1. Department of Pathogenic Organism Biology, Henan University of Chinese Medicine, Zhengzhou, Henan Province 450046, P. R. China
2. Department of Otolaryngology Head and Neck Surgery, The First Affliated Hospital, Zhengzhou University, Zhengzhou, Henan Province 450052, P. R. China
3. Department of Immunology & Microbiology, Basic Medical College, Zhengzhou University, Zhengzhou, Henan Province 450001, P. R. China
4. Department of Immunology & Microbiology, Guangdong Medical University, Dongguan, Guangdong Province 523808, P. R. China