A novel mouse model of Staphylococcus aureus chronic osteomyelitis that closely mimics the human infection: an integrated view of disease pathogenesis.
Osteomyelitis is a serious bone infection typically caused by Staphylococcus aureus. The pathogenesis of osteomyelitis remains poorly understood, mainly for lack of experimental models that closely mimic human disease. We describe a novel murine model of metastatic chronic osteomyelitis initiated after intravenous inoculation of S. aureus microorganisms. The bacteria entered bones through the bloodstream and, after an acute phase with progressive growth (first 2 weeks after infection), they remained at constant numbers for up to 56 days (chronic phase). Clinical signs of illness and systemic inflammation were apparent only during the acute phase. Bone destruction and remodeling processes were readily detectable by magnetic resonance and X-ray imaging 3 weeks after infection, and high levels of bone deformation were observed during the chronic phase. Histological examination of infected bones demonstrated suppurative inflammation with foci of intense bacterial multiplication and necrosis during acute infection and osteoclastic resorption accompanied by new woven bone formation during chronic infection. Transmission electron microscopy revealed S. aureus microorganisms forming microcolonies within the nonmineralized collagen matrix or located intracellularly within neutrophils. In summary, our mouse model of staphylococcal hematogenous osteomyelitis precisely reproduces most features of the human disease. Although the extent of lesions in the chronic phase was subject to variation, this model is ideal for testing and monitoring novel treatment modalities via noninvasive imaging.
Infection Immunology Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany.
Sarah A
SA
Horst
Verena
V
Hoerr
Andreas
A
Beineke
Carolin
C
Kreis
Lorena
L
Tuchscherr
Julia
J
Kalinka
Sabine
S
Lehne
Ina
I
Schleicher
Gabriele
G
Köhler
Thomas
T
Fuchs
Michael J
MJ
Raschke
Manfred
M
Rohde
Georg
G
Peters
Cornelius
C
Faber
Bettina
B
Löffler
Eva
E
Medina
D000818:Animals; D001696:Biomechanical Phenomena; D002908:Chronic Disease; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging / Q000382:microbiology / Q000473:pathology; D021621:Imaging, Three-Dimensional; D007249:Inflammation / Q000473:pathology; D008279:Magnetic Resonance Imaging; D051379:Mice; D008810:Mice, Inbred C57BL; D010019:Osteomyelitis / Q000382:microbiology* / Q000473:pathology* / Q000503:physiopathology; D011859:Radiography; D013203:Staphylococcal Infections / Q000382:microbiology* / Q000473:pathology* / Q000503:physiopathology; D013211:Staphylococcus aureus / Q000502:physiology*; D013977:Tibia / Q000000981:diagnostic imaging / Q000382:microbiology / Q000473:pathology / Q000648:ultrastructure; D013997:Time Factors