cocirculation of avian h9n2 and contemporary "human" h3n2 influenza a viruses in pigs in southeastern china: potential for genetic reassortment?pigs are permissive to both human and avian influenza viruses and have been proposed to be an intermediate host for the genesis of pandemic influenza viruses through reassortment or adaptation of avian viruses. prospective virological surveillance carried out between march 1998 and june 2000 in hong kong, special administrative region, people's republic of china, on pigs imported from southeastern china, provides the first evidence of interspecies transmission of avian h9n2 viruses to pigs and d ...200111559800
genetic analysis of six endangered local duck populations in china based on microsatellite markers.seventeen microsatellite loci were used to assess the genetic variation and population structure of six endangered duck populations in china. pic, heterozygosity with two estimators of genetic differentiation (f(st) and g(st)), and nei's standard genetic distance were evaluated. the results showed that these six endangered duck populations showed high polymorphism. the proportion of inter-population subdivision among the six duck populations ranged between 17.0 and 14.7%. the average heterozygos ...200718037138
genetic evolution of h9 subtype influenza viruses from live poultry markets in shanghai, china.h9n2 influenza viruses have become established and maintain long-term endemicity in poultry. the complete genomes of seven avian h9n2 influenza viruses were characterized. these seven influenza virus isolates were obtained from live poultry markets in shanghai, china, in 2002 and from 2006 to 2008. genetic analysis revealed that all seven isolates had an rssr motif at the cleavage site of hemagglutinin (ha), indicating low pathogenicity in chickens. phylogenetic analyses indicated that the seven ...200919656985
[investigation on the source of the first human of avian influenza a (h5n1) case in beijing.].to investigate the source of the first human case of avian influenza a (h5n1) infection in beijing.200920193576
isolation and characterization of a reovirus causing spleen necrosis in pekin ducklings.high rates of mortality for pekin ducklings have been recorded in several duck farms in china since 2006. dead ducklings were characterized by spleen necrosis, suggesting microbial infection as a cause of disease. laboratory investigations led to the isolation of a virus strain from the spleen tissues of dead ducklings, designated drv-hc. subsequent experimental infections with drv-hc resulted in marked spleen necrosis in the ducklings similar to those observed in the natural outbreaks. electron ...201120970930
potential risk of zoonotic transmission from young swine to human: seroepidemiological and genetic characterization of hepatitis e virus in human and various animals in beijing, china.the aim of this study was to further investigate the prevalence of infection and genotype of hepatitis e virus (hev) among different species of animals, people whose works are related to pigs and the general population in the suburb of beijing, china. serum and faecal samples were collected from 10 animal species and humans. anti-hev was detected by enzyme immunoassays (eia); hev rna was amplified by reverse transcription-nested polymerase chain reaction (rt-npcr) method. pcr products were clone ...201121914080
isolation and characterization of h4n6 avian influenza viruses from mallard ducks in beijing, china.the novel h7n9 influenza virus, which has caused severe disease in humans in china, is a reassortant with surface genes derived from influenza viruses in wild birds. this highlights the importance of monitoring influenza viruses in these hosts. however, surveillance of influenza virus in wild birds remains very limited in china. in this study, we isolated four h4n6 avian influenza viruses (aivs) from mallard ducks in beijing wetland park, which is located on the east asia-australasia migratory f ...201728877243
Epidemiological investigation and genome analysis of duck circovirus in Southern China.Duck circovirus (DuCV), a potential immunosuppressive virus, was investigated in Southern China from March 2006 to December 2009 by using a polymerase chain reaction (PCR) based method. In this study, a total of 138 sick or dead duck samples from 18 different farms were examined with an average DuCV infection rate of ~35%. It was found that ducks between the ages of 40~60 days were more susceptible to DuCV. There was no evidence showing that the DuCV virus was capable of vertical transmission. F ...201121979568
contribution of chinese pekin duck complement component c3d-p29 repeats to enhancement of th2-biased immune responses against ndv f gene induced by dna immunization.c3d, a split product of c3, interacts with its receptor (cr2 or cd21) on b cells and follicular dendritic cells (fdcs) and is crucial for induction and maintenance of a normal humoral immune response. this fragment of complement protein c3 (c3d) has also been shown to enhance b cell responses when complexed with antigen and c3d fusion increased th2-biased immune response by inducing il-4 production.201020148704
origin and domestication history of peking ducks deltermined through microsatellite and mitochondrial marker order to elucidate the domestication history of peking ducks, 190 blood samples from six chinese indigenous duck breeds were collected with 186 individuals genotyped by 15 microsatellite markers. both the f(st) and nei's standard genetic distances (d(s)) from the microsatellite data indicated high genetic differentiation between peking duck and other chinese indigenous breeds. the haplotype network with mtdna data showed that most of the peking duck haplotypes were distinctly different from t ...200919937201
[genetic diversity of duck breeds: a study with microsatellite markers].thirty two microsatellite markers were utilized to analyze the genetic diversity and germplasm characteristics of five fujian native duck breeds (jinding duck, liancheng white duck, putian black duck, shanma duck, and muscovy duck) and two reference duck breeds (beijing duck and khaki campbell duck). by using the markers, 371 alleles in test duck breeds were detected. the average allelic number per locus was 11.719, average value of pic was 0.522, average number of effective alleles was from 5.1 ...200919449585
continuing evolution of h9n2 influenza viruses in southeastern china.h9n2 influenza viruses are panzootic in domestic poultry in eurasia and since 1999 have caused transient infections in humans and pigs. to investigate the zoonotic potential of h9n2 viruses, we studied the evolution of the viruses in live-poultry markets in hong kong in 2003. h9n2 was the most prevalent influenza virus subtype in the live-poultry markets between 2001 and 2003. antigenic and phylogenetic analysis of hemagglutinin (ha) showed that all of the 19 isolates found except one belonged t ...200415280470
distributions of the cardiac plexuses and ganglia in the beijing duck.distributions of the cardiac plexuses and cardiac ganglia were gross-anatomically and histologically studied in eight beijing ducks. the cardiac plexuses consisted of two components, the cardiac nerve arising from the sympathetic trunk and the cranial and caudal cardiac nerves arising from the vagus. branches of these nerves made the cardiac plexuses on the epicardium. the cardiac plexuses could be divided into the six plexuses, that is, the right and left coronary plexuses, pericardiac transver ...19979192367
spectrum of liver disease and duck hepatitis b virus infection in a large series of chinese ducks with hepatocellular carcinoma.the striking difference in the geographical distribution of liver cancer in ducks raised the question of whether duck hepatitis b virus (dhbv), like mammalian hepadnaviruses, could be an oncogenic agent. hepatocellular carcinomas (hccs) have been found only in domestic ducks in qidong, china, where hepatitis b virus infection and aflatoxin b1 (afb1) are both risk factors and where a high frequency of human hccs has been reported. to date, the study of liver pathology occurring in chinese ducks h ...19957768491
characterization of the pathogenicity of members of the newly established h9n2 influenza virus lineages in asia.the reported transmission of avian h9n2 influenza viruses to humans and the isolation of these viruses from hong kong poultry markets lend urgency to studies of their ecology and pathogenicity. we found that h9n2 viruses from north america differ from those of asia. the north american viruses, which infect primarily domestic turkeys, replicated poorly in inoculated chickens. phylogenetic analysis of the hemagglutinin and nucleoprotein genes indicated that the asian h9n2 influenza viruses could b ...200010662623
large-scale survey of cryptosporidium spp. in chickens and pekin ducks (anas platyrhynchos) in henan, china: prevalence and molecular characterization.few data are available on the molecular characterization of cryptosporidium spp. in chickens and ducks in china. in this study, 2579 faecal samples from 46 chicken farms and eight pekin duck farms in 21 prefectures in henan province were examined. the overall infection rate of cryptosporidium was 10.6% (163/1542) in layer chickens (10 out of 17 farms), 3.4% (16/473) in broilers (five out of 29 farms), and 16.3% (92/564) in pekin ducks (four out of eight farms), respectively. the highest infectio ...201021154053
[hepatitis e virus (hev) genotype and the prevalence of anti-hev in 8 species of animals in the suburbs of beijing.].to investigate the prevalence of anti-hepatitis e virus (hev) and genotypes of hepatitis e virus in 8 species of animals including swine, cattle, sheep, horse, donkey, dog, chicken and duck in the suburb of beijing.201020302698
the genesis and evolution of h9n2 influenza viruses in poultry from southern china, 2000 to 2005.h9n2 influenza viruses have become established in terrestrial poultry in different asian countries over the last 2 decades. our previous study demonstrated that quail harbor increasingly diverse novel h9n2 reassortants, including both chicken/beijing/1/94 (ck/bei-like) and quail/hong kong/g1/97 (g1-like) viruses. however, since 1999, the genesis and evolution of h9n2 viruses in different types of poultry have not been investigated systematically. in the present study, h9n2 viruses isolated from ...200717652402
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