Pierre-Yves Daoust

Publications of Pierre-Yves Daoust

• Replication of low pathogenic avian influenza virus in naturally infected Mallard ducks (Anas platyrhynchos) causes no morphologic lesions.

  Authors: Pierre-Yves Daoust, Frederick S B Kibenge, Ron A M Fouchier, Marco W G van de Bildt, Debby van Riel, Thijs Kuiken

  Journal of wildlife diseases. 04/2011; 47(2):401-9.

  Although the Mallard (Anas platyrhynchos) is considered an important maintenance host for low pathogenic avian influenza (LPAI) viruses, viral cell tropism and pathology in naturally infected birdsAlthough the Mallard (Anas platyrhynchos) is considered an important maintenance host for low pathogenic avian influenza (LPAI) viruses, viral cell tropism and pathology in naturally infected birds are largely unknown. In August 2006, we collected 19 free-living hatch-year Mallards that were positive for LPAI virus by real-time reverse-transcriptase polymerase chain reaction (RRT-PCR) in combined oropharyngeal and cloacal swabs. We investigated virus infection and associated lesions in the digestive and respiratory tracts by RRT-PCR, virus culture, immunohistochemistry (IHC), and histology. By RRT-PCR, 15 birds were positive in cloacal bursa, colon/cloaca, or both, and three were positive in lungs. Virus was isolated from eight birds and typed as H2N3 (three birds), H3N3 (two birds), H3N8 (one bird), H4N6 (one bird), and H?N3 (one bird). By IHC, birds were positive in the cloacal bursa (eight birds), colon (three), cecum (two), or ileum (one). Cell types infected were superficial epithelial cells of the bursa and epithelial cells of the intestinal villi and, less commonly, mucosal glands. By histology, there was no evidence of lesions associated with LPAI virus infection. These results show that epithelia of the cloacal bursa and of the lower intestine are important sites of natural LPAI virus infection in free-living hatch-year Mallards. The lack of lesions associated with this infection suggests that there is a strong selection by LPAI virus to cause minimal virulence in this maintenance host species.

• Canine distemper virus-associated encephalitis in free-living lynx (lynx canadensis) and bobcats (lynx rufus) of eastern Canada.

  Authors: Pierre-Yves Daoust, Scott R McBurney, Dale L Godson, Marco W G van de Bildt, Albert D M E Osterhaus

  Journal of wildlife diseases. 08/2009; 45(3):611-24.

  Between 1993 and 1999, encephalitis caused by morbillivirus was diagnosed by immunohistochemistry and histology in six lynx (Lynx canadensis) and one bobcat (Lynx rufus) in the eastern CanadianBetween 1993 and 1999, encephalitis caused by morbillivirus was diagnosed by immunohistochemistry and histology in six lynx (Lynx canadensis) and one bobcat (Lynx rufus) in the eastern Canadian provinces of New Brunswick and Nova Scotia. Five of the six cases in lynx occurred within an 11-mo period in 1996-97. A second bobcat with encephalitis caused by unidentified protozoa and a nematode larva also had immunohistochemical evidence of neurologic infection by morbillivirus. The virus was identified as canine distemper virus (CDV) by reverse transcriptase polymerase chain reaction and nucleotide sequencing in four of five animals from which frozen tissue samples were available, and it was isolated in cell culture from one of them. To our knowledge, this is the first report of disease caused by CDV in free-living felids in North America.

• Bacterial flora of free-living double-crested cormorant (Phalacrocorax auritus) chicks on Prince Edward Island, Canada, with reference to enteric bacteria and antibiotic resistance.

  Authors: Greg Dobbin, Harry Hariharan, Pierre-Yves Daoust, Shebel Hariharan, Susan Heaney, Mada Coles, Lawrence Price, C Anne Muckle

  Comparative immunology, microbiology and infectious diseases. 01/2005; 28(1):71-82.

  Cloacal and pharyngeal swabs from 100 tree-nesting Double-crested cormorant (DCC) chicks were examined by culture for commensal and potentially pathogenic bacteria. No Salmonella or ErysipelothrixCloacal and pharyngeal swabs from 100 tree-nesting Double-crested cormorant (DCC) chicks were examined by culture for commensal and potentially pathogenic bacteria. No Salmonella or Erysipelothrix were isolated from the cloacal swabs. Twenty-two cloacal swabs were positive for Campylobacter, of which 14 were C. jejuni, C. coli, and 1 C. lari. None belonged to common serotypes isolated from humans or animals in recent years in Canada. Tests for antimicrobial drug resistance among 187 commensal Escherichia coli isolates from the cloacal swabs indicated that < or =5% were resistant to any of the 12 antibiotics tested. This contrasts with the frequently high resistance rates among E. coli isolates from poultry. Pharyngeal swabs from DCC were negative for Pasteurella multocida. Culture of cloacal swabs from 100 ground-nesting DCC chicks resulted in the recovery of 19 Salmonella isolates, all of which were S. enterica serotype Typhimurium. None of these isolates were resistant to any of the 12 antibiotics tested. Altogether, these findings suggest that DCC from this region are not being colonized with commensal or potentially pathogenic enteric bacteria from agricultural or human sources and that enteric bacteria isolated from these birds are unlikely to contribute to a gene pool of antimicrobial drug resistance.

• Health status of harp seals (Phoca groenlandica) and hooded seals (Cystophora cristata) on Sable Island, Nova Scotia, Canada, concurrent with their expanding range.

  Authors: Zoe Lucas, Pierre-Yves Daoust, Gary Conboy, Michael Brimacombe

  Journal of wildlife diseases. 02/2003; 39(1):16-28.

  Beach surveys for harp (Phoca groenlaandica) and hooded (Cystophora cristata) seals documented a dramatic increase in their numbers on Sable Island in mid 1990s. In the 1980s, no more than fiveBeach surveys for harp (Phoca groenlaandica) and hooded (Cystophora cristata) seals documented a dramatic increase in their numbers on Sable Island in mid 1990s. In the 1980s, no more than five animals of both species were observed on this island each year, however, during late 1994 to 1998, 1,191 harp and 870 hooded seals, mostly young animals, were recorded. Although some of these seals had been killed by sharks, most (roughly 75%) were found alive or as intact carcasses on the beach, and some of the live seals were later found dead. Emaciation/starvation was considered the primary cause of death in seals that were not obviously killed by sharks. Factors that may have compounded this poor body condition included gastric impaction with abnormal ingesta, hemorrhagic diathesis possibly induced by parasitic migration and secondary vasculitis, and stomatitis (in hooded seals only). Some harp and hooded seals expanding their range in recent years may be unable to feed successfully, although the reasons for this are unclear.

• Animal welfare and the harp seal hunt in Atlantic Canada.

  Authors: Pierre-Yves Daoust, Alice Crook, Trent K Bollinger, Keith G Campbell, James Wong

  The Canadian veterinary journal. La revue vétérinaire canadienne. 10/2002; 43(9):687-94.

  Much attention has been given over the years to animal welfare issues surrounding the seal hunt in Atlantic Canada. However, very little information is available on this subject in the scientificMuch attention has been given over the years to animal welfare issues surrounding the seal hunt in Atlantic Canada. However, very little information is available on this subject in the scientific literature. This article reports the results of observations made by representatives of the Canadian Veterinary Medical Association at the hunt in recent years and compares them with observations made by members of the International Fund for Animal Welfare. The conclusion is that the large majority of seals taken during this hunt (at best, 98% in work reported here) are killed in an acceptably humane manner. However, the small proportion of animals that are not killed effectively justifies continued attention to this hunt on the part of the veterinary profession.