Journal article
The Impact of Staphylococcus Aureus Concentration on the Development of Pulmonary Lesions and Cytokine Expression After Intravenous Inoculation of Pigs
University of Copenhagen1
National Veterinary Institute, Technical University of Denmark2
Division of Veterinary Diagnostics and Research, National Veterinary Institute, Technical University of Denmark3
Innate Immunology, Division of Veterinary Diagnostics and Research, National Veterinary Institute, Technical University of Denmark4
Acute respiratory distress syndrome is a common complication in severe sepsis. In pigs, the lungs play an important role in clearing systemic bacterial infections due to pulmonary intravascular macrophages found specifically in pigs. However, this increases the exposure of the porcine lungs to pathogens and potential injury.
The authors propose that increasing the concentration of the inoculum without changing the bacterial dose will lead to severe sepsis with pronounced pulmonary lesions. This could potentially create a risk of cytokine spillover to the circulation, leading to an increased systemic response. Eight Danish Landrace pigs, approximately 10 weeks old, were inoculated twice with a low or once with a high concentration of Staphylococcus aureus.
Three pigs were sham-inoculated. The animals were grouped based on macro- and microscopic lung lesions. The mRNA expression of local pulmonary inflammatory markers was compared to protein levels of systemic inflammatory markers. The most severe pulmonary lesions were observed in animals receiving the high S. aureus concentration, indicating that severity of lesions is dependent on inoculum concentration rather than total numbers of bacteria.
Furthermore, local mRNA expression of inflammatory cytokines appeared to be dependent on the magnitude and severity of tissue destruction, including the ability to confine the lesions. Increasing mRNA levels of serum amyloid A could be a confident marker of severity of pulmonary lesions. Since no correlation was observed between local and systemic levels of inflammatory cytokines, this finding could indicate an ability of the porcine lung to compartmentalize the local inflammatory response and thus restrict systemic contribution.
Language: | English |
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Publisher: | SAGE Publications |
Year: | 2012 |
Pages: | 950-962 |
ISSN: | 15442217 , 01913808 , 03009858 and 23806893 |
Types: | Journal article |
DOI: | 10.1177/0300985812439726 |
ORCIDs: | Skovgaard, Kerstin , Heegaard, Peter M. H. , 0000-0001-7277-7829 and 0000-0003-1539-9491 |
Bacterial concentration Cytokine Histopathology Lung Porcine model RT-qPCR Staphylococcus aureus Swine
Animals Bacterial Load Biomarkers Bronchoalveolar Lavage Fluid Cytokines Disease Models, Animal Female Infectious Disease Lymph Nodes Macrophages, Alveolar RNA, Messenger Respiratory Distress Syndrome Sepsis Severity of Illness Index Specific Pathogen-Free Organisms Staphylococcal Infections Sus scrofa Swine Diseases bacterial concentration cytokine histopathology lung porcine model swine