Comparative performance of the Roche COBAS Amplicor assay and an in-house real-time PCR assay for diagnosis of Chlamydia trachomatis infection

Abstract

This study investigated the comparative performance of the Amplicor assay and an in-house semi-automated, multiplex real-time PCR for the diagnosis of genital chlamydial infection. Four different assays, the COBAS Amplicor CT test (Amplicor PCR), in-house real-time PCR (IHRT-PCR), in-house nested cryptic plasmid PCR and in-house nested major outer membrane protein PCR, were performed on genital swabs from 1000 consecutive patients attending a genitourinary medicine clinic. The samples were designated true positive if Chlamydia trachomatis DNA was detected by at least two of the four above-mentioned assays while a sample was defined as true negative if C. trachomatis DNA was detected in only one or none of the assays. By this criterion, there were 129 true positive and 871 true negative samples for C. trachomatis DNA in this cohort. Amplicor PCR designated 144 samples positive: 128 (89 %) of 144 samples were true positive and 16 (11 %) were false positive. IHRT-PCR detected 126 of 129 true positive samples and did not generate any false positive results. The sensitivity of IHRT-PCR was comparable with, and specificity was higher than, Amplicor PCR for the diagnosis of genital chlamydial infection.

Detection ofChlamydia trachomatisandNeisseria gonorrhoeaein an STI population: performances of the Presto CT-NG assay, the Lightmix Kit 480 HT CT/NG and the COBAS Amplicor with urine specimens and urethral/cervicovaginal samples

“…Performance of the COBAS Amplicor regarding C trachomatis detection in this study was comparable with its performance in other studies 10 11. In these other studies, similar high sensitivities, specificities, PPVs and NPVs were achieved, as we found in this study.…”

Decline in the Prevalence of HIV and Sexually Transmitted Infections Among Female Sex Workers in Benin Over 15 Years of Targeted Interventions

“…13 The use of the BD ProbeTec in the 2008 study could possibly have biased the observed differences between 2005 and 2008. However, since Amplicor is generally less specific and more sensitive for both NG and CT than ProbeTec, [44][45][46][47] although some studies found them as quite equivalent, 42,48 the upward trend in NG from 2005 to 2008 could be more pronounced than observed, which would not affect our conclusions.…”

Validation of a laboratory-developed real-time PCR protocol for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine

“…This study has validated the C trachomatis assay previously described by Jalal et al ,7 for use with first-void urine specimens.…”