Moe C L, Gentsch J, Ando T, Grohmann G, Monroe S S, Jiang X, Wang J, Estes M K, Seto Y, Humphrey C
Viral Gastroenteritis Section, Centers for Disease Control and Prevention, Atlanta, Georgia 30333.
J Clin Microbiol. 1994 Mar;32(3):642-8. doi: 10.1128/jcm.32.3.642-648.1994.
Norwalk virus (NV) and other small round-structured viruses (SRSVs) are frequent causes of gastroenteritis outbreaks. The recent cloning and sequencing of the NV genome has made it possible to detect NV and Norwalk-related viruses from fecal specimens by reverse transcription (RT)-PCR. We applied this technique to the examination of a total of 139 fecal specimens from 19 outbreaks characterized by NV serology, including 56 samples from 7 NV outbreaks, 36 from 6 Norwalk-related virus outbreaks, and 47 from 6 outbreaks with SRSVs visualized by electron microscopy that were serologically unrelated to NV. Three primer pairs were evaluated: two pairs in the polymerase region of NV and one pair near the 3' end of the genome. When one set of primers (primer pair 51-3) from the polymerase region was used, 40% of all samples were positive by RT-PCR and specimens from the NV outbreaks were more likely to be positive (64%) than those from outbreaks associated with Norwalk-related viruses (44%) or SRSVs (8%). To determine the relationship of the outbreak strains to NV, we compared the sequences of a 145-base portion of the polymerase gene from 10 specimens obtained from five different outbreaks characterized as NV by serology. No two outbreak strains had the same sequence in this 145-base portion of the polymerase gene, and the identities of the nucleotide and amino acid sequences of these products compared with the sequences of the corresponding region of NV ranged from 62 to 79% and 69 to 90%, respectively. Because of sequence diversity in the polymerase region, the successful application of RT-PCR to investigations of outbreaks of suspected NV-associated gastroenteritis will depend on the use of either multiple primer pairs or primers made against regions of the genome that are more conserved.
诺如病毒（NV）和其他小圆结构病毒（SRSVs）是肠胃炎暴发的常见病因。最近对NV基因组的克隆和测序使得通过逆转录（RT）-PCR从粪便标本中检测NV和诺如病毒相关病毒成为可能。我们将这项技术应用于检测19起以NV血清学为特征的暴发事件中的总共139份粪便标本，其中包括来自7起NV暴发事件的56份样本、来自6起诺如病毒相关病毒暴发事件的36份样本以及来自6起通过电子显微镜观察到的SRSVs暴发事件（血清学上与NV无关）的47份样本。评估了三对引物：两对在NV的聚合酶区域，一对在基因组3'端附近。当使用来自聚合酶区域的一组引物（引物对51-3）时，所有样本中有40%通过RT-PCR呈阳性，NV暴发事件的标本比与诺如病毒相关病毒（44%）或SRSVs（8%）相关的暴发事件的标本更有可能呈阳性（64%）。为了确定暴发毒株与NV的关系，我们比较了从5起不同的经血清学鉴定为NV的暴发事件中获得的10份标本的聚合酶基因145个碱基部分的序列。在聚合酶基因的这145个碱基部分，没有两个暴发毒株具有相同的序列，这些产物的核苷酸和氨基酸序列与NV相应区域序列的同一性分别为62%至79%和69%至90%。由于聚合酶区域存在序列多样性，RT-PCR在疑似NV相关肠胃炎暴发调查中的成功应用将取决于使用多对引物或针对基因组中更保守区域设计的引物。
