1. Key Laboratory of Zoonosis,
Ministry of Education, Jilin University, Xian Da Lu 5333, Changchun 130062, China
2. Institute of Pathogen Biology, Chinese Academy of Medical Sciences, Dongdan
San Tiao 9, Beijing 100730, China
3. Department of Microbiology, Tumour-
and Cell Biology, Karolinska Institutet, Nobels väg 16, SE171 71 Stockholm, Sweden