title: Autofluorescence in samples obtained from chronic biofilm infections--"all that glitters is not gold".
abstract: When looking at tissue sections of ex vivo samples, autofluorescence can be a major cause of artifacts and misinterpretations. We here reiterate evidence that autofluorescing granules, often hemosiderin but also ceroid or mucinogen granules, are severe obstacles when imaging and diagnosing biofilm infections through fluorescent imaging techniques. We used confocal laser scanning microscopy with spectral analysis for autofluorescence detection as well as standard histological stains in order to identify the culprit and show that these granules might very well be mistaken for bacterial biofilms. Furthermore, we hypothesize that the increased amount of autofluorescing granules may be a consequence of prolonged inflammation as a consequence of chronic biofilm infections.
authors: Costerton Biofilm Center, Department of International Health, Immunology & Microbiology, The faculty of Health and Medical Sciences, The University of Copenhagen, Denmark The Department of Clinical Microbiology, Rigshospitalet, Denmark sreis@sund.ku.dk.
authors: Steffen
authors: S
authors: Eickhardt
authors: Costerton Biofilm Center, Department of International Health, Immunology & Microbiology, The faculty of Health and Medical Sciences, The University of Copenhagen, Denmark The Department of Clinical Microbiology, Rigshospitalet, Denmark.
authors: Kasper N
authors: KN
authors: Kragh
authors: Ear Nose Throat Department, North Zealand Hospital, Denmark.
authors: Stine
authors: S
authors: Schrøder
authors: The Department of Biomedicine, The faculty of Health and Medical Sciences, The University of Copenhagen, Denmark.
authors: Steen Seier
authors: SS
authors: Poulsen
authors: Department of Vascular Surgery, Rigshospitalet, University of Copenhagen, Denmark.
authors: Henrik
authors: H
authors: Sillesen
authors: Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore.
authors: Michael
authors: M
authors: Givskov
authors: Costerton Biofilm Center, Department of International Health, Immunology & Microbiology, The faculty of Health and Medical Sciences, The University of Copenhagen, Denmark The Department of Clinical Microbiology, Rigshospitalet, Denmark.
authors: Niels
authors: N
authors: Høiby
authors: Costerton Biofilm Center, Department of International Health, Immunology & Microbiology, The faculty of Health and Medical Sciences, The University of Copenhagen, Denmark The Department of Clinical Microbiology, Rigshospitalet, Denmark.
authors: Thomas
authors: T
authors: Bjarnsholt
authors: Costerton Biofilm Center, Department of International Health, Immunology & Microbiology, The faculty of Health and Medical Sciences, The University of Copenhagen, Denmark The Department of Clinical Microbiology, Rigshospitalet, Denmark.
authors: Morten
authors: M
authors: Alhede
mesh_terms: D001419:Bacteria / Q000737:chemistry*; D018441:Biofilms / Q000254:growth & development*; D003951:Diagnostic Errors; D005453:Fluorescence; D018613:Microscopy, Confocal; D061848:Optical Imaging / Q000379:methods*; D010336:Pathology / Q000379:methods*; D013057:Spectrum Analysis
keywords: Biofilm; CLSM; autofluorescence; hemosidirin