title: Agr function is upregulated by photodynamic therapy for Staphylococcus aureus and is related to resistance to photodynamic therapy.
abstract: Photodynamic therapy (PDT) has been considered a feasible alternative for antimicrobial therapy of multidrug-resistant pathogens. However, bacterial response mechanisms against PDT-generated photo-oxidative stress remain largely unknown. Herein, it is shown that the accessory gene regulator Agr is involved in Staphylococcus aureus response to photo-oxidative stress generated by laser-induced PDT with the photosensitizer chlorin e6 . Transcriptional profiling revealed that sublethal PDT induces a general stress response and also activates Agr-dependent gene regulation. Moreover, mutant S. aureus lacking Agr function showed hypersusceptibility to two independent PDT conditions with higher energy densities, demonstrating Agr-dependent S. aureus resistance against PDT.
authors.affiliation: Department of Microbiology and Immunology, Chosun University School of Dentistry, Gwangju, 501-759, Korea.
authors.forename: Hee Jeong
authors.initials: HJ
authors.lastname: Park
authors.forename: Yeon-Hee
authors.initials: YH
authors.lastname: Moon
authors.forename: Hyo-Eun
authors.initials: HE
authors.lastname: Yoon
authors.forename: Yoon Mee
authors.initials: YM
authors.lastname: Park
authors.forename: Jung-Hoon
authors.initials: JH
authors.lastname: Yoon
authors.forename: Iel Soo
authors.initials: IS
authors.lastname: Bang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002735:Chlorophyllides; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D006801:Humans; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011166:Porphyrins / Q000627:therapeutic use; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: C095698:Agr protein, Staphylococcus aureus; D001426:Bacterial Proteins; D002735:Chlorophyllides; D017319:Photosensitizing Agents; D011166:Porphyrins; D015534:Trans-Activators; C062985:phytochlorin
keywords: accessory gene regulator; antimicrobial therapy; multidrug resistance; photodynamic therapy