Search

Breakthrough fungaemias due to Candida albicans and Candida parapsilosis appearing during fluconazole therapy in neonates and infants were assessed for risk factors and outcome. Forty fungaemias occurred during therapy with fluconazole within a 12 year national survey and were compared with 161 cases of non-breakthrough paediatric fungaemias. The agar disc diffusion test method was used for antifungal susceptibility testing and the Vitek system for species identification. Univariate and multivariate analysis for risk factors for breakthrough fungaemia were carried out. All the fungaemias were a result of strains susceptible to fluconazole at 0.25-4 mg/L in vitro [C. albicans (85%) and C. parapsilosis (15%)]. The mean number of positive blood cultures per episode was 2.2. Sixteen children had 'early' breakthrough fungaemias (within 4-5 days) and 24 fungaemias appeared on day 6 and later. Mean fluconazole MICs in the 'early' group were 1.2, and 2.8 mg/L in the 'late' group (P < 0.03, t-test). However, no difference was observed in the average dose of fluconazole used in the two groups. Neonatal age, total parenteral nutrition, very low birth weight, before surgery, central or umbilical venous catheterization and artificial ventilation were all significantly related to breakthrough fungaemia in univariate analysis but only central or umbilical venous catheterization were significant in multivariate analysis. The outcome of breakthrough fungaemia was better overall and attributable mortalities in non-breakthrough fungaemia was significantly higher in comparison with breakthrough fungaemia.

Abstract: Amphotericin B (AmB) resistance in Candida spp. is very rare. Three cases of fungemia, due to amphotericin B-resistant Candida spp. in pediatric patients after previous neurosurgery for brain tumors, are reported. The Candida strains – one C. guillermondii, one C. lusitaniae, and one C. parapsilosis– showed minimum inhibitory concentrations (MICs) to AmB of 2–4 μg/ml. Two of the three patients had been pretreated with AmB for 5–11 days. All three patients were successfully treated with intravenous fluconazole (6–10 mg/kg per day) for 16–28 days, and all survived. Despite AmB resistance in Candida spp. being very rare, C. lusitaniae, C. guillermondii, and C. parapsilosis isolates in documented infections should be tested for AmB resistance, mainly in patients not responding to therapy with AmB.

Abstract: The aim of this study was to test the antifungal susceptibility of 262 bloodstream yeast isolates (164 Candida albicans strain, 88 non-albicans Candida spp. and 10 non-Candida yeasts) recovered from 169 surgical, neonatal, critically ill intensive care unit patients (ICU), and cancer patients (mixed patient population) to amphotericin B (AmB), fluconazole (FLU), 5-flucytosine (5-FC), itraconazole (ITRA), ketoconazole (KETO), miconazole (MICO), and nystatin (NYS), in order to correlate in-vitro resistance to fluconazole with the outcome of fungemia. The agar disk diffusion test was used to assess the susceptibility of the 262 bloodstream yeasts isolates. In addition, 78 strains isolated from cancer patients were also tested with the E-test. There were no differences in the susceptibility of the various C. albicans strains tested, except in 40 isolates from surgery patients, which showed a somewhat lower susceptibility to KETO and MICO to (3.7–5.5% resistance). There were no C. albicans strains resistant to AmB, NYS, or FLU. There were slight differences in the susceptibility patterns of the 88 non-albicans Candida spp. (NAC) isolates. Resistance to AmB and NYS appeared in 1 strain of C. guillermondii (minimum inhibitory concentration; MIC to AmB; 4 μg/ml) and in 1 strain of C. parapsilosis (MIC to NYS, 8 μg/ml and MIC to AmB, 2 μg/ml). All other NACs were susceptible to both polyenes (AmB and NYS). Nine of the 11 strains of C. krusei were resistant to FLU (MIC ≥ 64 μg/ml), the 2 exceptions showed, respectively, MICs for FLU of 6 and 32 μg/ml ("dose-dependent" susceptibility). However, only 2 of 29 C. glabrata strains were fully FLU-resistant (MIC ≥ 64 μg/ml), 27 being susceptible with MIC values of 0.5–8 μg/ml. Apart from 9 C. krusei and 2 C. glabrata strains, 2 C. parapsilosis strains and 1 strain of C. tropicalis were also FLU-resistant. Among the 88 NACs, 17.04% were FLU-resistant and 3.7% were KETO- and ITRA-resistant. Resistance to 5-FC and AmB was minimal. We compared the outcomes of patients infected with FLU-resistant vs FLU-susceptible yeasts in 161 evaluable patients treated with FLU. Attributable mortality was significantly higher (19.0% vs 8.6%; P < 0.01) in patients infected with the FLU-resistant yeasts.