Autofluorescence imaging device for real-time detection and tracking of pathogenic bacteria in a mouse skin wound model: preclinical feasibility studies

Abstract

Bacterial infection significantly impedes wound healing. Clinical diagnosis of wound infections is subjective and suboptimal, in part because bacteria are invisible to the naked eye during clinical examination. Moreover, bacterial infection can be present in asymptomatic patients, leading to missed opportunities for diagnosis and treatment. We developed a prototype handheld autofluorescence (AF) imaging device (Portable Real-time Optical Detection, Identification and Guidance for Intervention - PRODIGI) to noninvasively visualize and measure bacterial load in wounds in real time. We conducted preclinical pilot studies in an established nude mouse skin wound model inoculated with bioluminescent Staphylococcus aureus bacteria. We tested the feasibility of longitudinal AF imaging for in vivo visualization of bacterial load in skin wounds, validated by bioluminescence imaging. We showed that bacteria (S. aureus), occult to standard examination, can be visualized in wounds using PRODIGI. We also detected quantitative changes in wound bacterial load over time based on the antibiotic treatment and the correlation of bacterial AF intensity with bacterial load. AF imaging of wounds offers a safe, noninvasive method for visualizing the presence, location, and extent of bacteria as well as measuring relative changes in bacterial load in wounds in real time.

Emerging Priorities for Microbiome Research

“…Other methods to explore include use of radio frequency identification (RFID) signal fluctuations to detect in real-time the presence or absence of bacteria, though specific information on bacterial strains have not been demonstrated (ElMahgoub and Shaban, 2014). Additionally, an auto-fluorescent device utilizing a broadband white LED output and dual-wavelength LED detection array may be capable of real-time detection of bacteria and is currently in preclinical studies (Wu et al, 2014).…”

Early optical diagnosis of pressure ulcers

“…Fluorescence image has been applied for assessment of connective tissue extracellular matrix in wounds (usually blue-green bands) (Douplik et al, 2010) and bacterial contamination (typically red wavelength ranges) (Wu et al, 2014). Fluorescence image has been applied for assessment of connective tissue extracellular matrix in wounds (usually blue-green bands) (Douplik et al, 2010) and bacterial contamination (typically red wavelength ranges) (Wu et al, 2014).…”

Autofluorescence of collagen fibres in scar

“…It was reported that accumulation of advance glycosylation end products (AGEs) produced autofluorescence . It is valuable for diagnosis and treatment of diabetes, clinical atherosclerosis, chronic kidney disease, and tissue wounds because of accumulation of AGEs during these diseases . This type of skin autofluorescence could be assessed with a special device‐AGE Reader, which has been known as a noninvasive marker for accumulation of AGEs.…”