Open Access Highly Accessed Research article

Differences in Haemophilus parasuis adherence to and invasion of AOC-45 porcine aorta endothelial cells

Rafael Frandoloso12*, Mateus Pivato12, Sonia Martínez-Martínez1, Elías F Rodríguez-Ferri1, Luiz Carlos Kreutz2 and César B Gutiérrez Martín1

Author Affiliations

1 Section of Microbiology and Immunology, Department of Animal Health, University of León, León, Spain

2 Laboratory of Microbiology and Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, Brazil

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BMC Veterinary Research 2013, 9:207  doi:10.1186/1746-6148-9-207

Published: 12 October 2013

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.

Conclusion

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.

Keywords:
Haemophilus parasuis; Glässer’s disease; AOC-45 cells; Adherence; Invasion