title: Proteolytic bacteria in the lower digestive tract of poultry may affect avian influenza virus pathogenicity.
abstract: Proteolytic cleavage of hemagglutinin is required for cell entry by receptor-mediated endocytosis and plays a key role in pathogenicity of the influenza virus. Despite several studies describing relationships between bacterial proteases and influenza A viral activation in mammals, very little is known about the role of the normal bacterial flora of birds on hemagglutinin activation. We examined the indigenous intestinal microflora of 100 mixed-sex, 27-d-old Ross chickens from a commercial poultry facility for protease-secreting bacteria. Protease-secreting bacteria were isolated from 82 of 100 chickens with 50 birds exhibiting 2 or more protease-secreting bacterial species. A total of 20 protease-secreting bacterial species were identified: 17 gram-positive cocci, 2 gram-positive rods, and 1 gram-negative rod. Enterococcus faecalis, Enterococcus gallinarum, and Proteus mirabilis were the most frequently observed protease-secreting bacterial species. The presence of proteolytic bacteria in the intestinal tract of poultry in this study suggests the possibility of yet-to-be-described role(s) in cleavage of hemagglutinin that may alter the pathogenicity of avian influenza viruses.
authors.affiliation: Department of Civil and Environmental Engineering, College of Engineering, The University of Texas at San Antonio 78249, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: King
authors.forename: M N
authors.initials: MN
authors.lastname: Guentzel
authors.forename: B P
authors.initials: BP
authors.lastname: Arulanandam
authors.forename: B
authors.initials: B
authors.lastname: Lupiani
authors.forename: J P
authors.initials: JP
authors.lastname: Chambers
mesh_terms: D000818:Animals; D002645:Chickens / Q000382:microbiology / Q000821:virology; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology*; D009980:Influenza A virus / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000821:virology*; D008297:Male; D010447:Peptide Hydrolases / Q000378:metabolism
chemical_list: D010447:Peptide Hydrolases