Seasonal pattern and HA, NA, PB2 gene phylogenetic analysis of avian influenza A (H7N9) virus in live poultry markets in Suzhou, China
ZHU Jie1, ZHANG Yan2, ZHANG Chao2, TANG Xinying2, ZHANG Hongbo2, WANG Xiang2, SONG Yufeng2, ZHOU Dongming2, WANG Qinglin1
1. Hunan Normal University School of Medicine, Changsha 410013, China; 2. Vaccine Research Center, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China
Abstract：A novel avian influenza A (H7N9) virus has caused epidemics during 2013 to 2014, and sporadic infections in 2015. To investigate the evolutionary history and seasonal variations of H7N9 in live poultry markets (LPMs), 2 655 pharyngeal swabs of chickens and ducks were collected from July to December 2013 in Suzhou, Jiangsu Province, China, which was one of the major epidemic areas in 2013. The results showed that the positive rate in winter was higher than that in summer and there were mixed infections among H5, H7, and H9 strains, suggesting the occurrence of multiple reassortment events. The HA, NA and PB2 genes from selected H7N9-positive samples were then sequenced to trace the evolutionary history of the novel H7N9 virus. Phylogenetic analysis revealed that all Suzhou isolates in this study were clustered around the novel H7N9 virus, but they also continued to evolve while circulating in the poultry. In fact, the PB2 gene of some sequenced samples was closely related to H5N1. This study identifies the genetic reassortment of a novel H7N9 virus in Suzhou and suggests that constant surveillance of all avian influenza virus subtypes in LPMs will help to track the source of newly emerging virulent viral strains.
朱杰1，张琰2，张超2，唐盺莹2，张洪波2，王祥2，宋宇峰2，周东明2，王庆林1. 苏州活禽市场禽流感病毒(H7N9)季节变化及HA、NA、PB2基因系统进化分析[J]. 微生物与感染, 2018, 13(3): 146-154.
ZHU Jie1, ZHANG Yan2, ZHANG Chao2, TANG Xinying2, ZHANG Hongbo2, WANG Xiang2, SONG Yufeng2, ZHOU Dongming2, WANG Qinglin1. Seasonal pattern and HA, NA, PB2 gene phylogenetic analysis of avian influenza A (H7N9) virus in live poultry markets in Suzhou, China. JOURNAL OF MICROBES AND INFECTIONS, 2018, 13(3): 146-154.
