Automated parasitological diagnosis in clinical microbiology laboratories

Although there is a low prevalence of parasitological infections in Europe, the diagnosis of intestinal parasites is still difficult and laborious for microbiology laboratories. Currently, antigen detection assays and molecular biology allow a more accurate diagnosis, but these techniques have limitations as they cannot detect all the possible parasites present in the samples. The objective of the study was to evaluate the accuracy and the usefulness of automated microscopy SediMAX2 (77 Elektronika, Budapest, Hungary) in the detection of parasitic infections from feces. A total of 197 formol-fixed stool samples were processed in parallel by wet mount examination and by SediMAX2. Sensitivities, specificities and predictive values were analyzed, reaching a sensitivity of 89.51% and a specificity of 98.15% and a very good positive predictive value (99.22%). SediMAX2 is a good tool for a reliable diagnosis of intestinal parasitic infections. The rapid processing and the flexibilty of storage of images analyzed make its incorporation into the day to day laboratory routine recommendable

Impact of the MALDI-TOF as a tool for bacterial identification in the frequency of isolation of Aerococcus spp and Actinotignum schaalii in urinary tract infection

Background: Actinotignum schaalii and the genus Aerococcus are considered emerging pathogens, since their isolation has been rising the last years thanks to the improvement of diagnosis techniques, such as the implementation of MALDI-TOF in microbiology laboratories for routine. Their patogenicity is nowadays well described in urinary tract infections affecting susceptible individuals, although both have been isolated from other biological samples. The aim of our study is to evaluate the impact of using mass spectrometry technology on the frequency of isolation of Aerococcus spp and A. schaalii in our hospital. Methods: From January 2014 and December 2015 44.654 urines were collected in our laboratory from patients that were expected to have an UTI. Samples were processed using a flow cytometer and cultured if applicable. After 48 h, microbial growth was assessed. Due to the suspicion of an Aerococcus spp or A. schaalii infection identification test was performed using Vitek2 until 2014 and MALDI-TOF from 2015. Results: Between the period of study, a total of 35 Aerococcus spp/A. schaalii isolates were collected from 34 patients. Six isolates were identified by Vitek2 and the other 29 were identified by MALDI-TOF. Out of 34 patients, 33 had at least one risk factor including age >65 years, immunosuppression or cancer, abnormality of the genitourinary tract, recurrent UTI, diabetes or a catheterization. Conclusions: Since the implementation of the MALDI-TOF in the laboratory the isolation of Aerococcus spp/A. schaalii has increased almost five times. The most frequent patient corresponds to an elderly patient with recurrent UTI and cancer. Resumen: Introducción: Actinotignum schaalii y el género Aerococcus son considerados patógenos emergentes debido al aumento en los últimos años de su aislamiento gracias a la mejora de las técnicas diagnósticas, como la implementación del MALDI-TOF en la rutina de los laboratorios de microbiología. Su patogenicidad está bien descrita en las infecciones del tracto urinario (ITU) en individuos susceptibles, aunque los dos géneros se han aislado también en otras muestras biológicas. El objetivo de nuestro estudio es evaluar el impacto del uso de la espectrometría de masas en la frecuencia de aislamiento de Aerococcus spp/A. schaalii en nuestro hospital. Métodos: Desde enero 2014 a diciembre 2015 se recibieron 44.654 orinas en nuestro hospital procedentes de pacientes con sospecha de ITU. Las muestras fueron procesadas por citometría de flujo y sembradas según criterios establecidos. Pasadas 48 h, se evaluó el crecimiento. Ante la sospecha de infección por Aerococcus spp/A. schaalii, se realizó un test de identificación con Vitek2® hasta 2014 y con MALDI-TOF desde 2015. Resultados: Durante el periodo de estudio se registraron 35 aislamientos de Aerococcus spp/A. schaalii correspondientes a 34 pacientes. Seis aislados se identificaron por Vitek2® y 29 por MALDI-TOF. De los 34 pacientes, 33 tenían como mínimo un factor de riesgo (>65 años, inmunosupresión o cáncer, anormalidades del tracto urinario, ITU recurrente, diabetes o cateterismo). Conclusiones: Desde la implementación del MALDI-TOF en el laboratorio, el aislamiento de Aerococcus spp/A. schaalii ha aumentado 5 veces. El perfil más afectado es el de un individuo de edad avanzada con ITU recurrentes y cáncer. Keywords: Urinary tract infection, Aerococcus spp, Actinotignum schaalii, MALDI-TOF, Palabras clave: Infección del tracto urinario, Aerococcus spp, Actinotignum schaalii, MALDI-TO