Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
Arch Virol. 2012 Feb;157(2):235-46. doi: 10.1007/s00705-011-1153-2. Epub 2011 Nov 3.
Recent evidence has indicated the cross-species transmission of hepatitis E virus (HEV) from pigs and wild boars to humans, causing zoonosis, mostly via consumption of uncooked or undercooked animal meat/viscera. However, no efficient cell culture system for swine and boar HEV strains has been established. We inoculated A549 cells with 12 swine and boar HEV strains of liver, feces, or serum origin at an HEV load of ≥2.0 × 10(4) copies per well and found that the HEV progeny replicated as efficiently as human HEV strains, with a maximum load of ~10(8) copies/ml. However, the HEV load in the culture medium at 30 days post-inoculation differed markedly by inoculum, ranging from 1.0 × 10(2) to 1.1 × 10(7) copies/ml upon inoculation at a lower load of approximately 10(5) copies per well. All progeny were passaged successfully onto A549 and PLC/PRF/5 cells. In sharp contrast, no progeny viruses were detectable in the culture supernatant upon inoculation with 13 swine and boar HEV strains at an HEV load of <1.8 × 10(4) copies per well. The present study also demonstrates that swine liver sold as food can be infectious, supporting the risk of zoonotic food-borne HEV infection.
最近的证据表明，戊型肝炎病毒（HEV）可在猪和野猪与人类之间发生跨物种传播，引起人畜共患病，主要通过食用未煮熟或未煮熟的动物肉/内脏。然而，尚未建立用于猪和野猪 HEV 株的有效细胞培养系统。我们以 HEV 载量≥2.0×10^4 拷贝/孔的方式将 12 株来自猪和野猪肝脏、粪便或血清的 HEV 株接种到 A549 细胞中，发现 HEV 后代的复制效率与人类 HEV 株一样高，最大载量约为 10^8 拷贝/ml。然而，接种后 30 天，培养液中的 HEV 载量因接种物而异，在较低的 10^5 拷贝/孔左右的负荷下接种时，范围从 1.0×10^2 到 1.1×10^7 拷贝/ml。所有后代均成功传代到 A549 和 PLC/PRF/5 细胞上。与此形成鲜明对比的是，当以 HEV 载量<1.8×10^4 拷贝/孔的方式接种 13 株猪和野猪 HEV 株时，在培养上清液中均未检测到后代病毒。本研究还表明，作为食品销售的猪肝脏可能具有传染性，支持食源性人畜共患 HEV 感染的风险。
