Isolation and phylogenetic analysis of h9n2 swine influenza virus from sick pigs in Southern China in 2010

In January, 201 0 before swine were infected with foot and mouth disease in Guangdong, some pigs have shown flu-like symptoms; cough, sneeze, runny nose and fever. Researchers collected the nasopharyngeal swab of all sick pigs as much as possible. One H9N2 influenza viruses were isolated from the pig population. The complete genome of one isolate, designated A/Swine/Guangdong/L1/2010(H9N2) was sequenced and compared with sequences available in GenBank. The results of analyses indicated that the sequence of A/Swine/Guangdong/L1/2010(H9N2) was similar to those of several avian influenza viruses. According to phylogenetic analysis of the complete gene sequences, A/Swine/Guangdong/L1/2010(H9N2) possibly originated from the reassortment of avian influenza viruses.