Data on fungemia epidemiology and antifungal susceptibility of isolates from children are scarce, leading frequently to pediatric empirical treatment based on available adult data. The present study was designed to update the epidemiological, mycological, and in vitro susceptibility data on fungal isolates from children with fungemia in Spain. All fungemia episodes were identified prospectively by blood culture over 13 months at 30 hospitals. Tests of susceptibility to amphotericin B, flucytosine, fluconazole, itraconazole, posaconazole, voriconazole, anidulafungin, caspofungin, and micafungin were performed at participant institutions by a microdilution colorimetric method. New species-specific clinical breakpoints for fluconazole, voriconazole, and echinocandins were also applied. A total of 203 episodes of fungemia in 200 children were identified. A higher proportion of fungal isolates was from general wards than intensive care units (ICU). Candida parapsilosis (46.8%), Candida albicans (36.5%), Candida tropicalis (5.9%), Candida glabrata (3.9%), and Candida guilliermondii (2.5%) were the leading species. C. parapsilosis was the predominant species except in neonates. C. albicans was the most frequent in neonatal ICU settings (51.9%). Intravascular catheter (79.3%), surgery (35%), prematurity (30%), and neutropenia (11%) were the most frequent predisposing factors. Most Candida isolates (95.1%) were susceptible to all antifungals. When the new species-specific clinical breakpoints were applied, all C. parapsilosis isolates were susceptible to echinocandins except one, which was micafungin resistant. This is the largest published series of fungemia episodes in the pediatric setting. C. parapsilosis is the most prevalent species in Spain, followed by C. albicans and C. tropicalis. Resistance to azole and echinocandin agents is extremely rare among Candida species. The fluconazole resistance rate in Spain has decreased in the last 10 years.

In the absence of clinical breakpoints (CBP), epidemiological cutoff values (ECVs) are useful to separate wild-type (WT) isolates (without mechanisms of resistance) from non-WT isolates (those that can harbor some resistance mechanisms), which is the goal of susceptibility tests. Sensititre YeastOne (SYO) is a widely used method to determine susceptibility of Candida spp. to antifungal agents. The CLSI CBP have been established, but not for the SYO method. The ECVs for four azoles, obtained using MIC distributions determined by the SYO method, were calculated via five methods (three statistical methods and based on the MIC50 and modal MIC). Respectively, the median ECVs (in mg/liter) of the five methods for fluconazole, itraconazole, posaconazole, and voriconazole (in parentheses: the percentage of isolates inhibited by MICs equal to or less than the ECVs; the number of isolates tested) were as follows: 2 (94.4%; 944), 0.5 (96.7%; 942), 0.25 (97.6%; 673), and 0.06 (96.7%; 849) for Candida albicans; 4 (86.1%; 642), 0.5 (99.4%; 642), 0.12 (93.9%; 392), and 0.06 (86.9%; 559) for C. parapsilosis; 8 (94.9%; 175), 1 (93.7%; 175), 2 (93.6%; 125), and 0.25 (90.4%; 167) for C. tropicalis; 128 (98.6%; 212), 4 (95.8%; 212), 4 (96.0%; 173), and 2 (98.5; 205) for C. glabrata; 256 (100%; 53), 1 (98.1%; 53), 1 (100%; 33), and 1 (97.9%; 48) for C. krusei; 4 (89.2%; 93), 0.5 (100%; 93), 0.25 (100%; 33), and 0.06 (87.7%; 73) for C. orthopsilosis. All methods included ≥94% of isolates and yielded similar ECVs (within 1 dilution). These ECVs would be suitable for monitoring emergence of isolates with reduced susceptibility by using the SYO method.

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Background: The new challenges involved in the chemotherapy of tuberculosis make it necessary to find novel drugs, especially ones that are useful in the latent phase of the disease. Methods: We evaluated the activity of linezolid and fluoroquinolones against logarithmic- and stationary-phase Mycobacterium tuberculosis. Results: We observed that linezolid exhibits antibacterial action, although slowly, in both situations. Quinolones with an 8-methoxy group exhibit greater activity than levofloxacin in logarithmic growth phases, whereas levofloxacin exhibits greater activity in stationary-phase growth. Conclusion: The study of the activity of drugs against the M. tuberculosis microorganism in the latent phase is one of the most important tools available in the fight against the tuberculosis epidemic, and both linezolid and the new fluoroquinolones appear to be promising drugs.