title: Evaluation of a dilution method for non-evaluable results in the detection of Chlamydia trachomatis and Neisseria gonorrhoeae with the Cobas 4800 platform.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  The data indicate no loss of sensitivity with this protocol; thus Cobas 4800 users could use this method without the need for alternative methods.
authors.affiliation: Unidad de Enfermedades Infecciosas y Microbiología Clínica, Hospital Universitario de Valme, Sevilla, España. Electronic address: manuel.parra.exts@juntadeandalucia.es.
authors.forename: Manuel
authors.initials: M
authors.lastname: Parra-Sánchez
authors.affiliation: Unidad de Enfermedades Infecciosas y Microbiología Clínica, Hospital Universitario de Valme, Sevilla, España.
authors.forename: Silvia
authors.initials: S
authors.lastname: García-Rey
authors.affiliation: Unidad de Enfermedades Infecciosas y Microbiología Clínica, Hospital Universitario de Valme, Sevilla, España.
authors.forename: Ismail
authors.initials: I
authors.lastname: Zakariya-Yousef Breval
authors.affiliation: Unidad de Enfermedades Infecciosas y Microbiología Clínica, Hospital Universitario de Valme, Sevilla, España.
authors.forename: Celestina
authors.initials: C
authors.lastname: Sierra-Atienza
authors.affiliation: Unidad de Enfermedades Infecciosas y Microbiología Clínica, Hospital Universitario de Valme, Sevilla, España.
authors.forename: Samuel
authors.initials: S
authors.lastname: Bernal-Martínez
authors.affiliation: Unidad de Enfermedades Infecciosas y Microbiología Clínica, Hospital Universitario de Valme, Sevilla, España.
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Palomares-Folía
mesh_terms: D015373:Bacterial Typing Techniques / Q000295:instrumentation* / Q000379:methods; D002353:Carrier State / Q000382:microbiology; D002584:Cervix Uteri / Q000382:microbiology; D002690:Chlamydia Infections / Q000382:microbiology; D002692:Chlamydia trachomatis / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000032:analysis* / Q000302:isolation & purification; D005122:Exudates and Transudates / Q000382:microbiology; D005260:Female; D006069:Gonorrhea / Q000382:microbiology; D006801:Humans; D008297:Male; D009344:Neisseria gonorrhoeae / Q000235:genetics / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction / Q000295:instrumentation* / Q000379:methods; D012007:Rectum / Q000382:microbiology; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*; D014556:Urine / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial
keywords: Chlamydia trachomatis; Inhibición; Inhibition; Neisseria gonorrhoeae; Polymerase Chain Reaction; Reacción en cadena de la polimerasa