Brain microabscesses in a porcine model of Staphylococcus aureus sepsis

Abstract

BackgroundSepsis caused by Staphylococcus aureus often leads to brain microabscesses in humans. Animal models of haematogenous brain abscesses would be useful to study this condition in detail. Recently, we developed a model of S. aureus sepsis in pigs and here we report that brain microabscesses develop in pigs with such induced S. aureus sepsis.Twelve pigs were divided into three groups. Nine pigs received an intravenous inoculation of S. aureus once at time 0 h (group 1) or twice at time 0 h and 12 h (groups 2 and 3). In each group the fourth pig served as control. The pigs were euthanized at time 12 h (Group 1), 24 h (Group 2) and 48 h (Group 3) after the first inoculation. The brains were collected and examined histopathologically.ResultsAll inoculated pigs developed sepsis and seven out of nine pigs developed brain microabscesses. The microabscesses contained S. aureus and were located in the prosencephalon and mesencephalon. Chorioditis and meningitis occurred from 12 h after inoculation.ConclusionsPigs with experimental S. aureus sepsis often develop brain microabscesses. The porcine brain pathology mirrors the findings in human sepsis patients. We therefore suggest the pig as a useful animal model of the development of brain microabscesses caused by S. aureus sepsis.

Bacterial Dissemination to the Brain in Sepsis

“…One could assume that any patient with bacteremia is at risk for developing microabscesses in multiple organ systems, and that this process underlies organ dysfunction in sepsis. Some common bacteria, such as Staphylococcus aureus, do form disseminated abscesses in the case of fulminant infection, including in the brain (30). Likewise, direct dissemination of Streptococcus to the myocardium contributes to cardiac dysfunction in models of pneumonia (31).…”