Candidemias caused by candida parapsilosis complex species: Epidemiology and antifungal susceptibility of strains

The frequency of invasive fungal infections is gradually increasing and Candida species are seen as the most common cause of invasive fungal infections. In recent years, it has been reported that the invasive candidiasis epidemiology has changed and non-albicans Candida species have been isolated more frequently. Among the causative agents of candidemia, C. parapsilosis is seen as the second or third most frequently isolated species. In this study, Candida parapsilosis complex strains, which were the cause of candidemia in 2014-2018, were identified at Akdeniz University Hospital by MALDI-TOF MS method, antifungal susceptibilities of strains and the clinical features of patients with candidemia were determined. Ninety six candidemic strains of C. parapsilosis complex were evaluated. Among the causative agents of candidemia, C. parapsilosis complex isolates were the second most frequently isolated species with 18.8%. All strains were defined as C. parapsilosis sensu stricto by MALDI-TOF MS. According to EUCAST (v 10.0), CLSI M27 S4 and CLSI M60 guidelines, fluconazole resistance was 6.3% and susceptible-dose dependent rates were 2.1%. Resistance rate was lower in CLSI M27 S3 and was found as 4.2%. Among the antifungal agents the highest resistance rate was determined for fluconazole. According to CLSI M27 S3, CLSI M27 S4 and CLSI M60, cross resistance was found in two strains against fluconazole and voriconazole; according to EUCAST (v 10.0) in three strains against all azoles. Echinocandin and amphotericin B resistance were not detected. The 11.5% strain was determined to be non-wild type for flucytosine. Half of the patients (n=48) were followed up in intensive care units and 23.9% was accepted as catheter related candidemia. The most common risk factors for candidemia were one or more broad-spectrum antibiotics usage (83.3%), urinary catheter (65.6%), central venous catheter (64.6%) and immunosuppressive therapy (40.6%). Antifungal therapy receiving rates for candidemia is 79.2%, the most commonly used agent was fluconazole and 30-day mortality associated with candidemia was detected as 34.4% (33/96). It was statistically determined that being over 65 years old, follow-up in the intensive care unit, broad-spectrum antibiotic usage before candidemia and urinary catheter implementation increased mortality by univariate analysis (p <0.05). As a result, in our study that we evaluated C. parapsilosis complex candidemia, it was found that there was no infection with cryptic species other than C. parapsilosis sensu stricto. Caution should be exercised due to the azol group antifungal resistance in C. parapsilosis sensu stricto isolates, mainly fluconazole, and susceptibility testings should be performed to provide appropriate antifungal therapy.