title: Improved detection of clinically relevant wound bacteria using autofluorescence image-guided sampling in diabetic foot ulcers.
abstract: Clinical wound assessment involves microbiological swabbing of wounds to identify and quantify bacterial species, and to determine microbial susceptibility to antibiotics. The Levine swabbing technique may be suboptimal because it samples only the wound bed, missing other diagnostically relevant areas of the wound, which may contain clinically significant bacteria. Thus, there is a clinical need to improve the reliability of microbiological wound sampling. To address this, a handheld portable autofluorescence (AF) imaging device that detects bacteria in real time, without contrast agents, was developed. Here, we report the results of a clinical study evaluating the use of real-time AF imaging to visualise bacteria in and around the wound bed and to guide swabbing during the clinical assessment of diabetic foot ulcers, compared with the Levine technique. We investigated 33 diabetic foot ulcers (n = 31 patients) and found that AF imaging more accurately identified the presence of moderate and/or heavy bacterial load compared with the Levine technique (accuracy 78% versus 52%, P = 0·048; adjusted diagnostic odds ratio 7·67, P < 0·00022 versus 3·07, P = 0·066) and maximised the effectiveness of bacterial load sampling, with no significant impact on clinical workflow. AF imaging may help clinicians better identify the wound areas with clinically significant bacteria, and maximise sampling of treatment-relevant pathogens.
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario Canada.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Ottolino-Perry
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario Canada.
authors.forename: Emilie
authors.initials: E
authors.lastname: Chamma
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario Canada.
authors.forename: Kristina M
authors.initials: KM
authors.lastname: Blackmore
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario Canada.
authors.forename: Liis
authors.initials: L
authors.lastname: Lindvere-Teene
authors.affiliation: MolecuLight, Inc., Toronto, Ontario Canada.
authors.forename: Danielle
authors.initials: D
authors.lastname: Starr
authors.affiliation: Hyperbaric Medicine, Judy Dan Research & Treatment Centre, Toronto, Ontario Canada.
authors.forename: Kim
authors.initials: K
authors.lastname: Tapang
authors.affiliation: Department of Dermatology, Toronto Western Hospital, University Health Network, Toronto, Ontario Canada.
authors.forename: Cheryl F
authors.initials: CF
authors.lastname: Rosen
authors.affiliation: Department of Biostatistics, University Health Network, Toronto, Ontario Canada.
authors.forename: Bethany
authors.initials: B
authors.lastname: Pitcher
authors.affiliation: Department of Biostatistics, University Health Network, Toronto, Ontario Canada.
authors.forename: Tony
authors.initials: T
authors.lastname: Panzarella
authors.affiliation: Hyperbaric Medicine, Judy Dan Research & Treatment Centre, Toronto, Ontario Canada.
authors.forename: Ron
authors.initials: R
authors.lastname: Linden
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario Canada.|Department of Medical Biophysics, University of Toronto, Toronto, Ontario Canada.|Techna Institute, Toronto, Ontario Canada.
authors.forename: Ralph S
authors.initials: RS
authors.lastname: DaCosta
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000302:isolation & purification*; D058491:Bacterial Load / Q000295:instrumentation*; D017719:Diabetic Foot / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061848:Optical Imaging; D015203:Reproducibility of Results; D013048:Specimen Handling / Q000379:methods*; D014946:Wound Infection / Q000175:diagnosis* / Q000382:microbiology*; D055815:Young Adult
keywords: Autofluorescence imaging; Clinical signs and symptoms; Diabetic foot ulcers; Levine technique; Microbiological sampling