title: Antifungal susceptibility profiles of bloodstream yeast isolates by Sensititre YeastOne over nine years at a large Italian teaching hospital.
abstract: Sensititre YeastOne (SYO) is an affordable alternative to the Clinical and Laboratory Standards Institute (CLSI) reference method for antifungal susceptibility testing. In this study, the MICs of yeast isolates from 1,214 bloodstream infection episodes, generated by SYO during hospital laboratory activity (January 2005 to December 2013), were reanalyzed using current CLSI clinical breakpoints/epidemiological cutoff values to assign susceptibility (or the wild-type [WT] phenotype) to systemic antifungal agents. Excluding Candida albicans (57.4% of all isolates [n = 1,250]), the most predominant species were Candida parapsilosis complex (20.9%), Candida tropicalis (8.2%), Candida glabrata (6.4%), Candida guilliermondii (1.6%), and Candida krusei (1.3%). Among the non-Candida species (1.9%), 7 were Cryptococcus neoformans and 17 were other species, mainly Rhodotorula species. Over 97% of Candida isolates were susceptible (WT phenotype) to amphotericin B and flucytosine. Rates of susceptibility (WT phenotype) to fluconazole, itraconazole, and voriconazole were 98.7% in C. albicans, 92.3% in the C. parapsilosis complex, 96.1% in C. tropicalis, 92.5% in C. glabrata, 100% in C. guilliermondii, and 100% (excluding fluconazole) in C. krusei. The fluconazole-resistant isolates consisted of 6 C. parapsilosis complex isolates, 3 C. glabrata isolates, 2 C. albicans isolates, 2 C. tropicalis isolates, and 1 Candida lusitaniae isolate. Of the non-Candida isolates, 2 C. neoformans isolates had the non-WT phenotype for susceptibility to fluconazole, whereas Rhodotorula isolates had elevated azole MICs. Overall, 99.7% to 99.8% of Candida isolates were susceptible (WT phenotype) to echinocandins, but 3 isolates were nonsusceptible (either intermediate or resistant) to caspofungin (C. albicans, C. guilliermondii, and C. krusei), anidulafungin (C. albicans and C. guilliermondii), and micafungin (C. albicans). However, when the intrinsically resistant non-Candida isolates were included, the rate of echinocandin nonsusceptibility reached 1.8%. In summary, the SYO method proved to be able to detect yeast species showing antifungal resistance or reduced susceptibility.
authors.affiliation: Institute of Public Health (Section of Hygiene), Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Brunella
authors.initials: B
authors.lastname: Posteraro
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Spanu
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Fiori
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Flavio
authors.initials: F
authors.lastname: De Maio
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: De Carolis
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Giaquinto
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Prete
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: De Angelis
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Torelli
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: D'Inzeo
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Antonietta
authors.initials: A
authors.lastname: Vella
authors.affiliation: Hospital Pharmacy, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: De Luca
authors.affiliation: Institute of Infectious Diseases, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Tumbarello
authors.affiliation: Institute of Public Health (Section of Hygiene), Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Walter
authors.initials: W
authors.lastname: Ricciardi
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy msanguinetti@rm.unicatt.it.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sanguinetti
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000935:Antifungal Agents / Q000494:pharmacology*; D003428:Cross Infection / Q000382:microbiology; D025141:Drug Resistance, Fungal; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D007558:Italy; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009181:Mycoses / Q000382:microbiology*; D015003:Yeasts / Q000187:drug effects*
chemical_list: D000935:Antifungal Agents