title: Confocal laser endomicroscopy for in vivo diagnosis of Clostridium difficile associated colitis - a pilot study.
abstract: BACKGROUND
  Clostridium difficile infection (CDI) is one of the most dreaded causes of hospital-acquired diarrhea. Main objective was to investigate whether confocal laser endomicroscopy (CLE) has the capability for in vivo diagnosis of C. difficile associated histological changes. Second objective was to prove the presence of intramucosal bacteria using CLE.
  
  
  METHODS
  80 patients were prospectively included, 10 patients were diagnosed with CDI based on toxigenic culture. To validate the presence of intramucosal bacteria ex vivo, CLE was performed in pure C. difficile culture; additionally fluorescence in situ hybridization (FISH) was performed. Finally, CLE with fluorescence labelled oligonucleotide probe specific for C. difficile was performed ex vivo in order to prove the presence of bacteria.
  
  
  RESULTS
  CLE identified CDI-associated histological changes in vivo (sensitivity and accuracy of 88.9% and 96.3%). In addition, intramucosal bacteria were visualized. The presence of these bacteria could be proven by CLE with labeled, specific molecular C. difficile probe and FISH-technique. Based on comparison between CLE and FISH analyses, sensitivity and specificity for the presence of intramucosal bacteria were 100%.
  
  
  CONCLUSIONS
  CLE has the potential for in vivo diagnosis of CDI associated colitis. In addition, CLE allowed the detection of intramucosal bacteria in vivo.
authors.affiliation: Department of Medicine I, University of Erlangen-Nuremberg, Erlangen, Germany. helmut.neumann@uk-erlangen.de
authors.forename: Helmut
authors.initials: H
authors.lastname: Neumann
authors.forename: Claudia
authors.initials: C
authors.lastname: Günther
authors.forename: Michael
authors.initials: M
authors.lastname: Vieth
authors.forename: Martin
authors.initials: M
authors.lastname: Grauer
authors.forename: Nadine
authors.initials: N
authors.lastname: Wittkopf
authors.forename: Jonas
authors.initials: J
authors.lastname: Mudter
authors.forename: Christoph
authors.initials: C
authors.lastname: Becker
authors.forename: Christoph
authors.initials: C
authors.lastname: Schoerner
authors.forename: Raja
authors.initials: R
authors.lastname: Atreya
authors.forename: Markus F
authors.initials: MF
authors.lastname: Neurath
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016360:Clostridioides difficile / Q000235:genetics / Q000302:isolation & purification; D003113:Colonoscopy / Q000379:methods; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis* / Q000382:microbiology; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007413:Intestinal Mucosa / Q000382:microbiology; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies