Detection of Mycobacterium avium subspecies paratuberculosis from patients with Crohn's disease using nucleic acid-based techniques: a systematic review and meta-analysis

Pathogenic mechanisms and etiologic aspects of Mycobacterium avium subspecies paratuberculosis as an infectious cause of cutaneous melanoma

Infectious etiologies have previously been proposed as causes of both melanoma and non-melanoma skin cancer. This exploratory overview explains and presents the evidence for the hypothesis that a microorganism excreted in infected ruminant animal feces, Mycobacterium avium subspecies paratuberculosis (MAP), is the cause of some cases of cutaneous melanoma (CM). Occupational, residential, and recreational contact with MAP-contaminated feces, soil, sand, and natural bodies of water may confer a higher rate of CM. Included in our hypothesis are possible reasons for the differing rates and locations of CM in persons with white versus nonwhite skin, why CM develops underneath nails and in vulvar skin, why canine melanoma is an excellent model for human melanoma, and why the Bacille Calmette-Guérin (BCG) vaccine has demonstrated efficacy in the prevention and treatment of CM. The pathogenic mechanisms and etiologic aspects of MAP, as a transmittable agent underlying CM risk, are carefully deliberated in this paper. Imbalances in gut and skin bacteria, genetic risk factors, and vaccine prevention/therapy are also discussed, while acknowledging that the evidence for a causal association between MAP exposure and CM remains circumstantial.

Mycobacterium avium subsp. paratuberculosis in Wild Boar (Sus scrofa) in Portugal

Paratuberculosis, or Johne's disease, caused by Mycobacterium avium subsp. paratuberculosis (MAP), is a chronic granulomatous enteritis affecting both domestic and wild ruminants. The agent was also found in wild mammals such as wild boar (Sus scrofa); however, the role of wild mammals in the epidemiology of MAP is unclear. During the research period, 941 free-ranging wild boar (S. scrofa) legally hunted in two locations in the central-eastern region of Portugal were examined. Ninety-seven wild boars exhibited one or more gross lesions and were tested for the presence of Mycobacterium avium subsp. paratuberculosis using acid-fast staining, mycobacterial culture, polymerase chain reaction (PCR), and histopathological examination. Forty-five animals (46.4%, 95% CI: 36.5-56.3%) were identified as infected, as indicated by positive results in culture and/or PCR. The findings revealed that the most significant risk factor was being a juvenile compared to yearlings and adults (OR = 10.2, 95% CI: 2.2-48.0). Based on our results, 37.9% (n = 11) of the infected animals were considered suitable for human consumption. Our findings offer novel insights into mycobacterial infections in wild boar populations in Portugal and suggest that wild boar could be a source of human infection if zoonotic potential is considered.

Shaping immunity: The influence of natural selection on population immune diversity

Humans exhibit considerable variability in their immune responses to the same immune challenges. Such variation is widespread and affects individual and population-level susceptibility to infectious diseases and immune disorders. Although the factors influencing immune response diversity are partially understood, what mechanisms lead to the wide range of immune traits in healthy individuals remain largely unexplained. Here, we discuss the role that natural selection has played in driving phenotypic differences in immune responses across populations and present-day susceptibility to immune-related disorders. Further, we touch on future directions in the field of immunogenomics, highlighting the value of expanding this work to human populations globally, the utility of modeling the immune response as a dynamic process, and the importance of considering the potential polygenic nature of natural selection. Identifying loci acted upon by evolution may further pinpoint variants critically involved in disease etiology, and designing studies to capture these effects will enrich our understanding of the genetic contributions to immunity and immune dysregulation.

Bayesian latent class modelling of true prevalence in animal subgroups with application to bovine paratuberculosis infection

The prevalence of an infectious disease of animals living in separate groups (e.g. herds) is naturally analyzed using a Bayesian hierarchical latent class model. We propose an extension to this methodology by including subgroup level prevalence measures within the groups of animals. As an application illustrating the merits of our methodology, we reassessed the prevalence of bovine paratuberculosis (PTBC) infection in Hungarian commercial dairy farms. Our aim was to consolidate previous findings using a large amount of recent data and priors based on historical data. To model the subgroup level infection prevalence within animal groups, we considered correlated prevalences following beta distributions derived from independent normally distributed random herd effects. In the application, infection status of herds was handled as latent classes, multiparous and primiparous cows as within-herd subgroups. The novel methodology allows us to estimate both the mean and median conditional within-herd true prevalence (CWHP) related to each animal subgroup as well as other measures characterizing the interrelation of subgroups. The results of the application aligned with the findings of the former PTBC study, while the more recent and considerably larger dataset and the use of historical priors increased the reliability of the results. The STAN and JAGS codes of the application are available in Supplementary material.

Cytokine expression in subjects with Mycobacterium avium ssp. paratuberculosis positive blood cultures and a meta-analysis of cytokine expression in Crohn's disease

Objectives

1) Culture Mycobacterium avium ssp. paratuberculosis (MAP)from blood, 2) assess infection persistence, 3) determine Crohn's disease (CD) cytokine expression, 4) compare CD cytokine expression to tuberculosis, and 5) perform a meta-analysis of cytokine expression in CD.

Methods

The Temple University/Abilene Christian University (TU/ACU) study had a prospective case control design with 201 subjects including 61 CD patients and 140 non-CD controls. The culture methods included MGIT, TiKa and Pozzato broths, and were deemed MAP positive, if IS900 PCR positive. A phage amplification assay was also performed to detect MAP. Cytokine analysis of the TU/ACU samples was performed using Simple Plex cytokine reagents on the Ella ELISA system. Statistical analyses were done after log transformation using the R software package. The meta-analysis combined three studies.

Results

Most subjects had MAP positive blood cultures by one or more methods in 3 laboratories. In our cytokine study comparing CD to non-CD controls, IL-17, IFNγ and TNFα were significantly increased in CD, but IL-2, IL-5, IL-10 and GM-CSF were not increased. In the meta-analysis, IL-6, IL-8 and IL-12 were significantly increased in the CD patients.

Conclusion

Most subjects in our sample had MAP infection and 8 of 9 subjects remained MAP positive one year later indicating persistent infection. While not identical, cytokine expression patterns in MAP culture positive CD patients in the TU/ACU study showed similarities (increased IL-17, IFNγ and TNFα) to patterns of patients with Tuberculosis in other studies, indicating the possibilities of similar mechanisms of pathogen infection and potential strategies for treatment.

Mycobacterium avium subsp. paratuberculosis and Crohn's disease: characterization of the interaction with different aspects of the disease

Crohn's disease (CD) is a chronic granulomatous inflammatory bowel disease with no fully understood etiology and cure. Mycobacterium avium subspecies paratuberculosis (MAP), the etiologic agent of paratuberculosis, is also isolated from samples from human patients with CD. Paratuberculosis is characterized by persistent diarrhea and progressive weight loss and primarily affects ruminants, which eliminate the agent via feces and milk. The involvement of MAP in the pathogenesis of CD and other intestinal diseases is unclear. Thus, the present study aimed to analyze immunological, socioepidemiological, biochemical, and therapeutic variables that may be related to the occurrence of MAP in blood samples and CD patients. The sampling was random, and the population of origin was the patients from the Bowel Outpatient Clinic of the Alpha Institute of Gastroenterology (IAG), Hospital das Clínicas, Universidade Federal de Minas Gerais (HC-UFMG). Blood samples were collected from 20 patients with CD, eight with ulcerative rectocolitis (UCR), and 10 control patients without inflammatory bowel diseases. Samples were subjected to real-time PCR for detection of MAP DNA, oxidative stress analyses, and socioepidemiological variables. MAP was detected in 10 (26.3%) of the patients, seven (70%) were CD patients, 2 (20%) were URC patients, and one (10%) was a non-IBD patient. MAP was found more frequently among CD patients, but not restricted to CD patients. The presence of MAP in the blood of these patients occurred simultaneously with an inflammatory response with an increase in neutrophils and significant alterations in the production of antioxidant enzymes such as catalase and GST.

The Development and Validation of Anti-paratuberculosis-nocardia Polypeptide Antibody [Anti-pTNP] for the Diagnosis of Crohn's Disease

BACKGROUND AND AIMS

Non-invasive biomarkers in sera of patients with inflammatory bowel disease [IBD] are not currently available for rapidly and accurately diagnosing the disease. We aimed to investigate and validate the potential roles of anti-paratuberculosis-nocardia polypeptide antibodies [anti-pTNP] in the diagnosis of IBD.

METHODS

Serum samples were collected from 502 patients with diagnosed Crohn's disease [CD], 141 patients with ulcerative colitis [UC], and 109 healthy donors. The levels of anti-pTNPs and anti-Saccharomyces cerevisiae antibodies [ASCAs] were determined by enzyme-linked immunosorbent assay. The effects of each variable on the diagnosis were analysed by receiver operating characteristic [ROC] analysis. We also performed an estimate study by first developing a clinical prediction model, with external validation in CD patients from nine IBD medical centres in China.

RESULTS

The levels of anti-pTNPs in sera of CD patients were higher than those in UC patients and healthy donors. The positive rates of anti-pTNPs were significantly higher in ileal CD patients than in ileocolonic and colonic CD patients, and the levels of anti-pTNP IgG in perianal patients were significantly higher than those in non-perianal CD patients. Of note, anti-pTNPs and perianal diseases were important predictors for active stage of CD patients. Discriminative ability to predict active CD patients was 0.918 (95% confidence interval [CI]:0.886-0.949).

CONCLUSIONS

Anti-pTNP functions as a novel biological marker for diagnosing CD and can be used to assess disease severity, particularly in those with lesion locations in the terminal ileum and stricturing and perianal diseases. A validated prediction model reveals that anti-pTNPs are useful for estimating the likelihood of active CD.

Mycobacterium avium ssp. paratuberculosis in the Food Supply: A Public Health Issue

This article examines the policy implications of Mycobacterium avium subspecies paratuberculosis (MAP) as a zoonotic pathogen and the public health risks posed by the presence of MAP in food, particularly milk products. Viable MAP has been cultured from commercially pasteurized milk in the US. Dairy pasteurization standards and regulations are examined in light of this finding. On the basis of the precautionary principle, the authors suggest options to reduce exposure to MAP, including (1) increased federal authority to regulate pasteurization of all dairy products, (2) modification of pasteurization standards in order to more effectively kill MAP, (3) removal of the Pasteurized Milk Ordinance (PMO) provision that allows states to override federal policy in intrastate dairy sales, and (4) creation of a mandatory Johne's Disease Control Program. These measures would reduce human exposure to MAP and may reduce the risk of diseases associated with MAP.

Revealing immune responses in the Mycobacterium avium subsp. paratuberculosis-infected THP-1 cells using single cell RNA-sequencing

Mycobacterium avium subsp. paratuberculosis (MAP) is a causative agent of Johne’s disease, which is a chronic and debilitating disease in ruminants. MAP is also considered to be a possible cause of Crohn’s disease in humans. However, few studies have focused on the interactions between MAP and human macrophages to elucidate the pathogenesis of Crohn’s disease. We sought to determine the initial responses of human THP-1 cells against MAP infection using single-cell RNA-seq analysis. Clustering analysis showed that THP-1 cells were divided into seven different clusters in response to phorbol-12-myristate-13-acetate (PMA) treatment. The characteristics of each cluster were investigated by identifying cluster-specific marker genes. From the results, we found that classically differentiated cells express CD14, CD36, and TLR2, and that this cell type showed the most active responses against MAP infection. The responses included the expression of proinflammatory cytokines and chemokines such as CCL4, CCL3, IL1B, IL8, and CCL20. In addition, the Mreg cell type, a novel cell type differentiated from THP-1 cells, was discovered. Thus, it is suggested that different cell types arise even when the same cell line is treated under the same conditions. Overall, analyzing gene expression patterns via scRNA-seq classification allows a more detailed observation of the response to infection by each cell type.

Economic losses due to Johne's disease (paratuberculosis) in dairy cattle

Johne's disease (JD), or paratuberculosis, is an infectious inflammatory disorder of the intestines primarily associated with domestic and wild ruminants including dairy cattle. The disease, caused by an infection with Mycobacterium avium subspecies paratuberculosis (MAP) bacteria, burdens both animals and producers through reduced milk production, premature culling, and reduced salvage values among MAP-infected animals. The economic losses associated with these burdens have been measured before, but not across a comprehensive selection of major dairy-producing regions within a single methodological framework. This study uses a Markov chain Monte Carlo approach to estimate the annual losses per cow within MAP-infected herds and the total regional losses due to JD by simulating the spread and economic impact of the disease with region-specific economic variables. It was estimated that approximately 1% of gross milk revenue, equivalent to US$33 per cow, is lost annually in MAP-infected dairy herds, with those losses primarily driven by reduced production and being higher in regions characterized by above-average farm-gate milk prices and production per cow. An estimated US$198 million is lost due to JD in dairy cattle in the United States annually, US$75 million in Germany, US$56 million in France, US$54 million in New Zealand, and between US$17 million and US$28 million in Canada, one of the smallest dairy-producing regions modeled.

Presence of Infection by Mycobacterium avium subsp. paratuberculosis in the Blood of Patients with Crohn's Disease and Control Subjects Shown by Multiple Laboratory Culture and Antibody Methods

Mycobacterium avium subspecies paratuberculosis (MAP) has long been suspected to be involved in the etiology of Crohn's disease (CD). An obligate intracellular pathogen, MAP persists and influences host macrophages. The primary goals of this study were to test new rapid culture methods for MAP in human subjects and to assess the degree of viable culturable MAP bacteremia in CD patients compared to controls. A secondary goal was to compare the efficacy of three culture methods plus a phage assay and four antibody assays performed in separate laboratories, to detect MAP from the parallel samples. Culture and serological MAP testing was performed blind on whole blood samples obtained from 201 subjects including 61 CD patients (two of the patients with CD had concurrent ulcerative colitis (UC)) and 140 non-CD controls (14 patients in this group had UC only). Viable MAP bacteremia was detected in a significant number of study subjects across all groups. This included Pozzato culture (124/201 or 62% of all subjects, 35/61 or 57% of CD patients), Phage assay (113/201 or 56% of all subjects, 28/61 or 46% of CD patients), TiKa culture (64/201 or 32% of all subjects, 22/61 or 36% of CD patients) and MGIT culture (36/201 or 18% of all subjects, 15/61 or 25% of CD patients). A link between MAP detection and CD was observed with MGIT culture and one of the antibody methods (Hsp65) confirming previous studies. Other detection methods showed no association between any of the groups tested. Nine subjects with a positive Phage assay (4/9) or MAP culture (5/9) were again positive with the Phage assay one year later. This study highlights viable MAP bacteremia is widespread in the study population including CD patients, those with other autoimmune conditions and asymptomatic healthy subjects.

General Overview of Nontuberculous Mycobacteria Opportunistic Pathogens: Mycobacterium avium and Mycobacterium abscessus

Nontuberculous mycobacteria (NTM) are emerging human pathogens, causing a wide range of clinical diseases affecting individuals who are immunocompromised and who have underlying health conditions. NTM are ubiquitous in the environment, with certain species causing opportunistic infection in humans, including Mycobacterium avium and Mycobacterium abscessus. The incidence and prevalence of NTM infections are rising globally, especially in developed countries with declining incidence rates of M. tuberculosis infection. Mycobacterium avium, a slow-growing mycobacterium, is associated with Mycobacterium avium complex (MAC) infections that can cause chronic pulmonary disease, disseminated disease, as well as lymphadenitis. M. abscessus infections are considered one of the most antibiotic-resistant mycobacteria and are associated with pulmonary disease, especially cystic fibrosis, as well as contaminated traumatic skin wounds, postsurgical soft tissue infections, and healthcare-associated infections (HAI). Clinical manifestations of diseases depend on the interaction of the host's immune response and the specific mycobacterial species. This review will give a general overview of the general characteristics, vulnerable populations most at risk, pathogenesis, treatment, and prevention for infections caused by Mycobacterium avium, in the context of MAC, and M. abscessus.

Anti-Mycobacterium paratuberculosis (MAP) therapy for Crohn's disease: an overview and update

The role of Mycobacterium avium subspecies paratuberculosis (MAP) in the pathogenesis of Crohn's disease (CD) has been strongly debated for many years. MAP is the known aetiological agent of Johne's disease, a chronic enteritis affecting livestock. At present, due to the paucity of high-quality data, anti-MAP therapy (AMT) is not featured in international guidelines as a treatment for CD. Although the much-quoted randomised trial of AMT did not show sustained benefits over placebo, questions have been raised regarding trial design, antibiotic dosing and the formulation used. There are several lines of evidence supporting the CD and MAP association with uncontrolled and controlled trials demonstrating effectiveness, including a retrospective review of cases treated at our own institution. Here, we provide an overview of the evidence supporting and refuting AMT in CD before focussing on updates of the current research in the field, including the ongoing trials with the novel RHB-104 formulation and the MAP vaccine trial. While controversial, gastroenterologists are often asked about long-term combination antibiotic therapy for CD. There has been broadcast and social media coverage surrounding this, particularly with regard to current trials. Although patients should not be deterred from treatments of proven effectiveness, this review aims to help with commonly asked questions and highlights our own approach for the use of anti-MAP in specific circumstances.

Probiotics in inflammatory bowel disease: Does it work?

The number of patients with inflammatory bowel disease (IBD), a group of diseases mainly represented by Crohn’s disease (CD) and ulcerative colitis (UC), has increased in recent decades. As a consequence, the number of people undergoing any drug treatment against these diseases has expanded. However, IBD conventional therapies present several limitations, which lead researchers to look for better alternatives to improve the quality of life of patients. Moreover, microbiome imbalance seems to play a crucial role in the pathogenesis of IBD, since important alterations in bacterial, viral, protist and fungal populations are observed in the gut microbiota of affected individuals. Given the importance of such life forms in that context, the use of probiotics becomes a plausible alternative for treating affected patients. Trials have been developed aiming the evaluation of probiotics potential to induce and to maintain remission in CD and UC. Regarding the tested microorganisms, various non-pathogenic bacteria and fungi have been assessed. However, consistent results have been obtained only with some of them, including Escherichia coli Nissle 1917, VSL#3, Saccharomyces boulardii, Lactobacillus, and Bifidobacterium. Therefore, this minireview aims to explore the role of microbiota in the genesis of such a disorder and to compile the most concrete data on probiotic-related efficiency in IBD treatment.

Profound remission in Crohn's disease requiring no further treatment for 3-23 years: a case series

Background

Crohn’s disease (CD) is rising in incidence and has a high morbidity and increased mortality. Current treatment use immunosuppressives but efficacy is suboptimal, and relapse is common. It has been shown that there is an imbalance present in the gut microbiome (dysbiosis) in CD with a possible infective aetiology—Mycobacterium avium subsp. paratuberculosis (MAP) being the most proposed. Antibacterial therapy and Faecal Microbiota Transplantation (FMT) are emerging treatments which can result in clinical and endoscopic remission, if employed correctly. The objective of this study was to report on the treatment and clinical outcomes of patients with CD in prolonged remission.

Results

Ten patients were identified to have achieved prolonged remission for 3–23 years (median 8.5 years). Of these, 7/10 took targeted Anti-MAP therapy (AMAT) for a median 36 months and then ceased AMAT treatment. After stopping AMAT five patients underwent Faecal Microbiota Transplantation (FMT) (average four infusions). In 4/7, AMAT was combined with infliximab (mean of six infusions) that was withdrawn within 6 months after fistulae resolution. One patient achieved deep mucosal healing with AMAT alone. Of the 3/10 patients not prescribed AMAT, one had a combination of anti-inflammatory agents and a single antibiotic (metronidazole) followed by FMT. The other two received only FMT for Clostridioides difficile Infection.

Conclusions

Prolonged remission has been achieved for 3–23 years with individualised treatments, with the majority using AMAT ± infliximab and FMT. Treatment with antibiotics and/or FMT provides a potential new avenue for treatment of CD. These findings should stimulate thinking, investigations and better therapy against MAP and the dysbiosis of the gut flora, to enable higher rates of prolonged remission.

Australian Veterinarians' Perceptions Regarding the Zoonotic Potential of Mycobacterium avium Subspecies Paratuberculosis

Public concerns over exposure to Mycobacterium avium subspecies paratuberculosis (MAP) or MAP components via foods of animal origin could have negative trade consequences, despite the absence of conclusive scientific evidence of a causal association between Mycobacterium avium subspecies paratuberculosis (MAP) and Crohn’s disease (CD). This study was conducted among Australian veterinarians to understand (a) their perceptions regarding the role of MAP in the causation of CD (an ordinal outcome), and (b) their consideration of the adoption of the precautionary principle against Johne’s disease (JD; a binary outcome). Ordinal and binary logistic regression analyses were performed to evaluate the association of explanatory variables with the above outcomes, respectively. Almost one-third of the respondents (32.2%) considered that MAP was likely to be involved in the causation of CD whereas more than two-thirds (69.8%) agreed with the adoption of the precautionary principle against JD. Veterinarians who were concerned about exposure to and/or getting infected with MAP were more likely to consider MAP as a causative agent of CD (odds ratio: 7.63; 95% CI: 1.55, 37.63) and favor the adoption of the precautionary principle against JD (odds ratio: 6.20; 95% CI: 1.90, 20.25). Those perceiving MAP as a causative agent of CD were also more likely to favor the adoption of the precautionary principle against JD (odds ratio: 13.2; 95% CI: 1.26, 138.90). The results suggest that Australian veterinarians, particularly those who consider MAP as a causative agent of CD are concerned about exposure to MAP and favor the adoption of the precautionary principle against JD. These findings can be useful for animal health authorities for designing JD control programs and policies.

Targeted Combination Antibiotic Therapy Induces Remission in Treatment-Naïve Crohn's Disease: A Case Series

Prospective trials of anti-mycobacterial antibiotic therapy (AMAT) have proven efficacious in Crohn’s disease (CD) but use as first-line treatment in CD has not been evaluated. This paper reports the outcomes of patients with CD treated with first-line AMAT. This paper consists of a case series of treatment-naïve CD patients who received AMAT as first-line treatment between 2007 and 2014 at a single center. AMAT treatment consisted of rifabutin, clofazimine and clarithromycin, plus either ciprofloxacin, metronidazole or ethambutol. Symptoms, inflammatory blood markers, colonoscopy and histology results, in addition to, the Crohn’s Disease Activity Index (CDAI) were tabulated from patients’ clinical records, and descriptive statistics were conducted. A Wilcoxon signed-rank test assessed the difference in CDAI scores before and while on AMAT. The statistical significance was set at 5%. Clinical remission (CDAI < 150) with rapid improvement in clinical symptoms and inflammatory markers was seen in all eight patients receiving AMAT as sole therapy by 6 weeks. In all eight patients, the median CDAI score decreased significantly, from 289 prior to treatment to 62 at the 12-month follow-up (p < 0.001). Follow-up colonoscopies showed healing of CD ulcers, no visible mucosal inflammation, restoration of normal vascular patterns and complete mucosal healing on histology samples. AMAT as first-line therapy demonstrated a rapid improvement of Crohn’s disease (not previously seen when used as second-line therapy).

Proposing BCG Vaccination for Mycobacterium avium ss. paratuberculosis (MAP) Associated Autoimmune Diseases

Bacille Calmette-Guerin (BCG) vaccination is widely practiced around the world to protect against the mycobacterial infection tuberculosis. BCG is also effective against the pathogenic mycobacteria that cause leprosy and Buruli's ulcer. BCG is part of the standard of care for bladder cancer where, when given as an intravesicular irrigant, BCG acts as an immunomodulating agent and lessens the risk of recurrence. Mycobacterium avium ss. paratuberculosis (MAP) causes a fatal enteritis of ruminant animals and is the putative cause of Crohn's disease of humans. MAP has been associated with an increasingly long list of inflammatory/autoimmune diseases: Crohn's, sarcoidosis, Blau syndrome, Hashimoto's thyroiditis, autoimmune diabetes (T1D), multiple sclerosis (MS), rheumatoid arthritis, lupus and Parkinson's disease. Epidemiologic evidence points to BCG providing a "heterologous" protective effect on assorted autoimmune diseases; studies using BCG vaccination for T1D and MS have shown benefit in these diseases. This article proposes that the positive response to BCG in T1D and MS is due to a mitigating action of BCG upon MAP. Other autoimmune diseases, having a concomitant genetic risk for mycobacterial infection as well as cross-reacting antibodies against mycobacterial heat shock protein 65 (HSP65), could reasonably be considered to respond to BCG vaccination. The rare autoimmune disease, relapsing polychondritis, is one such disease and is offered as an example. Recent studies suggesting a protective role for BCG in Alzheimer's disease are also explored. BCG-induced energy shift from oxidative phosphorylation to aerobic glycolysis provides the immunomodulating boost to the immune response and also mitigates mycobacterial infection-this cellular mechanism unifies the impact of BCG on the disparate diseases of this article.

Differential Genotyping of Mycobacterium avium Complex and Its Implications in Clinical and Environmental Epidemiology

In recent decades, the incidence and prevalence of nontuberculous mycobacteria (NTM) have greatly increased, becoming a major worldwide public health problem. Among numerous NTM species, the Mycobacterium avium complex (MAC) is the most predominant species, causing disease in humans. MAC is recognized as a ubiquitous microorganism, with contaminated water and soil being established sources of infection. However, the reason for the recent increase in MAC-associated disease has not yet been fully elucidated. Furthermore, human MAC infections are associated with a variety of infection sources. To improve the determination of infection sources and epidemiology of MAC, feasible and reliable genotyping methods are required to allow for the characterization of the epidemiology and biology of MAC. In this review, we discuss genotyping methods, such as pulsed-field gel electrophoresis, a variable number of tandem repeats, mycobacterial interspersed repetitive-unit-variable number of tandem repeats, and repetitive element sequence-based PCR that have been applied to elucidate the association between the MAC genotypes and epidemiological dominance, clinical phenotypes, evolutionary process, and control measures of infection. Characterizing the association between infection sources and the epidemiology of MAC will allow for the development of novel preventive strategies for the effective control of MAC infection.

Role of intestinal microbiota and metabolites in inflammatory bowel disease

Objective:

The metabolites produced by the gut microbiota are of interest to scientists. The objective of this review was to provide an updated summary of progress regarding the microbiota and their metabolites and influences on the pathogenesis of inflammatory bowel disease (IBD).

Data sources:

The author retrieved information from the PubMed database up to January 2018, using various combinations of search terms, including IBD, microbiota, and metabolite.

Study selection:

Both clinical studies and animal studies of intestinal microbiota and metabolites in IBD were selected. The information explaining the possible pathogenesis of microbiota in IBD was organized.

Results:

In IBD patients, the biodiversity of feces/mucosa-associated microbiota is decreased, and the probiotic microbiota is also decreased, whereas the pathogenic microbiota are increased. The gut microbiota may be a target for diagnosis and treatment of IBD. Substantial amounts of data support the view that the microbiota and their metabolites play pivotal roles in IBD by affecting intestinal permeability and the immune response.

Conclusions:

This review highlights the advances in recent gut microbiota research and clarifies the importance of the gut microbiota in IBD pathogenesis. Future research is needed to study the function of altered bacterial community compositions and the roles of metabolites.

Serological Testing for Mycobacterial Heat Shock Protein Hsp65 Antibody in Health and Diseases

Mycobacterial heat shock protein 65 gene (Hsp65) has been widely used for classification of Mycobacterial species, and detection of Mycobacterial genes by molecular methods and has proven useful in identification of Mycobacterial infection in various clinical conditions. Circulating antibody against Mycobacterial hsp65 has been found in many clinical diseases including autoimmune diseases (Crohn's disease, lupus erythematosus, multiple sclerosis, diabetes, etc.), atherosclerosis and cancers. The prevalence of anti-Hsp65 antibody in the normal healthy population is unknown. We determined the blood levels of antibody against Mycobacterial hsp65 in the normal population represented by 288 blood donors of the American Red Cross and tested the blood of 109 patients with Crohn's disease and 28 patients with Sjogren's syndrome for comparison. The seroprevalence of anti-Hsp65 IgG in the normal population of Red Cross donors was 2.8% (8 of 288 positive). The Hsp65 antibody levels were significantly elevated in patients with Crohn's disease and Sjogren's syndrome. The prevalence of Hsp65 antibody in Crohn's disease patients was 67.9% (74 of 109 patients), and 85.7% for Sjogren's patients (24 of 28 patients). Our data indicate that anti-Hsp65 antibody is rare in the normal population, but frequent in chronic diseases. The presence of circulating Hsp65 antibody reflects an abnormal immune (adaptive) response to Mycobacterial exposure in patients with chronic diseases, thus differentiating the patients with chronic diseases from those clinical mimics.

Cows Get Crohn's Disease and They're Giving Us Diabetes

Increasingly, Johne's disease of ruminants and human Crohn's disease are regarded as the same infectious disease: paratuberculosis. Mycobacterium avium ss. paratuberculosis (MAP) is the cause of Johne's and is the most commonly linked infectious cause of Crohn's disease. Humans are broadly exposed to MAP in dairy products and in the environment. MAP has been found within granulomas such as Crohn's disease and can stimulate autoantibodies in diseases such as type 1 diabetes (T1D) and Hashimoto's thyroiditis. Moreover, beyond Crohn's and T1D, MAP is increasingly associated with a host of autoimmune diseases. This article suggests near equivalency between paucibacillary Johne's disease of ruminant animals and human Crohn's disease and implicates MAP zoonosis beyond Crohn's disease to include T1D.

Environmental Risk Factors for Inflammatory Bowel Diseases: An Umbrella Review of Meta-analyses

BACKGROUND & AIMS

Multiple environmental factors have been associated with the development of inflammatory bowel diseases (IBDs). We performed an umbrella review of meta-analyses to summarize available epidemiologic evidence and assess its credibility.

METHODS

We systematically identified and appraised meta-analyses of observational studies examining environmental factors and risk of IBD (Crohn's disease [CD] or ulcerative colitis [UC]). For each meta-analysis, we considered the random effects estimate, its 95% confidence interval, the estimates of heterogeneity, and small-study effects, and we graded the evidence according to prespecified criteria. Methodologic quality was assessed with AMSTAR (ie, A Measurement Tool to Assess Systematic Reviews) 2.

RESULTS

We examined 183 estimates in 53 meta-analyses of 71 environmental factors related to lifestyles and hygiene, surgeries, drug exposures, diet, microorganisms, and vaccinations. We identified 9 factors that increase risk of IBD: smoking (CD), urban living (CD and IBD), appendectomy (CD), tonsillectomy (CD), antibiotic exposure (IBD), oral contraceptive use (IBD), consumption of soft drinks (UC), vitamin D deficiency (IBD), and non-Helicobacter pylori-like enterohepatic Helicobacter species (IBD). We identified 7 factors that reduce risk of IBD: physical activity (CD), breastfeeding (IBD), bed sharing (CD), tea consumption (UC), high levels of folate (IBD), high levels of vitamin D (CD), and H pylori infection (CD, UC, and IBD). Epidemiologic evidence for all of these associations was of high to moderate strength; we identified another 11 factors associated with increased risk and 16 factors associated with reduced risk with weak credibility. Methodologic quality varied considerably among meta-analyses. Several associations were based on findings from retrospective studies, so it is not possible to determine if these are effects of IBD or the results of recall bias.

CONCLUSIONS

In an umbrella review of meta-analyses, we found varying levels of evidence for associations of different environmental factors with risk of IBD. High-quality prospective studies with analyses of samples from patients with recent diagnoses of IBD are needed to determine whether these factors cause or are results of IBD and their pathogenic mechanisms.

Whole exome sequencing of patients who resolved Crohn's disease and complex regional pain syndrome following treatment for paratuberculosis

BACKGROUND

A whole exome sequencing study was performed on an extended family including a patient with Crohn's disease (CD) and a patient with complex regional pain syndrome (CRPS). The patient with CD and the patient with CRPS have experienced resolution of their disease following treatment for paratuberculosis. The study was performed in order to determine if there is an unusual mutation in this extended family that would explain the susceptibility to mycobacterial infection among many of the members.

RESULTS

We identified sets of rare single nucleotide polymorphisms (SNPs) that were shared among affected family members, including variants in two genes, IL15RA and CASP10, which have established roles in the immune response. In addition, the CD and CRPS patients were found to have heterozygous mutations in MBL2 and DDX58, mutations that have been associated with susceptibility to tuberculosis.

CONCLUSIONS

The IL15RA and CASP10 variants may contribute to the disease symptoms exhibited in this family. The finding of SNPs associated with immune function supports a complementary role of infection and genetics in these diseases.

Prevalence of Mycobacterium avium subspecies paratuberculosis IS 900 DNA in biopsy tissues from patients with Crohn's disease: histopathological and molecular comparison with Johne's disease in Fars province of Iran

BACKGROUND

Crohn's disease is a chronic enteritis of humans that affects the gastrointestinal tract, especially the terminal ileum, cecum and colon. The etiology of this disease is still unknown but seems to be multifactorial. There are reports about the potential link between Crohn's disease in humans and the causative agent of Johne's disease in ruminants. Because of the prevalence of Johne's disease in the Fars Province of Iran, the aim of this study was to investigate the prevalence of MAP in the biopsy tissues of patients affected by Crohn's disease in this area.

METHODS

The study was performed from April 2015 to June 2017 at Namazi Hospital, Shiraz University of Medical Sciences, and School of Veterinary Medicine, Shiraz University, Shiraz, Iran. Intestinal biopsies of 30 patients (12 male and 18 female; mean age, 34 years; range 4-77 years) with the confirmed diagnosis of Crohn's disease and 30 patients diagnosed as non-inflammatory bowel disease (19 male and 11 female; mean age, 38 years; range 13-68 years) were studied by molecular, histopathological and histochemical methods. Also, similar numbers of adult goats affected by Johne's disease were studied, comparatively. DNA extractions of tissue specimens were subjected to PCR to amplify a 413-bp sequence of the IS900 gene.

RESULTS

Using IS900-PCR, the overall prevalence of MAP in patients affected by Crohn's disease and non-inflammatory bowel disease were 47 and 13%, respectively. In addition, the prevalence of MAP in goats affected by Johne's disease was 70%. Using acid-fast histochemical staining, only 7% of Crohn's disease patients were weakly positive as paucibacillary and 43% of Johne's disease cases were moderate to strongly positive as multibacillary. Histopathologically, granulomatous enteritis (83 and 90%), lymphoplasmacytic enteritis (17 and 14%), edema and lymphangiectasia (67 and 96%), and vasculitis (20 and 73%) were common findings in Crohn's and Johne's diseases, respectively.

CONCLUSION

Our findings demonstrate a remarkable association between MAP and CD in this population, and support an etiologic relationship between MAP infection in humans and the development of CD. MAP infection in human tissue may display species-specific pathologic findings, as occurs with other zoonotic pathogens.

Detection of Mycobacterium avium subsp. paratuberculosis in an Egyptian mixed breeding farm and comparative molecular characterisation of isolates from cattle, camels and cats – a case report

The present study records and investigates an outbreak of Johne’s Disease in a mixed breeding camel – cattle farm and the possible role of non-domestic non-ruminants animals in the epidemiology of Mycobacterium avium subspecies paratuberculosis in Egypt. For this reason, faecal samples were collected from 24 dairy cattle and from 15 one humped Arabian camels suffering from diarrhoea. Moreover, intestinal tissue samples were provided from 7 cats and 2 rats that were caught from the same farm and were euthanized before necropsy. Samples were examined using traditional culture and IS900 PCR techniques together with the application of BstEII-IS900 RFLP for typing of obtained isolates. Interestingly, MAP was recovered from cattle (n=8) and from camels (n=3) and non-domestic cats (n=3) reared under local conditions in this farm in Egypt. The obtained results highlight the potential role of cats in the epidemiology of MAP, a subject which needs further investigation and might have a public health importance, catsbeing common members of many families.

Phagocytosis and Epithelial Cell Invasion by Crohn's Disease-Associated Adherent-Invasive Escherichia coli Are Inhibited by the Anti-inflammatory Drug 6-Mercaptopurine

Adherent-invasive Escherichia coli (AIEC) strains are overrepresented in the dysbiotic microbiota of Crohn’s disease (CD) patients, and contribute to the onset of the chronic inflammation typical of the disease. However, the effects of anti-inflammatory drugs used for CD treatment on AIEC virulence have not yet been investigated. In this report, we show that exposure of AIEC LF82 strain to amino-6-mercaptopurine (6-MP) riboside, one of the most widely used anti-inflammatory drugs in CD, impairs its ability to adhere to, and consequently to invade, human epithelial cells. Notably, phagocytosis of LF82 treated with 6-MP by human macrophages is also reduced, suggesting that 6-MP affects AIEC cell surface determinants involved both in interaction with epithelial cells and in uptake by macrophages. Since a main target of 6-MP in bacterial cells is the inhibition of the important signal molecule c-di-GMP, we also tested whether perturbations in cAMP, another major signaling pathway in E. coli, might have similar effects on interactions with human cells. To this aim, we grew LF82 in the presence of glucose, which leads to inhibition of cAMP synthesis. Growth in glucose-supplemented medium resulted in a reduction in AIEC adhesion to epithelial cells and uptake by macrophages. Consistent with these results, both 6-MP and glucose can affect expression of cell adhesion-related genes, such as the csg genes, encoding thin aggregative fimbriae (curli). In addition, glucose strongly inhibits expression of the fim operon, encoding type 1 pili, a known AIEC determinant for adhesion to human cells. To further investigate whether 6-MP can indeed inhibit c-di-GMP signaling in AIEC, we performed biofilm and motility assays and determination of extracellular polysaccharides. 6-MP clearly affected biofilm formation and cellulose production, but also, unexpectedly, reduced cell motility, itself an important virulence factor for AIEC. Our results provide strong evidence that 6-MP can affect AIEC-host cell interaction by acting on the bacterial cell, thus strengthening the hypothesis that mercaptopurines might promote CD remission also by affecting gut microbiota composition and/or physiology, and suggesting that novel drugs targeting bacterial virulence and signaling might be effective in preventing chronic inflammation in CD.

Protein Kinase G Induces an Immune Response in Cows Exposed to Mycobacterium avium Subsp. paratuberculosis

To establish infection, pathogens secrete virulence factors, such as protein kinases and phosphatases, to modulate the signal transduction pathways used by host cells to initiate immune response. The protein MAP3893c is annotated in the genome sequence of Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of Johne's disease, as the serine/threonine protein kinase G (PknG). In this work, we report that PknG is a functional kinase that is secreted within macrophages at early stages of infection. The antigen is able to induce an immune response from cattle exposed to MAP in the form of interferon gamma production after stimulation of whole blood with PknG. These findings suggest that PknG may contribute to the pathogenesis of MAP by phosphorylating macrophage signalling and/or adaptor molecules as observed with other pathogenic mycobacterial species.

Mycobacterium avium subspecies paratuberculosis - an important food borne pathogen of high public health significance with special reference to India: an update

This review underlines the public health significance of 'Indian Bison Type' of Mycobacterium avium subspecies paratuberculosis (MAP) and also its potential as 'zoonotic infection'. In the absence of control programs, bio-load of MAP is increasing and if we take total population of animals (500 million plus) and human beings (1.23 billion plus) into account, the number of infected animals and human beings will run into millions in India. Our research on screening of over 26,000 domestic livestock for MAP infection using 4 different diagnostic tests (microscopy, culture, ELISA and PCR), during last 31 years has shown that the average bio-load of MAP in the livestock population of India is very high (cattle 43%, buffaloes 36%, goats 23% and sheep 41%). 'Mass screening' of 28,291 human samples between 2008-2016 revealed also high bio-load of MAP. It has been proved that MAP is not in-activated during pasteurization and therefore live bacilli are continuously reaching human population by consumption of even pasteurized milk and other milk products. Live bacilli have also been recovered from meat products and the environment thus illustrating the potential of MAP as pathogen of public health concern. However, at present, there is inadequate scientific evidence to confirm a conclusive link between MAP infection and Johne's disease in ruminants and some cases of Crohn's disease in human beings.

Could Mycobacterium avium subspecies paratuberculosis cause Crohn's disease, ulcerative colitis…and colorectal cancer?

Infectious agents are known causes of human cancers. Schistosoma japonicum and Schistosoma mansoni cause a percentage of colorectal cancers in countries where the respective Schistosoma species are prevalent. Colorectal cancer is a complication of ulcerative colitis and colonic Crohn’s disease, the two main forms of idiopathic inflammatory bowel disease (IIBD). Mycobacterium avium subspecies paratuberculosis (MAP), the cause of a chronic intestinal disease in domestic and wild ruminants, is one suspected cause of IIBD. MAP may therefore be involved in the pathogenesis of IIBD-associated colorectal cancer as well as colorectal cancer in individuals without IIBD (sporadic colorectal cancer) in countries where MAP infection of domestic livestock is prevalent and MAP’s presence in soil and water is extensive. MAP organisms have been identified in the intestines of patients with sporadic colorectal cancer and IIBD when high magnification, oil immersion light microscopy (×1000 total magnification rather than the usual ×400 total magnification) is used. Research has demonstrated MAP’s ability to invade intestinal goblet cells and cause acute and chronic goblet cell hyperplasia. Goblet cell hyperplasia is the little-recognized initial pathologic lesion of sporadic colorectal cancer, referred to as transitional mucosa, aberrant crypt foci, goblet cell hyperplastic polyps or transitional polyps. It is the even lesser-recognized initial pathologic feature of IIBD, referred to as hypermucinous mucosa, hyperplastic-like mucosal change, serrated epithelial changes, flat serrated changes, goblet cell rich mucosa or epithelial hyperplasia. Goblet cell hyperplasia is the precursor lesion of adenomas and dysplasia in the classical colorectal cancer pathway, of sessile serrated adenomas and serrated dysplasia in the serrated colorectal cancer pathway, and of flat and elevated dysplasia and dysplasia-associated lesions or masses in IIBD-associated intestinal cancers. MAP’s invasion of intestinal goblet cells may result in the initial pathologic lesion of IIBD and sporadic colorectal cancer. MAP’s persistence in infected intestines may result in the eventual development of both IIBD-associated and sporadic colorectal cancer.

Johne's disease in cattle: an in vitro model to study early response to infection of Mycobacterium avium subsp. paratuberculosis using RNA-seq

Johne's disease is a chronic granulomatous enteritis caused by Mycobacterium avium subsp. paratubercolosis (MAP) which affects ruminants worldwide and has a significant economic impact. MAP has also been associated with human Crohn's disease, although this connection is not well established. MAP is highly adapted for survival within host macrophages and prevents macrophage activation, blocks phagosome acidification and maturation, and attenuates presentation of antigens to the immune system. The consequence is a very long silent infection before clinical signs are observed. The present work examined the transcriptome of bovine monocyte-derived macrophages (MDM) infected with the L1 strain of MAP at 2h, 6h and 24h post infection using RNA-seq. Pathway over-representation analysis of genes differentially expressed between infected vs. control MDM identified that immune related pathways were affected. Genes belonging to the cytokine-cytokine receptor interaction pathway and members of the JAK-STAT pathway, which is involved in the regulation of immune response, were up-regulated. However, in parallel inhibitors of immune functions were activated, including suppressor of cytokine signaling (SOCS) and cytokine-inducible SH2-containing protein (CISH), which most likely suppresses IFNγ and the JAK/STAT signaling cascade in infected MDM, which may favour MAP survival. After exposure, macrophages phagocytise pathogens, activate the complement cascade and the adaptive immune system through the antigen presentation process. However, data presented here suggest that genes related to phagocytosis and lysosome function are down regulated in MAP infected MDM. Genes of MHC class II and complement pathway were also down-regulated. This study therefore shows that MAP infection is associated with changes in expression of genes related to the host immune response that may affect its ability to survive and multiply inside the host cell.

The Consensus from the Mycobacterium avium ssp. paratuberculosis (MAP) Conference 2017

On March 24 and 25, 2017 researchers and clinicians from around the world met at Temple University in Philadelphia to discuss the current knowledge of Mycobacterium avium ssp. paratuberculosis (MAP) and its relationship to human disease. The conference was held because of shared concern that MAP is a zoonotic bacterium that poses a threat not only to animal health but also human health. In order to further study this problem, the conferees discussed ways to improve MAP diagnostic tests and discussed potential future anti-MAP clinical trials. The conference proceedings may be viewed on the www.Humanpara.org website. A summary of the salient work in this field is followed by recommendations from a majority of the conferees.

Knowledge gaps that hamper prevention and control of Mycobacterium avium subspecies paratuberculosis infection

In the last decades, many regional and country-wide control programmes for Johne's disease (JD) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were not followed, including the introduction of infected replacement cattle, because tests to identify infected animals were unreliable, and uptake by farmers was not high enough because of a perceived low return on investment. In the absence of a cure or effective commercial vaccines, control of JD is currently primarily based on herd management strategies to avoid infection of cattle and restrict within-farm and farm-to-farm transmission. Although JD control programmes have been implemented in most developed countries, lessons learned from JD prevention and control programmes are underreported. Also, JD control programmes are typically evaluated in a limited number of herds and the duration of the study is less than 5 year, making it difficult to adequately assess the efficacy of control programmes. In this manuscript, we identify the most important gaps in knowledge hampering JD prevention and control programmes, including vaccination and diagnostics. Secondly, we discuss directions that research should take to address those knowledge gaps.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): paratuberculosis

Paratuberculosis has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of paratuberculosis to be listed, Article 9 for the categorisation of paratuberculosis according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to paratuberculosis. The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, paratuberculosis can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL. The disease would comply with the criteria in Sections 3, 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (c), (d) and (e) of Article 9(1). The animal species to be listed for paratuberculosis according to Article 8(3) criteria are several species of mammals and birds as susceptible species and some species of the families Bovidae, Cervidae and Leporidae as reservoirs.

Anaerobic adaptation of Mycobacterium avium subspecies paratuberculosis in vitro: similarities to M. tuberculosis and differential susceptibility to antibiotics

Background

Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne’s disease in ruminants and is associated with Crohn’s disease (CD) in humans, although the latter remains controversial. In this study, we investigated the ability of MAP to adapt to anaerobic growth using the “Wayne” model of non-replicating persistence (NRP) developed for M. tuberculosis.

Results

All strains adapted to anaerobiosis over time in a manner similar to that seen with MTB. Susceptibility to 12 antibiotics varied widely between strains under aerobic conditions. Under anaerobic conditions, no drugs caused significant growth inhibition (>0.5 log) except metronidazole, resulting in an average decrease of ~2 logs.

Conclusions

These results demonstrate that MAP is capable of adaptation to NRP similar to that observed for MTB with differential susceptibility to antibiotics under aerobic versus anaerobic conditions. Such findings have significant implications for our understanding of the pathogenesis of MAP in vivo and the treatment of CD should this organism be established as the causative agent.

Mycobacterium avium subsp. paratuberculosis (Map) Fatty Acids Profile Is Strain-Dependent and Changes Upon Host Macrophages Infection

Johne's disease is a chronic granulomatous enteritis of ruminants caused by the intracellular bacterium Mycobacterium avium subsp. paratuberculosis (Map). We previously demonstrated that Map isolates from sheep persisted within host macrophages in lower CFUs than cattle isolates after 7 days of infection. In the current study, we hypothesize that these phenotypic differences between Map isolates may be driven be the fatty acids (FAs) present on the phosphadidyl-1-myo-inositol mannosides of the Map cell wall that mediate recognition by the mannose receptors of host macrophages. FAs modifications may influence Map's envelope fluidity ultimately affecting pathogenicity. To test this hypothesis, we investigated the responses of two Map isolates from cattle (K10 isolate) and sheep (2349/06-1) to the bovine and ovine macrophage environment by measuring the FAs content of extracellular and intracellular bacteria. For this purpose, macrophages cell lines of bovine (BOMAC) and ovine (MOCL-4) origin were infected with the two isolates of Map for 4 days at 37°C. The relative FAs composition of the two isolates recovered from infected BOMAC and MOCL-4 cells was determined by gas chromatography and compared with that of extracellular bacteria and that of bacteria grown in Middlebrook 7H9 medium. Using this approach, we demonstrated that the FAs composition of extracellular and 7H9-grown bacteria was highly conserved within each Map isolate, and statistically different from that of intracellular bacteria. Analysis of FAs composition from extracellular bacteria enabled the distinction of the two Map strains based on the presence of the tuberculostearic acid (18:0 10Me) exclusively in the K10 strain of Map. In addition, significant differences in the content of Palmitic acid and cis-7 Palmitoleic acid between both isolates harvested from the extracellular environment were observed. Once the infection established itself in BOMAC and MOCL-4 cells, the FAs profiles of both Map isolates appeared conserved. Our results suggest that the FAs composition of Map might influence its recognition by macrophages and influence the survival of the bacillus within host macrophages.

CD4 T Cell Dependent Colitis Exacerbation Following Re-Exposure of Mycobacterium avium ssp. paratuberculosis

Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of Johne's disease (JD), a chronic inflammatory bowel disease of cattle characterized by intermittent to chronic diarrhea. In addition, MAP has been isolated from Crohn's disease (CD) patients. The impact of MAP on severity of clinical symptoms in JD as well as its role in CD are yet unknown. We have previously shown that MAP is able to colonize inflamed enteric tissue and to exacerbate the inflammatory tissue response (Suwandi et al., 2014). In the present study, we analyzed how repeated MAP administration influences the course of dextran sulfate sodium (DSS)-induced colitis. In comparison to mice exposed to DSS or MAP only, repeated exposure of DSS-treated mice to MAP (DSS/MAP) revealed a significantly enhanced clinical score, reduction of colon length as well as severe CD4⁺ T cell infiltration into the colonic lamina propria. Functional analysis identified a critical role of CD4⁺ T cells in the MAP-induced disease exacerbation. Additionally, altered immune responses were observed when closely related mycobacteria species such as M. avium ssp. avium and M. avium ssp. hominissuis were administered. These data reveal the specific ability of MAP to aggravate intestinal inflammation and clinical symptoms. Overall, this phenotype is compatible with similar disease promoting capabilites of MAP in JD and CD.

Mycobacterium avium subsp. paratuberculosis and associated risk factors for inflammatory bowel disease in Iranian patients

Background

Inflammatory bowel disease (IBD) is described as a relapsing condition with high morbidity and uncertain complex pathogenesis. The association of Mycobacterium avium ssp. paratuberculosis (MAP) with Crohn’s disease (CD) in human has been debated for decades, however there is no confirmed data to verify such relations in Iran. The aim of this study was to investigate risk factors and a possible role of MAP in Iranian patients with CD.

Methods

Anti-MAP antibodies were detected in serum of IBD patients and subjects without IBD (nIBD) through ELISA; MAP DNA and viable MAP cells were identified in patients’ biopsies through nested PCR and direct culture methods, respectively. Principal component analysis (PCA) was used to investigate the risk factors in relation to IBD and MAP infection.

Results

Positivity for IS900 PCR was detected in 64% (n = 18) of CD, 33% (n = 10) of ulcerative colitis (UC) and 9.7% (n = 6) of nIBD samples. Live MAP cells were isolated from biopsies of 2 CD patients only. Among 28 patients with CD, 46% (n = 13) and 39% (n = 11) were positive for antibodies against MAP3865c_133–141 and MAP3865c_125–133 peptides, respectively, whereas much lower seroreactivity was detected in UC subjects accounting for 3% (n = 1) for MAP3865c_133–141 and 16.7% (n = 5) for MAP3865c_125–133. A high immune reactivity to MAP epitopes among CD patients was positively correlated with consumption of fast food meals and IBD familiarity. For both CD and UC, breastfeeding period and consumption of fruit/vegetables presented negative correlation with the presence of anti-MAP antibodies.

Conclusions

This study provided evidences that high prevalence of MAP DNA and anti-MAP antibodies in CD patients is significantly associated with the development of CD. Despite the role of several factors contributing to IBD, the presence of MAP DNA and anti-MAP antibodies in Iranian CD patients highlights a possible transmission of MAP from animal-derived products to humans.

Mycobacterium avium ssp. paratuberculosis detection in animals, food, water and other sources or vehicles of human exposure: A scoping review of the existing evidence

Mycobacterium avium ssp. paratuberculosis is the etiologic agent of Johne's disease in ruminants and is hypothesized to be an infectious cause of Crohn's disease, as well as some other human diseases. Due to key knowledge gaps, the potential public health impact of M. paratuberculosis is unknown. This scoping review aims to identify and characterised the evidence on potential sources and vehicles of M. paratuberculosis exposure for humans to better understand how exposure is likely to occur. Evidence from 255 primary research papers is summarized; most examined the prevalence or concentration of M. paratuberculosis in animals (farmed domestic, pets and wildlife) (n=148), food for human consumption (62) (milk, dairy, meat, infant formula) or water (drinking and recreational) and the environment (farm, pasture and areas affected by runoff water) (20). The majority of this research has been published since 2000 (Figure- abstract). Nine case-control studies examining risk factors for Crohn's disease highlighted significant associations with the consumption of processed meats and cheese, while direct contact with ruminants, high risk occupations (farmer, veterinarian), milk consumption and water source were factors not associated with the disease and/or M. paratuberculosis exposure status. Molecular epidemiology studies demonstrated strain-sharing between species. Produce and seafood were the only previously suggested sources of human exposure for which there was no supporting evidence identified in this scoping review. The results of this review indicate that ruminant populations from around the globe are infected with M. paratuberculosis and many non-ruminant species have also been found to carry or be infected with M. paratuberculosis. Several potential sources for human exposure to M. paratuberculosis were identified; however there remain important gaps in quantitative information on the prevalence and concentration of M. paratuberculosis in contaminated sources of exposure. This information is critical to understanding the risk of exposure, opportunities for risk mitigation interventions and modelling exposures to distill the importance of various sources of human exposure to M. paratuberculosis including direct contact with animals and the environment as well as consumption of contaminated foods and water. Results of this study may be used to prioritize future research and to support evidence-informed decision-making on the M. paratuberculosis issue.

Dysbiosis of the Fecal Microbiota in Cattle Infected with Mycobacterium avium subsp. paratuberculosis

Johne's disease (JD) is a chronic, intestinal infection of cattle, caused by Mycobacterium avium subsp. paratuberculosis (MAP). It results in granulomatous inflammation of the intestinal lining, leading to malabsorption, diarrhea, and weight loss. Crohn’s disease (CD), a chronic, inflammatory gastrointestinal disease of humans, has many clinical and pathologic similarities to JD. Dysbiosis of the enteric microbiota has been demonstrated in CD patients. It is speculated that this dysbiosis may contribute to the intestinal inflammation observed in those patients. The purpose of this study was to investigate the diversity patterns of fecal bacterial populations in cattle infected with MAP, compared to those of uninfected control cattle, using phylogenomic analysis. Fecal samples were selected to include samples from 20 MAP-positive cows; 25 MAP-negative herdmates; and 25 MAP-negative cows from a MAP-free herd. The genomic DNA was extracted; PCR amplified sequenced on a 454 Roche platform, and analyzed using QIIME. Approximately 199,077 reads were analyzed from 70 bacterial communities (average of 2,843 reads/sample). The composition of bacterial communities differed between the 3 treatment groups (P < 0.001; Permanova test). Taxonomic assignment of the operational taxonomic units (OTUs) identified 17 bacterial phyla across all samples. Bacteroidetes and Firmicutes constituted more than 95% of the bacterial population in the negative and exposed groups. In the positive group, lineages of Actinobacteria and Proteobacteria increased and those of Bacteroidetes and Firmicutes decreased (P < 0.001). Actinobacteria was highly abundant (30% of the total bacteria) in the positive group compared to exposed and negative groups (0.1–0.2%). Notably, the genus Arthrobacter was found to predominate Actinobacteria in the positive group. This study indicates that MAP-infected cattle have a different composition of their fecal microbiota than MAP-negative cattle.

Asia-Pacific consensus statements on Crohn's disease. Part 2: Management

The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology (APAGE) with the goal of developing best management practices, coordinating research and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis (UC) with specific relevance to the Asia-Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis and management of Crohn's disease (CD). The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia-Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses and treatment availability. It does not intend to be all-comprehensive and future revisions are likely to be required in this ever-changing field.

Intestinal Behçet's Disease: A True Inflammatory Bowel Disease or Merely an Intestinal Complication of Systemic Vasculitis?

Behçet's disease (BD) is a multi-systemic inflammatory disorder of an unknown etiology and shows a chronic recurrent clinical course. When the disease involves the alimentary tract, it is called intestinal BD because of its clinical importance. Intestinal BD is more frequently reported in East Asian countries than in Western or Middle Eastern countries. While any part of the gastrointestinal tract can be involved, the most common location of intestinal BD is the ileocecal area. A few, large, deep ulcerations with discrete border are characteristic endoscopic findings of intestinal BD. Currently, there is no single gold standard test or pathognomonic finding of intestinal BD. However, recently developed novel diagnostic criteria and a disease activity index have helped in assessing intestinal BD. As intestinal BD shares a lot of characteristics with inflammatory bowel disease, including genetic background, clinical manifestations, and therapeutic strategies, distinguishing between the two diseases in clinical practice is quite difficult. However, biologic agents such as anti-tumor necrosis factor α antibody shows a considerable efficacy similar to inflammatory bowel disease cases. It is important to distinguish and treat those two disease entities separately from the standpoint of precise medicine. Clinicians should require comprehensive knowledge regarding the similarities and differences between intestinal BD and inflammatory bowel disease for making an accurate clinical decision.

Mycobacterium avium subspecies hominissuis in Crohn's disease: a case report

We have cultured Mycobacteria avium subspecies hominissuis (MAH) from the blood of a patient with Crohn’s disease. The patient is a 21 year-old-female with a diagnosis of Crohn’s disease for two years. She had been treated with corticosteroids and Humira for six months. A blood specimen was cultured in a specialized medium, and there was visible bacterial growth present in the liquid culture medium after eight weeks. PCR analysis of the bacterial growth and subsequent direct sequencing of the PCR amplicon confirmed the presence of MAH. The significance of this finding is discussed.

Crohn's disease-specific anti-CUZD1 pancreatic antibodies are absent in ruminants with paratuberculosis

BACKGROUND

Pancreatic autoantibodies (PABs) specifically recognizing GP2 and/or CUZD1 are present in more than 35% of patients with Crohn's disease (CrD). We have recently provided evidence of the presence of GP2-specific PABs in ruminants with paratuberculosis (ptb), a Mycobacterium avium paratuberculosis (MAP)-induced disease resembling CrD.

OBJECTIVE

To assess whether anti-CUZD1 antibodies are also present in ruminants with ptb.

METHODS

A total of 110 samples (73 cattle/37 sheep) were studied including 40 with ptb (24 cattle/16 sheep; 20 anti-GP2 antibody pos) and 70 without ptb (49 cattle/21 sheep; 10 anti-GP2 antibody pos). The samples were pre-characterized for anti-MAP and anti-GP2 antibodies by ELISA. Evidence of MAP was confirmed by PCR. Anti-CUZD1 antibody testing was performed by indirect immunofluorescence (IIF) based on transfected HEK293 cells expressing CUZD1. Anti-sheep or anti-cattle specific antisera were used as revealing antibodies.

RESULTS

None of the ruminant sera had anti-CUZD1 antibodies by IIF testing at dilutions varying from 1/10 to 1/160. Methodological flaws were prevented by a series of tests. Control sera from anti-CUZD1 positive CrD samples have shown anti-CUZD1 antibody reactivity at various concentrations. Antibody reactivity to GP2-expressing HEK293 cells has confirmed the reactivity to GP2 in ruminant sera found positive for anti-GP2 antibodies by ELISA.

CONCLUSION

The present study has found no evidence of anti-CUZD1 PABs in MAP-induced ptb. Our findings indicate that the induction of CUZD1-specific PABs is unrelated to MAP infection and that the mechanisms responsible for the loss of tolerance to GP2 and CUZD1 are probably quite distinct.

Prevalence of Mycobacterium avium subsp. paratuberculosis and Escherichia coli in blood samples from patients with inflammatory bowel disease

Mycobacterium avium subsp. paratuberculosis (MAP) and adherent-invasive Escherichia coli (AIEC) have been implicated as primary triggers in Crohn's disease (CD). In this study, we evaluated the prevalence of MAP and E. coli (EC) DNA in peripheral blood from 202 inflammatory bowel disease (IBD) patients at various disease periods and compared against 24 cirrhotic patients with ascites (CIR) (non-IBD controls) and 29 healthy controls (HC). MAP DNA was detected by IS900-specific nested PCR, EC DNA by malB-specific nested PCR and AIEC identity, in selected samples, by sequencing of fimH gene. CD patients with active disease showed the highest MAP DNA prevalence among IBD patients (68 %). Infliximab treatment resulted in decreased MAP detection. CIR patients had high individual and coinfection rates (75 % MAP, 88 % EC and 67 % MAP and EC), whilst HC controls had lower MAP prevalence (38 %) and EC was undetectable in this control group. EC DNA prevalence in IBD patients was highly associated with CD, and 80 % of EC from the selected samples of CD patients analyzed carried the fimH30 allele, with a mutation strongly associated with AIEC. Our results show that coinfection with MAP and AIEC is common and persistent in CD, although the high MAP and EC detection in CIR patients suggested that colonization is, at least, partially dependent on increased gut permeability. Nevertheless, facilitative mechanisms between a susceptible host and these two potential human pathogens may allow their implication in CD pathogenesis.

The zoonotic potential of Mycobacterium avium ssp. paratuberculosis: a systematic review and meta-analyses of the evidence

This systematic review-meta-analysis appraises and summarizes all the available research (128 papers) on the zoonotic potential of Mycobacterium avium ssp. paratuberculosis. The latter has been debated for a century due to pathogenic and clinical similarities between Johne's disease in ruminants and Crohn's disease (108 studies) in humans and recently for involvement in other human diseases; human immunodeficiency virus (HIV) infection (2), sarcoidosis (3), diabetes mellitus type 1 (T1DM) (7) and type 2 (3), multiple sclerosis (5) and Hashimoto's thyroiditis (2). Meta-analytical results indicated a significant positive association, consistently across different laboratory methods for Crohn's disease [odds ratio (OR) range 4·26-8·44], T1DM (OR range 2·91-9·95) and multiple sclerosis (OR range 6·5-7·99). The latter two and the thyroiditis hypothesis require further investigation to confirm the association. Meta-regression of Crohn's disease studies using DNA detection methods indicated that choice of primers and sampling frame (e.g. general population vs. hospital-based sample) explained a significant proportion of heterogeneity. Other epidemiological studies demonstrated a lack of association between high-risk occupations and development of Crohn's disease. Due to knowledge gaps in understanding the role of M. paratuberculosis in the development or progression of human disease, the evidence at present is not strong enough to inform the potential public health impact of M. paratuberculosis exposure.

Matrix metalloproteinases in inflammatory bowel disease: an update

Matrix metalloproteinases (MMPs) are known to be upregulated in inflammatory bowel disease (IBD) and other inflammatory conditions, but while their involvement is clear, their role in many settings has yet to be determined. Studies of the involvement of MMPs in IBD since 2006 have revealed an array of immune and stromal cells which release the proteases in response to inflammatory cytokines and growth factors. Through digestion of the extracellular matrix and cleavage of bioactive proteins, a huge diversity of roles have been revealed for the MMPs in IBD, where they have been shown to regulate epithelial barrier function, immune response, angiogenesis, fibrosis, and wound healing. For this reason, MMPs have been recognised as potential biomarkers for disease activity in IBD and inhibition remains a huge area of interest. This review describes new roles of MMPs in the pathophysiology of IBD and suggests future directions for the development of treatment strategies in this condition.