Department of Food and Nutrition, Chung-Ang University, Anseong 17546, Republic of Korea.
Department of Food Science and Technology, Chung-Ang University, Anseong 17546, Republic of Korea.
Int J Food Microbiol. 2019 Jun 16;299:58-63. doi: 10.1016/j.ijfoodmicro.2019.03.017. Epub 2019 Mar 28.
Bivalve molluscan shellfish, such as oysters, clams, and cockles, are well-recognized as vectors that concentrate foodborne pathogens by filter feeding. The objective of this study was to investigate the distribution and persistence of hepatitis A virus (HAV) in experimentally contaminated oysters that were either fed or not fed with algae. Oysters were experimentally contaminated with HAV and maintained in depuration conditions. qRT-PCR, immunohistochemistry (IHC), and in situ hybridization (ISH) were performed on oyster samples collected at 0, 1, 3, 5, and 7 days post-inoculation. When HAV-contaminated oysters were depurated for 7 days, HAV was detected in 91.1-97.8% of the digestive glands and gills. While the high viral load in the digestive glands in oysters did not change significantly regardless of algae-feeding, the viral load of the gills gradually decreased in both groups during the depuration. HAV antigen and RNA were detected in the digestive diverticula and connective tissues by both IHC and ISH. HAV was detected in the stomach, intestine, and gills by only ISH. The distribution of HAV in various oyster tissues may explain the persistence of contamination in oysters during the depuration process.
双壳贝类软体动物，如牡蛎、蛤和贻贝，是通过滤食作用浓缩食源性病原体的公认载体。本研究的目的是研究甲型肝炎病毒（HAV）在实验污染的牡蛎中的分布和持久性，这些牡蛎要么通过喂食藻类，要么不喂食藻类。将牡蛎用 HAV 进行实验性污染，并在净化条件下进行维持。在接种后 0、1、3、5 和 7 天采集牡蛎样本，进行 qRT-PCR、免疫组织化学（IHC）和原位杂交（ISH）。当受 HAV 污染的牡蛎被净化 7 天时，在 91.1-97.8%的消化腺和鳃中检测到 HAV。尽管在藻类喂养的情况下，消化腺中高病毒载量没有明显变化，但在净化过程中，两组的鳃病毒载量逐渐下降。通过 IHC 和 ISH，在消化憩室和结缔组织中都检测到 HAV 抗原和 RNA。仅通过 ISH 在胃、肠和鳃中检测到 HAV。HAV 在各种牡蛎组织中的分布可以解释在净化过程中牡蛎污染的持续存在。
