title: Photodynamic antibacterial and antibiofilm activity of RLP068/Cl against Staphylococcus aureus and Pseudomonas aeruginosa forming biofilms on prosthetic material.
abstract: Prosthetic joint infections (PJIs) are becoming a growing public health concern in developed countries as more people undergo arthroplasty for bone fixation or joint replacement. Because a wide range of bacterial strains responsible for PJIs can produce biofilms on prosthetic implants and because the biofilm structure confers elevated bacterial resistance to antibiotic therapy, new drugs and therapies are needed to improve the clinical outcome of treatment of PJIs. Antimicrobial photodynamic therapy (APDT), a non-antibiotic broad-spectrum antimicrobial treatment, is also active against multidrug-resistant micro-organisms such as meticillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. APDT uses a photosensitiser that targets bacterial cells following exposure to visible light. APDT with RLP068/Cl, a novel photosensitiser, was studied by confocal laser scanning microscopy (CLSM) to evaluate the disruption of MRSA and P. aeruginosa biofilms on prosthetic material. Quantitative CLSM studies showed a reduction in biofilm biomass (biofilm disruption) and a decrease in viable cell numbers, as determined by standard plate counting, in the S. aureus and P. aeruginosa biofilms exposed to APDT with the photosensitiser RLP068/Cl. APDT with RLP068/Cl may be a useful approach to the treatment of PJI-associated biofilms.
authors.affiliation: Laboratory of Clinical Chemistry and Microbiology, IRCCS Galeazzi Orthopaedic Institute, Milan, Italy.
authors.forename: Christian
authors.initials: C
authors.lastname: Vassena
authors.affiliation: Virology Program, National Institute of Molecular Genetics (INGM), Milan, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Fenu
authors.affiliation: Molteni Therapeutics s.r.l., via I. Barontini 8, 50018 Scandicci, Florence, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Giuliani
authors.affiliation: Molteni Therapeutics s.r.l., via I. Barontini 8, 50018 Scandicci, Florence, Italy.
authors.forename: Lia
authors.initials: L
authors.lastname: Fantetti
authors.affiliation: Molteni Therapeutics s.r.l., via I. Barontini 8, 50018 Scandicci, Florence, Italy.
authors.forename: Gabrio
authors.initials: G
authors.lastname: Roncucci
authors.affiliation: Virology Program, National Institute of Molecular Genetics (INGM), Milan, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Simonutti
authors.affiliation: Center for Reconstructive Surgery of Osteoarticular Infections (C.R.I.O.), IRCCS Galeazzi Orthopaedic Institute, Milan, Italy.
authors.forename: Carlo Luca
authors.initials: CL
authors.lastname: Romanò
authors.affiliation: Virology Program, National Institute of Molecular Genetics (INGM), Milan, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: De Francesco
authors.affiliation: Laboratory of Clinical Chemistry and Microbiology, IRCCS Galeazzi Orthopaedic Institute, Milan, Italy; Laboratory of Technical Sciences for Laboratory Medicine, Department of Biomedical Science for Health, University of Milan, Milan, Italy. Electronic address: lorenzo.drago@unimi.it.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Drago
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development / Q000528:radiation effects; D015169:Colony Count, Microbial; D003470:Culture Media; D005840:Gentian Violet; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D008027:Light; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development / Q000528:radiation effects / Q000648:ultrastructure; D050296:Microbial Viability / Q000187:drug effects / Q000528:radiation effects; D018613:Microscopy, Confocal; D009942:Organometallic Compounds / Q000494:pharmacology*; D017319:Photosensitizing Agents / Q000494:pharmacology*; D019736:Prostheses and Implants / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000254:growth & development / Q000528:radiation effects / Q000648:ultrastructure; D014025:Titanium
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D007211:Indoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; C477806:RLP068; D014025:Titanium; D005840:Gentian Violet
keywords: Antibiofilm photodynamic activity; Bacterial biofilm; Confocal laser scanning microscopy; Prosthetic joint infections