Evaluation of a simple, rapid and field-adapted diagnostic assay for enterotoxigenic E. coli and Shigella.
Evaluation of a simple, rapid and field-adapted diagnostic assay for enterotoxigenic E. coli and Shigella.
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DOI：
10.1371/journal.pntd.0010192
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发表时间：
2022-03
影响因子：
3.8
通讯作者：
Chakraborty S
中科院分区：
文献类型：
--
作者：
Connor S;Velagic M;Zhang X;Johura FT;Chowdhury G;Mukhopadhyay AK;Dutta S;Alam M;Sack DA;Wierzba TF;Chakraborty S
了解全球肠道致病性E.大肠杆菌（ETEC）和志贺氏菌腹泻以及评估控制这两种重要病原体的疫苗的成本效益一直受到缺乏快速、简单、灵敏并可应用于流行国家的诊断测试的阻碍。我们之前开发了一种简单快速的检测方法，快速环介导等温扩增诊断试验（RLDT），用于检测ETEC和志贺菌属。（志贺氏菌）。在本研究中，RLDT检测与定量PCR（qPCR）、培养和常规PCR检测ETEC和志贺菌进行了比较。使用先前从流行国家采集的粪便样本、从前往流行国家的旅行者采集的粪便样本以及来自ETEC对照人类感染模型研究的样本进行了该验证。还验证了来自干燥粪便斑点的RLDT的性能。与qPCR相比，RLDT的灵敏度和特异性极佳（分别为99%和99.2%），对于ETEC的单个毒素基因为92.3%至100%，对于志贺氏菌为100%。与RLDT相比，培养的敏感性较低。使用不同来源的样本或中重度腹泻或无症状感染的粪便样本，RLDT的性能无显著差异。RLDT在检测滤纸上干燥粪便样品中的ETEC和志贺氏菌方面同样表现良好。本研究确定RLDT具有足够的灵敏度和特异性，可用作流行国家检测ETEC和志贺氏菌的简单快速诊断方法，以确定这些病原体在国家和国家以下各级的疾病负担。这些信息对于指导公共卫生和政策制定者优先考虑资源，加速开发和引入针对这些肠道感染的有效预防和/或治疗干预措施至关重要。产肠毒素大肠大肠杆菌（ETEC）和志贺氏菌属（Shigella）在全球造成严重的发病率和死亡率，特别是在低收入和中等收入国家。由于检测志贺氏菌的培养方法不敏感，而且用于检测ETEC的方法在专业化、设备齐全的实验室之外不可行，因此这些病原体在国家和国家以下各级的真实负担大多不可用。这两种病原体的发病率和死亡率估计对于评估它们在中低收入国家的相对公共卫生重要性至关重要。我们开发了一种用于检测ETEC和志贺氏菌的简单快速诊断方法，称为RLDT（快速环介导等温扩增诊断试验）。在这项研究中，我们评估了RLDT与其他目前可用的检测方法相比，使用以前收集的粪便样本。结果表明，RLDT检测方法对ETEC和志贺菌的检测具有较高的灵敏度和特异性，可在50 min内获得结果。RLDT对这些病原体的敏感性高于培养。我们的结论是，RLDT可以作为一种快速，简单的诊断测试，以确定负担的ETEC和志贺氏菌在LMIC以及在这些病原体的临床疫苗试验。
Understanding the global burden of enterotoxigenic E. coli (ETEC) and Shigella diarrhea as well as estimating the cost effectiveness of vaccines to control these two significant pathogens have been hindered by the lack of a diagnostic test that is rapid, simple, sensitive, and can be applied to the endemic countries. We previously developed a simple and rapid assay, Rapid Loop mediated isothermal amplification based Diagnostic Test (RLDT) for the detection of ETEC and Shigella spp. (Shigella). In this study, the RLDT assay was evaluated in comparison with quantitative PCR (qPCR), culture and conventional PCR for the detection of ETEC and Shigella. This validation was performed using previously collected stool samples from endemic countries, from the travelers to the endemic countries, as well as samples from a controlled human infection model study of ETEC. The performance of RLDT from dried stool spots was also validated. RLDT resulted in excellent sensitivity and specificity compared to qPCR (99% and 99.2% respectively) ranging from 92.3 to 100% for the individual toxin genes of ETEC and 100% for Shigella. Culture was less sensitive compared to RLDT. No significant differences were noted in the performance of RLDT using samples from various sources or stool samples from moderate to severe diarrhea or asymptomatic infections. RLDT performed equally well in detection of ETEC and Shigella from the dried stool samples on filter papers. This study established that RLDT is sufficiently sensitive and specific to be used as a simple and rapid diagnostic assay to detect ETEC and Shigella in endemic countries to determine disease burden of these pathogens in the national and subnational levels. This information will be important to guide public health and policy makers to prioritize resources for accelerating the development and introduction of effective preventative and/or treatment interventions against these enteric infections. Enterotoxigenic E. coli (ETEC) and Shigella spp (Shigella) causes significant global morbidity and mortality, especially in low-and middle-income countries (LMICs). Since culture methods to detect Shigella are not sensitive, and the methods used to detect ETEC have not been feasible outside of specialized, well-equipped laboratories, the true burden of these pathogens at national and sub-national levels are mostly not available. Morbidity and mortality estimates, for these two pathogens are crucial to assess their relative public health importance in LMICs. We developed a simple and rapid diagnostic assay called the RLDT (Rapid Loop-mediated isothermal amplification based Diagnostic Test) for detection of ETEC and Shigella. In this study we evaluated RLDT compared to other currently available assays using previously collected stool samples. Our data showed that the RLDT assay exhibited high sensitivity and specificity for detection of ETEC and Shigella, with its result available within 50 minutes. The sensitivity of RLDT was higher than culture for these pathogens. We conclude that RLDT could be used as a rapid and simple diagnostic test to determine the burden of ETEC and Shigella in LMICs as well as in clinical vaccine trials of these pathogens.
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影响因子：
5.5
作者：
Khalil I;Walker R;Porter CK;Muhib F;Chilengi R;Cravioto A;Guerrant R;Svennerholm AM;Qadri F;Baqar S;Kosek M;Kang G;Lanata C;Armah G;Wierzba T;Hasso-Agopsowicz M;Giersing B;Louis Bourgeois A
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通讯作者：
Walker, Richard I.
影响因子：
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作者：
Harro, Clayton;Chakraborty, Subhra;Sack, David A.
通讯作者：
Sack, David A.