RESUMEN
OBJECTIVE: To apply a sequencing-based molecular method to identify clinically relevant fungi to species level. METHOD: Thirty-six fungi not identifiable at a species level by a conventional approach and 39 invasive clinical samples were prospectively evaluated. The results were compared with those obtained by conventional methods. RESULTS: Molecular methods allowed rapid and reliable identification of fungi at species level, including both from organisms grown in culture and those in clinical samples. CONCLUSION: Molecular methods show clear advantages for fungal identification, including rapid identification at species level and high negative predictive value.
Asunto(s)
ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Hongos/aislamiento & purificación , Técnicas de Diagnóstico Molecular , Micología/métodos , Micosis/microbiología , Ribotipificación/métodos , Proteínas Fúngicas/genética , Hongos/clasificación , Hongos/genética , Hongos/crecimiento & desarrollo , Humanos , Factor 1 de Elongación Peptídica/genética , Reacción en Cadena de la Polimerasa/métodos , Valor Predictivo de las Pruebas , Estudios Prospectivos , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido Nucleico , Especificidad de la Especie , Factores de Tiempo , Tubulina (Proteína)/genéticaRESUMEN
Detection of Arcanobacterium haemolyticum is based upon typical beta-hemolysis and colony morphology, but it may go undetected if only conventional sheep blood agar media for detection of beta-hemolytic streptococci are used. The influence of different culture media, atmospheres, and times of incubation for the recognition of colonies of 47 isolates of A. haemolyticum was studied. After 48 h of incubation, trypticase soy agar with 5% horse blood in 5% CO(2) was the best medium.
Asunto(s)
Actinomycetaceae/aislamiento & purificación , Técnicas Bacteriológicas/métodos , Medios de Cultivo , Actinomycetaceae/fisiología , Animales , Hemólisis , Caballos , Factores de TiempoRESUMEN
The aim of this study was to assess the phenotypic and genotypic diversity of 56 Arcanobacterium haemolyticum isolates isolated from 51 patients attending primary health care centres and emergency units in the health area of Santander (Cantabria, northern Spain). Phenotypic characterization was based on morphological, biochemical, and antigenic tests. Species identification was confirmed by amplification and sequencing of the 16S rDNA gene. Antimicrobial susceptibility testing was determined by microdilution following the Clinical and Laboratory Standards Institute recommendations for coryneform bacteria. Genetic diversity was evaluated using BOX-PCR and pulsed-field gel electrophoresis. Eighty percent of the isolates had an identical BOX-PCR pattern, suggesting the spread of a single clone. The present report provides extensive information on the phenotypic and genotypic characterization of A. haemolyticum.