Schilling-Loeffler Katja, Meyer Dirk, Wolff Alexander, Santamaría-Palacios Jorge, Reich Felix, Johne Reimar
German Federal Institute of Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany.
Universidad de Burgos, Facultad de Ciencias, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
Int J Food Microbiol. 2025 Feb 2;429:111018. doi: 10.1016/j.ijfoodmicro.2024.111018. Epub 2024 Dec 11.
The zoonotic hepatitis E virus (HEV) can cause acute and chronic hepatitis in humans. Meat from domestic pigs, which represent a major animal reservoir of HEV, plays a key role in HEV transmission. Although pork meat products can contain HEV-RNA, it is unknown whether infectious HEV is still present after their manufacturing process. Here, we used a newly developed method for virus extraction from sausages and a quantitative method for detecting HEV infectivity in artificially contaminated sausages to investigate the HEV inactivation during production of spreadable pork liver sausage and salami-like raw pork sausage. The cell culture-adapted HEV genotype 3c strain 47832c was used to contaminate meat preparations intended for production of sausages, which were manufactured based on recipes commonly used in Germany. According to these recipes, spreadable liver sausages of a certain diameter are to be held in a water bath at 70 °C for 30 min. Therefore, the HEV inoculated liver sausage preparations were filled into conical tubes and heated in a 70 °C water bath. After 21 min, the sausages reached a core temperature of 70 °C and samples were taken after further incubation for up to 18 min. For the raw sausages, the HEV inoculated meat preparation was filled into natural casings and sausages were cured at 18 °C and 80 % relative humidity. Samples were taken for up to 21 days. HEV was extracted from all samples, which were quantitatively analyzed for infectious virus and viral RNA using cell culture and RT-qPCR, respectively. During liver sausage production, infectious HEV decreased by four log immediately after reaching the core temperature of 70 °C and was completely inactivated (>4.3 log decrease) 2 min later (23 min heat treatment). In contrast, the HEV-RNA amount decreased only marginally (<0.6 log) throughout the whole incubation time. During raw sausage manufacturing, infectious HEV decreased only slightly (<1.3 log) over three weeks of curing, while the HEV-RNA amount remained unchanged. It can be concluded that the intended heating regime during production of spreadable liver sausages leads to an inactivation of HEV, indicating a low risk of HEV infection for consumers if these sausages are manufactured properly. In contrast, HEV was only slightly inactivated during production of salami-like raw pork sausage. Therefore, raw sausage can contain infectious HEV if starting material with a high HEV amount was used for production. Viral RNA testing cannot be used to predict infectivity of HEV in meat products.
人畜共患的戊型肝炎病毒（HEV）可导致人类急性和慢性肝炎。家猪是HEV的主要动物宿主，猪肉在HEV传播中起着关键作用。尽管猪肉制品可能含有HEV-RNA，但在其制造过程之后是否仍存在传染性HEV尚不清楚。在此，我们使用一种新开发的从香肠中提取病毒的方法以及一种检测人工污染香肠中HEV传染性的定量方法，来研究可涂抹猪肝香肠和意大利腊肠样生猪肉香肠生产过程中HEV的灭活情况。采用细胞培养适应的HEV 3c基因型47832c毒株污染用于生产香肠的肉类制品，这些香肠是根据德国常用的配方制作的。根据这些配方，将一定直径的可涂抹肝香肠在70°C水浴中保持30分钟。因此，将接种HEV的肝香肠制品装入锥形管中，在70°C水浴中加热。21分钟后，香肠的中心温度达到70°C，在进一步孵育长达18分钟后取样。对于生香肠，将接种HEV的肉类制品装入天然肠衣中，香肠在18°C和80%相对湿度下腌制。取样长达21天。从所有样品中提取HEV，分别使用细胞培养和RT-qPCR对传染性病毒和病毒RNA进行定量分析。在肝香肠生产过程中，传染性HEV在中心温度达到70°C后立即下降了4个对数，并在2分钟后（热处理23分钟）完全灭活（下降>4.3个对数）。相比之下，在整个孵育期间，HEV-RNA量仅略有下降（<0.6个对数）。在生香肠制造过程中，传染性HEV在三周的腌制过程中仅略有下降（<1.3个对数），而HEV-RNA量保持不变。可以得出结论，可涂抹肝香肠生产过程中的预期加热方式会导致HEV灭活，这表明如果这些香肠制作得当，消费者感染HEV的风险较低。相比之下，在意大利腊肠样生猪肉香肠生产过程中HEV仅略有灭活。因此，如果使用高HEV含量的原料生产，生香肠可能含有传染性HEV。病毒RNA检测不能用于预测肉类制品中HEV的传染性。
