Cong Yan-Long, Wang Chun-Feng, Yan Chun-Mei, Peng Jin-Shan, Jiang Zhan-Lei, Liu Jin-Hua
Laboratory of Infectious Diseases, College of Animal Science and Veterinary Medicine, Jilin University, Changchun 130062, People's Republic of China.
Virus Genes. 2008 Jun;36(3):461-9. doi: 10.1007/s11262-008-0227-z. Epub 2008 Apr 10.
In 2004, H9N2 influenza A viruses were isolated from pigs with respiratory syndrome in commercial swine farms in Henan province, China. Antigenic and genetic characterization were performed for seven swine H9N2 influenza viruses. The hemagglutinin antigenicity of swine H9N2 viruses was similar to those of avian H9N2 viruses of A/duck/Hong Kong/Y280/1997 (Dk/HK/Y280/97)-like sublineage prevalent in China. It is noteworthy that the neuraminidase of these isolates had no deletions in the stalk, which was seldom observed in those viruses of Dk/HK/Y280/97-like sublineage. Genetic analysis revealed that all seven isolates had an -R-S-S-R- motif at the HA cleavage site, which was the same as those of Dk/HK/Y280/97-like viruses established in avian population in China. Phylogenetic analyses showed that the seven swine H9N2 viruses were completely derived from avian influenza viruses of Dk/HK/Y280/97-like sublineage. The present results indicated that avian-to-pig interspecies transmission of H9N2 viruses continued to exist in China through 2004; therefore, surveillance of swine influenza should be given a high priority.
2004年，在中国河南省的商业性养猪场中，从患有呼吸道综合征的猪体内分离出了H9N2甲型流感病毒。对7株猪源H9N2流感病毒进行了抗原性和基因特性分析。猪源H9N2病毒的血凝素抗原性与在中国流行的A/鸭/香港/Y280/1997（鸭/香港/Y280/97）样亚系禽流感H9N2病毒相似。值得注意的是，这些分离株的神经氨酸酶在柄部没有缺失，而在鸭/香港/Y280/97样亚系的那些病毒中很少观察到这种情况。基因分析表明，所有7株分离株在HA裂解位点都有一个-R-S-S-R-基序，这与在中国禽类群体中建立的鸭/香港/Y280/97样病毒相同。系统发育分析表明，这7株猪源H9N2病毒完全源自鸭/香港/Y280/97样亚系的禽流感病毒。目前的结果表明，直到2004年H9N2病毒的禽到猪的种间传播在中国仍然存在；因此，猪流感监测应被高度重视。
