Two novel reassortant H 11 N 8 avian influenza viruses occur in wild birds found in East Dongting Lake , China

During the surveillance of avian influenza viruses in East Dongting Lake, China (2014–2015), two H11N8 avian influenza viruses were detected in the bean goose (Anser fabalis) and the falcated teal (Anas falcata). Phylogenetic analysis showed that these two novel reassortant H11N8 avian influenza viruses contain genes from poultry and wild birds. This is the first report detecting the H11N8 subtype influenza virus from wild birds in Asia. These findings indicate a dissemination of avian influenza virus along the East Asian-Australian flyway. In addition, the interaction between poultry and wild birds was addressed suggesting the need for intensive surveillance of wild bird populations. H11 avian influenza viruses (AIVs) have been widely detected in domestic poultry and in wild birds [2, 15, 33]. H11N1 virus was identified in India among wild aquatic birds in 2007 [23]. By 2010, the H11N2 and H11N8 viruses were detected among wild bird populations in the Ukraine [21]. Subsequently, in 2011 and 2013, the H11N3 virus was isolated from domestic ducks in China [3, 29]. Since 1997, the H11N9 virus has been identified from geographic locations ranging from Eastern Asia to North America [13, 15, 18]. The East Dongting Lake National Nature Reserve (29.32°N, 112.98°E) in the Hunan Province, China, is a large natural area forming part of the more extensive Dongting Lake wetlands. This environment is listed as an important bird area for water birds in large numbers and serves as a significant overwintering area for migratory birds along the East Asia-Australia flyway [31]. Typically, there is a peak in the number of wild birds between December and February [19]. In this geographic location, domestic ducks share the same water area with migratory birds. This juxtaposition of populations provides an opportunity for AIVs to spread between migratory birds and domestic poultry via the direct or indirect fecal-oral-route. This dissemination appears to be the cause of viral reassortants [8, 27]. The cocirculating AIVs of different origins and subtypes may serve as donors of diverse gene segments for each other and generate new genetic combinations (reassortants). Two H11N8 AIVs were identified from fecal samples of waterfowl in the East Dongting Lake between December 2014 and February 2015. Fresh feces were collected in 2 ml Eppendorf tubes with 1 ml of viral transport media. Within 6 h, the samples were transported to the laboratory at 4 °C and stored at − 80 °C until further use. The viral RNAs present in the feces were extracted by the MagMAXTM Pathogen RNA/DNA kit (Applied Biosystems, Foster City, CA, USA) on the Magmax-96 Express (Applied Biosystems) instrument following the manufacturer’s instructions. Influenza A viral RNA was detected by Real time reverse transcription-PCR on ABI 7500 (Applied Biosystems) targeting the matrix gene [12]. Eight gene segments of each virus were amplified with PrimeScriptTM One-step RT-PCR kit Ver.2 kit (TaKaRa, Biotechnology [Dalian] Handling Editor: Carolina Scagnolari. Jing Liu and Lichen Zhou contributed equally to this work. Electronic supplementary material The online version of this article (https ://doi.org/10.1007/s0070 5-019-04168 -2) contains supplementary material, which is available to authorized users. * Tianhou Wang thwang@bio.ecnu. edu.cn 1 School of Life Sciences, East China Normal University, Shanghai 200062, China 2 Shanghai Zoo, Shanghai 200336, China 3 Key Laboratory of Agro-ecological Processes in Subtropical Regions, Chinese Academy of Sciences, Changsha 410125, Hunan, China 4 Institute of Eco-Chongming, East China Normal University, Shanghai 200062, China