Effect of Blue Light and Photosensitizers on Cutibacterium acnes on Shoulder Periprosthetic Joint Infection Isolates

Abstract

Abstract. Introduction: Cutibacterium acnes is gaining recognition as a leading pathogen after orthopaedic shoulder procedures. Photodynamic therapy, a combination of light and a photosensitizer, has demonstrated antimicrobial activity against C. acnes in the treatment of acne vulgaris. We sought to evaluate the effect of photodynamic therapy using blue light and photosensitizers on C. acnes isolates from shoulder prosthetic joint infections.Methods: C. acnes strains isolated from 19 patients with shoulder PJI were exposed to blue light alone (415 nm) or in combination with photosensitizers (fluorescein, riboflavin and demeclocycline). C. acnes strains were divided into 4 categories: Highly Sensitive (HS), Sensitive (S), Weakly Sensitive (WS), Resistant to blue light.Results: 13 of 19 C. acnes strains (68%) were S or HS to blue light alone. Of these 19 strains tested, 11 were tested with blue light and fluorescein or blue light plus riboflavin. Fluorescein (1 µg/mL) enhanced the effect of blue light in 6 of 11 strains (55%). Blue light plus riboflavin (10 µg/mL) resulted enhanced killing in 3 of 11 strains (27%), but produced a paradoxical photoprotective effect in 4 of 11 strains (36%), resulting in a net decrease compared to blue light alone. Demeclocycline, however, enhanced the effect of blue light in 16 of 17 strains (94 %).Conclusions: Blue light with the addition of photosensitizers killed C. acnes from periprosthetic shoulder infections in vitro, with demeclocycline having the most pronounced effect.

Hyperspectral assessment of acne skin exposed to intense pulsed light (IPL) intense pulsed light in acne treatment

“…It is associated with the current inflammation, also with the participation of melanocytes (which increases the likelihood of postinflammatory hyperpigmentation), increased microcirculation (acne lesions are characterized by lymphocytic infiltration and an increase in the expression of inflammatory vascular markers, e.g., VCAM-1, ICAM-1), which promote angiogenesis 21,22 and involving Cutibacterium acnes, producing porphyrins. 23 The melanin absorbs a wide range of the light spectrum, and the longer the wavelength, the less light is absorbed by melanin. 24 The melanin is one of the first chromophores to encounter light in its path.…”

“…The low reflectance in the range of 400–599 nm may be caused by the accumulation of chromophores in the skin that absorbs waves in this range, 20 which would explain the lowest skin reflectance in cases with moderate acne. It is associated with the current inflammation, also with the participation of melanocytes (which increases the likelihood of postinflammatory hyperpigmentation), increased microcirculation (acne lesions are characterized by lymphocytic infiltration and an increase in the expression of inflammatory vascular markers, e.g., VCAM‐1, ICAM‐1), which promote angiogenesis 21,22 and involving Cutibacterium acnes, producing porphyrins 23 …”

Techniques for Decreasing Bacterial Load for Open Shoulder Surgery

“…Ultraviolet in combination with photosensitizing antibiotics against C. acnes has also been studied as a prophylactic 40,41 . Bhargava et al 40 found that 94% of C. acnes strains (16 of 17) isolated from shoulder PJI were sensitive to blue light with demeclocycline (a tetracycline antibiotic used as a photosensitizer) in vitro. Cotter et al 41 evaluated the efficacy of BPO, blue light therapy (BLT), and BPO followed by BLT against C. acnes in shoulder arthroplasty patients.…”

The use of light in the treatment of acne vulgaris—a review

“…Porphyrins—products of C . acnes metabolism—are aromatic compounds, classified as photosensitizing substances, intensively absorbing light with a wavelength of 400–450 nm, and to a lesser extent in long visible bands, such as orange (590–635 nm) and red light (635 –700 nm) 20 …”

“…Porphyrins-products of C. acnes metabolism-are aromatic compounds, classified as photosensitizing substances, intensively absorbing light with a wavelength of 400-450 nm, and to a lesser extent in long visible bands, such as orange (590-635 nm) and red light (635 -700 nm). 20 The wavelength determines not only the absorption behavior but also the depth of light penetration-in the visible spectral range, the latter increases with wavelength. By using different cutoff filters (515-755 nm), which only allow a specific spectrum to be penetrated, the optimal wavelength spectrum can be filtered to suit the target structure depth (vessels of different depths and sizes, hair follicles, pigment structures).…”