Evaluation of Molecular Serotyping Assays for Shigella flexneri Directly on Stool Samples.
Evaluation of Molecular Serotyping Assays for Shigella flexneri Directly on Stool Samples.
复制标题
直接在粪便样品上的志贺氏菌柔韧性分子血清分型测定评估。
DOI：
10.1128/jcm.02455-20
复制
发表时间：
2021-01-21
影响因子：
9.4
通讯作者：
Houpt E
中科院分区：
文献类型：
--
作者：
Liu J;Pholwat S;Zhang J;Taniuchi M;Haque R;Alam M;Ochieng JB;Jones JA;Platts-Mills JA;Tennant SM;Houpt E
福氏志贺氏菌在世界范围内流行，是许多国家最常见的志贺氏菌种。至少存在19种弗氏沙门氏菌血清型，血清型信息对于流行病学和疫苗开发目的很重要。福氏志贺氏菌在世界范围内流行，是许多国家最常见的志贺氏菌种。至少存在19种弗氏沙门氏菌血清型，血清型信息对于流行病学和疫苗开发目的很重要。我们评估了o抗原修饰基因实时PCR检测的性能，以确定分离物和直接粪便样本的主要血清型。试验分为两个多重组：一个组包括gtrII、gtrV、gtrX、oac和wzx6，用于鉴定福氏沙门氏菌2a、2b、3a、5a、5b、6和X血清型；另一个组包括ipaH、gtrI、gtrIc和gtrIV，用于确认志贺氏菌检测，并进一步鉴定福氏沙门氏菌1a、1b、1d、3b、4a、4b、7a和7b血清型。我们首先评估了283株志贺氏菌分离株，与常规血清分型相比，PCR血清分型显示97.0%（95%置信区间，93.0% ~ 99.0%）的敏感性和99.9%（99.9% ~ 100%）的特异性。然后将该测定法用于直接粪便标本。采用174份志贺氏菌培养阳性粪便样本进行验证，并对164份衍生样本进行进一步测试，建立了定量检测算法。与血清分型相比，粪便PCR分型的灵敏度为93%(89% ~ 96%)，特异性为99%（99% ~ 100%）。大多数差异是基因型-表型不一致，而不是基因型失败。这些实时PCR检测方法为福氏沙门氏菌血清型鉴定提供了一种高效的新方法。
Shigella flexneri is prevalent worldwide and is the most common Shigella species in many countries. At least 19 S. flexneri serotypes exist, and serotype information is important for epidemiologic and vaccine development purposes. Shigella flexneri is prevalent worldwide and is the most common Shigella species in many countries. At least 19 S. flexneri serotypes exist, and serotype information is important for epidemiologic and vaccine development purposes. We evaluated the performance of real-time PCR assays for O-antigen modification genes to identify the major serotypes on isolates and direct stool samples. The assays were formulated into two multiplex panels: one panel included gtrII, gtrV, gtrX, oac, and wzx6 to identify S. flexneri serotypes 2a, 2b, 3a, 5a, 5b, 6, and X, and the other panel included ipaH, gtrI, gtrIc, and gtrIV to confirm Shigella detection and further identify S. flexneri serotypes 1a, 1b, 1d, 3b, 4a, 4b, 7a, and 7b. We first evaluated 283 Shigella isolates, and PCR serotyping demonstrated 97.0% (95% confidence interval, 93.0% to 99.0%) sensitivity and 99.9% (99.9% to 100%) specificity compared to conventional serotyping. The assays then were utilized on direct stool specimens. A quantitative detection algorithm was developed with a validation set of 174 Shigella culture-positive stool samples and further tested with a derivation set of 164 samples. The PCR serotyping on stool achieved 93% (89% to 96%) sensitivity and 99% (99% to 100%) specificity compared to serotyping. Most discrepancies were genotypic-phenotypic discordance, not genotypic failure. These real-time PCR assays provide an efficient and novel tool for S. flexneri serotype identification.