ABSTRACT
Antecedentes: Las infecciones fúngicas invasivas han ido aumentando y las levaduras del género Candida son la principal causa de las mismas. Las especies distintas de Candida albicans son cada vez más frecuentes y algunas pueden presentar patrones variables de sensibilidad a los antimicóticos, por lo que es importante la correcta identificación de la especie. Los métodos de identificación convencionales con los que cuentan la mayoría de los laboratorios pueden presentar inconvenientes. La espectrometría de masas (MALDI-TOF MS) surgió como una alternativa a los mismos. Objetivos: Evaluar la concordancia de los resultados de identificación de diferentes especies de Candida mediante dostécnicas: una convencional (galerías API) y MALDI-TOF MS. Métodos: Se analizaron las siguientes especies y número de aislamientos: Candida parapsilosis (28), Candida glabrata (34), Candida krusei (24), Candida tropicalis (45), Candida guilliermondii (30), C. albicans (28), Candida dubliniensis (6), Candida kefyr (1) y Candida lipolytica (1) del cepario de RMCABA; también se utilizaron las cepas C. parapsilosis 22019, C. glabrata 90030, C. krusei 6258 y C. albicans 68548, pertenecientes a la American Type Culture Collection (ATCC). Las discrepancias en la identificación se resolvieron mediante genotipificación. Resultados y conclusiones: La concordancia directa entre la identificación convencional y MALDI-TOF MS fue del 92,5% (186/201)
Background: Invasive fungal infections are increasing, and Candida yeasts are the main cause. Species other than Candida albicans are becoming more frequent, and some of them may have variable patterns of susceptibility to antifungal agents, making it important to identify them correctly. Conventional identification methods used by most laboratories may present with drawbacks. Mass spectrometry (MALDI-TOF MS) has emerged as an alternative method. Aims: The aim of this study was to evaluate the concordance of the identification, at species level, by conventional methods (API) and MALDI-TOF MS. Methods: The following species and number of isolates were studied: Candida parapsilosis (28), Candida glabrata (34), Candida krusei (24), Candida tropicalis (45), Candida guilliermondii (30), C. albicans (28), Candida dubliniensis (6), Candida kefyr (1), and Candida lipolytica (1) from the strain collection of Autonomous City of Buenos Aires Mycology Network (RMCABA). The strains C. parapsilosis 22019, C. glabrata 90030, C. krusei 6258 and C. albicans 68548 from the American Type Culture Collection (ATCC) were also included. Discrepancies were resolved by genotyping. Results and conclusions: The direct concordance between the conventional identification method and MALDI-TOF MS was 92.5% (186/201)
Subject(s)
Humans , Candida/isolation & purification , Candidiasis/microbiology , Yeasts/isolation & purification , Invasive Fungal Infections/microbiology , Antifungal Agents/pharmacokinetics , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Candida/classification , Yeasts/classification , Microbial Sensitivity TestsABSTRACT
BACKGROUND: Invasive fungal infections are increasing, and Candida yeasts are the main cause. Species other than Candida albicans are becoming more frequent, and some of them may have variable patterns of susceptibility to antifungal agents, making it important to identify them correctly. Conventional identification methods used by most laboratories may present with drawbacks. Mass spectrometry (MALDI-TOF MS) has emerged as an alternative method. AIMS: The aim of this study was to evaluate the concordance of the identification, at species level, by conventional methods (API) and MALDI-TOF MS. METHODS: The following species and number of isolates were studied: Candida parapsilosis (28), Candida glabrata (34), Candida krusei (24), Candida tropicalis (45), Candida guilliermondii (30), C. albicans (28), Candida dubliniensis (6), Candida kefyr (1), and Candida lipolytica (1) from the strain collection of Autonomous City of Buenos Aires Mycology Network (RMCABA). The strains C. parapsilosis 22019, C. glabrata 90030, C. krusei 6258 and C. albicans 68548 from the American Type Culture Collection (ATCC) were also included. Discrepancies were resolved by genotyping. RESULTS AND CONCLUSIONS: The direct concordance between the conventional identification method and MALDI-TOF MS was 92.5% (186/201).
Subject(s)
Candida/classification , Candida/isolation & purification , Humans , Mycology/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
Dentro del género Candida, la especie más frecuentemente aislada de materiales clínicos es Candida albicans. Debido a la emergencia de otras especies que pueden presentar mayor índice de resistencia a los antifúngicos, se hace necesaria la identificación rápida de aquellas. El objetivo del presente trabajo fue evaluar el rendimiento del sistema RapID™ Yeast Plus a partir de subcultivos en 2 formulaciones diferentes, agar Sabouraud dextrosa modificado por Emmons (medio indicado en el inserto del equipo) y agar Sabouraud glucosado, que es el utilizado habitualmente en los laboratorios de la Ciudad Autónoma de Buenos Aires. Se estudiaron 166 cepas de muestras clínicas provenientes de los distintos hospitales que integran la Red de Micología de la Ciudad de Buenos Aires. De los resultados obtenidos se concluye que se deben mantener las condiciones y el medio de cultivo indicado por el fabricante
Within the genus Candida, Candida albicans is the most commonly isolated species from clinical samples. Due to the emergence of other species which can show a higher index of antifungal resistance, a fast identification of these species is necessary. The aim of this work was to evaluate the performance of the RapID Yeast Plus system from two different subculture media formulations: Sabouraud dextrose agar adjusted by Emmons (the medium is indicated in the equipment insert) and Sabouraud glucose agar, which is the most frequently used in Buenos Aires City laboratories. One hundred and sixty-six clinical sample strains coming from different hospitals belonging to the Mycology Network of Buenos Aires City were studied. From the obtained results, we conclude that the conditions and culture medium indicated by the manufacturer should be followed
Subject(s)
Yeasts/isolation & purification , Candida/classification , Diagnostic Techniques and Procedures , Culture Media/analysis , Candidiasis/diagnosis , Evaluation StudyABSTRACT
Within the genus Candida, Candida albicans is the most commonly isolated species from clinical samples. Due to the emergence of other species which can show a higher index of antifungal resistance, a fast identification of these species is necessary. The aim of this work was to evaluate the performance of the RapID Yeast Plus system from two different subculture media formulations: Sabouraud dextrose agar adjusted by Emmons (the medium is indicated in the equipment insert) and Sabouraud glucose agar, which is the most frequently used in Buenos Aires City laboratories. One hundred and sixty-six clinical sample strains coming from different hospitals belonging to the Mycology Network of Buenos Aires City were studied. From the obtained results, we conclude that the conditions and culture medium indicated by the manufacturer should be followed.
Subject(s)
Candida/isolation & purification , Candidiasis/microbiology , Culture Media , Mycology/methods , Candida/growth & development , Chromogenic Compounds , Colorimetry , Humans , Mycological Typing Techniques/methods , Mycology/instrumentation , Reproducibility of ResultsABSTRACT
The aim of this investigation was to evaluate the performance of Vitek 2 YST cards (bioMérieux, Inc., Hazelwood, MO, USA) for the identification of yeasts of the genus Candida. A total of 168 isolates were analyzed and the results were compared to those of the API 20 C AUX (24%) o API ID 32 C (76%) kits (bioMérieux, Marcy L'Etoile, France). Each isolate was grown in chromogenic agar and in corn meal agar (Oxoid, UK) to observe its micromorphology. C. albicans and C. dublininesis were identified by additional biochemical and molecular tests. The agreement observed was 98.3%. Only three isolates were incorrectly identified by Vitek 2: one strain of C .tropicalis and one strain of C. krusei were identified as C. parapsilosis by YST while one strain of C. krusei was identified with low discrimination. The average time for obtaining results was 18.25 h. Vitek 2 is a simple, safe and useful system for the identification of significant Candida species.
Subject(s)
Candida/isolation & purification , Mycology/instrumentation , Mycology/methods , HumansABSTRACT
El objetivo del trabajo fue evaluar el desempeño de las tarjetas YST del sistema Vitek 2 para la identificación de levaduras del género Candida. Se analizaron 168 aislamientos; los resultados fueron comparados con los obtenidos por los equipos API 20C AUX (24 %) o API ID 32C (76 %). Cada cepa se subcultivó en agar cromogénico para levaduras y se observó la micromorfología. C. albicans y C. dubliniensis fueron identificadas a través de pruebas bioquímicas y moleculares adicionales. La concordancia observada fue del 98,3 %. Solo tres cepas no fueron identificadas correctamente por el sistema Vitek 2: una cepa de C. tropicalis y una de C. krusei fueron identificadas erróneamente como C. parapsilosis y otra cepa de C. krusei fue identificada de manera incompleta por el software del equipo. El tiempo promedio de identificación con las tarjetas YST fue de 18,25 h. El sistema Vitek 2 surge como un método confiable, simple y efectivo para la identificación de las principales especies del género Candida
The aim of this investigation was to evaluate the performance of Vitek 2 YST cards (bioMérieux, Inc., Hazelwood, MO, USA) for the identification of yeasts of the genus Candida. A total of 168 isolates were analyzed and the results were compared to those of the API 20C AUX (24%) o API ID 32C (76%) kits (bioMérieux, Marcy L'Etoile, France). Each isolate was grown in chromogenic agar and in corn meal agar (Oxoid, UK) to observe its micromorphology. C. albicans and C. dublininesis were identified by additional biochemical and molecular tests. The agreement observed was 98.3%. Only three isolates were incorrectly identified by Vitek 2: one strain of C .tropicalis and one strain of C. krusei were identified as C. parapsilosis by YST while one strain of C. krusei was identified with low discrimination. The average time for obtaining results was 18.25 h. Vitek 2 is a simple, safe and useful system for the identification of significant Candida species
Subject(s)
Candida/classification , Mycological Typing Techniques/methods , Candida/isolation & purification , Evaluation Studies as TopicABSTRACT
The aim of this investigation was to evaluate the performance of Vitek 2 YST cards (bioMérieux, Inc., Hazelwood, MO, USA) for the identification of yeasts of the genus Candida. A total of 168 isolates were analyzed and the results were compared to those of the API 20 C AUX (24
) o API ID 32 C (76
) kits (bioMérieux, Marcy LEtoile, France). Each isolate was grown in chromogenic agar and in corn meal agar (Oxoid, UK) to observe its micromorphology. C. albicans and C. dublininesis were identified by additional biochemical and molecular tests. The agreement observed was 98.3
. Only three isolates were incorrectly identified by Vitek 2: one strain of C .tropicalis and one strain of C. krusei were identified as C. parapsilosis by YST while one strain of C. krusei was identified with low discrimination. The average time for obtaining results was 18.25 h. Vitek 2 is a simple, safe and useful system for the identification of significant Candida species.
Subject(s)
Candida/isolation & purification , Mycology/instrumentation , Mycology/methods , HumansABSTRACT
Antecedentes. La incidencia de las especies fúngicas como patógenos hospitalarios varía según las regiones. Objetivos. Registrar la incidencia y etiología de las fungemias en hospitales de la ciudad de Buenos Aires entre enero de 2005 y diciembre de 2008, conocer sus modificaciones en los 4 años, el tiempo de detección en hemocultivos automatizados y por lisis centrifugación, y su relación con sexo, edad y enfermedad de base. Métodos. Estudio multicéntrico observacional de fungemias en 16 hospitales de la Red de Micología de la ciudad de Buenos Aires. Resultados. Se procesaron 190.920 hemocultivos: 182.050 automatizados y 8.870 por lisis-centrifugación. En 1.020 se recuperaron elementos micóticos. La incidencia global de fungemias fue 1,72 por 1.000 ingresos. Los episodios correspondieron a 683 candidemias (68%), y los restantes 325 (32%) fueron: 214 aislamientos de Cryptococcus, 105 de Histoplasma, 7 de Rhodotorula, 5 de Trichosporon, 2 de Pichia, 2 de Acremonium, uno de Saccharomyces y uno de Fusarium. La incidencia de candidemias fue de 1,15/1.000 ingresos con amplia variación entre centros (0,35 a 2,65). El 97% de las levaduras se detectaron en los primeros 2 días de incubación. Candida albicans se recuperó en el 43% de los episodios. En fungemias diferentes a candidemias, predominaron las causadas por Cryptococcus e Histoplasma capsulatum. Conclusiones. La incidencia se mantuvo estable en el período estudiado. Predominaron las fungemias por Candida. C. albicans estuvo implicada en menos de la mitad de los episodios. La recuperación de Cryptococcus e H. capsulatum estuvo fuertemente asociada a pacientes VIH reactivos(AU)
Background. The incidence of fungi like pathogens in hospitals varies by regions. Objectives. Our goal was not only to record the incidence and etiology of fungaemia, but also the change during the 4 years analysed, to determine the time of detection in automated blood culture and by lysis-centrifugation, and finally to assess the gender, age and underlying disease of the patients with fungaemia. Methods. An observational multicentre study of fungaemia was conducted in hospitals in the Mycology Network of Buenos Aires. Results. A total of 190,920 blood cultures were processed: 182,050 automated blood culture and 8,870 lysis-centrifugation. Fungi were recovered in 1,020 episodes. The overall incidence of fungaemia was 1.72/1,000 admissions; 683 episodes were due to Candida (68%), and 325 (32%) to other fungi: 214 Cryptococcus, 105 Histoplasma, 7 Rhodotorula, 5 Trichosporon, 2 Pichia, 2 Acremonium, one Saccharomyces and one Fusarium. The incidence of candidaemia was 1.15/1,000 admissions with a wide variation between centres (0.35 to 2.65). Most Candida isolates (97%) were detected in the first 2 days of incubation. Candida albicans was recovered in 43% of the episodes. In fungaemia other than candidaemia, the predominant fungi were Cryptococcus and Histoplasma capsulatum. Conclusions. The incidence remained stable during the study period. Fungaemia by Candida were predominant. C. albicans was involved in less than a half of the episodes. The recovery of Cryptoccocus and H. capsulatum is strongly associated with HIV patients(AU)
Subject(s)
Fungemia/epidemiology , Fungemia/prevention & control , Cryptococcus/isolation & purification , Cryptococcus/pathogenicity , Histoplasma/isolation & purification , Candida/isolation & purification , Rhodotorula/isolation & purification , Fungemia/microbiology , Cryptococcus , Histoplasma , Histoplasma/pathogenicity , Mycology/methods , Mycology/standards , Prospective StudiesABSTRACT
BACKGROUND: The incidence of fungi like pathogens in hospitals varies by regions. OBJECTIVES: Our goal was not only to record the incidence and etiology of fungaemia, but also the change during the 4 years analysed, to determine the time of detection in automated blood culture and by lysis-centrifugation, and finally to assess the gender, age and underlying disease of the patients with fungaemia. METHODS: An observational multicentre study of fungaemia was conducted in hospitals in the Mycology Network of Buenos Aires. RESULTS: A total of 190,920 blood cultures were processed: 182,050 automated blood culture and 8,870 lysis-centrifugation. Fungi were recovered in 1,020 episodes. The overall incidence of fungaemia was 1.72/1,000 admissions; 683 episodes were due to Candida (68%), and 325 (32%) to other fungi: 214 Cryptococcus, 105 Histoplasma, 7 Rhodotorula, 5 Trichosporon, 2 Pichia, 2 Acremonium, one Saccharomyces and one Fusarium. The incidence of candidaemia was 1.15/1,000 admissions with a wide variation between centres (0.35 to 2.65). Most Candida isolates (97%) were detected in the first 2 days of incubation. Candida albicans was recovered in 43% of the episodes. In fungaemia other than candidaemia, the predominant fungi were Cryptococcus and Histoplasma capsulatum. CONCLUSIONS: The incidence remained stable during the study period. Fungaemia by Candida were predominant. C. albicans was involved in less than a half of the episodes. The recovery of Cryptoccocus and H. capsulatum is strongly associated with HIV patients.
