Spatiotemporal progression of localized bacterial peritonitis before and after open abdomen lavage monitored by in vivo bioluminescent imaging
Accepted 21 May 2009. published online 07 September 2009.
Background
Bacterial peritonitis is a life-threatening abdominal infection associated with high morbidity and mortality. The rat is a popular animal model for studying peritonitis and its treatment, but longitudinal monitoring of the progression of peritonitis in live animals has been impossible until now and thus required a large number of animals. Our objective was to develop a noninvasive in vivo imaging technique to monitor the spatiotemporal spread of bacterial peritonitis.
Methods
Peritonitis was induced in 8 immunocompetent male Wistar rats by placing fibrin clots containing 5 × 108 cells of both Bacteroides fragilis (American Type Tissue Culture [ATCC)] 25285 and bioluminescent Escherichia coli Xen14. After 1 or 2 days, infected clots were removed and open abdomen lavage was performed. In vivo bioluminescent imaging was used to monitor the spread of peritonitis.
Results
Bioluminescent in vivo imaging showed an increase in the area of spread, and the number of E. coli tripled into the rat's abdominal cavity on day 1 after clot insertion; however, on day 2, encapsulation of the clot confined bacterial spread. Bioluminescent E. coli respread over the peritoneal cavity after lavage; within 10 days, however, in vivo imaging showed a decrease of 3–4 orders of magnitude in bacterial load.
Conclusion
Bioluminescent in vivo imaging can be effectively used to monitor the spatiotemporal behavior of the peritonitis during 3 different stages of the disease process: initiation, treatment, and follow-up. Imaging allows researchers to repeatedly image the same animal, thereby reducing variability and providing greater confidence in determining treatment efficacies for therapeutic interventions using a small number of animals.
aDepartment of Biomedical Engineering, University Medical Center Groningen (UMCG), University of Groningen, Groningen, The Netherlands
bDepartment of Surgery, University Medical Center Groningen (UMCG), University of Groningen, Groningen, The Netherlands
cBioOptical Imaging Center Groningen, University Medical Center Groningen (UMCG), University of Groningen, Groningen, The Netherlands
Reprint requests: Prashant K. Sharma, PhD, Department of Biomedical Engineering (Sector F), University Medical Center Groningen and University of Groningen, P.O. Box 196, 9700 AD Groningen, The Netherlands.
Supported in part by research grant no. SNO-T-0501157 from Stichting Nuts-Ohra, The Netherlands.
ABSTRACT