{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T08:40:50Z","timestamp":1772613650290,"version":"3.50.1"},"reference-count":22,"publisher":"BMJ","issue":"3","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sex Transm Infect"],"accepted":{"date-parts":[[2012,11,3]]},"published-print":{"date-parts":[[2013,5]]},"abstract":"<jats:sec><jats:title>Objectives<\/jats:title><jats:p>Identification of genetic targets specific to<jats:italic>Neisseria gonorrhoeae<\/jats:italic>for use in molecular detection methods has been a challenge. The<jats:italic>porA<\/jats:italic>pseudogene in<jats:italic>N gonorrhoeae<\/jats:italic>has been commonly used but recently gonococcal isolates giving a negative result in these PCRs have been reported. Here we describe the characterisation of two such gonococcal isolates received by the reference service at the Health Protection Agency, London, England.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Phenotypic characterisation was achieved using conventional biochemical and immunological tests, matrix-assisted laser desorption\/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS), antimicrobial susceptibility testing, serovar determination and detection of meningococcal PorA using monoclonal antibody 4BG4-E7. Genetic species confirmation was determined using commercial and in house PCRs and<jats:italic>16S rRNA<\/jats:italic>gene sequencing. Molecular typing using the<jats:italic>N gonorrhoeae<\/jats:italic>multi-antigen sequence typing (NG-MAST) and multilocus sequence typing (MLST) was performed. The DNA sequence of the full-length gonococcal<jats:italic>porA<\/jats:italic>pseudogene was determined and compared with published sequences.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Both isolates were confirmed, biochemically and immunologically as<jats:italic>N gonorrhoeae<\/jats:italic>, but repeatedly gave negative results with two in house real-time PCR assays for the<jats:italic>porA<\/jats:italic>pseudogene. Further characterisation of these isolates identified the presence of a meningococcal<jats:italic>porA<\/jats:italic>sequence and showed these isolates belong to serovar Bropyst, and to NG-MAST sequence type (ST) 5967 and MLST ST1901.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Gonococcal isolates that give false negative results with<jats:italic>porA<\/jats:italic>pseudogene PCR assays have now been identified in four countries, three of which are in Europe, and do not appear clonal. This report highlights the genetic diversity of<jats:italic>N gonorrhoeae<\/jats:italic>, which remains a challenge for the molecular detection methods.<\/jats:p><\/jats:sec>","DOI":"10.1136\/sextrans-2012-050829","type":"journal-article","created":{"date-parts":[[2012,12,15]],"date-time":"2012-12-15T02:05:45Z","timestamp":1355537145000},"page":"197-201","source":"Crossref","is-referenced-by-count":39,"title":["Evolution of<i>Neisseria gonorrhoeae<\/i>is a continuing challenge for molecular detection of gonorrhoea: false negative gonococcal<i>porA<\/i>mutants are spreading internationally"],"prefix":"10.1136","volume":"89","author":[{"given":"Catherine A","family":"Ison","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniel","family":"Golparian","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pamela","family":"Saunders","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stephanie","family":"Chisholm","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Magnus","family":"Unemo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2012,12,13]]},"reference":[{"issue":"Suppl","key":"2024051410003680000_89.3.197.1","doi-asserted-by":"crossref","first-page":"S24","DOI":"10.1128\/CMR.2.Suppl.S24","article-title":"Gene transfer in Neisseria gonorrhoeae","volume":"2","author":"Biswas","year":"1989","journal-title":"Clin Microbiol Rev"},{"key":"2024051410003680000_89.3.197.2","doi-asserted-by":"publisher","DOI":"10.7326\/0003-4819-142-11-200506070-00010"},{"key":"2024051410003680000_89.3.197.3","doi-asserted-by":"publisher","DOI":"10.1136\/sti.2008.035469"},{"key":"2024051410003680000_89.3.197.4","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.41.2.835-837.2003"},{"key":"2024051410003680000_89.3.197.5","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.01217-11"},{"key":"2024051410003680000_89.3.197.6","unstructured":"Health Protection Agency 2010. Guidance for gonorrhoea testing in England and Wales. http:\/\/www.hpa.org.uk\/webc\/HPAwebFile\/HPAweb_C\/1267550166455 (accessed 19 Nov 2012)."},{"key":"2024051410003680000_89.3.197.7","doi-asserted-by":"publisher","DOI":"10.1258\/ijsa.2009.009160"},{"key":"2024051410003680000_89.3.197.8","doi-asserted-by":"publisher","DOI":"10.1071\/SH07050"},{"key":"2024051410003680000_89.3.197.9","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0463.2005.apm_206.x"},{"key":"2024051410003680000_89.3.197.10","doi-asserted-by":"publisher","DOI":"10.1080\/00313020600928253"},{"key":"2024051410003680000_89.3.197.11","doi-asserted-by":"publisher","DOI":"10.1080\/00313020500254552"},{"key":"2024051410003680000_89.3.197.12","doi-asserted-by":"publisher","DOI":"10.2353\/jmoldx.2006.060024"},{"key":"2024051410003680000_89.3.197.13","doi-asserted-by":"crossref","first-page":"pii=19874","DOI":"10.2807\/ese.16.21.19874-en","article-title":"False-negative results using Neisseria gonorrhoeae porA pseudogene PCR\u2014a clinical gonococcal isolate with an N. meningitidis porA sequence, Australia, March 2011","volume":"16","author":"Whiley","year":"2011","journal-title":"Euro Surveill"},{"key":"2024051410003680000_89.3.197.14","doi-asserted-by":"crossref","first-page":"pii=20101","DOI":"10.2807\/ese.17.09.20101-en","article-title":"Identification of Neisseria gonorrhoeae isolates with a recombinant porA gene in Scotland, United Kingdom, 2010 to 2011","volume":"17","author":"Eastick","year":"2012","journal-title":"Euro Surveill"},{"key":"2024051410003680000_89.3.197.15","doi-asserted-by":"crossref","first-page":"pii=20102","DOI":"10.2807\/ese.17.09.20102-en","article-title":"Clinical Neisseria gonorrhoeae isolate with a N. meningitidis porA gene and no prolyliminopeptidase activity, Sweden 2011\u2014danger of false negative genetic and culture diagnostic results","volume":"17","author":"Golparian","year":"2012","journal-title":"Euro Surveill"},{"key":"2024051410003680000_89.3.197.16","doi-asserted-by":"publisher","DOI":"10.1097\/01.olq.0000154495.24519.bf"},{"key":"2024051410003680000_89.3.197.17","doi-asserted-by":"publisher","DOI":"10.1097\/OLQ.0b013e3181644bc9"},{"key":"2024051410003680000_89.3.197.18","doi-asserted-by":"publisher","DOI":"10.1016\/j.diagmicrobio.2007.12.007"},{"key":"2024051410003680000_89.3.197.19","doi-asserted-by":"publisher","DOI":"10.1086\/383047"},{"key":"2024051410003680000_89.3.197.20","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.01010-09"},{"key":"2024051410003680000_89.3.197.21","doi-asserted-by":"publisher","DOI":"10.1034\/j.1600-0463.2000.d01-90.x"},{"key":"2024051410003680000_89.3.197.22","first-page":"E061109.2","article-title":"A variant of Chlamydia trachomatis with deletion in cryptic plasmid: implications for use of PCR diagnostic tests","volume":"11","author":"Ripa","year":"2006","journal-title":"Euro Surveill"}],"container-title":["Sexually Transmitted Infections"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/sextrans-2012-050829","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,5,14]],"date-time":"2024-05-14T17:01:07Z","timestamp":1715706067000},"score":1,"resource":{"primary":{"URL":"https:\/\/sti.bmj.com\/lookup\/doi\/10.1136\/sextrans-2012-050829"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012,12,13]]},"references-count":22,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2013,4,12]]},"published-print":{"date-parts":[[2013,5]]}},"alternative-id":["10.1136\/sextrans-2012-050829"],"URL":"https:\/\/doi.org\/10.1136\/sextrans-2012-050829","relation":{},"ISSN":["1368-4973","1472-3263"],"issn-type":[{"value":"1368-4973","type":"print"},{"value":"1472-3263","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012,12,13]]}}}