Prospective Multicenter Study of the Epidemiology, Molecular Identification, and Antifungal Susceptibility of Candida parapsilosis, Candida orthopsilosis, and Candida metapsilosis Isolated from Patients with Candidemia

Abstract

ABSTRACTA 13-month prospective multicenter study including 44 hospitals was carried out to evaluate the epidemiology ofCandida parapsilosiscomplex candidemia in Spain. Susceptibility to amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, caspofungin, and micafungin was tested by the microdilution colorimetric method. A total of 364C. parapsilosiscomplex isolates were identified by molecular methods:C. parapsilosis(90.7%),Candida orthopsilosis(8.2%), andCandida metapsilosis(1.1%). Most candidemias (C. parapsilosis, 76.4%;C. orthopsilosis, 70.0%;C. metapsilosis, 100%) were observed in adults. NoC. orthopsilosisorC. metapsilosiscandidemias occurred in neonates.C. parapsilosiswas most frequent in adult intensive care unit (28.8%), surgery (20.9%), and internal medicine (19.7%) departments; andC. orthopsilosiswas most frequent in hematology (28.6%), pediatrics (12.0%), and neonatology (11.5%) departments. The geographic distribution ofC. orthopsilosisandC. metapsilosiswas not uniform. According to CLSI clinical breakpoints, allC. orthopsilosisandC. metapsilosisisolates were susceptible to the nine agents tested. Resistance (MICs > 1 mg/liter) was observed only inC. parapsilosis: amphotericin B, posaconazole, itraconazole, and caspofungin (0.3% each), anidulafungin (1.9%), and micafungin (2.5%). Applying the new species-specific fluconazole and echinocandin breakpoints, the rates of resistance to fluconazole forC. parapsilosisandC. orthopsilosisincreased to 4.8% and 0.3%, respectively; conversely, forC. parapsilosisthey shifted from 1.9 to 0.6% (anidulafungin) and from 2.5 to 0.6% (micafungin). Our study confirms the different prevalence ofC. parapsilosiscomplex candidemia among age groups: neitherC. orthopsilosisnorC. metapsilosiswas isolated from neonates; interestingly,C. metapsilosiswas isolated only from adults and the elderly. The disparity in antifungal susceptibility among species could be important for therapy.