Mesenchymal stem cells have significant anti-infective effect on methicillin-resistant Staphylococcus epidermidis vascular graft infections.

Abstract

This study aims to evaluate the effects of mesenchymal stem cell (MSC) implantation on vascular graft infections caused by methicillin-resistant Staphylococcus epidermidis (MRSE) and compare with antibiotic treatment. Healthy adult 56 Wistar rats (age, over 5 months; weighing, 300-350 g) were divided into eight groups. Group 1 was defined as the control group and group 2 was defined as the infected control group. Groups 3 and 4 were defined as Dacron grafted and MRSE infected groups, treated with tigecycline and MSCs, respectively. Groups 5 and 6 were performed polytetrafluoroethylene (PTFE) graft and infected with MRSE. These groups were also administered tigecycline and MSC treatment, respectively. Groups 7 and 8 were infected with MRSE without graft administration and were also performed tigecycline and MSC treatment, respectively. Grafts and soft tissue specimens were collected at 13 days postoperatively. Colony counts of peri-graft tissue were performed. All samples were evaluated by enzyme-linked immunosorbent assay (ELISA) for the markers that determine stem cell activity. The overall success of the treatments was assessed by the number of rats with MRSE recurrence, regardless of graft used. The difference between the untreated group 2, tigecycline groups (3, 5 and 7) and MSCs groups (4, 6 and 8) were statistically significant. Success of MSC and tigecycline treatments was similar in Dacron, PTFE, and non-grafted groups. There was a resistance of MRSE infection in Dacron groups to MSC and tigecycline treatments. This was considered to be indicative of the susceptibility of the Dacron grafts to infection. However, there was no significant difference between group 2 and Dacron groups in terms of bacterial colonization. ELISA results were significant in three cytokines. Mesenchymal stem cells can be considered as an alternative treatment option on its own or part of a combination therapy for control of vascular graft infections.