Federal Research Institute for Animal Health, Institute of Infectology, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany.
Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany.
Virol J. 2023 Oct 13;20(1):234. doi: 10.1186/s12985-023-02206-9.
The mosquito-borne flaviviruses West Nile virus (WNV) and Usutu virus (USUV) pose a significant threat to the health of humans and animals. Both viruses co-circulate in numerous European countries including Germany. Due to their overlapping host and vector ranges, there is a high risk of co-infections. However, it is largely unknown if WNV and USUV interact and how this might influence their epidemiology. Therefore, in-vitro infection experiments in mammalian (Vero B4), goose (GN-R) and mosquito cell lines (C6/36, CT) were performed to investigate potential effects of co-infections in vectors and vertebrate hosts. The growth kinetics of German and other European WNV and USUV strains were determined and compared. Subsequently, simultaneous co-infections were performed with selected WNV and USUV strains. The results show that the growth of USUV was suppressed by WNV in all cell lines. This effect was independent of the virus lineage but depended on the set WNV titre. The replication of WNV also decreased in co-infection scenarios on vertebrate cells. Overall, co-infections might lead to a decreased growth of USUV in mosquitoes and of both viruses in vertebrate hosts. These interactions can strongly affect the epidemiology of USUV and WNV in areas where they co-circulate.
蚊媒传播的黄病毒西尼罗河病毒（WNV）和乌苏图病毒（USUV）对人类和动物的健康构成重大威胁。这两种病毒在包括德国在内的许多欧洲国家共同传播。由于它们的宿主和传播媒介范围重叠，存在着高度的合并感染风险。然而，WNV 和 USUV 是否相互作用以及这可能如何影响它们的流行病学，在很大程度上尚不清楚。因此，在哺乳动物（Vero B4）、鹅（GN-R）和蚊子细胞系（C6/36、CT）中进行了体外感染实验，以研究合并感染在媒介和脊椎动物宿主中的潜在影响。确定并比较了德国和其他欧洲的 WNV 和 USUV 株的生长动力学。随后，用选定的 WNV 和 USUV 株进行了同时合并感染。结果表明，在所有细胞系中，WNV 均抑制了 USUV 的生长。这种效应不依赖于病毒谱系，但取决于设定的 WNV 滴度。在脊椎动物细胞的合并感染情况下，WNV 的复制也减少了。总的来说，合并感染可能导致蚊子中 USUV 的生长减少，以及脊椎动物宿主中两种病毒的生长减少。这些相互作用会强烈影响它们共同传播地区的 USUV 和 WNV 的流行病学。
