Epidemiological Analysis and Genetic Characterization of Parvovirus in Ducks in Northern Vietnam Reveal Evidence of Recombination.

In total, 130 tissue-pooled samples collected from ducks in some provinces/cities in north Vietnam were examined for waterfowl parvovirus genome identification. Twenty-six (20%) samples were positive for the parvovirus infection, based on polymerase chain reaction analysis. Of the 38 farms tested, 14 (36.

Duck circovirus in northern Vietnam: genetic characterization and epidemiological analysis.

In the present study, tissue samples collected from 130 ducks from clinically suspected commercial flocks and diseased birds in six provinces of northern Vietnam were tested for duck circovirus (DuCV) infection. The DuCV genome was detected in 56 out of 130 (43.08%) duck samples by PCR.

Establishment of an In Vitro Model of Persistent Chicken Anemia Virus Infection.

Persistent infection of chicken anemia virus (CAV) in chickens has been suspected to result in immunosuppression and exogenous virus contamination within vaccine production. However, no direct evidence for persistent CAV infection has thus far been obtained. In this study, we aimed to establish an in vitro model of persistent CAV infection.

Evaluation of the replication and pathogenicity of a variant avian paramyxovirus serotype 6 in mice.

Avian paramyxoviruses (APMVs) have been evaluated for their potential use as vaccine vectors, sparking research efforts leading to a better understanding of APMVs' replication and pathogenicity. However, within APMV serotypes, significant genetic diversity exists, and the infectivity of variant strains in mammals has not been studied. We utilized a mouse model to evaluate the pathogenicity of a variant strain of APMV-6 (APMV-6/red-necked stint/Japan/8KS0813/2008) in comparison with the prototype APMV-6 strain (APMV-6/duck/Hong Kong/18/199/1977).

Genetic characterization of H5N2 influenza viruses isolated from wild birds in Japan suggests multiple reassortment.

Low-pathogenic avian influenza viruses (LPAIVs) of the H5 subtype can mutate to highly pathogenic forms, potentially destabilizing the poultry industry. Wild migratory birds are considered a natural reservoir of LPAIVs capable of dispersing both high- and low-pathogenic forms of the virus. Therefore, surveillance and characterization of AIV in wild birds are essential.

Development of a blocking latex agglutination test for the detection of antibodies to chicken anemia virus.

A blocking latex agglutination test (b-LAT) developed in this study was evaluated for the detection of antibodies against chicken anemia virus (CAV) in chickens. Polystyrene latex beads were coupled with a neutralizing monoclonal antibody (mAb) to CAV (mAb-beads). When mAb-beads were mixed with antigens prepared from the lysate of MDCC-MSB1 cells infected with CAV, agglutination occurred.

Genetic characterization of a rare H12N3 avian influenza virus isolated from a green-winged teal in Japan.

This study reports on the genetic characterization of an avian influenza virus, subtype H12N3, isolated from an Eurasian green-winged teal (Anas crecca) in Japan in 2009. The entire genome sequence of the isolate was analyzed, and phylogenetic analyses were conducted to characterize the evolutionary history of the isolate. Phylogenetic analysis of the hemagglutinin and neuraminidase genes indicated that the virus belonged to the Eurasian-like avian lineage.

Characterization of a genetic and antigenic variant of avian paramyxovirus 6 isolated from a migratory wild bird, the red-necked stint (Calidris ruficollis).

A hemagglutinating virus (8KS0813) was isolated from a red-necked stint. Hemagglutination inhibition and neutralization tests indicated that 8KS0813 was antigenically related to a prototype strain, APMV-6/duck/Hong Kong/18/199/77, but with an 8- and 16-fold difference, respectively, in their titers. The full genome sequence of 8KS0813 showed 98.

Genetic characterization of an H5N1 avian influenza virus from a vaccinated duck flock in Vietnam.

This study reports the genetic characterization of a highly pathogenic avian influenza virus subtype H5N1 isolated from a moribund domestic duck in central Vietnam during 2012. In the moribund duck's flock, within 6 days after vaccination with a commercial H5N1 vaccine (Re-5) to 59-day-old birds, 120 out of 2,000 ducks died. Genetic analysis revealed a substantial number of mutations in the HA gene of the isolate in comparison with the vaccine strains, Re-1 and Re-5.