Table 1

 Arguments for and against a Mycobacterium avium subspecies paratuberculosis (MAP) causation of Crohn’s disease

MAP, Mycobacterium avium subspecies paratuberculosis; PCR, polymerase chain reaction; FISH, fluorescent in situ hybridisation; HIV, human immunodeficiency virus.
(1) Clinical and pathological similarities between Johne’s and Crohn’s diseases3,4
(2) Presence in food chain (milk, meat) and water supplies7,8
(3) Increased detection of MAP in Crohn’s disease tissues by culture, PCR, FISH5,6,33
(4) Positive blood cultures of MAP in Crohn’s disease patients11
(5) Increased serological responses to MAP in Crohn’s disease patients20,34
(6) Detection of MAP in human breast milk by culture and PCR9
(7) Progression of cervical lymphadenopathy to distal ileitis in a patient with MAP infection35
(8) Therapeutic responses to combination antituberculosis therapy that include macrolide antibiotics10,24
(1) Differences in clinical and pathological responses in Johne’s and Crohn’s diseases4
(2) Lack of epidemiological support of transmissible infection36
(3) No evidence of transmission to humans in contact with animals infected with MAP
(4) Genotypes of Crohn’s disease and bovine MAP isolates not similar18
(5) Variability in detection of MAP by PCR (0–100% in Crohn’s disease and ulcerative colitis tissues)8 and serological testing37
(6) No evidence of mycobacterial cell wall by histochemical staining
(7) No worsening of Crohn’s disease with immunosuppressive agents or HIV infection
(8) No documented cell mediated immune responses to MAP in patients with Crohn’s disease20
(9) No therapeutic response to traditional antimycobacterial antibiotics23