Development and characterization of a fecal-induced peritonitis model of murine sepsis: results from a multi-laboratory study and iterative modification of experimental conditions

Neha Sharma; Damian Chwastek; Dhruva J Dwivedi; Jared Schlechte; Ian-Ling Yu; Braedon McDonald; Jaskirat Arora; Erblin Cani; Mikaela Eng; Doreen Engelberts; Eva Kuhar; Sarah K Medeiros; Stephane L Bourque; Gediminas Cepinskas; Sean E Gill; Forough Jahandideh; Kimberly F Macala; Sareh Panahi; Cynthia Pape; David Sontag; Janet Sunohara-Neilson; Dean A Fergusson; Alison E Fox-Robichaud; Patricia C Liaw; Manoj M Lalu; Asher A Mendelson; National Preclinical Sepsis Platform, Sepsis Canada

doi:10.1186/s40635-023-00533-3

Development and characterization of a fecal-induced peritonitis model of murine sepsis: results from a multi-laboratory study and iterative modification of experimental conditions

Intensive Care Med Exp. 2023 Jul 17;11(1):45. doi: 10.1186/s40635-023-00533-3.

Authors

Neha Sharma^#^{1

2}, Damian Chwastek^#³, Dhruva J Dwivedi^{1

4}, Jared Schlechte^{5

6}, Ian-Ling Yu^{5

6}, Braedon McDonald^{5

6}, Jaskirat Arora^{1

2}, Erblin Cani^{1

2}, Mikaela Eng^{1

2}, Doreen Engelberts³, Eva Kuhar³, Sarah K Medeiros^{1

2}, Stephane L Bourque⁷, Gediminas Cepinskas^{8

9}, Sean E Gill^{8

10}, Forough Jahandideh³, Kimberly F Macala^{7

11}, Sareh Panahi⁷, Cynthia Pape⁸, David Sontag¹², Janet Sunohara-Neilson¹³, Dean A Fergusson^{14

15}, Alison E Fox-Robichaud^{1

4}, Patricia C Liaw^{1

4}, Manoj M Lalu^#^{16

17

18}, Asher A Mendelson^#¹⁹; National Preclinical Sepsis Platform, Sepsis Canada

Affiliations

¹ Thrombosis and Atherosclerosis Research Institute, Hamilton, ON, Canada.
² Department of Medical Sciences, McMaster University, Hamilton, ON, Canada.
³ Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.
⁴ Department of Medicine, McMaster University, Hamilton, ON, Canada.
⁵ Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
⁶ Department of Critical Care Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
⁷ Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada.
⁸ Centre for Critical Illness Research, Lawson Health Research Institute, London, ON, Canada.
⁹ Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
¹⁰ Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
¹¹ Department of Critical Care Medicine, Royal Alexandra Hospital, University of Alberta, Edmonton, AB, Canada.
¹² Department of Medicine, Section of Critical Care Medicine, Rady Faculty of Health Sciences, University of Manitoba, Health Sciences Centre Winnipeg, Rm GF-234, 820 Sherbrook St, Winnipeg, MB, R3A 1R9, Canada.
¹³ Animal Care and Veterinary Services, Western University, London, ON, Canada.
¹⁴ Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.
¹⁵ Clinical Epidemiology Program, Blueprint Translational Group, Ottawa Hospital Research Institute, 501 Smyth Road, P.O. Box 201B, Ottawa, ON, K1H 8L6, Canada.
¹⁶ Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada. [email protected].
¹⁷ Clinical Epidemiology Program, Blueprint Translational Group, Ottawa Hospital Research Institute, 501 Smyth Road, P.O. Box 201B, Ottawa, ON, K1H 8L6, Canada. [email protected].
¹⁸ Department of Anesthesiology and Pain Medicine, The Ottawa Hospital, Ottawa, ON, Canada. [email protected].
¹⁹ Department of Medicine, Section of Critical Care Medicine, Rady Faculty of Health Sciences, University of Manitoba, Health Sciences Centre Winnipeg, Rm GF-234, 820 Sherbrook St, Winnipeg, MB, R3A 1R9, Canada. [email protected].

^# Contributed equally.

Abstract

Background: Preclinical sepsis models have been criticized for their inability to recapitulate human sepsis and suffer from methodological shortcomings that limit external validity and reproducibility. The National Preclinical Sepsis Platform (NPSP) is a consortium of basic science researchers, veterinarians, and stakeholders in Canada undertaking standardized multi-laboratory sepsis research to increase the efficacy and efficiency of bench-to-bedside translation. In this study, we aimed to develop and characterize a 72-h fecal-induced peritonitis (FIP) model of murine sepsis conducted in two independent laboratories. The experimental protocol was optimized by sequentially modifying dose of fecal slurry and timing of antibiotics in an iterative fashion, and then repeating the experimental series at site 1 and site 2.

Results: Escalating doses of fecal slurry (0.5-2.5 mg/g) resulted in increased disease severity, as assessed by the modified Murine Sepsis Score (MSS). However, the MSS was poorly associated with progression to death during the experiments, and mice were found dead without elevated MSS scores. Administration of early antibiotics within 4 h of inoculation rescued the animals from sepsis compared with late administration of antibiotics after 12 h, as evidenced by 100% survival and reduced bacterial load in peritoneum and blood in the early antibiotic group. Site 1 and site 2 had statistically significant differences in mortality (60% vs 88%; p < 0.05) for the same dose of fecal slurry (0.75 mg/g) and marked differences in body temperature between groups.

Conclusions: We demonstrate a systematic approach to optimizing a 72-h FIP model of murine sepsis for use in multi-laboratory studies. Alterations to experimental conditions, such as dose of fecal slurry and timing of antibiotics, have clear impact on outcomes. Differences in mortality between sites despite rigorous standardization warrants further investigations to better understand inter-laboratory variation and methodological design in preclinical studies.

Keywords: Animal models of sepsis; Fecal-induced peritonitis; Multi-laboratory; National Preclinical Sepsis Platform; Preclinical reproducibility; Preclinical sepsis; Sepsis.