title: Differences in Haemophilus parasuis adherence to and invasion of AOC-45 porcine aorta endothelial cells.
abstract: BACKGROUND
  The pathogenesis of Haemophilus parasuis depends on the bacterium's ability to interact with endothelial cells and invade adjacent tissues. In this study, we investigated the abilities of eight H. parasuis reference strains belonging to serovars 1, 2, 4, 5, 7, 9, 10 and 13 to adhere to and invade porcine aortic endothelial cells (AOC-45 cell line).
  
  
  RESULTS
  The strains belonging to serovars 1, 2 and 5 were able to attach at high rates between 60 and 240 min of incubation, and serovars 4, 7 and 13 had moderate attachment rates; however, the strains belonging to serovars 9 and 10 had low adherence at all time points. Strong adherence was observed by scanning electron microscopy for the strains of serovars 5 and 4, which had high and moderate numbers, respectively, of H. parasuis cells attached to AOC-45 cells after 240 min of incubation. The highest invasiveness was reached at 180 min by the serovar 4 strain, followed by the serovar 5 strain at 240 min. The invasion results differed substantially depending on the strain.
  
  
  CONCLUSIONS
  The reference strains of H. parasuis serovars 1, 2, 4 and 5 exhibited high adhesion and invasion levels to AOC-45 porcine aorta endothelial cells, and these findings could aid to better explain the pathogenesis of the disease caused by these serovars.
authors.affiliation: Section of Microbiology and Immunology, Department of Animal Health, University of León, León, Spain. rfran@upf.br.
authors.forename: Rafael
authors.initials: R
authors.lastname: Frandoloso
authors.forename: Mateus
authors.initials: M
authors.lastname: Pivato
authors.forename: Sonia
authors.initials: S
authors.lastname: Martínez-Martínez
authors.forename: Elías F
authors.initials: EF
authors.lastname: Rodríguez-Ferri
authors.forename: Luiz Carlos
authors.initials: LC
authors.lastname: Kreutz
authors.forename: César B Gutiérrez
authors.initials: CB
authors.lastname: Martín
mesh_terms: D000818:Animals; D001011:Aorta; D001422:Bacterial Adhesion / Q000502:physiology*; D002460:Cell Line; D042783:Endothelial Cells / Q000382:microbiology* / Q000648:ultrastructure; D044137:Haemophilus parasuis / Q000502:physiology* / Q000648:ultrastructure; D013552:Swine