Diabetic foot infections are an increasing healthcare issue and managing these infections can be difficult. A recent innovation in the way they are managed in the Hull clinic is the use of antibiotic impregnated (generally Gentamicin and Vancomycin) STIMULAN beads. Often only a couple of beads can be used in a foot wound making it a very uneconomical strategy if the beads can’t be stored and used on other wounds. There is no recommended quality assurance method provided by the manufacturers to validate this practice leading to this study.


Five beads were removed from a batch; at 1, 4, 8 and 12 week intervals for testing:

Bacterial Challenge: a 10mL spot of bead suspension was placed on Mueller Hinton seeded with ATCC 29213 and ATCC 25922 and incubated in Air, at 35±1ºC for 18±2hrs; zones of inhibition were read and recorded.

TDM: Vancomycin and Gentamicin levels present in each bead was established by analysing 50mL of suspension (1:5 DF) using a therapeutic drug monitoring assay.


Beads were microbiologically active for 12 weeks with no notable loss of potency.

Bacterial challenge: range 17-23mm, av. 20.4mm and range 11-20mm, av. 17.5mm.

TDM Assay: Vancomycin range 62.01 – 110.18 Av. 88.88mg/L, Gentamicin range 20.38 – 27.41 Av.23.20mg/L.


Quality assurance of the STIMULAN beads can be established using standard TDM assays and microbiological activity, enabling a kit to be used for up to 12 weeks with clinical confidence.

  • This is an open-access article distributed under the terms of the Creative Commons Attribution License.

Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error