Related Experiment Video
Updated: Nov 1, 2025
Chronic Salmonella Infection Induced Intestinal Fibrosis
Published on: September 22, 2019
A Mycobacterium species for Crohn's disease?
John M Aitken1, Khoi Phan2, Samantha E Bodman1
1Otakaro Pathways, Christchurch, New Zealand.
Abstract:
In ruminants Mycobacterium avium subspecies paratuberculosis (MAP) is the causative organism of a chronic granulomatous inflammatory bowel disease called Johne's disease (JD). Some researchers have hypothesised that MAP is also associated with Crohn's disease (CD), an inflammatory bowel disease in humans that shares some histological features of JD. Despite numerous attempts to demonstrate causality by researchers, direct microbiological evidence of MAP involvement in CD remains elusive. Importantly, it has not been possible to reliably and reproducibly demonstrate mycobacteria in the tissue of CD patients. Past attempts to visualise mycobacteria in tissue may have been hampered by the use of stains optimised for Mycobacterium tuberculosis complex (MTB) and the lack of reliable bacteriological culture media for both non-tuberculous mycobacteria (NTM) and cell-wall-deficient mycobacteria (CWDM). Here we describe a Ziehl-Neelsen (ZN) staining method for the demonstration of CWDM in resected tissue from patients with Crohn's disease, revealing the association of CWDM in situ with host tissue reactions, and posit this as a cause of the tissue inflammation. Using the ZN stain described we demonstrated the presence of CWDM in 18 out of 18 excised tissue samples from patients diagnosed as having Crohn's disease, and in zero samples out of 15 non-inflammatory bowel disease controls.
Insights
A novel Ziehl-Neelsen staining method revealed cell-wall-deficient mycobacteria (CWDM) in all Crohn's disease (CD) tissue samples. This finding suggests CWDM may cause inflammation in CD patients, unlike previous elusive MAP links.
Area of Science:
- Microbiology
- Gastroenterology
- Immunology
Background:
- Mycobacterium avium subspecies paratuberculosis (MAP) is linked to Johne's disease (JD) in ruminants.
- Crohn's disease (CD) in humans shares histological similarities with JD, prompting research into MAP's role.
- Previous studies failed to provide definitive microbiological evidence of MAP in CD tissues.
Purpose of the Study:
- To develop and apply a novel staining method for detecting cell-wall-deficient mycobacteria (CWDM) in human inflammatory bowel disease tissues.
- To investigate the presence and association of CWDM with host tissue reactions in Crohn's disease.
- To explore CWDM as a potential causative agent for inflammation in Crohn's disease.
Main Methods:
- Development of a modified Ziehl-Neelsen (ZN) staining technique optimized for visualizing CWDM.
- Application of the ZN stain to resected tissue samples from patients diagnosed with Crohn's disease.
- Comparison of stained tissue samples from CD patients with non-inflammatory bowel disease controls.
Main Results:
- The novel ZN staining method successfully demonstrated the presence of CWDM in 100% (18/18) of excised Crohn's disease tissue samples.
- CWDM were observed in situ, showing an association with host tissue reactions indicative of inflammation.
- Zero out of 15 control tissue samples from non-inflammatory bowel disease patients showed any evidence of CWDM.
Conclusions:
- The study presents a reliable method for detecting CWDM in Crohn's disease tissues.
- The consistent presence of CWDM in CD tissues suggests a strong association and potential causative role in the disease.
- This research offers a new perspective on the etiology of Crohn's disease, shifting focus to CWDM as a potential trigger for inflammation.
Related Concept Videos
01:30Inflammatory Bowel Disease II: Crohn's Disease
Inflammatory bowel disease, commonly known as IBD, refers to a collection of disorders that lead to persistent inflammation of the gastrointestinal tract. The two types of IBD are ulcerative colitis, which impacts the colon, and Crohn's disease, which can involve any part of the gastrointestinal segment.
Crohn's disease
Crohn's disease is a chronic, systemic inflammatory bowel disease (IBD) that predominantly affects the gastrointestinal tract. It is marked by...
01:24Drugs for Treatment of Crohn's Disease in IBD Using Biologic Agents: Anti-TNF
01:30Bacterial Phylum Actinobacteria
01:29Drugs for Treatment of Crohn's Disease in IBD Using Immunomodulatory Agents
01:27Inflammatory Bowel Disease I: Ulcerative Colitis
Inflammatory bowel disease, or IBD, encompasses a group of disorders characterized by chronic inflammation or ulceration of the gastrointestinal tract.
Risk Factors
The exact cause of IBD remains unclear, although it is believed to be due to a mix of genetic, environmental, microbial, and immune factors. Genetic factors are significant in determining susceptibility to IBD, with family history being a critical risk factor. Individuals with a first-degree relative who has IBD are at...
01:17Chronic Bowel Disorders: Introduction
Irritable Bowel Syndrome (IBS) is a common disorder affecting the gastrointestinal tract. The distinctive feature is recurrent abdominal pain associated with altered bowel movements, manifesting as constipation, diarrhea, or fluctuating between both. The...