title: Bioimage analysis of Shigella infection reveals targeting of colonic crypts.
abstract: Few studies within the pathogenic field have used advanced imaging and analytical tools to quantitatively measure pathogenicity in vivo. In this work, we present a novel approach for the investigation of host-pathogen processes based on medium-throughput 3D fluorescence imaging. The guinea pig model for Shigella flexneri invasion of the colonic mucosa was used to monitor the infectious process over time with GFP-expressing S. flexneri. A precise quantitative imaging protocol was devised to follow individual S. flexneri in a large tissue volume. An extensive dataset of confocal images was obtained and processed to extract specific quantitative information regarding the progression of S. flexneri infection in an unbiased and exhaustive manner. Specific parameters included the analysis of S. flexneri positions relative to the epithelial surface, S. flexneri density within the tissue, and volume of tissue destruction. In particular, at early time points, there was a clear association of S. flexneri with crypts, key morphological features of the colonic mucosa. Numerical simulations based on random bacterial entry confirmed the bias of experimentally measured S. flexneri for early crypt targeting. The application of a correlative light and electron microscopy technique adapted for thick tissue samples further confirmed the location of S. flexneri within colonocytes at the mouth of crypts. This quantitative imaging approach is a novel means to examine host-pathogen systems in a tailored and robust manner, inclusive of the infectious agent.
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 75724 Paris, France; INSERM, U1202, 75015 Paris, France;
authors.forename: Ellen T
authors.initials: ET
authors.lastname: Arena
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 75724 Paris, France; INSERM, U1202, 75015 Paris, France;
authors.forename: Francois-Xavier
authors.initials: FX
authors.lastname: Campbell-Valois
authors.affiliation: Center for Innovation & Technological Research, Imagopole-Plateforme D'Imagerie Dynamique, Institut Pasteur, 75724 Paris, France;
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Tinevez
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 75724 Paris, France; INSERM, U1202, 75015 Paris, France;
authors.forename: Giulia
authors.initials: G
authors.lastname: Nigro
authors.affiliation: Center for Innovation & Technological Research, Ultrapole, Institut Pasteur, 75724 Paris, France;
authors.forename: Martin
authors.initials: M
authors.lastname: Sachse
authors.affiliation: Center for Innovation & Technological Research, Ultrapole, Institut Pasteur, 75724 Paris, France;
authors.forename: Maryse
authors.initials: M
authors.lastname: Moya-Nilges
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 75724 Paris, France; INSERM, U1202, 75015 Paris, France;
authors.forename: Katharina
authors.initials: K
authors.lastname: Nothelfer
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 75724 Paris, France; INSERM, U1202, 75015 Paris, France;
authors.forename: Benoit
authors.initials: B
authors.lastname: Marteyn
authors.affiliation: Center for Innovation & Technological Research, Imagopole-Plateforme D'Imagerie Dynamique, Institut Pasteur, 75724 Paris, France;
authors.forename: Spencer L
authors.initials: SL
authors.lastname: Shorte
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 75724 Paris, France; INSERM, U1202, 75015 Paris, France; Collège de France, 75005 Paris, France psanson@pasteur.fr.
authors.forename: Philippe J
authors.initials: PJ
authors.lastname: Sansonetti
mesh_terms: D000818:Animals; D003106:Colon / Q000382:microbiology*; D004405:Dysentery, Bacillary / Q000473:pathology*; D006168:Guinea Pigs; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology; D012763:Shigella flexneri / Q000472:pathogenicity*
keywords: Shigella flexneri; bioimage analysis; host–pathogen interactions; intestinal crypts; tissue microbiology