Jump to ContentJump to Main Navigation
Show Summary Details
More options …

Journal of Laboratory Medicine

Official Journal of the German Society of Clinical Chemistry and Laboratory Medicine

Editor-in-Chief: Schuff-Werner, Peter

Ed. by Ahmad-Nejad, Parviz / Bidlingmaier, Martin / Bietenbeck, Andreas / Conrad, Karsten / Findeisen, Peter / Fraunberger, Peter / Ghebremedhin, Beniam / Holdenrieder, Stefan / Kiehntopf, Michael / Klein, Hanns-Georg / Kohse, Klaus P. / Kratzsch, Jürgen / Luppa, Peter B. / Meyer, Alexander von / Nebe, Carl Thomas / Orth, Matthias / Röhrig-Herzog, Gabriele / Sack, Ulrich / Steimer, Werner / Weber, Thomas / Wieland, Eberhard / Winter, Christof / Zettl, Uwe K.

IMPACT FACTOR 2018: 0.389

CiteScore 2018: 0.22

SCImago Journal Rank (SJR) 2018: 0.156
Source Normalized Impact per Paper (SNIP) 2018: 0.089

See all formats and pricing
More options …
Volume 43, Issue 4


Performance assessment of the Allplex™ STI Essential real-time PCR assay for the diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis infections in genital and extra-genital sites

Sylvain Robinet / François Parisot
Published Online: 2019-08-02 | DOI: https://doi.org/10.1515/labmed-2019-0030



Commercial kits performing Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) nucleic acid amplification tests (NAATs) for genital samples are recommended in association with culture, but the majority of real-time polymerase chain reaction (PCR) methods have not received regulatory approval for diagnostics in extra-genital sites. Since 2017, only the Hologic® Aptima Combo2 assay has an in vitro diagnostic (IVD) certification from the European Medicine Evaluation Agency.


We assessed the Allplex™ STI-Essential Assay (EA) for the diagnosis of NG and CT in both genital and extra-genital sites. The performance of the extraction step was studied by means of a standard curve between the concentration of expected cultivable gonococci and the cycle threshold (Ct). Three later-generation NAATs were used as comparators, particularly to assess the specificity (Sp).


A relation between the gonococcal concentration, expressed as colony-forming unit (CFU) per milliliter logarithm, and the Ct was shown to be linear irrespective of the matrices (95% confidence interval [CI]). The detection limit was 10 CFU/mL, contrasting with the relatively poor sensitivity of culture due to inhibitory effects such as pH and the overgrowth of the commensal flora. NG molecular diagnostic is complex and the method comparisons showed some discrepancies when Ct was above 34. We decided to include interpretative comments on our reports on the basis of the Ct result. For CT, comparisons displayed a satisfactory agreement, and the detection limit was 50 copies/mL.


The Seegene Allplex™ STI-EA showed acceptable performance characteristics for the detection of genital and extra-genital NG and CT.

Reviewed publication

Ahmad-NejadP.Edited by: GhebremedhinB.

Keywords: Chlamydia trachomatis; extra-genital specimens; Neisseria gonorrhoeae; real-time PCR; sexually transmitted diseases


  • 1.

    World Health Organisation. Global strategy for the prevention and control of sexually transmitted infections: 2006–2015. Breaking the chain of transmission. Available at: https://www.who.int/reproductivehealth/publications/rtis/9789241563475/en/ Accessed: 8 Jun 2017.

  • 2.

    Center for Disease Control and Prevention. Sexually Transmitted Disease Surveillance. Atlanta, GA: Department of Health and Human Services, 2017. Available at: https://www.cdc.gov/std/stats17/default.htm. Accessed: 9 Oct 2018.

  • 3.

    Ndeikoundam N, Viriot D, Fournet N, De Barbeyrac B, Goubard A, Dupin N, et al. Bacterial sexually transmitted infections in France: recent trends and characteristics in 2015. Bull Epidemiol Hebd 2016;41–42:738–44.Google Scholar

  • 4.

    French National Authority for Health (HAS). Evaluation of nucleic acid amplification tests (NAATs) for detecting Neisseria gonorrhoeae. 2015. Available at: http://www.has-sante.fr/portail/jcms/c_2035591/fr/evaluation-des-tests-d-amplification-des-acides-nucleiques-taan-recherchant-neisseria-gonorrhoeae. Accessed: 4 Dec 2015.

  • 5.

    Bignell C, Unemo M. 2012 European guideline on the diagnosis and treatment of gonorrhea in adults. Int J STD AIDS 2013;24:85–92.PubMedCrossrefGoogle Scholar

  • 6.

    Bolan GA, Sparling PF, Wasserheit JN. The emerging threat of untreatable gonococcal infection. N Engl J Med 2012;366:485–7.CrossrefPubMedGoogle Scholar

  • 7.

    Boyadzhyan B, Yashina T, Yatabe JH, Patnaik M, Hill CS. Comparison of the APTIMA CT and GC assays with the APTIMA combo 2 assay, the Abbott LCx assay, and direct fluorescent-antibody and culture assays for detection of Chlamydia trachomatis and Neisseria gonorrhoeae. J Clin Microbiol 2004;42:3089–93.CrossrefPubMedGoogle Scholar

  • 8.

    Ota KV, Tamari IE, Smieja M, Jamieson F, Jones KE, Towns L, et al. Detection of Neisseria gonorrhoeae and Chlamydia trachomatis in pharyngeal and rectal specimens using the BD Probetec ET system, the gen-probe Aptima combo 2 assay and culture. Sex Transm Infect 2009;85:182–6.Web of ScienceCrossrefPubMedGoogle Scholar

  • 9.

    Robinet S, Parisot F. Accreditation of a multiplex real time PCR assay for detection and semi-quantitative determination of pathogens responsible of sexually-transmitted infections. Ann Biol Clin 2018;76:459–76.Web of ScienceGoogle Scholar

  • 10.

    Sonnenberg P, Clifton S, Beddows S, Field N, Soldan K, Tanton C, et al. Prevalence, risk factors, and uptake of interventions for sexually transmitted infections in Britain: findings from the National Surveys of Sexual Attitudes and Lifestyles (Natsal). Lancet 2013;382:1795–806.PubMedWeb of ScienceCrossrefGoogle Scholar

  • 11.

    Kent CK, Chaw JK, Wong W, Liska S, Gibson S, Hubbard G, et al. Prevalence of rectal, urethral, and pharyngeal chlamydia and gonorrhea detected in 2 clinical settings among men who have sex with men: San Francisco, California, 2003. Clin Infect Dis 2005;41:67–74.CrossrefPubMedGoogle Scholar

  • 12.

    Patton ME, Kidd S, Llata E, Stenger M, Braxton J, Asbel L, et al. Extragenital gonorrhea and chlamydia testing and infection among men who have sex with men-STD surveillance network, United States, 2010–2012. Clin Infect Dis 2014;58:1564–70.PubMedWeb of ScienceCrossrefGoogle Scholar

  • 13.

    Venter JM, Mahlangu PM, Müller EE, Lewis DA, Rebe K, Struthers H, et al. Comparison of an in-house real-time duplex PCR assay with commercial HOLOGIC® APTIMA assays for the detection of Neisseria gonorrhoeae and Chlamydia trachomatis in urine and extra-genital specimens. BMC Infect Dis 2019;19:6.CrossrefWeb of SciencePubMedGoogle Scholar

  • 14.

    Centers for Disease Control and Prevention. Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae 2014. MMWR Recomm Rep 2014;63:1–19.PubMedGoogle Scholar

  • 15.

    Carlin EM, Ziza JM, Keat A, Janier M. 2014 European Guideline on the management of sexually acquired reactive arthritis. Int J STD AIDS 2014;25:901–12.Web of ScienceCrossrefPubMedGoogle Scholar

  • 16.

    Field N, Kennedy I, Folkard K, Duffell S, Town K, Ison CA, et al. Screening for gonorrhea using samples collected through the English national Chlamydia screening programme and risk of false positives: a national survey of local authorities. Br Med J Open 2014;4:e006067.Google Scholar

  • 17.

    Luijt D, Di Lorenzo C, van Loon AM, Unemo M. Most but not all laboratories can detect the recently emerged Neisseria gonorrhoeae porA mutants – results from the QCMD 2013 N. gonorrhoeae external quality assessment programme. Euro Surveill 2014;19:pii=20711.PubMedGoogle Scholar

  • 18.

    Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159–74.PubMedCrossrefGoogle Scholar

  • 19.

    Fleiss JL. Measuring nominal scale agreement among many raters. Psychological Bulletin 1971;76:378–82.CrossrefGoogle Scholar

  • 20.

    Pettit RK, McAllister SC, Hamer TA. Response of gonococcal clinical isolates to acidic conditions. J Med Microbiol 1999;48:149–56.CrossrefPubMedGoogle Scholar

  • 21.

    Unemo M, Shafer WM. Antimicrobial resistance in Neisseria gonorrhoeae in the 21st century: past, evolution, and future. Clin Microbiol Rev 2014;27:587–613.CrossrefWeb of SciencePubMedGoogle Scholar

  • 22.

    Golparian D, Ohlsson A, Janson H, Lidbrink P, Richtner T, Ekelund O, et al. Four treatment failures of pharyngeal gonorrhea with ceftriaxone (500 mg) or cefotaxime (500 mg), Sweden, 2013 and 2014. Euro Surveill 2014;19:pii=20862.PubMedGoogle Scholar

  • 23.

    Barry PM, Klausner JD. The use of cephalosporins for gonorrhea: the impending problem of resistance. Expert Opin Pharmacother 2009;10:555–77.PubMedCrossrefWeb of ScienceGoogle Scholar

  • 24.

    Soufir JC. Secretions of the male reproductive system and fertility. Med Reprod 2010;12:216–24.Google Scholar

  • 25.

    Scrivener Y, Cribier B. Infections urogénitales á gonocoques et á Chlamydia (en dehors de la maladie de Nicolas-Favre): épidémiologie, diagnostic, évolution, traitement [Urogenital gonococcal and chlamydial infections (Lymphogranuloma venereum excepted): epidemiology, diagnosis, evolution, treatment]. Rev Prat 2001;51:453–8.Google Scholar

  • 26.

    Allen McCutchan J, Wunderlich A, Braude AI. Role of urinary solutes in natural immunity to gonorrhea. Infect Immunity 1977;15:149–55.Google Scholar

  • 27.

    Field N, Clifton S, Alexander S, Ison CA, Hughes G, Beddows S, et al. Confirmatory assays are essential when using molecular testing for Neisseria gonorrhoeae in low-prevalence settings: insights from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Sex Transm Infect 2015;91:338–41.PubMedWeb of ScienceCrossrefGoogle Scholar

  • 28.

    Katz AR, Effler PV, Ohye RG, Brouillet B, Lee MV, Whiticar PM. False-positive gonorrhea test results with a nucleic acid amplification test: the impact of low prevalence on positive predictive value. Clin Infect Dis 2004;38:814–9.PubMedCrossrefGoogle Scholar

  • 29.

    Chow EP, Fehler G, Read TR, Tabrizi SN, Hocking JS, Denham I, et al. Gonorrhoea notifications and nucleic acid amplification testing in a very low-prevalence Australian female population. Med J Aust 2015;202:321–3.Web of ScienceCrossrefGoogle Scholar

  • 30.

    Fifer H, Ison CA. Nucleic acid amplification tests for the diagnosis of Neisseria gonorrhoeae in low-prevalence settings: a review of the evidence. Sex Transm Infect 2014;90:577–9.CrossrefWeb of ScienceGoogle Scholar

  • 31.

    Upton A, Bromhead C, Whiley DM. Neisseria gonorrhoeae false-positive result obtained from a pharyngeal swab by using the Roche cobas 4800 CT/NG assay in New Zealand in 2012. J Clin Microbiol 2013;51:1609–10.Web of ScienceCrossrefPubMedGoogle Scholar

About the article

Correspondence: Sylvain Robinet, PhD, Eurofins – Clinical Diagnostics, Laboratory of Medical Microbiology, 2 rue Eugène Coste, 06300 Nice, France

Received: 2019-02-27

Accepted: 2019-06-18

Published Online: 2019-08-02

Published in Print: 2019-08-27

Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

Research funding: None declared.

Employment or leadership: None declared.

Honorarium: None declared.

Competing interests: The funding organization(s) played no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.

Citation Information: Journal of Laboratory Medicine, Volume 43, Issue 4, Pages 191–200, ISSN (Online) 2567-9449, ISSN (Print) 2567-9430, DOI: https://doi.org/10.1515/labmed-2019-0030.

Export Citation

© 2019 Walter de Gruyter GmbH, Berlin/Boston.Get Permission

Comments (0)

Please log in or register to comment.
Log in