The Finnish New Variant of <em>Chlamydia trachomatis</em> with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 Test
In 2019, more than 200 cases of <i>Chlamydia trachomatis</i> negative/equivocal by the Aptima Combo 2 assay (AC2, target: 23S rRNA) with slightly elevated relative light units (RLUs), but positive by the Aptima <i>Chlamydia trachomatis</i> assay (ACT, target: 16S rRNA) have b...
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MDPI AG
2019-07-01
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| Series: | Microorganisms |
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| Online Access: | https://www.mdpi.com/2076-2607/7/8/227 |
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| author | Kati Hokynar Kaisu Rantakokko-Jalava Antti Hakanen Marika Havana Laura Mannonen Pia Jokela Satu Kurkela Maija Lappalainen Magnus Unemo Mirja Puolakkainen |
| author_facet | Kati Hokynar Kaisu Rantakokko-Jalava Antti Hakanen Marika Havana Laura Mannonen Pia Jokela Satu Kurkela Maija Lappalainen Magnus Unemo Mirja Puolakkainen |
| author_sort | Kati Hokynar |
| collection | DOAJ |
| description | In 2019, more than 200 cases of <i>Chlamydia trachomatis</i> negative/equivocal by the Aptima Combo 2 assay (AC2, target: 23S rRNA) with slightly elevated relative light units (RLUs), but positive by the Aptima <i>Chlamydia trachomatis</i> assay (ACT, target: 16S rRNA) have been detected in Finland To identify the cause of the AC2 CT false-negative specimens, we sequenced parts of the CT 23S rRNA gene in 40 specimens that were AC2 negative/equivocal but ACT positive. A single nucleotide polymorphism (SNP; C1515T in the <i>C. trachomatis</i> 23S rRNA gene) was revealed in 39 AC2/ACT discordant specimens. No decrease in the number of mandatorily notified <i>C. trachomatis</i> cases was observed nationally in Finland in 2010–2019. When RLUs obtained for AC2 negative specimens were retrospectively evaluated in 2011–2019, a continuous increase in the proportion of samples with RLUs 10–19 was observed since 2014, and a slight increase in the proportion of samples with RLUs 20–84 in 2017–2019, indicating that the Finnish new variant of <i>C. trachomatis</i> might have been spreading nationally for several years. This emphasizes that careful surveillance of epidemiology, positivity rate and test performance are mandatory to detect any changes affecting detection of infections. |
| first_indexed | 2024-04-12T08:18:34Z |
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| id | doaj.art-29954f075c114428a20c21939a4bdc93 |
| institution | Directory Open Access Journal |
| issn | 2076-2607 |
| language | English |
| last_indexed | 2024-04-12T08:18:34Z |
| publishDate | 2019-07-01 |
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| series | Microorganisms |
| spelling | doaj.art-29954f075c114428a20c21939a4bdc932022-12-22T03:40:42ZengMDPI AGMicroorganisms2076-26072019-07-017822710.3390/microorganisms7080227microorganisms7080227The Finnish New Variant of <em>Chlamydia trachomatis</em> with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 TestKati Hokynar0Kaisu Rantakokko-Jalava1Antti Hakanen2Marika Havana3Laura Mannonen4Pia Jokela5Satu Kurkela6Maija Lappalainen7Magnus Unemo8Mirja Puolakkainen9Virology, University of Helsinki and Helsinki University Hospital, 00014 Helsinki, FinlandDepartment of Clinical Microbiology, Turku University Hospital, 20500 Turku, FinlandDepartment of Clinical Microbiology, Turku University Hospital, 20500 Turku, FinlandSYNLAB Finland, 00310 Helsinki, FinlandVirology, University of Helsinki and Helsinki University Hospital, 00014 Helsinki, FinlandVirology, University of Helsinki and Helsinki University Hospital, 00014 Helsinki, FinlandVirology, University of Helsinki and Helsinki University Hospital, 00014 Helsinki, FinlandVirology, University of Helsinki and Helsinki University Hospital, 00014 Helsinki, FinlandWorld Health Organization (WHO) Collaborating Centre for Gonorrhoea and other Sexually Transmitted Infections (STIs), National Reference Laboratory for STIs, Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, SE-701 85 Örebro, SwedenVirology, University of Helsinki and Helsinki University Hospital, 00014 Helsinki, FinlandIn 2019, more than 200 cases of <i>Chlamydia trachomatis</i> negative/equivocal by the Aptima Combo 2 assay (AC2, target: 23S rRNA) with slightly elevated relative light units (RLUs), but positive by the Aptima <i>Chlamydia trachomatis</i> assay (ACT, target: 16S rRNA) have been detected in Finland To identify the cause of the AC2 CT false-negative specimens, we sequenced parts of the CT 23S rRNA gene in 40 specimens that were AC2 negative/equivocal but ACT positive. A single nucleotide polymorphism (SNP; C1515T in the <i>C. trachomatis</i> 23S rRNA gene) was revealed in 39 AC2/ACT discordant specimens. No decrease in the number of mandatorily notified <i>C. trachomatis</i> cases was observed nationally in Finland in 2010–2019. When RLUs obtained for AC2 negative specimens were retrospectively evaluated in 2011–2019, a continuous increase in the proportion of samples with RLUs 10–19 was observed since 2014, and a slight increase in the proportion of samples with RLUs 20–84 in 2017–2019, indicating that the Finnish new variant of <i>C. trachomatis</i> might have been spreading nationally for several years. This emphasizes that careful surveillance of epidemiology, positivity rate and test performance are mandatory to detect any changes affecting detection of infections.https://www.mdpi.com/2076-2607/7/8/227<i>Chlamydia trachomatis</i>mutationnucleic acid amplification testdiagnosticsfalse negative |
| spellingShingle | Kati Hokynar Kaisu Rantakokko-Jalava Antti Hakanen Marika Havana Laura Mannonen Pia Jokela Satu Kurkela Maija Lappalainen Magnus Unemo Mirja Puolakkainen The Finnish New Variant of <em>Chlamydia trachomatis</em> with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 Test Microorganisms <i>Chlamydia trachomatis</i> mutation nucleic acid amplification test diagnostics false negative |
| title | The Finnish New Variant of <em>Chlamydia trachomatis</em> with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 Test |
| title_full | The Finnish New Variant of <em>Chlamydia trachomatis</em> with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 Test |
| title_fullStr | The Finnish New Variant of <em>Chlamydia trachomatis</em> with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 Test |
| title_full_unstemmed | The Finnish New Variant of <em>Chlamydia trachomatis</em> with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 Test |
| title_short | The Finnish New Variant of <em>Chlamydia trachomatis</em> with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 Test |
| title_sort | finnish new variant of em chlamydia trachomatis em with a single nucleotide polymorphism in the 23s rrna target escapes detection by the aptima combo 2 test |
| topic | <i>Chlamydia trachomatis</i> mutation nucleic acid amplification test diagnostics false negative |
| url | https://www.mdpi.com/2076-2607/7/8/227 |
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