title: Antimicrobial blue light therapy for multidrug-resistant Acinetobacter baumannii infection in a mouse burn model: implications for prophylaxis and treatment of combat-related wound infections.
abstract: In this study, we investigated the utility of antimicrobial blue light therapy for multidrug-resistant Acinetobacter baumannii infection in a mouse burn model. A bioluminescent clinical isolate of multidrug-resistant A. baumannii was obtained. The susceptibility of A. baumannii to blue light (415 nm)-inactivation was compared in vitro to that of human keratinocytes. Repeated cycles of sublethal inactivation of bacterial by blue light were performed to investigate the potential resistance development of A. baumannii to blue light. A mouse model of third degree burn infected with A. baumannii was developed. A single exposure of blue light was initiated 30 minutes after bacterial inoculation to inactivate A. baumannii in mouse burns. It was found that the multidrug-resistant A. baumannii strain was significantly more susceptible than keratinocytes to blue light inactivation. Transmission electron microscopy revealed blue light-induced ultrastructural damage in A. baumannii cells. Fluorescence spectroscopy suggested that endogenous porphyrins exist in A. baumannii cells. Blue light at an exposure of 55.8 J/cm(2) significantly reduced the bacterial burden in mouse burns. No resistance development to blue light inactivation was observed in A. baumannii after 10 cycles of sublethal inactivation of bacteria. No significant DNA damage was detected in mouse skin by means of a skin TUNEL assay after a blue light exposure of 195 J/cm(2).
authors.affiliation: Wellman Center for Photomedicine Department of Dermatology, Harvard Medical School, Boston Department of Burn and Plastic Surgery, Guangzhou Red Cross Hospital, Jinan University, Guangzhou.
authors.forename: Yunsong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Wellman Center for Photomedicine School of Medicine, Tongji University, Shanghai, China.
authors.forename: Yingbo
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Wellman Center for Photomedicine Department of Dermatology, Harvard Medical School, Boston Defense Institute of Physiology and Allied Sciences, Delhi, India.
authors.forename: Asheesh
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Wellman Center for Photomedicine Department of Dermatology, Harvard Medical School, Boston.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Infectious Disease Service, Brooke Army Medical Center.
authors.forename: Clinton K
authors.initials: CK
authors.lastname: Murray
authors.affiliation: Department of Orthopaedic Surgery, Massachusetts General Hospital.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Vrahas
authors.affiliation: Wellman Center for Photomedicine.
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Sherwood
authors.affiliation: US Army Institute of Surgical Research, Fort Sam Houston, Texas.
authors.forename: David G
authors.initials: DG
authors.lastname: Baer
authors.affiliation: Wellman Center for Photomedicine Department of Dermatology, Harvard Medical School, Boston Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hamblin
authors.affiliation: Wellman Center for Photomedicine Department of Dermatology, Harvard Medical School, Boston.
authors.forename: Tianhong
authors.initials: T
authors.lastname: Dai
mesh_terms: D000151:Acinetobacter Infections / Q000628:therapy; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000528:radiation effects* / Q000648:ultrastructure; D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use; D002056:Burns / Q000382:microbiology / Q000628:therapy*; D004249:DNA Damage / Q000528:radiation effects; D004195:Disease Models, Animal; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D015603:Keratinocytes; D051379:Mice; D008807:Mice, Inbred BALB C; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D010789:Phototherapy; D014946:Wound Infection / Q000382:microbiology* / Q000628:therapy*
chemical_list: D000890:Anti-Infective Agents
keywords: Acinetobacter baumannii; Blue light; burn; infection; mouse model; multidrug resistance