RESUMEN
Diarrheagenic E. coli (DEC) are one of the most common causes for diarrhea worldwide, especially in children. We evaluated the rapid RIDA ® GENE (RG) real-time multiplex PCR assays (R-Biopharm, Darmstadt, Germany) for the detection of the most important diarrheagenic E. coli. Three hundred fifteen liquid or non-formed stool specimens were examined. The results of the RG multiplex assays were compared to specific PCR methods. The sensitivity and specificity of the RG PCRs were as follows, 100%/100% for the detection of EHEC, 96.3% and 99% for EPEC, 100% and 100% for the detection of EAEC, ETEC and EIEC, respectively. Overall, the RG real-time PCR system for the detection of DEC tested in this study provided reliable and rapid results and shows the ability as a useful addendum for the detection of diarrheagenic E. coli in the medical laboratory.
Asunto(s)
Diarrea/diagnóstico , Infecciones por Escherichia coli/diagnóstico , Escherichia coli/aislamiento & purificación , Heces/microbiología , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa Multiplex/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Adulto , Niño , Preescolar , Estudios de Cohortes , Diarrea/microbiología , Escherichia coli/clasificación , Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: The aim of this multicenter study was to establish a diagnostic algorithm using molecular methods for the diagnosis of C. difficile-associated infection (CDI). In addition patient specific data were taken into consideration for the interpretation of the results. METHODS: We compared the performance of six different commercially available PCR-tests, two toxin immunoassays, and a glutamat-dehydrogenase test by analysing liquid stool specimens from patients with suspected CDI. Toxigenic culture on CLO-agar was used as reference method. RESULTS: In total 250 stool specimens were collected at two study sites. 77 (30.8%) stool samples were culture-positive for toxigenic C. difficile. 173 (69.2%) specimens showed no growth of C. difficile. As a result, each of the PCR assays tested for C. difficile had a significantly higher sensitivity (94.8% - 100%) and NPV (97.6% - 100%) than the TOX-EIA with a sensitivity of 57.1% and NPV of 83.8%. Specificity of the PCR tests was 94.1% to 96.0% and PPV between 86.5% and 91.6%. The analysis of the patient data revealed a significant difference (p-value 0.0202) between toxin-positive and toxin-negative patients regarding prior antibiotic treatment, especially for cephalosporins. CONCLUSIONS: Our findings support the recommendation to restrict the use of antibiotics as a cornerstone in the prevention of CDI. We conclude that all of the PCR assays evaluated in this study can be applied in a diagnostic algorithm.
