UVC Light Prophylaxis for Cutaneous Wound Infections in Mice

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>UVC light has long been known to be highly germicidal but has not been much developed as a therapy for infections. This study investigated the potential of UVC light for the prophylaxis of infections developing in highly contaminated superficial cutaneous wounds.<jats:italic>In vitro</jats:italic>studies demonstrated that the pathogenic bacteria<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">Pseudomonas aeruginosa</jats:named-content>and<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">Staphylococcus aureus</jats:named-content>were inactivated at UVC light exposures much lower than those needed for a similar effect on mammalian keratinocytes. Mouse models of partial-thickness skin abrasions infected with bioluminescent<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">P. aeruginosa</jats:named-content>and<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">S. aureus</jats:named-content>were developed. Approximately 10<jats:sup>7</jats:sup>bacterial cells were inoculated onto wounds measuring 1.2 by1.2 cm on the dorsal surfaces of mice. UVC light was delivered at 30 min after bacterial inoculation. It was found that for both bacterial infections, UVC light at a single radiant exposure of 2.59 J/cm<jats:sup>2</jats:sup>reduced the bacterial burden in the infected mouse wounds by approximately 10-fold in comparison to those in untreated mouse wounds (<jats:italic>P</jats:italic>&lt; 0.00001). Furthermore, UVC light increased the survival rate of mice infected with<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">P. aeruginosa</jats:named-content>by 58.3% (<jats:italic>P</jats:italic>= 0.0023) and increased the wound healing rate in mice infected with<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">S. aureus</jats:named-content>by 31.2% (<jats:italic>P</jats:italic>&lt; 0.00001). DNA lesions were observed in the UVC light-treated mouse wounds; however, the lesions were extensively repaired by 48 h after UVC light exposure. These results suggested that UVC light may be used for the prophylaxis of cutaneous wound infections.</jats:p>

Blue Light Rescues Mice from Potentially Fatal Pseudomonas aeruginosa Burn Infection: Efficacy, Safety, and Mechanism of Action

“…As a nonantibiotic approach, the development of light-based antimicrobial therapy, including photodynamic therapy (PDT) (8)(9)(10)(11)(12)(13) and UVC irradiation therapy (14)(15)(16)(17)(18)(19), has been extensively investigated as an alternative to conventional antibiotics. An advantage of light-based antimicrobial therapies includes their equal killing effectiveness regardless of antibiotic resistance.…”

Ultraviolet Radiation in Wound Care: Sterilization and Stimulation

“…3 and 4). 53 Further, UVC light increased the survival rate of mice infected with P. aeruginosa (58%) and increased the woundhealing rate in mice infected with S. aureus (31%).…”

“…UVC irradiation (254 nm) was applied to each wound (for 180 s, irradiance 15.54 mW/cm 2 ). In addition to eradication of MRSA infection upon UVC exposure, progression toward wound closure as marked by presence of epithelial buds, improved 53 To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound epithelialization, return of normal skin color surrounding the wound, and the emergence of healthy granulation tissue was noted. Moreover, in the latter two cases, full wound closure was achieved.…”

“…There is a growing body of literature examining the antimicrobial effects of UVC irradiation at 254 nm. Using mouse models, Dai et al 53 investigated the potential of UVC light for the prophylaxis of infections developing in highly contaminated superficial cutaneous wounds. Mouse models of partial-thickness skin abrasions infected with bioluminescent Pseudomonas aeruginosa and Staphylococcus aureus were developed.…”

Effect of Low-Level Laser Therapy and Ultraviolet-C Irradiation on Partial-Thickness Burn Wound Healing: A Randomized Controlled Trial

“…Additionally, elevated procollagen mRNA levels have been reported in cutaneous wounds following laser treatment [15]. In addition to the eradication of microorganisms that can impede wound healing [16], the impacts of UVC on wound healing incorporate hyperplasia and enhanced re-epithelialization or desquamation of the leading edge of periulcer epidermal cells, granulation tissue formation and sloughing of necrotic tissue [17] ; histamine release, which adds to the increased skin blood flow [18]; increased vascular permeability, which prompts to cellular elements of repair in the dermis [19]; and accelerated rate of DNA, RNA, and protein synthesis [20]. However, the literature provides only a few studies that examine the effects of low-level laser therapy and ultraviolet-C on human wound healing, which are poorly controlled or provide little detail on their protocol.…”