Surgical procedure of rat PVGI model.

(a) Anesthetized rat with shaved and exposed chest prior to surgery. (b) Incision with view to the space created between the right sternocleidomastoid and the omohyoid muscle. (c) Common carotid artery exposed and ligated. (d) Blue arrow shows exposed common carotid artery, prior to insertion of graft. (e) Graft inserted in common carotid artery and secured with ligatures. (f) Green arrow shows graft with blood flow inserted in to common carotid artery. (g) Rat post-surgery, with wound closed with sutures.</p

Dissemination of infection.

(A) Percentage of animals in each treatment group with infections in the liver, kidney or spleen. The animals could have infection in more than one organ. (B): Percentage of animals in each treatment group with systemic infection (infection in either liver, kidney or spleen). NaCl (n = 8), Vanco (n = 8), Vanco+tPA (n = 8), Vanco+Rif (n = 18), Vanco+Rif+tPA (n = 16). Vanco = Vancomycin, Rif = Rifampicin.</p

Histological and immunohistochemic images of infected and sterile graft, artery and sorrounding tissue from rats 19 days after insertion.

A: Normal left a. carotis (HE), bar = 250 μm. B: Right a. carotis 19 days after insertion of a vascular graft. Neointima (ni) formation, tunica media atrophy (arrow) and fibrosis of tunica adventitia (HE), bar = 100 μm. C-F: Right a. carotis 19 days after insertion of a vascular graft and inoculation with Staphylococcus aureus. C: Pink fibrin (f) is present within graft lumen. Neutrophil granulocyte (ng) infiltration, broken elastic bands (arrow) and surrounding macrophages and collagen producing fibroblasts (HE), bar = 200 μm. D: Masson trichrome staining to identify collagen in blue, bar = 200 μm. E: Red S. aureus positive bacteria located on fibrin within graft lumen (IHC), bar = 100 μm. F: Red S. aureus positive bacteria located on the vessel surface towards the graft. Insert shows red positive bacteria within a macrophage (IHC), bar = 80 μm.</p

Effect of antibiotics and tPA on biofilms formed on grafts <i>in vivo</i> after a 7-day treatment period.

Each data point represents median Log10 CFU/mL of three replicates from one graft. Error bars represent median with IQR. Pairwise comparison of treatment groups (Mann-Whitney test, *p≤0.05 **p≤0.005).</p

Qualitative results on bacterial growth from explanted grafts.

Qualitative results on bacterial growth from explanted grafts.</p

Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines checklist.

Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines checklist.</p

Mean relative weight changes post-infection compared to starting weight.

NaCl (n = 8), Vanco (n = 8), Vanco+rif (n = 18), Vanco+tPA (n = 8), Vanco+Rif+tPA (n = 16). Vanco: Vancomycin, Rif: Rifampicin, tPA: tissue plasminogen activator. Symbols are mean values whereas error bars show one standard deviation.</p

Minimum biofilm eradication concentration for MRSA FPR3757.

Minimum biofilm eradication concentration for MRSA FPR3757.</p

Confocal laser scanning microscopy images of the MRSA biofilm formed in prosthetic vascular grafts in rats after 10 days of infection.

CLSM images of the biofilm formed at the vascular graft dissected crosswise (A) and lengthwise (B). Cells (bacterial and murine) are shown in blue (SYTO41) and fibrin is shown in green (anti-fibrin antibody, 59D8, Atto488 conjugated rabbit IgG). The 2D images are shown as two-channel. Scale bar 50 μm. (PDF)</p

Tissue plasminogen activator (tpa) does not affect fibrin in the in vivo biofilm from rat prosthetic vascular graft infections.

CLSM images of the MRSA biofilm formed in prosthetic vascular grafts in rats after 19 days of infection (A) treated with NaCl and (B) treated with tPA. Cells (bacterial and murine) are shown in blue (SYTO41) and fibrin is shown in green (anti-fibrin antibody, 59D8, Atto488 conjugated rabbit IgG). The 2D images are shown as two-channel. Scale bar = 50 μm. (C) Quantification of 2D CLSM images in Daime based on three biological replicates (total n = 18).</p