Fluorescent Light Energy in the Management of Multi Drug Resistant Canine Pyoderma: A Prospective Exploratory Study

Abstract

The increase in prevalence of staphylococcal antimicrobial resistance has been also associated with pyoderma in dogs, and prolonged antibiotic treatment, as often needed in severe cases of pyoderma, has been related to influencing possible development of multidrug resistance (MDR). Fluorescent light energy (FLE) has been indicated to improve pyoderma lesions as adjunct therapy to systemic antibiotics. In the present study, we evaluated the effect of FLE on clinical signs of MDR canine deep pyoderma (CDP) and interdigital furunculosis (CIF) when administered as solely management. Sixteen client-owned dogs affected by CIF (five dogs) and CDP (eleven dogs) were scored using a dedicated scoring system and received a single FLE applications twice weekly, until clinical resolution was achieved. Mean time to achieve complete resolution was 5.20 ± 3.56 weeks (median 3 weeks) for CIF cases and 4.18 ± 1.47 weeks (median 4 weeks) for CDP ones. FLE shows promise as an aid to managing clinical signs while reducing reliance on antibiotics for MDR CDP and CIF. In this study, FLE was responsible for the decrease in lesion scores and resolution of MDR pyoderma infection without any adjunct therapy, having a potential useful role to play in antibiotic stewardship programs, efficiently promoting complete clinical resolution of MDR lesions while optimizing the use of antibiotics.

In vitro evaluation of bactericidal effects of fluorescent light energy on Staphylococcus pseudintermedius and S. aureus

“…34 The effects of FLE on skin infections in dogs has been investigated in vivo. 9,12,14,[18][19][20] These in vivo studies found that FLE used either in conjunction with systemic antibiotics or as a sole treatment is associated with shorter times to clinical resolution than systemic antibiotics alone for both superficial and deep bacterial infections. 9,12,18,20,35 In a study on otitis externa in dogs, FLE was shown to be associated with the better patient outcomes than conventional topical antibiotic therapy.…”

“…11 These new wavelengths then interact with endogenous chromophores within bacterial cells and biological tissues to create various effects depending on the individual wavelengths. This modality has been used in veterinary medicine to treat superficial pyoderma, 12 perianal sinuses, 13 otitis externa, 14 acute traumatic wounds, 15 chronic wounds 16 and surgical wounds 17 in dogs, as well as adjunctive or sole treatment in the management of deep pyoderma 9,18,19 and interdigital pyoderma. 19,20 These studies were performed with a commercially available form of FLE which utilises a topical photoconverting hydrogel containing specialised exogenous chromophores (Phovia; Vetoquinol).…”

“…This modality has been used in veterinary medicine to treat superficial pyoderma, 12 perianal sinuses, 13 otitis externa, 14 acute traumatic wounds, 15 chronic wounds 16 and surgical wounds 17 in dogs, as well as adjunctive or sole treatment in the management of deep pyoderma 9,18,19 and interdigital pyoderma. 19,20 These studies were performed with a commercially available form of FLE which utilises a topical photoconverting hydrogel containing specialised exogenous chromophores (Phovia; Vetoquinol). The gel is exposed to blue light-emitting diodes (bLED) and emits lowenergy fluorescence.…”

“…Staphylococcus pseudintermedius was chosen because it was the most common bacterial species cultured in previous in vivo studies on FLE in dogs and is considered the most common causative agent in canine bacterial skin infections. [18][19][20][21] Both meticillin-susceptible (MSSP) and meticillinresistant (MRSP) isolates of S. pseudintermedius were included as meticillin resistance is becoming an increasing problem. 21 Meticillin-resistant S. aureus (MRSA) was chosen because S. aureus was cultured in previous in vivo canine studies on FLE and the effects of blue light have been investigated in vitro on MRS isolates.…”

“…21 Meticillin-resistant S. aureus (MRSA) was chosen because S. aureus was cultured in previous in vivo canine studies on FLE and the effects of blue light have been investigated in vitro on MRS isolates. 5,[18][19][20] The secondary objective of this study was to determine if there is a difference in treatment outcomes between the following categories: (i) treatment with a single exposure to bLED light; (ii) treatment with two consecutive exposures to a bLED; (iii) treatment with a single exposure to FLE; and (iv) treatment with two consecutive exposures to FLE. The treatment categories were chosen to replicate the manufacturer recommendations for the commercially available FLE system and to determine whether bactericidal effects are a result of the blue light alone, or the fluorescence produced by the interaction of the blue LED lamp and the photoconverting hydrogel.…”