Photodynamic therapy for methicillin‐resistant Staphylococcus aureus infection in a mouse skin abrasion model

Abstract

Background and Objective Methicillin-resistant Staphylococcus aureus (MRSA) skin infections are now known to be a common and important problem in the Unites States. The objective of this study was to investigate the efficacy of photodynamic therapy (PDT) for the treatment of MRSA infection in skin abrasion wounds using a mouse model. Study Design/Materials and Methods A mouse model of skin abrasion wound infected with MRSA was developed. Bioluminescent strain of MRSA, a derivative of ATCC 33591, was used to allow the real-time monitoring of the extent of infection in mouse wounds. PDT was performed with the combination of a polyethylenimine (PEI)–ce6 photosensitizer (PS) and non-coherent red light. In vivo fluorescence imaging was carried out to evaluate the effect of photobleaching of PS during PDT. Results In vivo fluorescence imaging of conjugate PEI–ce6 applied in mice indicated the photobleaching effect of the PS during PDT. PDT induced on average 2.7 log10 of inactivation of MRSA as judged by loss of bioluminescence in mouse skin abrasion wounds and accelerated the wound healing on average by 8.6 days in comparison to the untreated infected wounds. Photobleaching of PS in the wound was overcome by adding the PS solution in aliquots. Conclusion PDT may represent an alternative approach for the treatment of MRSA skin infections.

In vitro and in vivo evaluation of biologically synthesized silver nanoparticles for topical applications: effect of surface coating and loading into hydrogels

“…The in vivo studies involved the evaluation of wound-healing-promoting activity of AgNPs-loaded hydrogel as described previously. 30 Then, in vivo antibacterial activity was evaluated, 41 and the protocols were approved by the Assiut University Animal Ethical Committee. Ethical and legal approvals were obtained prior to the commencement of the study and all the animal experiments were approved by the Institutional Animal Ethical Committee of Faculty of Pharmacy, Assiut University, and it adheres to the Guide for the Care and Use of Laboratory Animals, 8th Edition, National Academies Press, Washington, DC, USA.…”

“…The antibacterial activity of 0.1% 10 mM PEG-coatedAgNPs-loaded Na CMC hydrogel (selected formulation, F3) was evaluated using a superficial skin infection model 41 using MRSA strain in animals and compared with that of 1% silver sulfadiazine cream, hydrogel blank formulation (3% Na CMC blank hydrogel), and a group of animals with no treatment as a control group.…”

In vitro antimicrobial activity of light-activated phthalocyanines

“…The advantage of photodynamic inactivation, based on the principle of targeted application of photosensitizer to the infected area and targeted irradiation, is minimizing the risk of damaging physiological microflora and host cells outside the treated area [3,4]. Photodynamic antimicrobial therapy has been studied largely in vitro under laboratory conditions but there have also been some studies on animal models [5,6]. Most recently the method has also been described in patients with periodontal disease [7,8] and diabetic foot infections [9].…”

Ctriporin, a New Anti-Methicillin-Resistant Staphylococcus aureus Peptide from the Venom of the Scorpion Chaerilus tricostatus

“…The second dose was 100 mg/kg. This treatment reduced peripheral blood neutrophils to Ͻ100/ml of blood (15).…”