title: On the prevalence of M. avium subspecies paratuberculosis DNA in the blood of healthy individuals and patients with inflammatory bowel disease.
abstract: BACKGROUND
  Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. However, because of appropriate immune responses and antibiotic therapy, overt mycobacterial diseases occur far less frequently. M. avium subspecies paratuberculosis (MAP) causes Johne's disease in ruminants, an affliction evocative of inflammatory bowel disease (IBD). Several agents used to treat IBD (5-ASA, methotrexate, azathioprine and its metabolite 6-MP) have recently been shown to be antiMAP antibiotics. We herein evaluate the prevalence of MAP DNA in healthy individuals and compare them with IBD patients on antiMAP antibiotics.
  
  
  METHODS
  We studied 100 healthy individuals (90 blood donors) and 246 patients with IBD. IS900 MAP DNA was identified using a nested primer PCR in the buffy coat of blood. Positive signal was confirmed as MAP by DNA sequence analysis. PCR positive results frequencies were compared according to medications used. Significance was accepted at p<0.05.
  
  
  RESULTS
  47% (47/100) healthy controls and 16% (40/246) IBD patients were IS900 positive (p<0.0001). MAP DNA was identified in 17% of 143 patients receiving mesalamine and 6% of 16 receiving sulfasalazine. None of the IBD patients receiving methotrexate (n = 9), 6-MP (n = 3), ciprofloxacin (n = 5) or Tacrolimus (n = 3) had MAP DNA detectable in their blood.
  
  
  CONCLUSIONS
  We found a disquietingly large percentage of healthy individuals have MAP DNA in their blood, the significance of which remains to be determined. Counter-intuitively, the incidence of MAP DNA was significantly lower in patients with IBD. Agents with the most potent in vitro antiMAP activity were associated with clearance of blood MAP DNA. We posit that the use antiMAP antibiotics was responsible for the decreased prevalence of MAP DNA in patients with IBD.
authors.affiliation: Departamento de Producción y Sanidad Animal, Instituto Vasco de Investigación y Desarrollo Agrario (NEIKER-Tecnalia), Derio, Bizkaia, Spain. rjuste@neiker.net
authors.forename: Ramon A
authors.initials: RA
authors.lastname: Juste
authors.forename: Natalia
authors.initials: N
authors.lastname: Elguezabal
authors.forename: Joseba M
authors.initials: JM
authors.lastname: Garrido
authors.forename: Andres
authors.initials: A
authors.lastname: Pavon
authors.forename: Maria V
authors.initials: MV
authors.lastname: Geijo
authors.forename: Iker
authors.initials: I
authors.lastname: Sevilla
authors.forename: Jose-Luis
authors.initials: JL
authors.lastname: Cabriada
authors.forename: Angel
authors.initials: A
authors.lastname: Tejada
authors.forename: Francisco
authors.initials: F
authors.lastname: García-Campos
authors.forename: Roberto
authors.initials: R
authors.lastname: Casado
authors.forename: Itziar
authors.initials: I
authors.lastname: Ochotorena
authors.forename: Ander
authors.initials: A
authors.lastname: Izeta
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Greenstein
mesh_terms: D003093:Colitis, Ulcerative / Q000382:microbiology; D004269:DNA, Bacterial / Q000097:blood*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology / Q000382:microbiology*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction
chemical_list: D004269:DNA, Bacterial