Waterfowl
Mostrando 13-24 de 30 artigos, teses e dissertações.
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13. H5N1 influenza: A protean pandemic threat
Infection with avian influenza A virus of the H5N1 subtype (isolates A/HK/212/03 and A/HK/213/03) was fatal to one of two members of a family in southern China in 2003. This incident was preceded by lethal outbreaks of H5N1 influenza in waterfowl, which are the natural hosts of these viruses and, therefore, normally have asymptomatic infection. The hemagglut
National Academy of Sciences.
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14. Subacute toxic effects of dietary T-2 toxin in young mallard ducks.
Young Mallard ducks (Anas platyrhynchos) were fed diets containing purified T-2 toxin at levels of 20 or 30 ppm for two or three weeks. Ingestion of T-2 toxin was associated with reduced weight gain and delayed development of adult plumage. Affected ducks developed caseonecrotic plaques throughout the upper alimentary tract, especially in oropharynx and vent
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15. Generation of a Highly Pathogenic Avian Influenza A Virus from an Avirulent Field Isolate by Passaging in Chickens
Highly virulent avian influenza viruses can arise from avirulent strains maintained in poultry, but evidence to support their generation from viruses in wild birds is lacking. The most likely mechanism for the acquisition of virulence by benign avian viruses is the introduction of mutations by error-prone RNA polymerase, followed by the selection of virulent
American Society for Microbiology.
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16. Reemerging H5N1 Influenza Viruses in Hong Kong in 2002 Are Highly Pathogenic to Ducks
Waterfowl are the natural reservoir of all influenza A viruses, which are usually nonpathogenic in wild aquatic birds. However, in late 2002, outbreaks of highly pathogenic H5N1 influenza virus caused deaths among wild migratory birds and resident waterfowl, including ducks, in two Hong Kong parks. In February 2003, an avian H5N1 virus closely related to one
American Society for Microbiology.
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17. Giardia sp. Cysts and Infectious Cryptosporidium parvum Oocysts in the Feces of Migratory Canada Geese (Branta canadensis)
Fecal droppings of migratory Canada geese, Branta canadensis, collected from nine sites near the Chesapeake Bay (Maryland), were examined for the presence of Cryptosporidium parvum and Giardia spp. Cryptosporidium sp. oocysts were found in feces at seven of nine sites, and Giardia cysts were found at all nine sites. The oocysts from three sites were infectio
American Society for Microbiology.
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18. 1917 Avian Influenza Virus Sequences Suggest that the 1918 Pandemic Virus Did Not Acquire Its Hemagglutinin Directly from Birds
Wild waterfowl captured between 1915 and 1919 were tested for influenza A virus RNA. One bird, captured in 1917, was infected with a virus of the same hemagglutinin (HA) subtype as that of the 1918 pandemic virus. The 1917 HA is more closely related to that of modern avian viruses than it is to that of the pandemic virus, suggesting (i) that there was little
American Society for Microbiology.
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19. Viability and infectivity of Cryptosporidium parvum oocysts are retained upon intestinal passage through a refractory avian host.
Six Cryptosporidium-free Peking ducks (Anas platyrhynchos) were each orally inoculated with 2.0 x 10(6) Cryptosporidium parvum oocysts infectious to neonatal BALB/c mice. Histological examination of the stomachs jejunums, ilea, ceca, cloacae, larynges, tracheae, and lungs of the ducks euthanized on day 7 postinoculation (p.i.) revealed no life-cycle stages o
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20. Role of domestic ducks in the propagation and biological evolution of highly pathogenic H5N1 influenza viruses in Asia
Wild waterfowl, including ducks, are natural hosts of influenza A viruses. These viruses rarely caused disease in ducks until 2002, when some H5N1 strains became highly pathogenic. Here we show that these H5N1 viruses are reverting to nonpathogenicity in ducks. Ducks experimentally infected with viruses isolated between 2003 and 2004 shed virus for an extend
National Academy of Sciences.
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21. Hemagglutination method for detection of freshwater cyanobacteria (blue-green algae) toxins.
Strains of the freshwater cyanobacteria (blue-green algae) Anabaena flosaquae and Microcystis aeruginosa produced toxins that caused intermittent but repeated cases of livestock, waterfowl, and other animal deaths. They also caused illness, especially gastrointestinal, in humans. The most common group of toxins produced by these two species were peptide toxi
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22. Salmonellae in Avian Wildlife in Norway from 1969 to 2000
Postmortem records of wild-living birds in Norway with laboratory-confirmed findings of salmonella infection were summarized for the period from 1969 to 2000. Salmonella spp. were isolated from 470 birds belonging to 26 species. The salmonella-positive birds included 441 small passerines, 15 gulls, 5 waterfowl, 4 birds of prey, 3 doves, and 2 crows. The bull
American Society for Microbiology.
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23. Matrix Gene of Influenza A Viruses Isolated from Wild Aquatic Birds: Ecology and Emergence of Influenza A Viruses
Wild aquatic birds are the primary reservoir of influenza A viruses, but little is known about the viruses' gene pool in wild birds. Therefore, we investigated the ecology and emergence of influenza viruses by conducting phylogenetic analysis of 70 matrix (M) genes of influenza viruses isolated from shorebirds and gulls in the Delaware Bay region and from du
American Society for Microbiology.
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24. Host-Adapted Cryptosporidium spp. in Canada Geese (Branta canadensis)
The prevalence and distribution of Cryptosporidium spp. in the fecal droppings of the free-living waterfowl Canada geese were examined at 13 sites in Ohio and Illinois. On the basis of the analysis of the small-subunit rRNA gene by PCR, followed by restriction fragment length polymorphism analysis and DNA sequencing, 49 (23.4%) of 209 fecal specimens collect
American Society for Microbiology.