False positives and negatives obtained with PCR-based identification of Staphylococcus aureus clonal complex 398.
False positives and negatives obtained with PCR-based identification of Staphylococcus aureus clonal complex 398.
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基于 PCR 的金黄色葡萄球菌克隆复合物 398 鉴定获得的假阳性和阴性结果。
DOI：
10.1128/jcm.03090-13
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发表时间：
2014
影响因子：
9.4
通讯作者：
Smith,TaraC
中科院分区：
文献类型：
--
作者：
Wardyn,ShyloE;Smith,TaraC
（CC 398）最近已成为全球重要的人畜共患病病原体（1）。牲畜，特别是猪，与这些生物的携带和传播有关，与牲畜密切接触的人也是如此。然而，ST 398菌株也在没有牲畜暴露的人群中发现（2，3），并在医院和医疗机构中引起感染（4）。由于ST 398分离株的脉冲场凝胶电泳（PFGE）无法用SmaI分型，属于各种各样的葡萄球菌蛋白A（spa）类型，并显示出许多不同的抗菌药物耐药模式，ST 398的检测不是一个快速的过程。货车Wamel等人使用先前从扩增片段长度多态性（AFLP）分析获得的两个ST 398特异性DNA序列创建了两个特异性PCR用于检测ST 398（5）。据报道，A07和CO 1引物组在对133株分离株进行检测时显示出100%的准确性。注意到货车Wamel等人的集合靶向转座子，Stegger等人使用CC 398谱系中高度保守的sau 1-hsdS 1序列开发了不同的PCR测定（6）。该靶点的PCR验证显示100%的特异性（235/235个样本）和100%的灵敏度（1，072/1，072个样本）。我们使用分别代表基因SAPIG 2194或SAPIG 2195的A07或CO 1引物组筛选了总共444株人类定植和14株人类感染分离株。所有分离株也进行spa分型，包括所有潜在假阳性和假阴性分离株在内的一个子集通过MLST进行分型。灵敏度为96.5%，特异性为98.3%（表1）。有三个假阴性，都是t571/ST 398。6个假阳性包括2个t922/ST 1分离株、1个t045/ST 1分离株、1个t337/ST 9分离株、1个t505/ST 45分离株和1个t002/ST 105分离株（表2）。我们用sau 1-hsdS 1检测试剂筛选了之前检测试剂的9个假阳性和假阴性。其中两个假阳性是阴性的，而其他四个仍然是阳性的。通过sau 1-hsdS 1 PCR检测，所有三个假阴性均为阳性（表2）。
(CC398) have emerged recently as important zoonotic agents worldwide (1). Livestock, especially swine, are implicated in carriage and transmission of these organisms, as are individuals who work closely with livestock. However, ST398 strains have also been found in people without livestock exposure (2, 3) and have caused infections within hospitals and health care facilities (4). Since ST398 isolates are pulsed-field gel electrophoresis (PFGE) nontypeable with SmaI, belong to a wide variety of staphylococcal protein A (spa) types, and show a number of different antimicrobial resistance patterns, detection of ST398 is not a quick process. van Wamel et al. created two specific PCRs for detection of ST398 using two ST398-specific DNA sequences previously obtained from amplified fragment length polymorphism (AFLP) analyses (5). A07 and CO1 primer sets were reported to show 100% accuracy when tested against 133 isolates. Noting that the van Wamel et al. sets were targeted to a transposon, Stegger et al. developed a different PCR assay using the highly conserved sau1-hsdS1 sequence in the CC398 lineage (6). PCR validation of this target showed 100% specificity (235/235 samples) and 100% sensitivity (1,072/1,072 samples).We screened a total of 444 human colonization and 14 human infection isolates using the A07 or CO1 primer set representing the gene SAPIG2194 or SAPIG2195, respectively. All isolates were also spa typed, and a subset, including all potential false-positive and false-negative isolates, were typed by MLST. Sensitivity was 96.5% and specificity was 98.3%(Table 1). There were three false negatives that were all t571/ST398. The six false positives included two t922/ST1 isolates, one t045/ST1 isolate, one t337/ST9 isolate, one t505/ST45 isolate, and one t002/ST105 isolate (Table 2). We screened the nine false positives and false negatives from the previous assay with the sau1-hsdS1 assay. Two of the false positives were negative by this assay, while the other four were still positive. All three false negatives were positive by the sau1-hsdS1 PCR assay (Table 2).