Research

Differential susceptibility of C57BL/6NCr and B6.Cg-Ptprc^a mice to commensal bacteria after whole body irradiation in translational bone marrow transplant studies

Raimon Duran-Struuck^1,2 , Adam Hartigan² , Shawn G Clouthier² , Melissa C Dyson¹ , Kathi Lowler² , Erin Gatza² , Isao Tawara² , Tomomi Toubai² , Elisabeth Weisiger² , Kelly Hugunin¹ , Pavan Reddy² and John E Wilkinson¹

¹Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA

²Department of Internal Medicine, Bone Marrow Transplant Section, University of Michigan Medical School, Ann Arbor, MI, USA

author email corresponding author email

Journal of Translational Medicine 2008, 6:10doi:10.1186/1479-5876-6-10

Published:	28 February 2008

Abstract

Background

The mouse is an important and widely utilized animal model for bone marrow transplant (BMT) translational studies. Here, we document the course of an unexpected increase in mortality of congenic mice that underwent BMT.

Methods

Thirty five BMTs were analyzed for survival differences utilizing the Log Rank test. Affected animals were evaluated by physical examination, necropsy, histopathology, serology for antibodies to infectious disease, and bacterial cultures.

Results

Severe bacteremia was identified as the main cause of death. Gastrointestinal (GI) damage was observed in histopathology. The bacteremia was most likely caused by the translocation of bacteria from the GI tract and immunosuppression caused by the myeloablative irradiation. Variability in groups of animals affected was caused by increased levels of gamma and X-ray radiation and the differing sensitivity of the two nearly genetically identical mouse strains used in the studies.

Conclusion

Our retrospective analysis of thirty five murine BMTs performed in three different laboratories, identified C57BL/6NCr (Ly5.1) as being more radiation sensitive than B6.Cg-Ptprc^a/NCr (Ly5.2). This is the first report documenting a measurable difference in radiation sensitivity and its effects between an inbred strain of mice and its congenic counterpart eventually succumbing to sepsis after BMT.