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JCM Accepts, published online ahead of print on 3 January 2007
J. Clin. Microbiol. doi:10.1128/JCM.01956-06
Copyright © 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
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Characteristics of the m2000 Automated Sample Preparation and Multiplex
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Real Time PCR System for the Detection of Chlamydia trachomatis and
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Neisseria gonorrhoeae
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Running Title: Abbott m2000 CT/NG Prototype Assay Study with Surplus
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Specimens
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R. Marshall *1, M. Chernesky 2, D. Jang2, E.W. Hook3, C. P. Cartwright 4, B.
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Howell-Adams1, S. Ho1, J. Welk1, J. Lai-Zhang1, J. Brashear1, B. Diedrich1, K.
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Otis1, E. Webb1, J. Robinson1, and H. Yu1
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Abbott Molecular Inc., Des Plaines, IL, USA;
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McMaster University/St. Joseph’s Healthcare, Hamilton, ON, Canada;
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University of Alabama, Birmingham, AL, USA;
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University of Minnesota Medical School
and Hennepin County Medical Center, Minneapolis, MN, USA
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*Corresponding author
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1300 E. Touhy Ave
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Des Plaines, IL 60018
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Tel: 224-361-7350
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Fax: 224-361-7507
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Email: [email protected]
Abbott m2000 CT/NG Prototype Assay Study with Surplus Specimens
December 19, 2006
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ABSTRACT
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We evaluated a new real time PCR based prototype assay for the detection of
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Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) developed by
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Abbott Molecular Inc. This assay is designed to be performed on the Abbott
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m2000™ real time instrument system that consists of m2000sp™ for sample
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preparation and m2000rt™ for real time PCR amplification and detection. Limit of
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detection of this prototype assay was determined to be 20 copies of target DNA
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for both CT and NG using serially diluted linearized plasmids. No cross-reactivity
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could be detected when 55 non-gonococcal Neisseria isolates and 3 non-
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trachomatis Chlamydia isolates were tested at 1 million copies of genome
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equivalent per reaction. Concordance with Roche AMPLICOR™, BDProbeTec™
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ET, and Gen-Probe APTIMA® Combo 2 were assessed using unlinked/de-
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identified surplus clinical specimens previously analyzed with these tests. For
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CT, concordance for positive results ranged from 93.7% to 100% while
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concordance for negative results ranged from 98.2% to 100%. For NG,
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concordance for positive and negative results ranged from 91.4% to 100%, and
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99.3 to 100%, respectively. A workflow analysis of the prototype assay was
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conducted to obtain information on throughput under laboratory conditions. At 48
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samples/run, the time to first result for both CT and NG was 4.5 hrs. A total of
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135 patient specimens could be analyzed in 8.9hr with 75 min hands-on time.
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This study demonstrated technical and clinical feasibility of the new Abbott real
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time PCR CT/NG assay.
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INTRODUCTION
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Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are
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common sexually transmitted microorganisms. These bacteria infect epithelial
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cells of the cervix and urethra of women and men, but symptoms of lower genital
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tract infection are expressed in only a small percentage of patients (1). Most
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infections remain undiagnosed and untreated; increasing the risk of ascending
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infections, especially in women, who may experience, pelvic inflammatory
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disease, ectopic pregnancy or infertility.
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epidemic” are so significant that public health authorities are initiating screening
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programs to identify and treat infected individuals and their partners. Traditional
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samples such as cervical and urethral swabs and less invasive clinical samples
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such as first void urine [FVU] and vaginal swabs have been shown to be effective
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indicators of infection when tested by nucleic acid amplification tests [NAATs]
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(2,3,8,11,14-19). For NAA testing to be successfully implemented in screening
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programs, assays will need to possess appropriate analytical performance
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characteristics and be sufficiently automated to enable large numbers of
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specimens to be analyzed rapidly with minimal intervention.
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magnetic sampler platform combined with homogeneous real-time multiplexed
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PCR has been developed for the diagnosis of urogenital infection with CT and
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NG with the dual goals of improving the workflow and diagnostic sensitivity and
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specificity of NAAT for these organisms. This report describes the characteristics
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of a prototype assay including its analytical sensitivity and specificity. Residual
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samples that had been tested using a variety of other assays were analyzed to
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The consequences of this “silent
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Abbott m2000 CT/NG Prototype Assay Study with Surplus Specimens
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An automated
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examine concordance of results across assay platforms. In addition, an analysis
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of the workflow, throughput and labor requirements of the m2000™ assay was
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performed.
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METHODS
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Clinical samples:
Cervical, vaginal and urethral specimens that had been
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analyzed
using
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BDProbeTec™ ET from Becton-Dickinson [n=496], or AMPLICOR™ CT from
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Roche [n=67], and FVU previously tested for CT and NG with either APTIMA®
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Combo 2 from Gen-Probe [n=496], or BDProbeTec ET [n=156] were shipped
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from the several laboratories to Abbott Laboratories for m2000 testing. All swab
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samples were collected in the proprietary transport devices provided by the
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various assay manufacturers and were stored and shipped per manufacturers’
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instructions. Swab specimens containing sufficient volume (minimum of 500µl)
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were tested directly on m2000. For swabs with no or not enough liquid media
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remaining, the volume was brought up to 1 mL using Abbott specimen transport
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buffer, allowing for further testing. FVU samples were collected in either the
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manufacturer supplied device (APTIMA Combo 2) or in DNA/RNA Protect™
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(Sierra Diagnostics, Sonora, CA) for BDProbeTec ET testing and were stored
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and shipped to Abbott per manufacturers’ instructions.
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samples were coded and patient identifiers removed. After blinded testing of
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samples in the m2000 system, concordance of positive and negative test results
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was determined by comparing m2000 results with those obtained using the FDA-
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cleared tests. Samples yielding discordant results for CT were subsequently
for
CT
either
LCx
from
Abbott
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[n=64],
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Abbott m2000 CT/NG Prototype Assay Study with Surplus Specimens
December 19, 2006
Prior to shipment, all
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retested using either the LCx CT assay or the Real Art C. trachomatis ™ PCR kit
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(artus, Hamburg, Germany).
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Magnetic sample preparations [sp]:
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technology [Abbott Molecular Inc.] captured DNA from 400 µL specimens and an
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internal control sequence (linearized plasmid DNA containing hydroxypyruvate
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reductase gene from the pumpkin plant) added to each specimen, using silica-
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based magnetic particles. The microparticles were washed 3 times, allowing for
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the removal of PCR amplification inhibitors. Each sample was eluted in 100 µL
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of elution buffer and 25 µL was added to an equal volume of PCR master mix. In
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this study, 48 specimens were processed per run.
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PCR amplification and real-time sequence detection: The assay amplifies a
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region of CT cryptic plasmid and a region in the NG opacity (Opa) gene, as well
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as an internal control. The master mix contained a CT probe labeled with 5’FAM-
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3’BHQ1 for the detection of a 102-base CT cryptic plasmid DNA amplicon; an NG
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probe labeled with 5’VIC-3’ BHQ2 for the detection of a 122-base Opa gene of
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NG DNA amplicon; and an internal control probe labeled with 5’NED-3’BHQ2 for
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the detection of a 129 base amplicon of the hydroxypyruvate reductase gene
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from the pumpkin plant. The homogenous assay format allowed for the detection
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of all 3 DNA sequences without the necessity of opening the reaction vessels.
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Amplification and detection was performed in an m2000rt™ PCR instrument.
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Analytical sensitivity and specificity: Serial dilutions of linearized plasmids
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containing the CT and NG target sequences were analyzed in the system to
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determine the limits of detection of the assay for each analyte. The CT dilution
The m2000sp™ sample preparation
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panel consisted of members at 20, 75, 300, 3X103, 4X104, and 8X105
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copies/assay.
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1.5X103, 1.5X104, and 3X105 copies/assay.
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replicates were analyzed. To assess analytical specificity, genomic DNA was
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prepared from a panel of 55 non-gonoccocal Neisseria organisms and 3 non-
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trachomatis Chlamydiae (Table 1) at 1 million copies/assay and analyzed in the
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m2000 system.
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Throughput experiments: During this study, a prototype m2000sp instrument
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capable of preparing and analyzing a maximum of 48 samples was utilized. Runs
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were conducted using various numbers of samples to determine both the time to
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first result and the time to completion (total run time and hands-on time) in both
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the sample preparation (sp) and real-time PCR (rt) components of the assay.
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RESULTS
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The NG dilution panel consisted of members at 20, 75, 300,
For each concentration, 16
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Analytical sensitivity of the m2000 real time PCR CT/NG prototype assay
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was assessed by analyzing a dilution series of 16 replications at each
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concentration level (8X105 copies/reaction to 20 copies/reaction) of linearized
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plasmid DNA. Representative amplification curves for the CT and NG
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components of the assay are shown in Figure 1.
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amplification corresponds to higher levels of target. The amplification curves of
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the 16 replicate samples at each concentration were tightly grouped particularly
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at or above 300 plasmid copies. A target concentration of 20 copies per reaction
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yielded robust amplification curves among all 16 replicates for each target,
Abbott m2000 CT/NG Prototype Assay Study with Surplus Specimens
December 19, 2006
Earlier detection of
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indicating that both CT and NG targets can be reproducibly detected at a level of
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20 genome equivalents per PCR reaction.
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All of the organisms included in the specificity panel (Table 1) gave
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negative results in the m2000 test when tested at 1 million genome equivalents
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per reaction (data not shown), a concentration of target significantly above what
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would be expected in a typical biological specimen. Six of the non-gonococcal
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Neisseria isolates (marked with asterisks) used in the specificity panel had
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previously been demonstrated to cross-react with the Amplicor N. gonorrhoeae
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assay (7).
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The workflow of a typical assay run of 48 samples is shown in Figure 2
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and includes the following steps: 1) 15 min hands-on, reagent set-up, and
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sample load on m2000sp; 2) 100 min walk-away automated DNA extraction
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(m2000sp); 3) 3 min hands-on PCR master mix reagent load on m2000sp; 4) 16
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min walk-away, automated PCR plate preparation (m2000sp); 5) 5 min hands-on,
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PCR plate seal and transfer to m2000rt; 6) 126 min walk-away, automated
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amplification and detection (m2000rt); 7) 2 min hands-on, result review and print
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out (m2000rt). Since the sp and rt components of the assay can be overlapped,
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preparation of the m2000sp for the second batch of samples was carried out
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during step 4 of processing the first batch of samples and the automated
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extraction for the second sample set was performed while the first batch of
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samples were undergoing simultaneous PCR-amplification and product detection
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on the m2000rt (step 6) as shown in Figure 2. This enabled a total of 45
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specimens to be analyzed in 4.5 hours, with the analysis of an additional 45
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specimens being completed in 6.7 hours. Analysis of a third set of 45 specimens
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could be commenced once the samples from the second sample batch reached
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step 4 of the process, enabling a maximum of 135 specimens to be analyzed and
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reported in 8.9 hours. For convenience, the final set of specimens could be left
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in the m2000rt at the conclusion of a shift to complete the analytical process, and
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the post-analytical steps completed the following day. The total hands-on time
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for completing three runs (135 specimens) was approximately 75 min.
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addition to the actual assay time, approximately 15 min of daily maintenance was
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required on the m2000sp and could be completed either prior to, or at the
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conclusion of, testing. No daily maintenance was required on the m2000rt.
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The concordance of the results obtained with the m2000 assay and other
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currently available assays is shown in Table 2.
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specimens, 99.1% (325/328) concordance was obtained with m2000 for
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BDProbeTec ET positive samples, 96.3% (26/27) for AMPLICOR positive
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samples and 100% (32/32) for LCx positive samples. The levels of concordance
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of m2000 for CT negative swab samples were 98.2% (165/168) with
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BDProbeTec ET, 100% (40/40) with AMPLICOR, and 100% (32/32) with LCx.
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Overall, the agreement for CT results on swab samples ranged from 98.5% to
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100%.
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concordant with 93.7% (59/63) of APTIMA Combo 2, and 96.8% (60/62) of
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BDProbeTec ET positive samples. Concordance of negative samples was 99.3%
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(430/433) with APTIMA Combo 2 and 98.9% (93/94) with BDProbeTec ET. The
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overall agreement of m2000 CT results on FVU with both APTIMA Combo 2 and
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For CT results of swab
For FVU specimens tested for CT, the m2000 assay result was
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December 19, 2006
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BDProbeTec ET was 98.6%. All FVU specimens (n=6) that on initial testing were
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negative in the m2000 CT assay but had been reported as positive in either the
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APTIMA Combo 2 (n=4) or BDProbeTec ET (n=2) assays were negative upon
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retesting with LCx CT, and both BDProbeTec ET positive/m2000 negative
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samples were also negative in the RealArt CT assay. The single urine sample
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that yielded a BDProbeTec ET negative/m2000 positive result on initial testing
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was negative by the LCx and positive by RealArt CT on repeat testing.
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Concordance of results for FVU samples tested for NG was 91.4% (32/35) for
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APTIMA Combo 2 positive samples and 100% (35/35) for BDProbeTec ET
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positive samples, with concordance for APTIMA Combo 2 and BDProbeTec ET
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negative samples being 99.3% (460/463) and 100% (121/121), respectively. The
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overall agreement on FVU NG results was 99.2% with APTIMA Combo 2 and
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100% with BDProbeTec ET. NG testing was not performed on all of the swab
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samples using BDProbeTec, Amplicor and LCx. Therefore no concordance on
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swab samples for NG results was available.
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DISCUSSION
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The new m2000 real time PCR prototype assay demonstrated an
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analytical sensitivity of 20 genome equivalents of DNA per reaction for both CT
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and NG. Since the cryptic plasmid of CT is typically present at approximately 7 to
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10 copies per elementary body (EB) (13), this corresponds to a detection limit of
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2 EBs. Similarly, approximately 11 copies of the Opa gene are found in the NG
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genome (12), thus, 20 copies of genomic DNA corresponds to approximately 2
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organisms. Further testing also revealed that the limit of detection for CT was
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December 19, 2006
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maintained when 20 copies of CT and 10 million copies of NG were co-present in
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a sample. Vice versa, the limit of detection for NG was maintained when 20
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copies of NG and 10 million copies of CT were co-present in a sample (data not
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shown). Previous studies have shown a range of analytical sensitivity endpoints
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for other commercial available assays. For example, Chong et al (4)
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demonstrated an endpoint of 12 EB's for the LCx Chlamydia test and 0.01 EB's
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for the APTIMA Combo 2 assay. For 15 common CT serovars, the package
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inserts report limits of detection of 1 IFU per reaction for COBAS AMPLICOR, 5-
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200 [median of 35] EBs per reaction for BDProbeTec ET, and 1 IFU per assay for
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APTIMA Combo 2. For NG, the package insert claims are 5 CFU/test on 15
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strains of NG for COBAS AMPLICOR, 5-25 cells per reaction [median of 10 cells]
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for 39 strains of NG for BDProbeTec ET, and 50 cells/assay on 57 strains of NG
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for APTIMA Combo 2.
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Prior to formally evaluating the new m2000 assay in clinical trials, we
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elected to perform a preliminary assessment of assay performance by testing
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residual material from swab and urine samples previously collected for, and
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tested by, other FDA-cleared assays. This protocol involved shipping of positive
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and negative samples to Abbott where they were tested in a blinded fashion. For
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each specimen type the agreements were close to 100% for CT or NG positive
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and negative samples suggesting that the m2000 assay may be expected to offer
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comparable clinical performance to that reported for currently available tests.
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Additional testing of the few samples yielding discordant results revealed
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somewhat inconsistent patterns of positive and negative results in the different
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December 19, 2006
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assays suggesting that most, if not all, of these specimens were low level
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positives producing inconsistent results near the limits of analytical sensitivity for
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the various assays. A multicenter evaluation of the BD Probe Tec ET system for
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CT and NG evaluated swabs and urine from men and women and compared
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performance to the LCx assay (17). The study found that the sensitivity rates for
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male urethral swab or FVU and female CS ranged from 92.5 to 98.5% but that
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female FVU rates were more than 10% lower for both CT and NG. This may be
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a reflection of lower analytical sensitivity (3) and inhibitors in urine (10), which
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have been reported for most assays including the ProbeTec ET test (5,6). The
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Roche COBAS AMPLICOR tests for CT and NG were evaluated in 8 US centers
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(11,16,20). For both organisms, urine sensitivity rates were usually lower than
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for swabs but comparisons were to cell culture and DFA and did not employ
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amplification methods other than PCR.
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revealed that 2.4% of the specimens were inhibitory when initially tested. The
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transcription
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demonstrated excellent sensitivity for CT and NG compared to other commercial
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NAAT's with a slightly lower value for NG detection in urine from asymptomatic
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women (8).
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mediated
amplification
The internal controls for AMPLICOR
assay
(APTIMA
Combo
2)
also
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The m2000 assay was also challenged for specificity by using numerous
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strains of non-gonoccocal Neisseria and 3 non-trachomatis strains of Chlamydia,
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and all yielded negative results at 1 million genome copies per reaction.Analytical
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specificity data reported in the package inserts of commercially available assays
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and in the present report are similar, with little or no specific cross-reactivity
Abbott m2000 CT/NG Prototype Assay Study with Surplus Specimens
December 19, 2006
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observed when physiological levels of nucleic acids from related organisms are
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tested in the assay.
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evaluations of current assays reported aberrant numbers of false positive results
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(11,16-18,20).
Not surprisingly, therefore, none of the multicenter
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Concern about the relative risk of false positive results increasing to an
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unacceptable level as NAA testing for CT and NG is expanded to low-prevalence
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populations has been expressed, including suggestions that all NAAT positive
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results be confirmed by retesting samples in the same assay or, ideally, a
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different one (6). The present study provides an insight into the feasibility of
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using the new m2000 real time PCR assay in this capacity, since it was capable
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of generating reliable results on specimens collected in transport systems not
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designed for the m2000. Although further laboratory validation is needed to fully
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substantiate the interchangibility of samples between the m2000 and other assay
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systems, this capability may help establish the optimal role, either confirmatory or
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screening, for the various testing platforms (8).
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Since the establishment of screening programs will undoubtedly increase
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testing volume for the laboratory, sample processing and testing workflow will
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become increasingly important and a preliminary assessment of these
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parameters was made for the m2000 system.
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maximum capacity of processing 96 samples at a time, matching 96 well PCR
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reactions on the thermal cycler. At the time of the study, however, software for
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handling only 48 samples per run was available for evaluation. Figure 2
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demonstrates the workflow of the assay. For both CT and NG results, time to first
The m2000 system has the
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December 19, 2006
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result on 45 specimens, was 4.5hrs. 90 patient specimens were tested in 6.7 hrs
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and 135 specimens were tested in 8.9 hrs. When the 96-samples/run capability
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becomes available, time to first result on 93 CT and NG patient results is
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estimated to be 5.6hrs, and 186 or 279 patient specimens can be tested using
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this format in 8hrs and 11hrs respectively.
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improvement compared to the manual versions of AMPLICOR, BDProbeTec ET,
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and APTIMA Combo 2, and would approach the throughput of automated
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BDProbeTec ET with Viper™ and Aptima Combo 2 with TIGRIS®. Hanson and
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Cartwright (9) adapted the automated liquid-handling Tecan Genesis RSP 100
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system to the LCx Chlamydia test and reported preservation of assay accuracy
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while reducing technician pipetting time by 75%. Vincelette et al (20) reported
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that COBAS AMPLICOR for CT allowed automation of amplification and
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detection. One technician performed 3 to 4 hours of hands-on work, while testing
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96 specimens in a workday. Significantly improving the efficiency of CT/NG NAA
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testing requires the kind of integrated approach to automating sample
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preparation, amplification, detection and reporting afforded by the Abbott m2000
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system.
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This would present a significant
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In conclusion, this study reports the first evaluation of the Abbott m2000
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prototype real time PCR CT/NG assay and demonstrated satisfactory preliminary
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analytical and clinical performance. The workflow assessment of the prototype
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assay also offered important throughput information to testing laboratories. More
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studies with larger patient sample size will be conducted to provide further
297
assessment of the clinical performance characteristics of the assay.
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expression in Neisseria. Annu Rev Microbiol. 44:451-477.
13. Palmer L, Falkow S. 1986. A common plasmid of Chlamydia trachomatis.
Plasmid 16[1]:52-62.
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14. Schachter, J., E.W. Hook III, W.M. McCormack, T.C. Quinn, M.
Chernesky, S. Chong, J.I. Girdner, P.B. Dixon, L. DeMeo, E. Williams, A.
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C
Cullen, and A. Lorincz. 1999. Ability of the Digene hybride capture II test
to identify Chlamydia trachomatis and Neisseria gonorrhoeae in cervical
specimens. J. Clin. Microbiol. 37[11]:3668-3671.
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15. Schachter, J., W.M. McCormack, M.A. Chernesky, D.H. Martin, B. Van der
Pol, P.A. Rice, E.W. Hook III, W.E. Stamm, T.C. Quinn, and J.M. Chow.
2003. Vaginal swabs are appropriate specimens for diagnosis of genital
tract infection with Chlamydia trachomatis. J Clin. Microbiol. 41[8]:3784-
3789.
16. Van der Pol, B., T.C.Quinn, C.A. Gaydos, K. Crotchfelt, J. Schachter, J.
Moncada, D. Jungkind, D.H. Martin, B. Turner, C. Peyton, and R.B. Jones.
2000. Multicenter evaluation of the AMPLICOR and automated COBAS
AMPLICOR CT/NG tests for detection of Chlamydia trachomatis. J Clin.
Microbiol. 38[3]:1105-1112.
Abbott m2000 CT/NG Prototype Assay Study with Surplus Specimens
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16
17. Van der Pol, B, D.V. Ferrero, L. Buck-Barrington, E. Hook III, C.
Lenderman, T. Quinn, C.A. Gaydos, J. Lovchik, J. Schacter, J. Moncada,
G. Hall, M.J. Tuohy, and R.B. Jones. 2001. Multicenter evaluation of the
BDProbeTec™ ET system for detection of Chlamydia trachomatis and
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Neisseria gonorrhoeae in urine specimens, female endocervical swabs,
and male urethral swabs. J. Clin. Microbiol. 39[3]:1008-1016.
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J. Blutman, and W.J. Payne. 2002. Evaluation of the Digene hybride
E
C
capture II assay with the rapid capture system for detection of Chlamydia
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19. van Dyck, E., M. Ieven, S. Pattyn, L. van Damme, and M. Laga. 2001.
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P.C. van Voorst Vader, A. Butcher, and M. Rosenstraus. 1999.
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Abbott m2000 CT/NG Prototype Assay Study with Surplus Specimens
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Table 1. Isolate composition of the Specificity Panel.
No. of
Strains
Tested
2
1
1
2
1
2
1
1
1
1
1
1
6
1
2
1
2
2
3
1
3
21
1
Organism
C. pneumoniae
C. psittaci
N. animalis
N. caniae
N. canis
N. cinerea
N. cuniculi
N. denitrificans
N. elongata elongata
N. elongata glycolytica
N. flavescens
N. iguanae
N. lactamica
N. macacae
N. meningitidis
N. meningitidis-B
N. meningitidis-C
N. meningitidis-D
N. mucosa
N. polysaccharea
N. sicca*
N. subflava*
N. weaveri
D
E
T
P
E
C
C
A
*1 of the 3 N. sicca Isolates and 5 of the 21 N. subflava isolates in the specificity
panel had previously been demonstrated to cross-react with the Roche Amplicor
N. gonorrhoeae assay (7).
Abbott m2000 CT/NG Prototype Assay Study with Surplus Specimens
December 19, 2006
18
Table 2. Concordance of m2000 CT and NG results with other amplification
assays.
Specimen
Type
Swabs
Urine
Tested
previously
by (n)
BDProbeTec
(496)
Amplicor
(67)
LCx (64)
Aptima
Combo 2
(496)
BDProbeTec
(156)*
m2000 CT concordance with
Positive
99.1%
(325/328)
96.3%
(26/27)
100% (32/32)
93.7%(59/63)
99.3%(430/433)
96.8%(60/62)
98.9%(93/94)
m2000 NG concordance with
Negatives
98.2%
(165/168)
Overall
Positives
Negatives
Overall
98.8%
ND
ND
ND
100% (40/40)
98.5%
ND
ND
ND
100% (32/32)
100%
ND
ND
ND
98.6%
91.4%(32/35)
99.3%(460/463)
99.2%
D
E
T
P
98.6%
100%(35/35)
100%(121/121)
* Urine specimens tested using BDProbeTec were collected, transported and
E
C
stored in DNA/RNA Protect and was validated by the laboratory.
C
A
Abbott m2000 CT/NG Prototype Assay Study with Surplus Specimens
December 19, 2006
19
100%
1.8
CT amplification
1.6
1.4
1.2
D
E
1
0.8
0.6
8e5
0.4
4e4
3e3
300
20
75
T
P
0.2
0
15
20
25
30
35
1.4
NG amplification
1.2
1
0.8
0.6
0.4
3e5
0.2
C
A
1.5e4
1.5e3
40
E
C
-0.2
300 75
45
20
0
15
20
25
30
35
40
45
-0.2
Cycle Number
Figure 1. Fluorescent detection during 45 amplification cycles of Chlamydia
trachomatis and Neisseria gonorrhoeae target DNA on cloned and quantified
linearized plasmid dilution series. The CT dilution panel consisted of members
at 20, 75, 300, 3X103, 4X104, and 8X105 copies/assay, and the NG dilution
panel consisted of members at 20, 75, 300, 1.5X103, 1.5X104, and 3X105
copies/assay as labeled by the curves.
Figure 2. Throughput with one m2000sp and one m2000rt.
m2000sp
m2000rt
m2000sp
m2000rt
m2000sp
D
E
8am 9am 10am 11am 12pm 1pm 2pm 3pm 4pm 5pm
45 specimens
48 samples
+ 3 controls
48 samples in 4.5 hrs
T
P
E
C
48 samples
C
A
90 specimens
+ 6 controls
48samples in 6.7 hrs
48 samples
m2000rt
Total hands-on time (for 3 runs) = 75min
48 samples
135 specimens
+ 9 controls
in 8.9 hrs