Beckman Erin, Saracino Ilaria, Fiorini Giulia, Clark Courtney, Slepnev Vladimir, Patel Denise, Gomez Clarissa, Ponaka Reddy, Elagin Vecheslav, Vaira Dino
Meridian Bioscience, Inc., Cincinnati, Ohio, USA.
Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
J Clin Microbiol. 2017 Aug;55(8):2400-2405. doi: 10.1128/JCM.00506-17. Epub 2017 May 17.
Clarithromycin-based regimens are commonly used as a first-line therapy for -positive patients; however, resistance to clarithromycin has led to treatment failures. The aim of this study was to evaluate the feasibility of using stool samples to detect the presence of DNA while concurrently detecting mutations associated with resistance to clarithromycin. For this purpose, total DNA was extracted from 294 raw stool specimens from -positive and -negative patients. TaqMan real-time PCR amplification was used to detect the presence of as well as to predict the phenotype of the organism and the related outcome for patients treated with clarithromycin. Clarithromycin resistance was determined upon analysis of the PCR result. Patients were also tested by a urea breath test and were subjected to esophagogastroduodenoscopy, followed by histology, culture, and a rapid urease test, in order to obtain a consensus patient infection status. Of 294 total stool samples, 227 were deemed true positive. The sensitivity of detection by PCR was 93.8%. Of 213 true-positive samples that were sequenced, 36.2% showed point mutations associated with clarithromycin resistance (A2142C, A2142G, A2143G). The final correlation of the mutant genotypes as determined by sequencing with the eradication of infection was 86%. We found that DNA can be detected in human stool specimens with high sensitivity and can therefore be used to determine the presence of the bacterium without obtaining a biopsy sample. Moreover, genotypic resistance to clarithromycin can be predicted without obtaining a biopsy sample, facilitating the choice of the right therapeutic approach.
基于克拉霉素的治疗方案通常被用作阳性患者的一线治疗；然而，对克拉霉素的耐药性已导致治疗失败。本研究的目的是评估使用粪便样本检测DNA的存在，同时检测与克拉霉素耐药相关的突变的可行性。为此，从阳性和阴性患者的294份原始粪便标本中提取了总DNA。使用TaqMan实时PCR扩增来检测的存在，以及预测生物体的表型和接受克拉霉素治疗患者的相关结果。通过分析PCR结果确定克拉霉素耐药性。还对患者进行了尿素呼气试验，并进行了食管胃十二指肠镜检查，随后进行组织学、培养和快速尿素酶试验，以获得患者感染状况的共识。在294份粪便样本中，227份被判定为真阳性。PCR检测的敏感性为93.8%。在213份进行测序的真阳性样本中，36.2%显示出与克拉霉素耐药相关的点突变（A2142C、A2142G、A2143G）。通过测序确定的突变基因型与感染根除的最终相关性为86%。我们发现，可以在人类粪便标本中高灵敏度地检测到DNA，因此无需获取活检样本即可用于确定细菌的存在。此外，无需获取活检样本即可预测对克拉霉素的基因型耐药性，这有助于选择正确的治疗方法。
