title: Mycobacterium avium paratuberculosis in Italy: commensal or emerging human pathogen?
abstract: BACKGROUND
  Specific bacterial infections or alterations of the gut microbiota likely trigger immuno-pathological phenomena associated with Crohn's disease and ulcerative colitis. Mycobacterium avium subspecies paratuberculosis is a candidate etiological agent of Crohn's disease. Definitive causal connection between Mycobacterium avium subspecies paratuberculosis infection and Crohn's disease has not been demonstrated.
  
  
  OBJECTIVE
  To determine the circulation of Mycobacterium avium subspecies paratuberculosis in Crohn's disease patients and water supplies in an Italian region where this bacterium is endemic in cattle farms.
  
  
  METHODS
  Mycobacterium avium subspecies paratuberculosis screening was performed on biopsies from human patients, and from water samples, using two different PCR procedures.
  
  
  RESULTS
  In hospitals where multiple specimens were obtained from different sites in the intestine, the prevalence of Mycobacterium avium subspecies paratuberculosis infection was 82.1% and 40% respectively in Crohn's disease and ulcerative colitis patients; in another hospital, where single specimens were obtained from patients, the bacterium was not detected. Control subjects also harboured Mycobacterium avium subspecies paratuberculosis, but at a lower prevalence. Tap water samples collected in the study area contained Mycobacterium avium subspecies paratuberculosis DNA.
  
  
  CONCLUSIONS
  The results of screenings for Mycobacterium avium subspecies paratuberculosis in humans are deeply influenced by both the number and location of the collected biopsies. There is a wide circulation of the organism in the study area, considering the prevalence in humans and its presence in drinking water.
authors.affiliation: Dipartimento di Patologia Animale, Igiene e Sanità Pubblica Veterinaria, Università degli Studi di Milano, Via Celoria 10, Milan, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Pistone
authors.forename: Piero
authors.initials: P
authors.lastname: Marone
authors.forename: Massimo
authors.initials: M
authors.lastname: Pajoro
authors.forename: Massimo
authors.initials: M
authors.lastname: Fabbi
authors.forename: Nadia
authors.initials: N
authors.lastname: Vicari
authors.forename: Silvio
authors.initials: S
authors.lastname: Daffara
authors.forename: Claudia
authors.initials: C
authors.lastname: Dalla Valle
authors.forename: Silvia
authors.initials: S
authors.lastname: Gabba
authors.forename: Davide
authors.initials: D
authors.lastname: Sassera
authors.forename: Annalisa
authors.initials: A
authors.lastname: Verri
authors.forename: Matteo
authors.initials: M
authors.lastname: Montagna
authors.forename: Sara
authors.initials: S
authors.lastname: Epis
authors.forename: Claudio
authors.initials: C
authors.lastname: Monti
authors.forename: Elena Giulia
authors.initials: EG
authors.lastname: Strada
authors.forename: Vittorio
authors.initials: V
authors.lastname: Grazioli
authors.forename: Norma
authors.initials: N
authors.lastname: Arrigoni
authors.forename: Attilio
authors.initials: A
authors.lastname: Giacosa
authors.forename: Claudio
authors.initials: C
authors.lastname: Bandi
mesh_terms: D016009:Chi-Square Distribution; D003093:Colitis, Ulcerative / Q000382:microbiology; D003424:Crohn Disease / Q000382:microbiology*; D004269:DNA, Bacterial / Q000302:isolation & purification*; D060766:Drinking Water / Q000382:microbiology*; D006801:Humans; D007422:Intestines / Q000382:microbiology; D007558:Italy / Q000453:epidemiology; D016927:Mycobacterium avium subsp. paratuberculosis / Q000302:isolation & purification*; D010283:Paratuberculosis / Q000150:complications / Q000453:epidemiology*; D015995:Prevalence
chemical_list: D004269:DNA, Bacterial; D060766:Drinking Water