Evidence of labile inhibitors in the detection ofChlamydia trachomatis in cervical specimens by polymerase chain reaction

Abstract

A total of 276 cervical swabs (241 from first visits and 35 from follow-up visits) from 241 women were tested for Chlamydia trachomatis by polymerase chain reaction (PCR) and enzyme immunoassay (EIA). Sixty-one smears (53 from first visits and 8 from follow-up visits) from 53 women were stained by direct fluorescent antibody (DFA). Twenty-one (8.7%) women had positive swabs in at least two different tests. All follow-up swabs (collected between 3 days and 3 weeks after the first clinical visit) were positive in at least one test when the woman had been positive at the first visit and no antibiotic treatment had been initiated. Including swabs from follow-up visits and DFA results, the respective sensitivities and specificities of the assays were as follows: PCR, 75.9% and 100%; EIA, 69% and 98.4%. The seven swabs that were false negative by PCR (tested initially after thawing from -20 degrees C) were mailed nonrefrigerated to the assay manufacturer, where they tested true positive. These data point to labile inhibitors of the PCR, predominantly cervical mucus.

Diagnosis of Chlamydia trachomatis infections in a sexually transmitted disease clinic: evaluation of a urine sample tested by enzyme immunoassay and polymerase chain reaction in comparison with a cervical and/or a urethral swab tested by culture and polymerase chain reaction

“…Labile inhibitors in cervical mucus cannot be removed by freezing and thawing, but can be inactivated by a brief warming to 95 °C, or by leaving at room temperature for 2 days [24–26]. A dilution of the sample, together with a brief warming, was recommended in order to eliminate inhibitors not removed by freezing and thawing [26], or simply by diluting the sample prior to testing [27–29].…”

Chlamydia trachomatisPersistence in the Female Mouse Genital Tract: Inducible Nitric Oxide Synthase and Infection Outcome

“…This finding included the Cy-treated NOS2 Ϫ/Ϫ mice from which viable organisms had been isolated. This finding was likely due to the effect of P4 pretreatment, which often results in a great deal of mucus, a known inhibitor of PCR (9). Although the presence of large amounts of mucus was also observed following P4 treatment in the primary infection, the effect on PCR was not observed, likely due to the large numbers of organisms present during that time frame.…”

Chlamydienscreening: Ist das Nachweisproblem gelöst?

“…Bei bis zu 40% solcher Patientinnen sind weniger als zehn Elementarkörperchen pro Entnahme vorhanden [20,21]. Werden die klinischen Proben für den Chlamydia trachomatis Cobas Amplicor nach den Angaben des Herstellers aufgearbeitet, so wird nur der 160.…”