Estrella Martín-Mazuelos

Diagnosis of invasive pulmonary aspergillosis (IPA) is challenging. The objective of the study was to assess the value of microbiological tests to the diagnosis of IPA in the absence of non-specific radiological data. A retrospective study of 23 patients with suspicion of IPA and positivity of some microbiological diagnostic tests was performed. These tests included conventional microbiological culture, detection of Aspergillus galactomannan (GM) antigen and in some patients (1 → 3)-β-d-glucan (BDG) and Aspergillus fumigatus DNA using the LightCycler^® SeptiFast test. In 10 patients with hematological malignancy, 6 cases were considered ‘probable’ and 4 ‘non-classifiable.’ In 8 patients with chronic lung disease, 7 cases were classified as ‘probable’ and 1 as ‘proven,’ and in 5 patients with prolonged ICU stay (>7 days), there were 2 ‘proven’ cases, 2 ‘non-classifiable’ and 1 putative case. Microbiological culture was positive in 17 cases and 18 Aspergillus spp. were isolated (one mixed culture). A. fumigatus was the most frequent (44.4%) followed by A. tubingensis. The Aspergillus galactomannan (GM) antigen assay was positive in 21 cases (91.3%). The GM antigen and the (1 → 3)-β-d-glucan (BDG) assays were both performed in 12 cases (52.2%), being positive in 9. The SeptiFast test was performed in 7 patients, being positive in 4. In patients with non-classifiable pulmonary aspergillosis and one or more positive microbiological tests, radiological criteria may not be considered a limiting factor for the diagnosis of IPA.

To determine the epidemiology of Candida bloodstream infections, variables influencing mortality, and antifungal resistance rates in ICUs in Spain. Prospective, observational, multicenter population-based study. Medical and surgical ICUs in 29 hospitals distributed throughout five metropolitan areas of Spain. Adult patients (≥ 18 yr) with an episode of Candida bloodstream infection during admission to any surveillance area ICU from May 2010 to April 2011. Candida isolates were sent to a reference laboratory for species identification by DNA sequencing and susceptibility testing using the methods and breakpoint criteria promulgated by the European Committee on Antimicrobial Susceptibility Testing. Prognostic factors associated with early (0-7 d) and late (8-30 d) mortality were analyzed using logistic regression modeling. We detected 773 cases of candidemia, 752 of which were included in the overall cohort. Among these, 168 (22.3%) occurred in adult ICU patients. The rank order of Candida isolates was as follows: Candida albicans (52%), Candida parapsilosis (23.7%), Candida glabrata (12.7%), Candida tropicalis (5.8%), Candida krusei (4%), and others (1.8%). Overall susceptibility to fluconazole was 79.2%. Cumulative mortality at 7 and 30 days after the first episode of candidemia was 16.5% and 47%, respectively. Multivariate analysis showed that early appropriate antifungal treatment and catheter removal (odds ratio, 0.27; 95% CI, 0.08-0.91), Acute Physiology and Chronic Health Evaluation II score (odds ratio, 1.11; 95% CI, 1.04-1.19), and abdominal source (odds ratio, 8.15; 95% CI, 1.75-37.93) were independently associated with early mortality. Determinants of late mortality were age (odds ratio, 1.04; 95% CI, 1.01-1.07), intubation (odds ratio, 7.24; 95% CI, 2.24-23.40), renal replacement therapy (odds ratio, 6.12; 95% CI, 2.24-16.73), and primary source (odds ratio, 2.51; 95% CI, 1.06-5.95). Candidemia in ICU patients is caused by non-albicans species in 48% of cases, C. parapsilosis being the most common among these. Overall mortality remains high and mainly related with host factors. Prompt adequate antifungal treatment and catheter removal could be critical to decrease early mortality.

Although epidemiological cutoff values (ECVs) have been established forCandidaspp. and the triazoles, they are based on MIC data from a single laboratory. We have established ECVs for eightCandidaspecies and fluconazole, posaconazole, and voriconazole based on wild-type (WT) MIC distributions for isolates ofC. albicans(n= 11,241 isolates),C. glabrata(7,538),C. parapsilosis(6,023),C. tropicalis(3,748),C. krusei(1,073),C. lusitaniae(574),C. guilliermondii(373), andC. dubliniensis(162). The 24-h CLSI broth microdilution MICs were collated from multiple laboratories (in Canada, Brazil, Europe, Mexico, Peru, and the United States). The ECVs for distributions originating from ≥6 laboratories, which included ≥95% of the modeled WT population, for fluconazole, posaconazole, and voriconazole were, respectively, 0.5, 0.06 and 0.03 μg/ml forC. albicans, 0.5, 0.25, and 0.03 μg/ml forC. dubliniensis, 8, 1, and 0.25 μg/ml forC. glabrata, 8, 0.5, and 0.12 μg/ml forC. guilliermondii, 32, 0.5, and 0.25 μg/ml forC. krusei, 1, 0.06, and 0.06 μg/ml forC. lusitaniae, 1, 0.25, and 0.03 μg/ml forC. parapsilosis, and 1, 0.12, and 0.06 μg/ml forC. tropicalis. The low number of MICs (ERG11,MDR1,CDR1, orCDR2) and 64 WT isolates indicated that our ECVs may be useful in distinguishing WT from non-WT isolates.

We report the molecular identifications and antifungal susceptibilities of the isolates causing fungemia collected in the CANDIPOP population-based study conducted in 29 Spanish hospitals. A total of 781 isolates (from 767 patients, 14 of them having mixed fungemia) were collected. The species found most frequently were Candida albicans (44.6%), Candida parapsilosis (24.5%), Candida glabrata (13.2%), Candida tropicalis (7.6%), Candida krusei (1.9%), Candida guilliermondii (1.7%), and Candida lusitaniae (1.3%). Other Candida and non- Candida species accounted for approximately 5% of the isolates. The presence of cryptic species was low. Compared to findings of previous studies conducted in Spain, the frequency of C. glabrata has increased. Antifungal susceptibility testing was performed by using EUCAST and CLSI M27-A3 reference procedures; the two methods were comparable. The rate of fluconazole-susceptible isolates was 80%, which appears to be a decrease compared to findings of previous studies, explained mainly by the higher frequency of C. glabrata . Using the species-specific breakpoints and epidemiological cutoff values, the rate of voriconazole and posaconazole in vitro resistance was low (FKS1 or FKS2 genes in echinocandin-resistant isolates revealed previously described point mutations. The decrease in the susceptibility to fluconazole in Spanish isolates should be closely monitored in future studies.

Since epidemiological cutoff values (ECVs) using CLSI MICs from multiple laboratories are not available for Candida spp. and the echinocandins, we established ECVs for anidulafungin and micafungin on the basis of wild-type (WT) MIC distributions (for organisms in a species-drug combination with no detectable acquired resistance mechanisms) for 8,210 Candida albicans , 3,102 C. glabrata , 3,976 C. parapsilosis , 2,042 C. tropicalis , 617 C. krusei , 258 C. lusitaniae , 234 C. guilliermondii , and 131 C. dubliniensis isolates. CLSI broth microdilution MIC data gathered from 15 different laboratories in Canada, Europe, Mexico, Peru, and the United States were aggregated to statistically define ECVs. ECVs encompassing 97.5% of the statistically modeled population for anidulafungin and micafungin were, respectively, 0.12 and 0.03 μg/ml for C. albicans , 0.12 and 0.03 μg/ml for C. glabrata , 8 and 4 μg/ml for C. parapsilosis , 0.12 and 0.06 μg/ml for C. tropicalis , 0.25 and 0.25 μg/ml for C. krusei , 1 and 0.5 μg/ml for C. lusitaniae , 8 and 2 μg/ml for C. guilliermondii , and 0.12 and 0.12 μg/ml for C. dubliniensis . Previously reported single and multicenter ECVs defined in the present study were quite similar or within 1 2-fold dilution of each other. For a collection of 230 WT isolates (no fks mutations) and 51 isolates with fks mutations, the species-specific ECVs for anidulafungin and micafungin correctly classified 47 (92.2%) and 51 (100%) of the fks mutants, respectively, as non-WT strains. These ECVs may aid in detecting non-WT isolates with reduced susceptibility to anidulafungin and micafungin due to fks mutations.

Epidemiological cutoff values (ECVs) were established for the new triazole isavuconazole andAspergillusspecies wild-type (WT) MIC distributions (organisms in a species-drug combination with no detectable acquired resistance mechanisms) that were defined with 855Aspergillus fumigatus, 444A. flavus, 106A. nidulans, 207A. niger, 384A. terreus, and 75A. versicolorspecies complex isolates; 22AspergillussectionUstiisolates were also included. CLSI broth microdilution MIC data gathered in Europe, India, Mexico, and the United States were aggregated to statistically define ECVs. ECVs were 1 μg/ml for theA. fumigatusspecies complex, 1 μg/ml for theA. flavusspecies complex, 0.25 μg/ml for theA. nidulansspecies complex, 4 μg/ml for theA. nigerspecies complex, 1 μg/ml for theA. terreusspecies complex, and 1 μg/ml for theA. versicolorspecies complex; due to the small number of isolates, an ECV was not proposed forAspergillussectionUsti. These ECVs may aid in detecting non-WT isolates with reduced susceptibility to isavuconazole due tocyp51A(anA. fumigatusspecies complex resistance mechanism among the triazoles) or other mutations.