The antibacterial effect of mesenchymThe antibacterial effect of mesenchymal stem cells on graft infections: An experimental studyal stem cells on graft infections: An experimental study

Abstract

Background: In this study, we aimed to investigate the antibacterial effects of mesenchymal stem cells, compared to tigecycline, on graft infection related with methicillin-resistant Staphylococcus epidermidis in a rat model.

Methods: A total of 42 male adult Wistar rats (age >6 months; weight 300 to 350 g) were divided into six groups including seven rats in each. Group 0 did not undergo any procedure; Group 1 was infected, but untreated; Group 2 was infected and treated with tigecycline without graft placement; Group 3 was infected and received mesenchymal stem cells without graft placement; Group 4 was infected and treated with tigecycline after graft placement; Group 5 was infected and treated with mesenchymal stem cells after graft placement. The pockets created were either left empty or implanted with Dacron grafts. Treatment was commenced at 48 h. Specimens were collected on Day 13. Perigraft tissues were evaluated histopathologically and bacterial colony numbers were counted.

Results: No bacterial colonization was observed in Group 0, whereas there was a significant colonization in Group 1. Complete eradication was achieved in Group 2 and Group 3 (graft-free groups), and near-complete eradication was achieved in Group 4 and Group 5 (graft-implanted groups). The histopathological findings significantly differed between Group 1-Group 2 and between Group 1-Group 3 (graft-free groups). The histopathological findings were similar between Group 2-Group 3 and between Group 4-Group 5.

Conclusion: Our study results suggest that mesenchymal stem cells may be a novel, contemporary alternative to antibiotherapy and may decrease the bio-burden of Staphylococcus at the infected graft areas, and mesenchymal stem cell treatment may be as effective as tigecycline.

Keywords: Infection; Staphylococcus epidermidis; mesenchymal stem cell; tigecycline; wound.

Figure 1. 1 cm² Dacron graft was implanted into the pockets of the rats in Groups 4 and 5.

Figure 2. Histopathological results of specimens (H-Ex40).

Figure 3. Colony numbers compared with Kruskal-Wallis test and pairwise comparisons of groups or Pearson’s chi-square test. MRSE: Methicillin-resistant Staphylococcus epidermidis; MSC: Mesenchymal stem cell.

Figure 4. Histopathological findings as assessed by chi-square test. MRSE: Methicillin-resistant Staphylococcus epidermidis; MSC: Mesenchymal stem cell.