Multicenter Study of Method-Dependent Epidemiological Cutoff Values for Detection of Resistance in Candida spp. and Aspergillus spp. to Amphotericin B and Echinocandins for the Etest Agar Diffusion Method

BSTRACT Method-dependent Etest epidemiological cutoff values (ECVs) are not available for susceptibility testing of either Candida or Aspergillus species with amphotericin B or echinocandins. In addition, reference caspofungin MICs for Candida spp. are unreliable. Candida and Aspergillus species wild-type (WT) Etest MIC distributions (microorganisms in a species-drug combination with no detectable phenotypic resistance) were established for 4,341 Candida albicans, 113 C. dubliniensis, 1,683 C. glabrata species complex (SC), 709 C. krusei, 767 C. parapsilosis SC, 796 C. tropicalis, 1,637 Aspergillus fumigatus SC, 238 A. flavus SC, 321 A. niger SC, and 247 A. terreus SC isolates. Etest MICs from 15 laboratories (in Argentina, Europe, Mexico, South Africa, and the United States) were pooled to establish Etest ECVs. Anidulafungin, caspofungin, micafungin, and amphotericin B ECVs (in micrograms per milliliter) encompassing �97.5% of the statistically modeled population were 0.016, 0.5, 0.03, and 1 for C. albicans; 0.03, 1, 0.03, and 2 for C. glabrata SC; 0.06, 1, 0.25, and 4 for C. krusei; 8, 4, 2, and 2 forC. parapsilosis SC; and 0.03, 1, 0.12, and 2 for C. tropicalis. The amphotericin B ECV was 0.25 � g/ml for C. dubliniensis and 2, 8, 2, and 16 � g/ml for the complexes of A. fumigatus, A. flavus, A. niger, and A. terreus, respectively. While anidulafung in Etest ECVs classified 92% of the Candida fks mutants evaluated as non-WT, the performance was lower for caspofungin (75%) and micafungin (84%) cutoffs. Finally, although anidulafungin (as an echinocandin surrogate susceptibility marker) and amphotericin B ECVs should identify Candida and Aspergillus isolates with reduced susceptibility to these agents using the Etest, these ECVs will not categorize a fungal isolate as susceptible or resistant, as breakpoints do. KEYWORDS ECVs, Etest ECVs, Etest MICs Candida, Etest MICs Aspergillus, WT isolates, amphotericin B resistance, antifungal resistance, echinocandin resistance, non-WT, susceptibility marke

Posaconazole MIC Distributions for Aspergillus fumigatus Species Complex by Four Methods: Impact of cyp51A Mutations on Estimation of Epidemiological Cutoff Values

ABSTRACT Estimating epidemiological cutoff endpoints (ECVs/ECOFFS) may be hindered by the overlap of MICs for mutant and nonmutant strains (strains harboring or not harboring mutations, respectively). Posaconazole MIC distributions for the Aspergillus fumigatus species complex were collected from 26 laboratories (in Australia, Canada, Europe, India, South and North America, and Taiwan) and published studies. Distributions that fulfilled CLSI criteria were pooled and ECVs were estimated. The sensitivity of three ECV analytical techniques (the ECOFFinder, normalized resistance interpretation [NRI], derivatization methods) to the inclusion of MICs for mutants was examined for three susceptibility testing methods (the CLSI, EUCAST, and Etest methods). The totals of posaconazole MICs for nonmutant isolates (isolates with no known cyp51A mutations) and mutant A. fumigatus isolates were as follows: by the CLSI method, 2,223 and 274, respectively; by the EUCAST method, 556 and 52, respectively; and by Etest, 1,365 and 29, respectively. MICs for 381 isolates with unknown mutational status were also evaluated with the Sensititre YeastOne system (SYO). We observed an overlap in posaconazole MICs among nonmutants and cyp51A mutants. At the commonly chosen percentage of the modeled wild-type population (97.5%), almost all ECVs remained the same when the MICs for nonmutant and mutant distributions were merged: ECOFFinder ECVs, 0.5 μg/ml for the CLSI method and 0.25 μg/ml for the EUCAST method and Etest; NRI ECVs, 0.5 μg/ml for all three methods. However, the ECOFFinder ECV for 95% of the nonmutant population by the CLSI method was 0.25 μg/ml. The tentative ECOFFinder ECV with SYO was 0.06 μg/ml (data from 3/8 laboratories). Derivatization ECVs with or without mutant inclusion were either 0.25 μg/ml (CLSI, EUCAST, Etest) or 0.06 μg/ml (SYO). It appears that ECV analytical techniques may not be vulnerable to overlap between presumptive wild-type isolates and cyp51A mutants when up to 11.6% of the estimated wild-type population includes mutants. KEYWORDS Aspergillus fumigatus, CLSI ECVs, ECVs, EUCAST ECVs, Etest, SYO, cyp51A mutants, posaconazole, triazole resistance, wild typ

Contribution of Candida biomarkers and DNA detection for the diagnosis of invasive candidiasis in ICU patients with severe abdominal conditions

BACKGROUND: To assess the performance of Candida albicans germ tube antibody (CAGTA), (1 → 3)-ß-D-glucan (BDG), mannan antigen (mannan-Ag), anti-mannan antibodies (mannan-Ab), and Candida DNA for diagnosing invasive candidiasis (IC) in ICU patients with severe abdominal conditions (SAC). METHODS: A prospective study of 233 non-neutropenic patients with SAC on ICU admission and expected stay ≥ 7 days. CAGTA (cutoff positivity ≥ 1/160), BDG (≥80, 100 and 200 pg/mL), mannan-Ag (≥60 pg/mL), mannan-Ab (≥10 UA/mL) were measured twice a week, and Candida DNA only in patients treated with systemic antifungals. IC diagnosis required positivities of two biomarkers in a single sample or positivities of any biomarker in two consecutive samples. Patients were classified as neither colonized nor infected (n = 48), Candida spp. colonization (n = 154) (low-grade, n = 130; high-grade, n = 24), and IC (n = 31) (intra-abdominal candidiasis, n = 20; candidemia, n = 11). RESULTS: The combination of CAGTA and BDG positivities in a single sample or at least one of the two biomarkers positive in two consecutive samples showed 90.3 % (95 % CI 74.2–98.0) sensitivity, 42.1 % (95 % CI 35.2–98.8) specificity, and 96.6 % (95 % CI 90.5–98.8) negative predictive value. BDG positivities in two consecutive samples had 76.7 % (95 % CI 57.7–90.1) sensitivity and 57.2 % (95 % CI 49.9–64.3) specificity. Mannan-Ag, mannan-Ab, and Candida DNA individually or combined showed a low discriminating capacity. CONCLUSIONS: Positive Candida albicans germ tube antibody and (1 → 3)-ß-D-glucan in a single blood sample or (1 → 3)-ß-D-glucan positivity in two consecutive blood samples allowed discriminating invasive candidiasis from Candida spp. colonization in critically ill patients with severe abdominal conditions. These findings may be helpful to tailor empirical antifungal therapy in this patient population

Evaluation of Disk Diffusion Method for Determining Posaconazole Susceptibility of Filamentous Fungi: Comparison with CLSI Broth Microdilution Method

The disk diffusion method was evaluated for determining posaconazole susceptibility against 78 strains of molds using two culture media in comparison with the CLSI (Clinical Laboratory Standards Institute) broth microdilution method (M38-A). A significant correlation between disk diffusion and microdilution methods was observed with both culture media

Comparison of Etest with Modified Broth Microdilution Method for Testing Susceptibility of Aspergillus spp. to Voriconazole

We compared the Etest with a broth microdilution method, performed according to a modified National Committee for Clinical Laboratory Standards guideline (M38-A), for determining the in vitro susceptibility of 77 isolates of Aspergillus spp. (26 A. fumigatus, 21 A. flavus, 10 A. terreus, 9 A. niger, 5 A. nidulellus, 4 A. glaucus, and 2 A. flavipes isolates). Overall, there was 92.2% agreement between both methods when Etest MICs were read at 24 h and 83.1% agreement when both methods were read at 48 h. When Etest MICs were read at 24 h, the agreement was >90% for all species tested except for A. fumigatus (84.6%). When Etest MICs were read at 48 h, the agreement ranged from 50 to 100%. The poorest agreement was seen with A. glaucus (50%) and A. fumigatus (65%). Where a discrepancy was observed between Etest and the reference method, the Etest MIC was generally higher. The Etest appears to be a suitable alternative procedure for testing the susceptibility of Aspergillus spp. to voriconazole

Anales de Edafología y Agrobiología Tomo 29 Número 5-6

Estado de nutrición, equilibrio nutritivo y rendimiento en el olivar de la provincia de Sevilla. II. Estudio sobre la variedad «Gordal», de mesa, por F. González García, A. Mª García Gómez, M. Chaves Sánchez y C. Mazuelos.--Estudio sobre el potasio asimilable en suelos de Tenerife y La Palma (Islas Canarias), por E. Fernández Caldas, A. Borges Pérez y J. J. Bravo Rodríguez.--Las aguas subterráneas de la isla de La Palma, por E. Fernández Caldas y J. J. Bravo Rodríguez.-- Espectros de absorción infrarroja de la fracción arcilla de sedimentos cuaternarios de la cuenca del Ebro, por M. C. Rodríguez-Pascual y E. Martínez Reyes.-- Estudio de la nutrición de diferentes Variedades de avena cultivadas en el campo. III. Relaciones existentes entre el exceso de bases y la capacidad de cambio catiónico (CEC) de diferentes tejidos vegetales, por A. Martín y S. Oliver.-- La nutrición de plantitas de Pinus radiata en estados de toxicidad de boro, por M. T. Marzo Muñioz Cobo y J.. Marcos de Lanuza.-- Nutrición de Eucalyptus globulus en sus primeros estados de desarrollo, por M. T. Marzo Muñoz-Cobo y J. Marcos de Lanuza. Potenciales bioeléctricos de las raíces. J. Consideraciones teóricas, por S. Oliver y T. Mendizábal.-- Potenciales bioeléctricos de las raíces. II. Medidas en soluciones ácidas, por S. Oliver y T. Mendizabal.—Notas. Conferencia de D. Manuel Lora Tamayo en Roma.-- Reunión del Instituto Nacional de Edafología y Agrobiología ]osé María Albareda.-- Reuniones para examinar la política científica española.-- Concesión de premios del C. S. l. C.-- Consejo Superior de Investigaciones Cientif1cas. Convocatoria de premios del año 1970.-- Premio Ibáñez Martín sobre Facultades Veterinarias.-- Convocatoria del premio José María Albareda.-- Reunión hispano-belga de minerales de la arcilla.-- Reunión del Comité Interinstitutos para el Estudio de Métodos Analíticos de Diagnóstico Foliar.-- VI Coloquio Internacional de Análisis de Plantas y Problemas de Fertilizantes y XVIII Congreso Internacional de Horticultura.-- Millón y medio de pesetas para el nuevo laboratorio del Coto de Doñana.-- Distinción al secretario del Instituto de Economía AgrariaPeer reviewe

Posaconazole MIC distributions for aspergillus fumigatus species complex by four methods: Impact of cyp51a mutations on estimation of epidemiological cutoff values

Estimating epidemiological cutoff endpoints (ECVs/ECOFFS) may be hindered by the overlap of MICs for mutant and nonmutant strains (strains harboring or not harboring mutations, respectively). Posaconazole MIC distributions for theAspergillus fumigatus species complex were collected from 26 laboratories (in Australia, Canada, Europe, India, South and North America, and Taiwan) and published studies. Distributions that fulfilled CLSI criteria were pooled and ECVs were estimated. The sensitivity of three ECV analytical techniques (the ECOFFinder, normalized resistance interpretation [NRI], derivatization methods) to the inclusion of MICs for mutants was examined for three susceptibility testing methods (the CLSI, EUCAST, and Etest methods). The totals of posaconazole MICs for nonmutant isolates (isolates with no known cyp51A mutations) and mutant A. fumigatus isolates were as follows: by the CLSI method, 2,223 and 274, respectively; by the EUCAST method, 556 and 52, respectively; and by Etest, 1,365 and 29, respectively. MICs for 381 isolates with unknown mutational status were also evaluated with the Sensititre Yeast- One system (SYO). We observed an overlap in posaconazole MICs among nonmutants and cyp51A mutants. At the commonly chosen percentage of the modeled wild-type population (97.5%), almost all ECVs remained the same when the MICs for nonmutant and mutant distributions were merged: ECOFFinder ECVs, 0.5 μg/ml for the CLSI method and 0.25 μg/ml for the EUCAST method and Etest; NRI ECVs, 0.5 μg/ml for all three methods. However, the ECOFFinder ECV for 95% of the nonmutant population by the CLSI method was 0.25 μg/ml. The tentative ECOFFinder ECV with SYO was 0.06 μg/ml (data from 3/8 laboratories). Derivatization ECVs with or without mutant inclusion were either 0.25 μg/ml (CLSI, EUCAST, Etest) or 0.06 μg/ml (SYO). It appears that ECV analytical techniques may not be vulnerable to overlap between presumptive wild-type isolates and cyp51A mutants when up to 11.6% of the estimated wild-type population includes mutants. © Copyright 2018 American Society for Microbiology. All Rights Reserved

Anales de Edafología y Agrobiología Tomo 26 Número 9-10

Complejos de adsorción de la montmorillonita con dimetilsuLfóxido, por S. González García, M. Sánchez Camazano y G. Dios Cancela .-- Estudio de la relación entre la capacidad de cambio catiónico de las raíces y la composición mineral de las plantas, por J. M. Albareda y A. Martín.-- Quelatos y agentes quelantes en Agricultura, por A. Aguilar y M. Lachica.-- Localización topográfica del hierro en preparaciones en lámina delgada de suelos por la técnica de la microrradiografía de contacto, por H. Carvajal Aced, M. Kress Voltz y J. García.-- Diagnóstico foliar y naturaleza del suelo en el olivar de verdeo en la provincia de Sevilla, por M. Chaves, C. Mazuelos, R. Romero.-- Estudio mineralógico de sedimentos de playas y ríos de la región de la Serranía de Ronda (Málaga), por J. J. Alonso y J. Beneyas.-- Identificación de pigmentos carotenoides en tallos de «Ürobanche Crenata», Forsk por L. Catalina.-- Suelos de zona húmeda española. I. Tipos principales y sus relaciones genéticas, por F. Guitián Ojea.--Factores en la reducción degradativa de ácidos húmicos, por J. Méndez .--Influencia de la forma de aplicación de superfosfato (marcado con 32P) en la absorción de fósforo por las raíces de frutales del género «Citrus», por V. Hernando, V. Lombardía y E. Sánchez Serrano.—Notas. Convocatoria del Premio «José Mª Albareda Herrera».-- Renovación de cargos directivos del C. S. I. C. y de los Patronatos.-- Nueva Directiva del Patronato Alonso de Herrera.-- Toma de posesión de nuevos directivos del C. S. I. C.-- Nombramientos y variaciones en los Centros.--Nombramiento del profesor Gamboa.-- Nuevo Catedrático.-- Conferencia del profesor Rivas Martínez.-- Conferencia del profesor H. Gaussen.-- Invitación al profesor Duchaufour.-- Congresos, reuniones internacionales y becas en el extranjeroPeer reviewe