Assuntos
Infecções por Bactérias Gram-Positivas/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase/métodos , Manejo de Espécimes/métodos , Enterococos Resistentes à Vancomicina/genética , Proteínas de Bactérias/genética , Carbono-Oxigênio Ligases/genética , Farmacorresistência Bacteriana Múltipla , Fezes/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Técnicas de Diagnóstico Molecular/instrumentação , Reação em Cadeia da Polimerase/instrumentação , Manejo de Espécimes/instrumentação , Enterococos Resistentes à Vancomicina/isolamento & purificaçãoRESUMO
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-ToF MS) has been introduced in clinical routine microbiology laboratories. For the rapid diagnosis of urinary tract infections, culture-independent methods prior MALDI-mediated identification have been described. Here, we describe a comparison of three of these methods based on their performance of bacterial identification and their potential as a routine tool for microbiology labs : (i) differential centrifugation, (ii) urine filtration and (iii) a 5-h bacterial cultivation on solid culture media. For 19 urine samples, all methods were directly compared and correct bacterial species identification by MALDI was used as performance indicator. A higher percentage of correct MALDI identification was obtained after filtration (78.9 %) and the growth-based method (84.2 %) as compared to differential centrifugation (68.4 %). Additional testing of 76 mono-microbial specimens (bacteriuria > 10(5) CFU/mL) confirmed the good performance of short growth with a 90.8 % correct MALDI score, with a potentially better fit to the routine workflow of microbiology labs.
