諾羅病毒是引起食品中毒和急性腸胃炎的主要病毒之一，在許多國家食品中毒案例中，發現牡蠣中的諾 羅病毒是導致食品中毒的元兇。本研究利用反轉錄反應及半巢式聚合酶鏈反應方法，自牡蠣檢體中擴增諾羅 病毒ORF1/2區域 (330 nt) 序列。結果自不同牡蠣檢體獲得11株具有諾羅病毒第一基因群 (GI) 的序列，經與基因 資料庫比對及繪製親緣樹狀分析圖以分析其基因型，其中九株與諾羅病毒第一基因群4型 (GI.4) 最相近，核酸 序列同源性為93.7-95.0%，與日本臨床分離株Saitama T69 (序列編號AB112125) 及韓國地下水分離株BU02-21 (序 列編號HQ148255)，核酸序列分別98.7%及97.7%以上相同。其餘2株與第一基因群14型 (GI.14) 最相近，核酸序 列96.4%以上相同，與台灣臨床分離株Taipei-93GI/04 (序列編號DQ263722)，核酸序列99.2%相同，胺基酸序列 100%相同。由親源樹狀分析結果顯示採購自市場的牡蠣中諾羅病毒陽性株屬於第一基因群4型及14型。本研 究發現之諾羅病毒序列已登錄於GenBank，其序列編號為GQ401120至GQ401130。

Noroviruses (NoV) have been considered one of the major viruses causing foodborne illness and nonbacterial gastroenteritis. NoV particularly found in oyster has been reported to cause serious foodborne illness in many countries. In this study, NoV in oyster purchased from different markets was detected using primers that amplify contiguous sequences in the ORF1/2 region (330 nt) of the NoV genome and hemi-nested PCR. The data from the phylogenetic analysis indicated that, among the 11 postitive strains detected, 9 strains belonged to the genotype GI.4. The nucleotide sequences of these strains were similar to those of Saitama T69/Japan (AB112125) and BU02-21GI/Korea (HQ148255) with 98.7% and 97.7% similarity, respectively. The other 2 strains belonged to the genotype GI.14 and their nucleotide and amino acid sequences showed high similarity to those of Taipei-93GI/04 (DQ263722) at 99.2% and 100%, respectively. Our results showed that NoV detected in oyster from markets were genotype GI.4 and GI.14. The nucleotide sequences obtained in this study were deposited in the GenBank with the following accession numbers GQ401120 to GQ401130.