scholarly journals Mycobacterium Avium Paratuberculosisand the Etiology of Crohn’s Disease: A Review of the Controversy from the Clinician’s Perspective

2010 ◽  
Vol 24 (10) ◽  
pp. 619-624 ◽  
Author(s):  
Greg Rosenfeld ◽  
Brian Bressler
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Mycobacterium Avium ◽  
Immunosuppressive Agents ◽  
Infectious Agent ◽  
Causative Role ◽  
Mycobacterium Avium Paratuberculosis ◽  
Considerable Research ◽  
Chronic Inflammatory Condition

Mycobacterium avium paratuberculosis(MAP) is an obligate intracellular organism that has frequently been associated with Crohn’s disease (CD). Because CD is a chronic inflammatory condition, many researchers have speculated that an infectious agent must be the cause of CD. MAP has often been proposed to be one such agent; however, despite considerable research, the evidence remains inconclusive. Higher levels of MAP have been found in the tissues and blood of CD patients than in controls, forming the foundation for much of the research into the role of MAP in CD and the primary argument in support of a causative role for MAP in CD. MAP is a slow-growing and fastidious organism that is difficult to grow in culture and, therefore, challenging to detect in patients. As a result, there has been variability in the results of studies attempting to detect the presence of MAP in CD patients, and considerable controversy over whether this organism has a causative role in the etiology of CD. Two main hypotheses exist with respect to the role of MAP in CD. The first is that MAP is a principal cause of CD, while the second is that MAP is more prevalent because of the immune dysfunction seen in CD but does not play a causative role. Clinicians are often faced with questions regarding the role of this organism and the need to treat it. The present article attempts to provide an overview of the controversy including the nature of the mycobacterium, the difficulty in detecting it, the use of antimycobacterial agents to treat it and the effect of immunosuppressive agents – all from a clinician’s perspective. Although the role of MAP in CD remains controversial and an area of considerable research, it is currently only of academic interest because there is no clinically useful test to identify the presence of the organism, and no evidence to support the use of antibiotics to eradicate it for the treatment of CD.

scholarly journals Nicotine Increases Macrophage Survival through α7nAChR/NF-κB Pathway in Mycobacterium avium paratuberculosis Infection

2021 ◽  
Vol 9 (5) ◽  
pp. 1086
Author(s):  
Dania AlQasrawi ◽  
Ebraheem Naser ◽  
Saleh A. Naser
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Mycobacterium Avium ◽  
Nuclear Translocation ◽  
Mycobacterium Avium Subspecies Paratuberculosis ◽  
Α7 Nicotinic Acetylcholine Receptor ◽  
Macrophage Response ◽  
Mycobacterium Avium Paratuberculosis ◽  
Cellular Survival

Recently, we reported that nicotine plays a role in the failure of the macrophage in the clearance of Mycobacterium avium subspecies paratuberculosis (MAP) during infection in Crohn’s disease smokers. We also demonstrated that nicotine enhances macrophages cellular survival during MAP infection. Blocking α7 nicotinic acetylcholine receptor (α7nAChR) with the pharmacological antagonist—mecamylamine—subverted the anti-inflammatory effect of nicotine in macrophages. Yet, it is still unknown how α7nAChR is involved in the modulation of the macrophage response during MAP infection. Here, we studied the mechanistic role of nicotine-α7nAChR interaction in modulating NF-ĸB survival pathway, autophagy, and effect on cathelicidin production in MAP-infected macrophages using THP-1 cell lines. Our results showed that nicotine upregulated α7nAChR expression by 5-folds during MAP infection compared to controls. Bcl-2 expression was also significantly increased after nicotine exposure. Moreover, Nicotine inhibited autophagosome formation whereas infection with MAP in absence of nicotine has significantly increased LC-3b in macrophages. Nicotine also further upregulated NF-ĸB subunits expression including Rel-B and p100, and increased nuclear translocation of p52 protein. We also discovered that cathelicidin production was significantly suppressed in MAP-infected macrophages, treatment with nicotine showed no effect. Overall, the study provides new insight toward understanding the cellular role of nicotine through α7nAChR/NF-ĸB p100/p52 signaling pathway in inducing anti-apoptosis and macrophage survival during MAP infection in Crohn’s disease smokers.

Tu1760 Functional Evidence for a Causative Role of the Intestinal Microbiota in Crohn's Disease-Like Ileitis Using Antibiotic-Treated and Germ-Free TNFDeltaare/+ Mice

2014 ◽  
Vol 146 (5) ◽  
pp. S-836
Author(s):  
Monika Schaubeck ◽  
Thomas Clavel ◽  
Nadine Waldschmitt ◽  
Jan Wehkamp ◽  
Ines Martinez ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Intestinal Microbiota ◽  
Causative Role ◽  
Germ Free ◽  
Tnfdeltaare Mice

scholarly journals Gastrointestinal: Mycobacterium avium paratuberculosis and Crohn's disease

2005 ◽  
Vol 20 (12) ◽  
pp. 1943-1943 ◽  
Author(s):  
RB Gearry ◽  
JM Aitken ◽  
RL Roberts ◽  
S Ismail ◽  
J Keenan ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Mycobacterium Avium ◽  
Mycobacterium Avium Paratuberculosis

scholarly journals Crohn's disease in people exposed to clinical cases of bovine paratuberculosis

2005 ◽  
Vol 134 (1) ◽  
pp. 49-56 ◽  
Author(s):  
P. H. JONES ◽  
T. B. FARVER ◽  
B. BEAMAN ◽  
B. ÇETINKAYA ◽  
K. L. MORGAN
Keyword(s):  
Ulcerative Colitis ◽  
Risk Factor ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Mycobacterium Avium ◽  
Causative Role ◽  
Dairy Farmers ◽  
The United Kingdom ◽  
Frequency Of Contact ◽  
Clinical Cases

SUMMARYMycobacterium aviumsubspeciesparatuberculosis(Map), the cause of ruminant paratuberculosis, has been proposed as the causative agent of Crohn's disease. The objective of this study was to determine whether exposure to clinical cases of bovine paratuberculosis was a risk factor for Crohn's disease. A questionnaire was sent to dairy farmers living on premises where the occurrence or absence of clinical cases of bovine paratuberculosis had previously been determined. The prevalence of Crohn's disease was found to be similar to that reported in other studies in the United Kingdom and showed no association with bovine paratuberculosis. There was, however, a univariate association with geographical region. Ulcerative colitis showed univariate associations with age, frequency of contact with cattle and with smoking. The results do not support the hypothesis thatMapplays a causative role in the aetiology of Crohn's disease.

Cross-reactivity between mycobacterium avium paratuberculosis and human intestinal antigens characterizes Crohn's disease

2003 ◽  
Vol 124 (4) ◽  
pp. A321
Author(s):  
Dimitrios Polymeros ◽  
Dimitrios P. Bogdanos ◽  
Ajeya Shetty ◽  
Roser Vega ◽  
Cinzia Papadia ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Mycobacterium Avium ◽  
Cross Reactivity ◽  
Mycobacterium Avium Paratuberculosis

scholarly journals Role of Fecal Diversion in Complex Crohn's Disease

2019 ◽  
Vol 32 (04) ◽  
pp. 273-279 ◽  
Author(s):  
John P. Burke
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Surgical Complication ◽  
Fecal Diversion ◽  
Fecal Stream ◽  
Primary Indication ◽  
Chronic Inflammatory Condition ◽  
Bowel Continuity ◽  
Control Disease

AbstractCrohn's disease (CD) is a chronic inflammatory condition of the gastrointestinal tract resulting in progressive tissue damage, which can result in strictures, fistulae, and abscesses formation. The triggering mechanism is thought to be in the fecal stream, and diversion of this fecal stream is sometimes required to control disease when all other avenues of medical and surgical management have been exhausted. Fecal diversion can be temporary or permanent with the indications being defunctioning a high-risk anastomosis, as a result of a surgical complication, for disease control, or due to severe colonic, rectal, or perianal disease. The incidence of ostomy formation in CD has increased epidemiologically over time. The primary indication for ostomy formation is severe perianal fistulizing disease. However, while 64% of patients have an early clinical response after diversion for refractory perianal CD, restoration of bowel continuity is attempted in only 35% of patients, and is successful in only 17%. The current review discusses the indications for ostomy creation in complex CD, strategies for procedure selection, and patient outcomes.

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