Background: Fungemia is a serious life-threating illness associated with high mortality. The gold standard for the diagnosis of fungemia is blood culture. Conventional biochemical methods for species identification typically take from 24 to 72 hours and a delay of 12 to 48 hours in appropriate antifungal therapy is associated with an increased risk of mortality. Rapid identification of fungi allows a more targeted empirical therapy and a better outcome of the patient, given the different antifungal susceptibility profile of some species. For these reasons, all blood cultures positive for fungi during the period from June 2015 to October 2019 were tested by means of a multiplex Real-Time PCR for rapid identification.
Materials/methods: All blood cultures positive for fungi by microscopic examination after Gram staining underwent BIOFIRE® FILMARRAY® Blood Culture Identification (BCID) panel, standard culture, identification by means of Vitek 2 and antifungal susceptibility testing by broth microdilution. Only blood cultures positive for single Candida species were included in the study. Median values of C-reactive protein and complete blood count from samples drawn concurrently with blood cultures were also evaluated.
Results: A total of 71 blood cultures were included in the study. The frequency of isolates was: Candida albicans: 34 (47.9%); Candida glabrata: 17 (23.9%); Candida parapsilosis 16 (22.6%); Candida tropicalis: 4 (5.6%). The agreement between FilmArray and Vitek 2 was of 100%. Respectively for C. albicans, C. glabrata, C. parapsilosis and C. tropicalis, a significant difference was found among median values of age: 69 vs 80 vs 61 vs 61 years (p=0.05); C-reactive protein: 9.9 vs 21.3 vs 8.3 vs 11.9 mg/dl (p=0.05); neutrophils: 7840 vs 10480 vs 4920 vs 4950 cells/microliter (p=0.012); neutrophil/lymphocyte ratio: 6.9 vs 18.1 vs 4.3 vs 5.0 (p=0.02). We found a significant greater proportion of C. glabrata isolates resistant to fluconazole: 8/17 (47.1%; chi square: 29.6; p<0.0001) and of C. parapsilosis isolates resistant to both anidulafungin: 11/16 (68.8%; chi square: 49.7; p<0.0001) and micafungin: 6/16 (37.5%; chi square: 26.6; p<0.0001).
Conclusions: In this study we found a greater inflammatory state associated with C. glabrata fungemia, possibly due to older age and underlying disease.