ABSTRACT
Introducción: Un porcentaje variable de muestras analizadas por el equipo cobas 4800 pueden dar un resultado invalidado por inhibición de la PCR o erróneo al no extraerse el ADN correctamente con el test cobas 4800 CT/NG. Método: Valoración de un protocolo de agitación y dilución de la muestra original (exudado u orina) en un total de 116 muestras. Para analizar la sensibilidad de este método, 100 muestras (exudados y orinas) con resultado conocido fueron retestadas. Resultados: Un 98,3% (114/116) de las muestras se resolvieron con este protocolo con un 100% de concordancia al consultar con datos clínicos, tinción de Gram y otras muestras analizadas en paralelo del mismo paciente. Discusión: Los datos indican que no hay pérdida de sensibilidad con este protocolo, por lo que los usuarios de esta plataforma podrían usarlo sin necesidad de métodos alternativos (AU)
Introduction: A variable percentage of samples analysed using the Cobas 4800 assay can give an invalid result by PCR inhibition or erroneous due to incorrect DNA extraction with the Cobas 4800 CT/NG test. Method: An analysis was performed using the vortex agitation and dilution protocol on the original sample (swab or urine) for a total of 116 samples. In order to analyse the sensitivity of this method, 100 samples (swabs and urine) with known results were retested. Results: A total of 98.3% (114/116) of the samples analysed were resolved with this protocol with 100% agreement after reviewing clinical data, Gram stain, and other samples analysed in parallel from the same patient. Discussion: The data indicate no loss of sensitivity with this protocol; thus Cobas 4800 users could use this method without the need for alternative methods (AU)
Subject(s)
Humans , Chlamydia trachomatis/isolation & purification , Chlamydia Infections/microbiology , Neisseria gonorrhoeae/isolation & purification , Gonorrhea/microbiology , Sexually Transmitted Diseases/microbiology , Indicator Dilution Techniques , Polymerase Chain Reaction/methods , Diagnostic Errors/prevention & controlABSTRACT
INTRODUCTION: A variable percentage of samples analysed using the Cobas 4800 assay can give an invalid result by PCR inhibition or erroneous due to incorrect DNA extraction with the Cobas 4800 CT/NG test. METHOD: An analysis was performed using the vortex agitation and dilution protocol on the original sample (swab or urine) for a total of 116 samples. In order to analyse the sensitivity of this method, 100 samples (swabs and urine) with known results were retested. RESULTS: A total of 98.3% (114/116) of the samples analysed were resolved with this protocol with 100% agreement after reviewing clinical data, Gram stain, and other samples analysed in parallel from the same patient. DISCUSSION: The data indicate no loss of sensitivity with this protocol; thus Cobas 4800 users could use this method without the need for alternative methods.
Subject(s)
Bacterial Typing Techniques/instrumentation , Chlamydia trachomatis/isolation & purification , DNA, Bacterial/analysis , Neisseria gonorrhoeae/isolation & purification , Real-Time Polymerase Chain Reaction/instrumentation , Specimen Handling/methods , Bacterial Typing Techniques/methods , Carrier State/microbiology , Cervix Uteri/microbiology , Chlamydia Infections/microbiology , Chlamydia trachomatis/genetics , DNA, Bacterial/isolation & purification , Exudates and Transudates/microbiology , Female , Gonorrhea/microbiology , Humans , Male , Neisseria gonorrhoeae/genetics , Real-Time Polymerase Chain Reaction/methods , Rectum/microbiology , Sensitivity and Specificity , Urine/microbiologyABSTRACT
INTRODUCTION: A prospective study was designed to assess the performance of the new CT OligoGen kit and the cobas 4800 assay for detection of Chlamydia trachomatis. METHODS: A set of samples that included urine samples (n = 212), endocervical (n = 167), rectal (n = 53), pharyngeal (n = 7) and urethral swabs (n = 3). The samples were sent from a regional sexually transmitted diseases (STD) clinic in Seville, Spain, and were collected from 261 men and 181 women. Discordant results were re-analyzed and clinical data and other tests were reviewed in order to resolve them. RESULTS: Sensitivity, specificity, positive predicative value (PPV), negative predictive value (NPV) and kappa value for C. trachomatis detection using the CT OligoGen kit were 98.5%, 100%, 100%, 95.4% and 0.97, respectively. Conclusions This new kit had a high sensitivity, specificity, PPV and NPV for C. trachomatis, therefore the performance profile confirms the usefulness and reliable results of this new assay
INTRODUCCIÓN: Se diseñó un estudio prospectivo para evaluar las características del nuevo kit CT OligoGen en comparación con el test cobas 4800 para la detección de Chlamydia trachomatis. MÉTODOS: Se analizaron una serie de muestras que incluían orinas (n = 212), exudados endocervicales (n = 167), rectales (n = 53), faríngeos (n = 7) y uretrales (n = 3). Estas muestras provenían de un centro de infecciones de transmisión sexual (Sevilla) y pertenecían a 261 hombres y 181 mujeres. Los resultados discordantes se reanalizaron y revisaron historias clínicas y otras pruebas para resolverlas. RESULTADOS: Los valores de sensibilidad, especificidad, valor predictivo positivo (VPP) y negativo (VPN) y valor kappa para el kit CT OligoGen fue 98,5%, 100%, 100%, 95,4% and 0,97, respectivamente. CONCLUSIONES: Este nuevo kit tuvo una alta sensibilidad, especificidad, VPP y VPN para la detección de C. trachomatis, por lo que esta evaluación confirma su utilidad y fiabilidad
Subject(s)
Humans , Chlamydia Infections/diagnosis , Chlamydia trachomatis/pathogenicity , Pathology, Molecular/methods , Sexually Transmitted Diseases, Bacterial/diagnosis , Prospective Studies , Reproducibility of Results , Reproducibility of ResultsABSTRACT
INTRODUCTION: A prospective study was designed to assess the performance of the new CT OligoGen kit and the cobas 4800 assay for detection of Chlamydia trachomatis. METHODS: A set of samples that included urine samples (n=212), endocervical (n=167), rectal (n=53), pharyngeal (n=7) and urethral swabs (n=3). The samples were sent from a regional sexually transmitted diseases (STD) clinic in Seville, Spain, and were collected from 261 men and 181 women. Discordant results were re-analyzed and clinical data and other tests were reviewed in order to resolve them. RESULTS: Sensitivity, specificity, positive predicative value (PPV), negative predictive value (NPV) and kappa value for C. trachomatis detection using the CT OligoGen kit were 98.5%, 100%, 100%, 95.4% and 0.97, respectively. CONCLUSIONS: This new kit had a high sensitivity, specificity, PPV and NPV for C. trachomatis, therefore the performance profile confirms the usefulness and reliable results of this new assay.
