Roy Felicia, Beirnes Jennifer, LeBlanc Jason J, Gibbons Suzanne, Sivro Aida, Severini Alberto
National Microbiology Laboratory Branch, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
Division of Microbiology, Department of Pathology and Laboratory Medicine, Nova Scotia Health, Halifax, Nova Scotia, Canada.
Microbiol Spectr. 2025 Mar 4;13(3):e0206224. doi: 10.1128/spectrum.02062-24. Epub 2025 Jan 23.
Nucleic acid amplification tests (NAATs) are the method of choice for diagnosis, but these strategies are susceptible to target site mutations. variants escaping detection with the Aptima Combo 2 (AC2) assay on the Hologic Panther instrument from 23S rRNA mutations have been reported in Nordic countries, England, Japan, and the United States. Given the potential for false negative results, this study investigated whether strains of with AC2 target site mutations were present in Canada. Surveillance was conducted in Canadian laboratories from 2019 to 2021. Specimens suspected of AC2 target site mutations included those with low-value detections on the AC2 assay, with subsequent high-value detections on the Aptima Chlamydia Trachomatis (ACT) assay used for confirmatory testing. Specimens with AC2/ACT discrepant results were subjected to sequencing of the AC2 target (i.e., 23S rRNA). Sequencing revealed 15 (4.8%) diagnostic escape variants which were carrying either C1514T, G1523A, or G1526A mutations. All specimens with diagnostic escape mutation were detected with a reformulated version of the AC2 assay. Overall, while the prevalence of variants was rare, their presence in the Canadian population supports the use of the new AC2 kit formulation and the need for ongoing genetic surveillance for NAAT-based assays.
Molecular tests are commonly used for the detection of sexually transmitted infections (STIs) like . Mutations impacting molecular target detection on the Hologic Panther AC2 assay have been reported in several countries, raising concerns about potential false negative results. This study showed target detection failures in specimens submitted for testing in Canadian laboratories from 2019 to 2021. A reformulated version of the AC2 molecular test is now available that can identify strains harboring target site mutations that were impacted by the previous test formulation. While target site mutations were rare in Canada, revealing their presence is important to ensure accurate molecular detection of with existing testing methods. This study supports ongoing genetic monitoring of molecular test target sites, as well as the use of the reformulated test to avoid false negative results and subsequent transmissions.
核酸扩增检测（NAATs）是诊断的首选方法，但这些策略易受靶位点突变影响。在北欧国家、英国、日本和美国，已报告了通过霍利克公司的Panther仪器上的Aptima Combo 2（AC2）检测法检测不到的23S rRNA突变的变异株。鉴于存在假阴性结果的可能性，本研究调查了加拿大是否存在具有AC2靶位点突变的菌株。于2019年至2021年在加拿大各实验室开展监测。怀疑有AC2靶位点突变的标本包括那些在AC2检测中检测值较低、随后在用于确证检测的Aptima沙眼衣原体（ACT）检测中检测值较高的标本。对AC2/ACT结果不一致的标本进行AC2靶标（即23S rRNA）测序。测序发现15个（4.8%）诊断逃逸变异株，它们携带C1514T、G1523A或G1526A突变。所有具有诊断逃逸突变的标本都通过重新配制的AC2检测法检测到。总体而言，虽然变异株的流行率很低，但它们在加拿大人群中的存在支持使用新的AC2试剂盒配方，以及对基于NAAT的检测进行持续基因监测的必要性。
分子检测常用于检测诸如[此处原文缺失具体疾病名称]等性传播感染（STIs）。在几个国家已报告了影响霍利克公司Panther AC2检测法中分子靶标检测的突变，这引发了对潜在假阴性结果的担忧。本研究显示了2019年至2021年在加拿大实验室提交用于[此处原文缺失具体疾病名称]检测的标本中存在靶标检测失败情况。现在有一种重新配制的AC2分子检测法，可识别携带受先前检测配方影响的靶位点突变的[此处原文缺失具体疾病名称]菌株。虽然靶位点突变在加拿大很少见，但发现它们的存在对于确保用现有检测方法准确进行[此处原文缺失具体疾病名称]的分子检测很重要。本研究支持对[此处原文缺失具体疾病名称]分子检测靶位点进行持续基因监测，以及使用重新配制的检测法以避免假阴性结果及后续传播。
