RESUMEN
Mass spectrometry (MS) is used in identification of positive blood culture, a contribution in the clinical management of septic patients. The protocol is labor intensive and disrupts the normal workflow in a clinical laboratory. We intended to make rapid diagnosis by using MS directly from shortly incubated blood agar plates (4 to 6 hours) comparing with results of the conventional method (MC). We worked in parallel 145 positive blood cultures, with correct identification by short method in 79% of cases. We observed better yield with non carbon bottles and with gramnegative rods. With this information we designed a rapid identification algorithm using MS, which allows advancing diagnosis in 12-16 hours, without increasing to the costs or work load, since extraction protocol is not used.
Asunto(s)
Algoritmos , Técnicas Bacteriológicas/métodos , Espectrometría de Masas , Sangre/microbiología , Medios de Cultivo/análisis , Pruebas de Sensibilidad MicrobianaRESUMEN
Mass spectrometry (MS) is used in identification of positive blood culture, a contribution in the clinical management of septic patients. The protocol is labor intensive and disrupts the normal workflow in a clinical laboratory. We intended to make rapid diagnosis by using MS directly from shortly incubated blood agar plates (4 to 6 hours) comparing with results of the conventional method (MC). We worked in parallel 145 positive blood cultures, with correct identification by short method in 79% of cases. We observed better yield with non carbon bottles and with gramnegative rods. With this information we designed a rapid identification algorithm using MS, which allows advancing diagnosis in 12-16 hours, without increasing to the costs or work load, since extraction protocol is not used.
Espectrometría de masas (EM) es utilizada en identificación de hemocultivo positivo (HMP), constituyendo un aporte en el manejo clínico de paciente séptico. El protocolo de identificación directa es ultra laborioso, interrumpiendo el flujo de trabajo normal del laboratorio. Con el objetivo de hacer identificación rápida, utilizamos EM a partir de placas de agar sangre con incubación breve (4 a 6 h), comparando resultados con el método convencional en HMP. Se trabajó 145 frascos de HMP, identificando correctamente por método acortado 79% de los microorganismos. El rendimiento fue mejor en frascos sin carbón activado y en la identificación de bacilos gramnegativo. Con esta información, diseñamos algoritmo para la identificación precoz de hemocultivo positivo mediante EM, procesando a ciegas a las 4 a 6 h de incubación, lo que permite adelantar el diagnóstico en 12-16 h respecto del método tradicional, sin aumentar los costos ni la carga de trabajo, ya que no se utiliza protocolo de extracción.