Clin Lab. 2022 Aug 1;68(8). doi: 10.7754/Clin.Lab.2021.210925.
Group A Streptococcus (GAS) is the most common bacterial cause of acute tonsillopharyngitis. In this study, it was aimed to evaluate the performance of a novel Loop Mediated Isothermal Amplification (LAMP) method in the rapid diagnosis of GAS in samples taken from children with a prediagnosis of acute bacterial tonsillopharyngitis by comparing it with culture and rapid antigen test (RAT) methods.
A total of 100 throat swab samples taken from children at the pediatrics outpatient clinic with suspected tonsillopharyngitis were included in the study. Throat swab samples were analyzed by RAT, throat culture, and LAMP method. GAS suspected colonies were identified with MALDI-TOF MS system. The isothermal amplification reaction for LAMP was conducted by a novel LAMP instrument.
According to the results of throat cultures; 53 of them were positive and 47 were negative in terms of GAS. Six (11.32%) of the culture positive samples were found to be negative by the RAT (sensitivity; 88.68%, specificity 100%). While the antigen test was positive, no culture negative sample was detected. One of the culture positive samples was found negative by LAMP. In two samples, while throat culture was negative, it was observed that LAMP was positive (sensitivity; 98.11%, specificity; 95.74%). In one of these samples, the bacteria grown in the culture were identified as Streptococcus dysgalactiae by mass spectrophotometry.
In this study, it was determined that the LAMP method used in the diagnosis of throat infections caused by GAS has high sensitivity and specificity. We believe that the instrument is easy to use, low cost, portable, and adaptable to point of care tests. There are very few studies in the literature regarding the use of the instrument in this field, and it should be evaluated in terms of its usability in daily practice with new studies.
A 组链球菌（GAS）是引起急性扁桃体咽炎的最常见细菌病因。在这项研究中，我们旨在通过与培养和快速抗原检测（RAT）方法比较，评估一种新型环介导等温扩增（LAMP）方法在诊断经预诊断为急性细菌性扁桃体咽炎的儿童咽拭子样本中 GAS 的性能。
共纳入 100 例来自儿科门诊疑似扁桃体咽炎的儿童的咽拭子样本。通过 RAT、咽拭子培养和 LAMP 方法对咽拭子样本进行分析。使用 MALDI-TOF MS 系统鉴定 GAS 可疑菌落。通过新型 LAMP 仪器进行等温扩增反应。
根据咽拭子培养结果；53 例 GAS 阳性，47 例 GAS 阴性。6 例（11.32%）培养阳性样本 RAT 检测结果为阴性（敏感性 88.68%，特异性 100%）。虽然抗原检测为阳性，但未检测到培养阴性样本。1 例培养阳性样本 LAMP 检测结果为阴性。在 2 例培养阴性的样本中，LAMP 检测结果为阳性（敏感性 98.11%，特异性 95.74%）。在其中 1 例样本中，通过质谱鉴定培养出的细菌为无乳链球菌。
在这项研究中，我们确定用于诊断由 GAS 引起的咽喉感染的 LAMP 方法具有较高的敏感性和特异性。我们认为该仪器使用方便、成本低、便携，并且可以适应即时检测。文献中关于该仪器在该领域的使用的研究很少，应通过新的研究评估其在日常临床实践中的可用性。
