Genetic characterization of H5N1 avian influenza viruses isolated in southern China during the 2003–04 avian influenza outbreaks

Abstract

The recent H5N1 avian influenza outbreaks in Asia spread over more than 8 countries. It has caused enormous economic loss and grand challenges for the public health. During these breakouts we isolated three strains of H5N1 Avian Influenza Virus (AIV) from chickens and one from duck in different farms of Southern China. We completely sequenced these four AIVs. Molecular characterization demonstrated that these strains retain the reported H5N1 AIV sequence properties relevant to virus virulence and host adaptation. Phylogeny results demonstrated that three of these isolates (except A/Chicken/Guangdong/174/04) were closely linked to other H5N1 AIVs isolated from the recent H5N1 outbreaks in Asia. Six of 8 segments (except PA and M) of A/Chicken/Guangdong/174/04 also shares a close linkage to other H5N1 AIVs isolated from the recent H5N1 outbreaks. However, the PA gene of A/Chicken/Guangdong/174/04 and another H5N1 strain forms a distinct subgroup along with an H6N1 AIV, and the M gene of A/Chicken/Guangdong/174/04 shows a close linkage to some H5N1 AIVs from aquatic species in China. Our findings suggest that a new genotype of AIV (in addition to previous reported ones) was present during the 2003-04 Asian bird flu outbreaks and that continuing virus surveillance of AIVs be conducted to monitor the evolutionary paths of the A/Chicken/Guangdong/174/04-like AIVs.

Avian-origin H3N2 canine influenza A viruses in Southern China

“…Four influenza A viruses were isolated: A/canine/Guangdong/01/2006(H3N2), A/canine/Guangdong/02/2006(H3N2), A/canine/Guangdong/01/2007(H3N2), and A/canine/Guangdong/02/2007(H3N2). The genomes of these viruses were fully sequenced as described before (Wan et al , 2005) and deposited in GenBank with the accession number GU433345-GU433376.…”

Newcastle Disease Virus-Based Live Attenuated Vaccine Completely Protects Chickens and Mice from Lethal Challenge of Homologous and Heterologous H5N1 Avian Influenza Viruses

“…In 1997, H5N1 AIV caused disease outbreaks in poultry in Hong Kong (31,32) and was transmitted into humans, causing six deaths (8,33). Starting from late 2003, H5N1 influenza viruses began to spread and caused disease outbreaks in China (39), Japan (21), South Korea (18), Thailand, Vietnam, Indonesia, Cambodia, Malaysia, and Laos (Office International des Epizooties [OIE]; http://www.oie.int), resulting in the destruction of hundreds of millions of poultry, including chickens, ducks, and geese. In May, 2005, an H5N1 highly pathogenic avian influenza virus (HPAIV) outbreak occurred in wild birds in Qinghai Lake, in western China (6,7,20).…”

Evolution of Highly Pathogenic H5N1 Avian Influenza Viruses in Vietnam between 2001 and 2007

“…Phylogenetic inferences relied on Maximum Parsimony (MP) and Neighbor-Joining (NJ) methods using PAUP* 4.0 Beta [32], as described earlier [33]. Maximum Likelihood (ML) tree estimation was evaluated using GARLI version 0.951 [34].…”