Lowmoung Taruta, Pombubpa Kannika, Duangdee Teerapong, Tipayamongkholgul Mathuros, Kittigul Leera
Department of Microbiology, Faculty of Public Health, Mahidol University, 420/1 Ratchawithi Road, Bangkok, 10400, Thailand.
Department of Marine Science, Faculty of Fisheries, Kasetsart University, Bangkok, 10900, Thailand.
Food Environ Virol. 2017 Dec;9(4):415-422. doi: 10.1007/s12560-017-9305-5. Epub 2017 May 26.
This study evaluated different tissues of naturally contaminated oysters (Crassostrea belcheri) for the presence of noroviruses. RNA from digestive tissues, gills, and mantle of the oysters was extracted and tested for norovirus genogroup (G) I, GII, and GIV using RT-nested PCR. In spiking experiments with a known norovirus, GII.4, the detection limits were 2.97 × 10 RNA copies/g of digestive tissues, 2.62 × 10 RNA copies/g of gills, and 1.61 × 10 RNA copies/g of mantle. A total of 85 oyster samples were collected from a fresh market in Bangkok, Thailand. Noroviruses were found in the oyster samples (40/85, 47%): GI (29/85, 34.1%), GII (9/85, 10.5%), mixed GI and GII (1/85, 1.2%), and GIV (1/85, 1.2%). All three genogroups were found in the digestive tissues of oysters. Norovirus GI was present in all three tissues with the highest frequency in the mantle, and was additionally detected in multiple tissues in some oysters. GII was also detected in all three tissues, but was not detected in multiple tissues in the same oyster. For genogroup I, only GI.2 could be identified and it was found in all tissues. For genogroup II, three different genotypes were identified, namely GII.4 which was detected in the gills and the mantle, GII.17 which was detected in the digestive tissues, and GII.21 which was detected in the mantle. GIV.1 was identified in the digestive tissues of one oyster. This is the first report on the presence of human GIV.1 in oyster in Thailand, and the results indicate oyster as a possible vehicle for transmission of all norovirus genogroups in Thailand.
本研究评估了自然污染的牡蛎（长巨牡蛎）不同组织中诺如病毒的存在情况。提取了牡蛎消化组织、鳃和外套膜的RNA，并用逆转录巢式PCR检测诺如病毒基因组（G）I、GII和GIV。在使用已知诺如病毒GII.4的加标实验中，消化组织的检测限为2.97×10 RNA拷贝/克，鳃为2.62×10 RNA拷贝/克，外套膜为1.61×10 RNA拷贝/克。从泰国曼谷的一个新鲜市场共采集了85个牡蛎样本。在牡蛎样本中发现了诺如病毒（40/85，47%）：GI（29/85，34.1%）、GII（9/85，10.5%）、GI和GII混合感染（1/85，1.2%）以及GIV（1/85，1.2%）。在牡蛎的消化组织中发现了所有三个基因组。诺如病毒GI在所有三种组织中均有发现，在外套膜中出现频率最高，并且在一些牡蛎的多个组织中也被检测到。GII也在所有三种组织中被检测到，但未在同一牡蛎的多个组织中被检测到。对于基因组I，仅鉴定出GI.2，且在所有组织中均有发现。对于基因组II，鉴定出三种不同的基因型，即在鳃和外套膜中检测到的GII.4、在消化组织中检测到的GII.17以及在外套膜中检测到的GII.21。在一只牡蛎的消化组织中鉴定出GIV.1。这是泰国首次报道在牡蛎中存在人源GIV.1，结果表明牡蛎可能是泰国所有诺如病毒基因组传播的载体。
