Analysing the microbiome of diabetic foot ulcers

Introduction: Diabetic foot ulcers (DFUs) are a major cause of
morbidity and mortality. The role of infection in the recurrence
and chronicity of DFUs is not well characterised, but is
recognised as an important determinant.
Objectives: This study aims to characterise the microbiome in
DFUs to determine whether or not key bacterial genera are
consistently represented or not.
Methods: DFUs of 16 patients with type II diabetes attending a
Diabetic Clinic at Ayr Hospital were swabbed. DNA from the
swabs was extracted using a combination of bead beating and
QIAmp mini DNA kit (Qiagen), then Next Generation Sequencing
(Illumina MiSeq) of the hypervariable V4 region of 16S rRNA was
performed.
Results: 216 unique operational taxonomic units (OTUs) were
identified in the sample set, with an mean of 42 per sample
(range 20 to 86). Of these, anaerobes (55%) dominated, followed
by facultative anaerobes (42%) and aerobes (3%), which came
from a variety of sources (environmental, skin commensals and
pathogens). The most common bacterium identified was the
anaerobe Finegoldia magna, with Streptococcus, Staphylococcus
and Anaerococcus species also isolated.
Conclusions: The microbiome of DFUs is heterogeneous and
dominated by anaerobic species, which has implication for
clinical management strategies.