therapeutic intervention. We sought to evaluate the epidemiology and susceptibility of invasive Candida ssp. isolates causing bloodstream infections at the NIH Clinical Center over a 14 year period.Methods Candida spp. isolates causing bloodstream infections between 2004 and 2018 were identified. Retrospective chart review was performed for infected patients in accordance with the IRB. All Candida isolates were recovered from frozen storage by plating onto Sabouraud Dextrose Agar, and isolate identities were confirmed by MALDI-TOF MS. Antifungal susceptibility testing was performed by broth microdilution and MICs were interpreted using current CLSI criteria.ResultsBetween 2004–2018, we identified 98 unique clinical isolates from 77 patients with candidemia. Records from 75 of these patients were able to be reviewed, and the 30-day and 90-day mortalities were 24% and 52%, respectively. The average age at the time of culture positivity was 41.3 years (range 6.5 to 76.9 years). Thirty-one of the patients were female and 44 were male. C. albicans only constituted 18% of isolates (N = 18) and was the third-most prevalent Candida species identified behind C. parapsilosis (28%, N = 27) and C. glabrata (23%, N = 23), and followed by C. tropicalis (8%, N = 8) and C. krusei (6%, N = 6). As expected, fluconazole resistance was prevalent among C. glabrata (70%, N = 16) and C. krusei (100%, N = 6); however, a sizable proportion of C. parapsilosis (11%, N = 3), C. tropicalis (63%, N = 5) and C. albicans (22%, N = 4) strains also exhibited fluconazole resistance.ConclusionOur findings illustrate a high prevalence of non-C. albicans Candida spp. as the causative agents of bloodstream infections among patients at our institution. The clinical risk factors associated with the development of candidemia and azole resistance, as well as the molecular mechanisms of antifungal resistance are under investigation.Disclosures All authors: No reported disclosures.