title: Monitoring of abdominal Staphylococcus aureus infection using magnetic resonance imaging: a murine animal model for hepatic and renal abscesses.
abstract: To establish a routine workflow for in vivo magnetic resonance imaging (MRI) of mice infected with bacterial biosafety level 2 pathogens and to generate a mouse model for systemic infection with Staphylococcus aureus suitable for monitoring by MRI. A self-contained acrylic glass animal bed complying with biosafety level 2 requirements was constructed. After intravenous infection with 105colony-forming units (CFU) (n = 3), 106CFU (n = 11) or 107CFU (n = 6) of S. aureus strain Newman, female Balb/c mice were whole-body scanned by 7T MRI. Abdominal infections such as abscesses were visualized using a standard T2-weighted scan. Infection monitoring was performed for each animal by measurements at 1, 3, and 7 days after infection. Intravenous pathogen application led to a dose-dependent decrease in survival probability (p = 0.03). In the group with the highest infectious dose the 7-day survival rate was 33 %. An intermediate S. aureus dose showed a survival rate of 80 %, whereas at the lowest infection dose, none of the animals died. All animals with the highest infection dose exhibited hepatic abscesses 4 days after inoculation, 80 % developed renal abscesses on the 3rd day. Mice obtaining the intermediate S. aureus load reached a plateau at day 4 with 72 % liver and 60 % renal abscess probability. No abscesses were observed in other abdominal organs at any time point. The implemented experimental setup provides a suitable and reliable in vivo MRI method to study murine abdominal infection models using BSL-2 pathogen. Systemic Staphylococcus aureus infection leads to a dose-dependent development of hepatic and renal abscesses.
authors: Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany. marie-luise.kromrey@uni-greifswald.de.
authors: M L
authors: ML
authors: Kromrey
authors: Friedrich Loeffler Institute of Medical Microbiology, University Greifswald, Greifswald, Germany.
authors: A
authors: A
authors: Göhler
authors: Institute for Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany.|Research Centre for Prevention and Health, Glostrup University Hospital, Glostrup, Denmark.
authors: N
authors: N
authors: Friedrich
authors: Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany.
authors: K
authors: K
authors: Kindermann
authors: Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany.
authors: S
authors: S
authors: Hadlich
authors: Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany.
authors: D
authors: D
authors: Puls
authors: Friedrich Loeffler Institute of Medical Microbiology, University Greifswald, Greifswald, Germany.
authors: I
authors: I
authors: Steinmetz
authors: Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany.
authors: J P
authors: JP
authors: Kühn
mesh_terms: D018784:Abdominal Abscess / Q000000981:diagnostic imaging* / Q000473:pathology; D000818:Animals; D058491:Bacterial Load; D004195:Disease Models, Animal; D005260:Female; D007674:Kidney Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D008107:Liver Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008807:Mice, Inbred BALB C; D013203:Staphylococcal Infections / Q000000981:diagnostic imaging* / Q000473:pathology; D013211:Staphylococcus aureus / Q000302:isolation & purification; D016019:Survival Analysis