Evaluation of a dilution method for non-evaluable results in the detection of Chlamydia trachomatis and Neisseria gonorrhoeae with the Cobas 4800 platform

Enferm Infecc Microbiol Clin. 2017 Jun-Jul;35(6):364-366. doi: 10.1016/j.eimc.2015.06.017. Epub 2015 Sep 26.
[Article in English, Spanish]

Abstract

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.

Keywords: Chlamydia trachomatis; Inhibición; Inhibition; Neisseria gonorrhoeae; Polymerase Chain Reaction; Reacción en cadena de la polimerasa.

Publication types

  • Validation Study

MeSH terms

  • Bacterial Typing Techniques / instrumentation*
  • Bacterial Typing Techniques / methods
  • Carrier State / microbiology
  • Cervix Uteri / microbiology
  • Chlamydia Infections / microbiology
  • Chlamydia trachomatis / genetics
  • Chlamydia trachomatis / isolation & purification*
  • DNA, Bacterial / analysis*
  • DNA, Bacterial / isolation & purification
  • Exudates and Transudates / microbiology
  • Female
  • Gonorrhea / microbiology
  • Humans
  • Male
  • Neisseria gonorrhoeae / genetics
  • Neisseria gonorrhoeae / isolation & purification*
  • Real-Time Polymerase Chain Reaction / instrumentation*
  • Real-Time Polymerase Chain Reaction / methods
  • Rectum / microbiology
  • Sensitivity and Specificity
  • Specimen Handling / methods*
  • Urine / microbiology

Substances

  • DNA, Bacterial