Review article: Mycobacterium avium subsp. paratuberculosis as one cause of Crohn's disease

Mapping Crohn's Disease Pathogenesis with Mycobacterium paratuberculosis: A Hijacking by a Stealth Pathogen

Mycobacterium avium ssp. paratuberculosis (MAP) has been implicated in the development of Crohn's disease (CD) for over a century. Similarities have been noted between the (histo)pathological presentation of MAP in ruminants, termed Johne's disease (JD), and appearances in humans with CD. Analyses of disease presentation and pathology suggest a multi-step process occurs that consists of MAP infection, dysbiosis of the gut microbiome, and dietary influences. Each step has a role in the disease development and requires a better understanding to implementing combination therapies, such as antibiotics, vaccination, faecal microbiota transplants (FMT) and dietary plans. To optimise responses, each must be tailored directly to the activity of MAP, otherwise therapies are open to interpretation without microbiological evidence that the organism is present and has been influenced. Microscopy and histopathology enables studies of the mycobacterium in situ and how the associated disease processes manifest in the patient e.g., granulomas, fissuring, etc. The challenge for researchers has been to prove the relationship between MAP and CD with available laboratory tests and methodologies, such as polymerase chain reaction (PCR), MAP-associated DNA sequences and bacteriological culture investigations. These have, so far, been inconclusive in revealing the relationship of MAP in patients with CD. Improved and accurate methods of detection will add to evidence for an infectious aetiology of CD. Specifically, if the bacterial pathogen can be isolated, identified and cultivated, then causal relationships to disease can be confirmed, especially if it is present in human gut tissue. This review discusses how MAP may cause the inflammation seen in CD by relating its known pathogenesis in cattle, and from examples of other mycobacterial infections in humans, and how this would impact upon the difficulties with diagnostic tests for the organism.

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.

Immunopathological mechanisms in the early stage of Mycobacterium avium subsp. paratuberculosis infection via different administration routes in a murine model

Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne's disease, a chronic emaciating disease of ruminants that causes enormous economic losses to the bovine industry, globally. However, there are still remaining clues to be solved in the pathogenesis and diagnosis of the disease. Therefore, an in vivo murine experimental model was tried to understand responses in early stage of MAP infection by oral and intraperitoneal (IP) routes. In the MAP infection size, and weight of spleen and liver were increased in the IP group compared with oral groups. Severe histopathological changes were also observed in the spleen and liver of IP infected mice at 12 weeks post-infection (PI). Acid-fast bacterial burden in the organs was closely related to histopathological lesions. In the cytokine production from splenocytes of MAP-infected mice, higher amounts of in TNF-α, IL-10, and IFN-γ were produced at early stage of IP-infected mice while IL-17 production was different at time and infected groups. This phenomenon may indicate the immune shift from Th1 to Th17 through the time course of MAP infection. Systemic and local responses in the MAP-infection were analyzed by using transcriptomic analysis in the spleens and mesenteric lymph nodes (MLN). Based on the analysis of biological processes at 6 weeks PI in spleen and MLN in each infection group, canonical pathways were analyzed with ingenuity pathway analysis in the immune responses and metabolism especially lipid metabolism. Infected host cells with MAP increased in the production of proinflammatory cytokines and reduced the availability of glucose at early stage of infection (p < 0.05). Also, host cells secreted cholesterol through cholesterol efflux to disturb energy source of MAP. These results reveal immunopathological and metabolic responses in the early stage of MAP infection through the development of a murine model.

First case of systemic fatal mycobacteriosis caused by Mycobacterium goodii in a pet Kenyan sand boa (Eryx colubrinus loveridgei)

BACKGROUND

Environmental nontuberculous mycobacteria species that are not members of the M. tuberculosis complex, are ordinary inhabitants of a wide variety of environmental reservoirs and their role in human and animal diseases has been fully recognized. Even if spontaneous mycobacterial infections have been reported in a wide variety of reptiles, this is the first report of systemic fatal mycobacteriosis sustained by Mycobacterium goodii in a pet reptile.  CASE PRESENTATION: An adult, wild caught (WC), male Kenyan sand boa (Eryx colubrinus loveridgei) age unknown, was presented for clinical examination due to decreased activity level, decreased appetite and diarrhea. Blood tests showed unreliable results. Coprologic exam showed a moderate to severe presence of flagellates. X rays and ultrasound showed moderate presence of air and faeces in the large intestine. The snake was hospitalized and oral metronidazole was chosen as antiprotozoal agent in association with subcutaneous warm fluids. The snake was discharged after 2 weeks therapy in good clinical condition. Faecal exam resulted negative. One month after, the snake was quickly hospitalized again because of a recrudescence of symptoms. Biochemistry showed severe increase of AST, ALT and biliary acids. Severe leucocytosis and moderate to severe anemia were highlighted. Ultrasound examination revealed a severe diffused alteration of the liver parenchyma and a fine needle aspiration was performed. The cytological diagnosis was mixed inflammation, with a numerous of unstained rod-shaped bacteria both inside macrophages and free in the sample. The snake's condition rapidly deteriorated and euthanasia was performed. The histology of the coelomic organs confirmed a systemic mycobacteriosis. Real-time PCR identified the mycobacteria as Mycobacterium goodii.

CONCLUSIONS

Species from the genus Mycobacterium are among the most important micro-organism including the causative agents of tuberculosis. Even if the general incidence of disease in reptiles due to mycobacteria is comparatively low, they can serve as reservoirs of many ubiquitous mycobacteria species. Mycobacterium goodii is a rapidly growing non-tuberculous mycobacterium that has recently been associated with severe infections in animals and humans. Although in this case the pathogenesis was not completely clear, we highlight the zoonotic risk of mycobacteriosis in exotic animals especially in WC specimens.

MiR-146a rs2910164 G > C polymorphism modulates Notch-1/IL-6 signaling during infection: a possible risk factor for Crohn's disease

BACKGROUND

MiR-146a, an effector mediator, targets Notch-1 and regulates the innate and adaptive immune systems response. Recently, we reported that Notch-1 signaling plays a key role in macrophage polarization and response during infection. We employed Mycobacterium avium paratuberculosis (MAP) infection in Crohn's disease (CD) as a model to demonstrate the role of Notch-1/IL-6 signaling on MCL-1 based apoptosis and intracellular MAP infection and persistence. This study was designed to investigate the impact of polymorphisms in miR146a on the immune response and infection in our MAP-CD model.

METHODS

We determined the incidence of miR-146a rs2910164 G > C in 42 blood samples from clinical CD patients and controls. We also measured the effect of rs2910164 on expression of Notch-1 and IL-6, and plasma IL-6 protein levels in our study group. Finally, we analyzed the blood samples for MAP DNA and studied any correlation with miR-146a polymorphism. Samples were analyzed for statistical significance using unpaired tow-tailed t-test, unpaired two-tailed z-score and odds ratio. P < 0.05 considered significant.

RESULTS

MiR-146a rs2910164 GC was detected at a higher incidence in CD (52.6%) compared to healthy controls (21.7%) rs2910164 GC Heterozygous polymorphism upregulated Notch-1 and IL-6, by 0.9 and 1.7-fold, respectively. As expected, MAP infection was detected more in CD samples (63%) compared to healthy controls (9%). Surprisingly, MAP infection was detected at a higher rate in samples with rs2910164 GC (67%) compared to samples with normal genotype (33%).

CONCLUSIONS

The data clearly associates miR-146a rs2910164 GC with an overactive immune response and increases the risk to acquire infection. The study is even more relevant now in our efforts to understand susceptibility to SARS-CoV-2 infection and the development of COVID-19. This study suggests that genetic variations among COVID-19 patients may predict who is at a higher risk of acquiring infection, developing exacerbating symptoms, and possibly death. A high scale study with more clinical samples from different disease groups is planned.

Pancreatic anti-GP2 and anti-Saccharomyces cerevisiae antibodies in ruminants with paratuberculosis: A better understanding of the immunopathogenesis of Crohn's disease

INTRODUCTION

Ruminants (cattle and sheep) with Mycobacterium avium (MAP)-induced paratuberculosis (ptb), the ruminant model of Crohn's disease (CD), exhibit pancreatic specific autoantibodies (PAB) against GP2 but not against CUZD1. Since anti-Saccharomyces cerevisiae antibodies (ASCAs) is a CD marker, we tested MAP-infected ptb ruminants for ASCA, and compared them with ruminants lacking evidence of anti-MAP serology or with ruminants, which were positive for anti-GP2 antibodies.

MATERIAL AND METHODS

A total of 98 samples from ruminants (48 cattle and 50 sheep) were studied. IgG anti-MAP antibodies, and CD-related ASCA and anti-GP2 antibodies were tested by modified ELISAs.

RESULTS

Nine cattle (18.75%) and 20 sheep (40%) were suffered from ptb. ASCA antibodies were present in 21/48 (43.7%) cattle and 10/50 (20%) sheep while anti-GP2 antibodies were present in 14/48 (29.2%) cattle, and 8/50 (16%) sheep. ASCA antibodies were more prevalent in anti-MAP antibody positive (14/29, 48.3%) than in anti-MAP negative ruminants (17/69, 24.6%, P=0.022) and also in anti-GP2 antibody positive (13/23, 56.5%) than in anti-GP2 negative ruminants (18/75, 24%, P=0.003). No association between ASCA and anti-MAP antibody concentrations were found (r=0.159, P=0.117). A significant association between ASCA and anti-GP2 antibody concentration were observed (r=0.211 and P=0.037).

CONCLUSION

ASCA are present in a significant proportion of ruminants with ptb and correlate with anti-GP2 antibody positivity, a finding further supporting the notion that Crohn's disease and ptb share common immunological mechanisms of antigen-driven loss of self-tolerance.

Divergent Effect of Cigarette Smoke on Innate Immunity in Inflammatory Bowel Disease: A Nicotine-Infection Interaction

Cigarette smoke (CS) has adverse effects in patients with Crohn’s disease (CD), an inflammatory bowel disease (IBD) that has been associated with microbial infection, immuno-dysregulation, and mucosal dysfunction. However, CS seems to provide relief and protection to patients with another IBD known as ulcerative colitis (UC). These two subsets are featured as M1- and M2-mediated responses, respectively. Nicotine is the most active, addictive, and studied ingredient in CS. The mechanism of how nicotine and/or other CS ingredients induce pro-inflammatory or anti-inflammatory phenotypes in IBD patients remains under investigation. Our most recent in vitro nicotine study provided significant insights toward understanding the contradictory effects of nicotine on IBD patients, and it elucidated the mechanistic role of α7nAChR in modulation of macrophages in tobacco smokers. Shifting the beneficial effect of nicotine to a harmful outcome in CD patients was linked to a nicotine-microbe interaction that supports a microbial etiology in CD pathogenesis. Among the most debated pathogens in CD etiology is Mycobacterium avium subspecies paratuberculosis (MAP). Other studies associated nicotine with upregulation of miR-124 expression in macrophages, which led to anti-inflammatory response. This review discusses published work on the role of nicotine in modulation of the innate immune response and subsequent signaling in macrophages in IBD subsets.

An Overview on Resistivity, Diagnostic Challenges and Zoonotic Significance of: Mycobacterium avium ssp. paratuberculosis (MAP)

Background:

Mycobacterium avium ssp. paratuberculosis (MAP) is a gram-positive, contagious, rod-shaped intracellular pathogen.

Methods:

MAP is the etiologic agent of Johne’s disease in cattle, and has tremendous economic effect in the ruminant industry. Simultaneously, the MAP has also been suspected as a cause of Crohn’s disease in humans.

Results:

There has been a challenge in the diagnosis of MAP due to its long incubation period, unknown pathogenesis & cross-reactivity among its closely related sub-species. The survival of MAP inside the host macrophages & monocytes, is still unclear. Resistivity & survival of MAP in the outside environment is also high.

Conclusion:

Thus, more research about its pathogenesis, control, and potential role as a zoonotic pathogen must be carried out in future.

MAP1981c, a Putative Nucleic Acid-Binding Protein, Produced by Mycobacterium avium subsp. paratuberculosis, Induces Maturation of Dendritic Cells and Th1-Polarization

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative pathogen of chronic granulomatous enteropathy (Johne's disease) in animals, and has been focused on its association with various autoimmune diseases in humans, including Crohn's disease. The discovery of novel mycobacterial antigens and exploring their role in host immunity can contribute to the advancement of effective defense strategies including vaccines and diagnostic tools. In a preliminary study, we identified cellular extract proteins of MAP that strongly react with the blood of patients with Crohn's disease. In particular, MAP1981c, a putative nucleic acid-binding protein, showed high expression levels and strong reactivity to IgG and IgM in the sera of patients. Here, we investigated the immunological features of MAP1981c and focused on its interaction with dendritic cells (DCs), confirming its immunomodulatory ability. MAP1981c was shown to recognize Toll-like receptor (TLR) 4, and induce DC maturation and activation by increasing the expression of co-stimulatory (CD80 and CD86) and MHC class I/II molecules and the secretion of pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) in DCs. This DC activation by MAP1981c was mediated by downstream signaling of TLR4 via MyD88- and TRIF-, MAP kinase-, and NF-κB-dependent signaling pathways. In addition, MAP1981c-treated DCs activated naïve T cells and induced the differentiation of CD4⁺ and CD8⁺ T cells to express T-bet, IFN-γ, and/or IL-2, but not GATA-3 and IL-4, thus indicating that MAP1981c contributes to Th1-type immune responses both in vitro and in vivo. Taken together, these results suggest that MAP1981c is a novel immunocompetent antigen that induces DC maturation and a Th1-biased response upon DC activation, suggesting that MAP1981c can be an effective vaccine and diagnostic target.

Endoscopic and clinical responses to anti-tubercular therapy can differentiate intestinal tuberculosis from Crohn's disease

BACKGROUND

Differentiation between intestinal tuberculosis and Crohn's disease is difficult and may require therapeutic trial with anti-tubercular therapy in tuberculosis-endemic regions.

AIM

To evaluate the role of therapeutic trial with anti-tubercular therapy in patients with diagnostic confusion between intestinal tuberculosis and Crohn's disease.

METHODS

We performed retrospective-comparative (n = 288: 131 patients who received anti-tubercular therapy before being diagnosed as Crohn's disease and 157 intestinal tuberculosis patients) and prospective-validation study (n = 55 patients with diagnostic confusion of intestinal tuberculosis/Crohn's disease). Outcomes assessed were global symptomatic response and endoscopic mucosal healing.

RESULTS

In the derivation cohort, among those eventually diagnosed as Crohn's disease, global symptomatic response with anti-tubercular therapy was seen in 38% at 3 months and in 37% who completed 6 months of anti-tubercular therapy. Ninety-four per cent of intestinal tuberculosis patients showed global symptomatic response by 3 months. Endoscopic mucosal healing was seen in only 5% of patients with Crohn's disease compared with 100% of intestinal tuberculosis patients. In the validation cohort, all the patients with intestinal tuberculosis had symptomatic response and endoscopic mucosal healing after 6 months of anti-tubercular therapy. Among the patients with an eventual diagnosis of Crohn's disease, symptomatic response was seen in 64% at 2 months and in 31% who completed 6 months of anti-tubercular therapy, none had mucosal healing.

CONCLUSIONS

Disproportionately lower mucosal healing rate despite an overall symptom response with 6 months of anti-tubercular therapy in patients with Crohn's disease suggests a need for repeat colonoscopy for diagnosing Crohn's disease. Patients with intestinal tuberculosis showing significant symptomatic response after 2-3 months of anti-tubercular therapy, suggest that symptom persistence after a therapeutic trial of 3 months of anti-tubercular therapy may indicate the diagnosis of Crohn's disease.

Amplified Fragment Length Polymorphism to Detect Clonal Diversity and Distribution of Mycobacterium Avium Subspecies Paratuberculosis in Selected Minnesota Dairy Cattle

The molecular ecology of Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of Johne's disease, is not well understood in the United States. In this study, a DNA fingerprinting method, amplified fragment length polymorphism (AFLP), was used to subtype the pathogen and assess the clonal diversity of MAP in Minnesota dairy herds. Fifty-six fecal culture test–positive isolates from various Minnesota counties and culture dates were analyzed in this study. The AFLP identified 11 profiles with 50% of isolates representing 1 major profile. The major profile was distributed across the state. The genetic diversity of bovine MAP clones in Minnesota based on AFLP analysis of this data appears to be relatively low.

Detection of Mycobacterium Avium Subsp. Paratuberculosis in Bovine Fecal Samples: Comparison of Three Polymerase Chain Reaction—Based Diagnostic Tests with a Conventional Culture Method

Three commercially available assays, designed to specifically detect the presence of Mycobacterium avium subsp. paratuberculosis (MAP) in fecal samples by IS900-PCR, were compared with a conventional culture method. Fecal samples from 100 dairy cows were tested. Fifty-four (67.5%) of 80 culture-positive samples were positive for an assay that detects MAP DNA by dot spot hybridization of polymerase chain reaction products (kit A), 48 (60%) were positive by an assay using ethidium bromide staining for agar gel visualization of amplification products (kit B), and 49 (61.3%) were positive by an assay in which amplified products are detected by a colorimetric detection system (kit C). Relative sensitivity of all tests increased in proportion to the presence of MAP in fecal samples. Specificity was 100% based on results from 20 culture-negative samples from an MAP-free herd.

Invited review: The economic impact and control of paratuberculosis in cattle

Paratuberculosis (also called Johne's disease) is a chronic disease caused by Mycobacterium avium ssp. paratuberculosis (MAP) that affects ruminants and other animals. The epidemiology of paratuberculosis is complex and the clinical manifestations and economic impact of the disease in cattle can be variable depending on factors such as herd management, age, infection dose, and disease prevalence, among others. Additionally, considerable challenges are faced in the control of paratuberculosis in cattle, such as the lack of accurate and reliable diagnostic tests. Nevertheless, efforts are directed toward the control of this disease because it can cause substantial economic losses to the cattle industry mainly due to increased premature culling, replacement costs, decreased milk yield, reduced feed conversion efficiency, fertility problems, reduced slaughter values, and increased susceptibility to other diseases or conditions. The variability and uncertainty surrounding the estimations of paratuberculosis prevalence and impact influence the design, implementation, and efficiency of control programs in diverse areas of the world. This review covers important aspects of the economic impact and control of paratuberculosis, including challenges related to disease detection, estimations of the prevalence and economic effects of the disease, and the implementation of control programs. The control of paratuberculosis can improve animal health and welfare, increase productivity, reduce potential market problems, and increase overall business profitability. The benefits that can derive from the control of paratuberculosis need to be communicated to all industry stakeholders to promote the implementation of control programs. Moreover, if the suspected link between Johne's disease in ruminants and Crohn's disease in humans was established, significant economic losses could be expected, particularly for the dairy industry, making the control of this disease a priority across dairy industries internationally.

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.

The Single Intradermal Cervical Comparative Test Interferes with Johne's Disease ELISA Diagnostics

Enzyme-linked immunosorbent assays (ELISA) of milk and serum samples are a routinely used method of screening herds for Mycobacterium avium subspecies paratuberculosis (MAP). Infection with MAP causes granulomatous enteritis of ruminants known as Johne's disease (JD). The sensitivity (Se) and specificity (Sp) of MAP ELISAs leads to difficulties in the identification of both infected and infectious animals. Interference with MAP ELISA Se and Sp has been reported in MAP seronegative cows following administration of purified protein derivative (PPD) as part of intradermal testing for bovine tuberculosis (bTB). The aim of this study is to examine the impact of the single intradermal cervical comparative test (SICCT) for bTB, on both serum and milk MAP ELISA tests, in a herd containing both seropositive and seronegative cows pre-SICCT. A secondary objective is to provide appropriate timing of JD ELISA tests in relation to the SICCT. A herd of 139 cows were serum and milk sampled pre- and post-SICCT administration. Prior to SICCT, 6% of the herd tested seropositive for MAP using milk ELISA, with 8% positive on serum. ID Screen Paratuberculosis Indirect Screening Test (ID Vet) was used to screen the herd. Within 14 days of PPD administration, a significant increase in the prevalence of seropositive cows was recorded. Identical prevalence's were recorded with both test matrices (39%). ELISA values remained significantly higher until day 43 post-SICCT in milk (P = 0.850), and day 71 in serum (P = 0.602). If the "new" positives detected post-bTB testing are deemed false positives due to generation of cross-reacting antibodies by administration of PPD, milk would appear a more suitable sample for JD ELISA testing within 2 months of SICCT. In summary, sampling for JD utilizing milk ELISA should be avoided in the 43-day period following PPD administration, with serum ELISA sampling avoided for an additional 28 days.

Sensitive and specific enzyme-linked immunosorbent assay for detecting serum antibodies against Mycobacterium avium subsp. paratuberculosis in fallow deer

The enzyme-linked immunosorbent assay (ELISA) is the diagnostic test most commonly used in efforts to control paratuberculosis in domestic ruminants. However, commercial ELISAs have not been validated for detecting antibodies against Mycobacterium avium subsp. paratuberculosis in wild animals. In this study, we compared the sensitivities and specificities of five ELISAs using individual serum samples collected from 41 fallow deer with or without histopathological lesions consistent with paratuberculosis. Two target antigenic preparations were selected, an ethanol-treated protoplasmic preparation obtained from a fallow deer M. avium subsp. paratuberculosis isolate (ELISAs A and B) and a paratuberculosis protoplasmic antigen (PPA3) (ELISAs C and D). Fallow deer antibodies bound to the immobilized antigens were detected by using a horseradish peroxidase (HRP)-conjugated anti-fallow deer IgG antibody (ELISAs A and C) or HRP-conjugated protein G (ELISAs B and D). A commercially available assay, ELISA-E, which was designed to detect M. avium subsp. paratuberculosis antibodies in cattle, sheep, and goats, was also tested. Although ELISAs A, C, and E had the same sensitivity (72%), ELISAs A and C were more specific (100%) for detecting fallow deer with lesions consistent with paratuberculosis at necropsy than was the ELISA-E (87.5%). In addition, the ELISA-A was particularly sensitive for detecting fallow deer in the latent stages of infection (62.5%). The antibody responses detected with the ELISA-A correlated with both the severity of enteric lesions and the presence of acid-fast bacteria in gut tissue samples. In summary, our study shows that the ELISA-A can be a cost-effective diagnostic tool for preventing the spread of paratuberculosis among fallow deer populations.

Association between maternal inflammatory bowel disease and adverse perinatal outcomes

OBJECTIVE

To examine whether inflammatory bowel disease (IBD) is associated with ischemic/inflammatory conditions during pregnancy.

STUDY DESIGN

A retrospective cohort study using the 2000 to 2012 Kaiser Permanente Southern California maternally-linked medical records (n=395 781). The two major subtypes of IBD, ulcerative colitis and Crohn's diseases were studied. Adjusted odds ratios (ORs) were used to quantify the associations.

RESULT

A pregnancy complicated by IBD was associated with increased incidence of small-for-gestational age birth (OR=1.46, 95% confidence interval (CI)=1.14 to 1.88), spontaneous preterm birth (OR=1.32, 95% CI=1.00 to 1.76) and preterm premature rupture of membranes (OR=1.95, 95% CI=1.26 to 3.02). Further stratifying by IBD subtypes, only ulcerative colitis was significantly associated with increased incidence of ischemic placental disease, spontaneous preterm birth and preterm premature rupture of membranes.

CONCLUSION

The findings underscore the potential impact of maternal IBD on adverse perinatal outcomes. Clinicians should be aware that the association between IBD and adverse perinatal outcome varies by IBD subtypes.

Paediatric gastrointestinal conditions and their oral implications

OBJECTIVES

The paediatric dentist must be familiar with a range of medical problems which can affect the mouth or general health of children. Dental clinicians are ideally placed to help with the detection of a range of gastrointestinal issues and should know when to refer to the paediatric specialist for advice.

METHODS

This article reviews the common gastrointestinal tract (GIT) conditions that can affect children reviewing the conditions, their usual treatments, and how they can influence the mouth and the oral environment. This article will review how the different conditions may produce oral symptoms and signs. The management of the oral problems and appropriate photographs are covered well in other texts and will not be included here.

CONCLUSION

The mouth is a specialised part of the GIT and can be involved in or affected by many of the diseases encountered in other GIT regions.

Mycobacterium avium subsp. paratuberculosis and multiple sclerosis in Sardinian patients: epidemiology and clinical features

BACKGROUND

Mycobacterium avium subspecies paratuberculosis (MAP) is an infectious factor recently found in association with multiple sclerosis (MS) in Sardinia.

OBJECTIVES

The objectives of this study were to confirm this association and evaluate its role in clinical features.

METHODS

A total of 436 patients and 264 healthy controls (HCs) were included. We examined the blood of each individual for MAPDNA and MAP2694 antibodies using IS900-specific PCR and ELISA, respectively. Differences in MAP presence between the MS group and HCs were evaluated. In MS patients, we considered: gender, age, age at onset, duration of disease, course, EDSS, therapy, relapse/steroids at study time, and oligoclonal bands (OBs).

RESULTS

MAPDNA and MAP2694 antibodies were detected in 68 MS and six HCs (p = 1.14 × 10(-11)), and 123 MS and 10 HCs (p = 2.59 × 10(-23)), respectively. OBs were found with reduced frequency in MAP-positive patients (OR = 0.52; p = 0.02). MAP2694 antibodies were detected more in patients receiving MS treatments (OR = 2.26; p = 0.01), and MAPDNA in subjects on steroids (OR = 2.65; p = 0.02).

CONCLUSION

Our study confirmed the association of MAP and MS in Sardinia. The low OB frequency in MAP patients suggests a peripheral role as a trigger in autoimmunity. MAP positivity might be influenced by steroids and MS therapy. Studies in other populations are needed to confirm the role of MAP in MS.

Anti-inflammatory and antiapoptotic responses to infection: a common denominator of human and bovine macrophages infected with Mycobacterium avium subsp. paratuberculosis

Mycobacterium avium subsp. paratuberculosis (Map) is the causative agent of a chronic intestinal inflammation in ruminants named Johne's disease or paratuberculosis and a possible etiopathological agent of human Crohn's disease (CD). Analysis of macrophage transcriptomes in response to Map infection is expected to provide key missing information in the understanding of the role of this pathogen in establishing an inappropriate and persistent infection in a susceptible host and of the molecular mechanisms that might underlie the early phases of CD. In this paper we summarize transcriptomic studies of human and bovine peripheral blood mononuclear cells (PBMC), monocyte-derived macrophages (MDMs), and macrophages-like cell lines in vitro infected with Map. Most studies included in this paper consistently reported common gene expression signatures of bovine and human macrophages in response to Map such as enhanced expression of the anti-inflammatory cytokines IL-10 and IL-6, which promote bacterial survival. Overexpression of IL-10 could be responsible for the Map-associated reduction in the expression of the proapoptotic TNF-α gene observed in bovine and human macrophages.

In vitro cytokine profiles and viability of different human cells treated with whole cell lysate of Mycobacterium avium subsp. paratuberculosis

Mycobacterium avium subsp. paratuberculosis (MAP) is a zoonotic pathogen, a very slow growing bacterium which is difficult to isolate and passage in conventional laboratory culture. Although its association with Johne's disease or paratuberculosis of cattle is well established, it has been only putatively linked to Crohn's disease in humans. Further, MAP has been recently suggested to be a trigger for other autoimmune diseases such as type-1 diabetes mellitus (T1DM). Recently, some studies have indicated that exposure to MAP is associated with elevated levels of antibodies against MAP lysate although the exact mechanism and significance of the same remains unclear. Further, the cytokine profiles relevant in MAP associated diseases of humans and their exact role in the pathophysiology are not clearly known. We performed in vitro cytokine analyses after exposing different cultured human cells to the whole cell lysate of MAP and found that MAP lysate induces secretion of cytokines IL-1β, IL-6, IL-8, IL-10 and TNF-α by human peripheral blood mononuclear cells (PBMCs). Also, it induces secretion of IL-8 by cultured human stomach adenocarcinoma cells (AGS) and PANC-1(human pancreatic carcinoma cell line) cells. We also found that MAP lysate induced cytotoxicity in PANC-1cells. Collectively, these results provide a much needed base-line data set of cytokines broadly signifying a MAP induced cellular response by human cells.

Immunization of adult dairy cattle with a new heat-killed vaccine is associated with longer productive life prior to cows being sent to slaughter with suspected paratuberculosis

The objective of this study was to evaluate the efficacy of a new heat-killed Mycobacterium avium ssp. paratuberculosis (MAP) vaccine for control of premature culling in tuberculosis-free dairy cattle. Feces and gastrointestinal tissues were collected from 50 vaccinated cows and 38 nonvaccinated cows at slaughter and analyzed by bacteriological culture and histopathology. Vaccination was associated with a significant reduction of the frequency of vaccinated animals with MAP in feces and gut tissues compared with the nonvaccinated animals. In addition, the frequency of vaccinated animals with heavy bacterial load in gut tissues was 40% lower than the frequency of the nonvaccinated animals with the same MAP load. The peak age of paratuberculosis-associated culling was from 4.5 to 5 yr old (21%) in the vaccinated animals and from 3 to 4.5 yr old (60%) in the nonvaccinated animals. The vaccinated and nonvaccinated animals with suspected paratuberculosis were culled at an average age of 4.7 and 3.7 yr old, respectively. Therefore, a significant increase in the productive life of the vaccinated animals sent to slaughter with suspected paratuberculosis was observed. In addition, our analysis revealed a positive effect of the vaccine on the carcass weights of the animals with severe histopathological lesions at slaughter compared with the nonvaccinated animals. In summary, our findings suggest a therapeutic effect of the vaccine and a significant attenuation of pre-existing infection in cows naturally infected with paratuberculosis that were adults at the time of vaccination.

Quantification of Mycobacterium avium subsp. paratuberculosis strains representing distinct genotypes and isolated from domestic and wildlife animal species by use of an automatic liquid culture system

Quantification of 11 clinical strains of Mycobacterium avium subsp. paratuberculosis isolated from domestic (cattle, sheep, and goat) and wildlife (fallow deer, deer, wild boar, and bison) animal species in an automatic liquid culture system (Bactec MGIT 960) was accomplished. The strains were previously isolated and typed using IS1311 PCR followed by restriction endonuclease analysis (PCR-REA) into type C, S, or B. A strain-specific quantification curve was generated for each M. avium subsp. paratuberculosis strain by relating the time to detection in the liquid culture system to the estimated log(10) CFU in each inoculum. According to their growth curves, the tested M. avium subsp. paratuberculosis strains were classified into two distinct groups. The first group included the S-type strain isolated from goat and all the sheep strains with C, S, and B genotypes. A second group contained the C- and B-type strains isolated from cattle, goat, and wildlife animals with the exception of the fallow deer strain. The strains isolated from cattle or sheep showed similar strain-specific standard curves irrespective of their genotype. In contrast, the strains isolated from goat or from wildlife animal species varied in their rates of growth in liquid culture. Universal-standard curves and algorithms for the quantification of each group of strains were generated. In addition, the liquid culture system was compared with a real-time quantitative PCR system for the quantification of the 11 M. avium subsp. paratuberculosis strains. Correlations between the estimated log(10) CFU and M. avium subsp. paratuberculosis DNA copy numbers were very high for all the tested strains (R ≥ 0.9).

Mycobacterium avium complex--the role of potable water in disease transmission

Mycobacterium avium complex (MAC) is a group of opportunistic pathogens of major public health concern. It is responsible for a wide spectrum of disease dependent on subspecies, route of infection and patients pre-existing conditions. Presently, there is limited research on the incidence of MAC infection that considers both pulmonary and other clinical manifestations. MAC has been isolated from various terrestrial and aquatic environments including natural waters, engineered water systems and soils. Identifying the specific environmental sources responsible for human infection is essential in minimizing disease prevalence. This paper reviews current literature and case studies regarding the wide spectrum of disease caused by MAC and the role of potable water in disease transmission. Potable water was recognized as a putative pathway for MAC infection. Contaminated potable water sources associated with human infection included warm water distribution systems, showers, faucets, household drinking water, swimming pools and hot tub spas. MAC can maintain long-term contamination of potable water sources through its high resistance to disinfectants, association with biofilms and intracellular parasitism of free-living protozoa. Further research is required to investigate the efficiency of water treatment processes against MAC and into construction and maintenance of warm water distribution systems and the role they play in MAC proliferation.

Alternative medicines as emerging therapies for inflammatory bowel diseases

Inflammatory bowel disease (IBD) can be divided into two major categories, ulcerative colitis (UC) and Crohn disease (CD). While the main cause(s) of IBD remain unknown, a number of interventional and preventive strategies have been proposed for use against CD and UC. Many reports have focused on the use of alternative natural medicines as potential therapeutic interventions in IBD patients with minimal side effects. While the use of alternative medicines may be effective in IBD patients that are refractory to corticosteroids or thiopurins, alternative treatment strategies are limited and require extensive clinical testing before being optimized for use in patients.

Ovine paratuberculosis: a seroprevalence study in dairy flocks reared in the marche region, Italy

In order to fulfil the seroprevalence gap on Mycobacterium avium subsp. paratuberculosis infection in ovine dairy farms of Marche region (central Italy), a stratified study was carried out on 2086 adult female sheep randomly chosen from 38 herds selected in Ancona and Macerata provinces. 73.7% flocks resulted infected by a commercial ELISA test (Pourquier, France), with a mean seroprevalence of 6.29% of sampled sheep in both provinces. A higher number of MAP seropositive ewes was recorded in the large herds' consistence than in the small and medium herds' consistence (P = 0.0269), and a greater percentage of infected sheep was obtained among female at early/late than in peak lactation stage (P = 0.0237). MAP infection was confirmed in 12.6% of infected farms by faecal culture. The true sheep-level seroprevalence was 15.1% ± 7.3%.

A 60-day probiotic protocol with Dietzia subsp. C79793-74 prevents development of Johne's disease parameters after in utero and/or neonatal MAP infection

The research reported herein was designed to assess whether the bacterium, Dietzia subspecies C79793-74, used as a probiotic, could prevent development of parameters indicative of bovine paratuberculosis after potential in utero, birthing and neonatal (colostrum) exposure to Mycobacterium avium subspecies paratuberculosis (MAP). Such exposure avenues are especially relevant for dairy farms practicing good management procedures since calves on these farms could be infected via dams that have yet to be identified as MAP-positive. Indeed, of 18 calves in the present study that became paratuberculosis parameter-positive, five had dams that were negative for all parameters pre-calving. Parameters used herein to define paratuberculosis status were serum ELISA, serum agar gel immunodiffusion, cultureable fecal MAP, histopathology at necropsy and clinical disease. Thirty-four newborn calves, whose dams were paratuberculosis-positive, were assigned to four different treatment groups. Ten were treated daily for 60 days with viable Dietzia added to their antibiotic-free milk feedings; none became positive for any parameter with age. In contrast, seven of eight calves that were not treated became positive for one or more paratuberculosis-associated parameter. Sixteen calves were treated with viable Dietzia for the first two days of life; eight were then not treated further, whereas the other eight were treated an additional 58 days with Dietzia added to tetracycline-fortified milk (Dietzia is sensitive to tetracycline). In these two groups, positivity developed in five of eight and six of eight, respectively. These results indicated that (a) a daily, 60-day treatment with viable Dietzia effectively prevented development of parameters indicative of paratuberculosis and (b) this treatment, in combination with good management practices, has the potential to eradicate MAP from animals/herds, which should curtail the spread of MAP. Such results should significantly reduce human exposure to MAP, which in turn, could have relevance for the controversial role of MAP in Crohn's disease, type-1 diabetes mellitus, sarcoidosis, Blau syndrome, ulcerative colitis, irritable bowel syndrome and multiple sclerosis.

Mycobacterium avium subsp paratuberculosis--incidences in milk and milk products, their isolation, enumeration, characterization, and role in human health

Mycobacterium avium subsp paratuberculosis (MAP), excreted in the feces and milk, is reported to be not easily inactivated by pasteurization and thermal treatments as other bacteria infecting humans and animals do. The D values of all MAP strains tested were considerably higher than those published for other pathogens. Culturing techniques for this organism are labor intensive. Although an increasing amount of scientific evidence suggests that this organism can be responsible for at least some cases of Crohn's disease (CD), there is controversy about MAP being a cause of CD in humans. In general, although some studies have described an association between the presence of MAP and CD, the role of Mycobacterium species and MAP in the etiology of this human disease remains unestablished. Although published reports indicate that it may not be completely inactivated by pasteurization of milk, the effectiveness of increasing the time or temperature in the pasteurization process has not been established and hence any potential benefit to human health cannot be determined. This article summarizes the incidences of MAP in milk and milk products with respect to human health and brief discussion of various serological as well as molecular techniques used for their isolation, enumeration, and characterization.

Postsurgical recurrence of ileal Crohn's disease: an update on risk factors and intervention points to a central role for impaired host-microflora homeostasis

BACKGROUND

A pressing need exists to identify factors that predispose to recurrence after terminal ileal resection for Crohn's disease (CD) and to determine effective prophylactic strategies. This review presents an up-to-date summary of the literature in the field and points to a role for bacterial overproliferation in recurrence.

METHODS

The literature (Medline, Embase, and the Cochrane Library, 1971-2009) on ileal CD and postoperative recurrence was searched, and 528 relevant articles were identified and reviewed.

RESULTS

Smoking is a key independent risk factor for recurrence. NOD2/CARD15 polymorphisms and penetrating phenotype are associated with aggressive disease and higher reoperation rates. Age at diagnosis, disease duration, gender, and family history are inconsistent predictors of recurrence. Prophylactic 5-aminosalicylic acid therapy and nitromidazole antibiotics are beneficial. Combination therapies with immunosuppressants are also effective. Anti-TNFalpha-based regimens show benefit but the evidence base is small. Corticosteroid, interleukin-10, and probiotic therapies are not effective. Wider, stapled anastomotic configurations are associated with reduced recurrence rates. Strictureplasty and laparoscopic approaches have similar long-term recurrence rates to open resection techniques. Length of resection and presence of microscopic disease at resection margins do not influence recurrence. A lack of consensus exists regarding whether the presence of granulomas or plexitis affects outcome.

CONCLUSIONS

Current evidence points to defects in mucosal immunity and intestinal dysbiosis of either innate (NOD2/CARD15) or induced (smoking) origin in postoperative CD recurrence. Prophylactic strategies should aim to limit dysbiosis (antibiotics, side-to-side anastomoses) or prevent downstream chronic inflammatory sequelae (anti-inflammatory, immunosuppressive, and immunomodulatory therapy).

Successful treatment of asymptomatic or clinically terminal bovine Mycobacterium avium subspecies paratuberculosis infection (Johne's disease) with the bacterium Dietzia used as a probiotic alone or in combination with dexamethasone: Adaption to chronic human diarrheal diseases

A naturally occurring gastrointestinal disease, primarily of ruminants (Johne disease), is a chronic debilitating disease that is caused by Mycobacterium avium subspecies paratuberculosis (MAP). MAP infection occurs primarily in utero and in newborns. Outside our Dietzia probiotic treatment, there are no preventive/curative therapies for bovine paratuberculosis. Interestingly, MAP is at the center of controversy as to its role in (cause of) Crohn disease (CD) and more recently, its role in diabetes, ulcerative colitis, and irritable bowel syndrome (IBS); the latter two, like CD, are considered to be a result of chronic intestinal inflammation. Treatments, both conventional and biologic agents, which induce and maintain remission are directed at curtailing processes that are an intricate part of inflammation. Most possess side effects of varying severity, lose therapeutic value, and more importantly, none routinely result in prevention and/or cures. Based on (a) similarities of Johne disease and Crohn disease, (b) a report that Dietzia inhibited growth of MAP under specific culture conditions, and (c) findings that Dietzia when used as a probiotic, (i) was therapeutic for adult bovine paratuberculosis, and (ii) prevented development of disease in MAP-infected calves, the goal of the present investigations was to design protocols that have applicability for IBD patients. Dietzia was found safe for cattle of all ages and for normal and immunodeficient mice. The results strongly warrant clinical evaluation as a probiotic, in combination with/without dexamethasone.

Genetic adult lactase persistence is associated with risk of Crohn's Disease in a New Zealand population

Background

Mycobacterium avium subspecies paratuberculosis (MAP) is an infective agent found in ruminants and milk products, which has been suggested to increase the risk of gastrointestinal inflammation in genetically susceptible hosts. It is hypothesized that lactase persistence facilitates exposure to such milk products increasing the likelihood of adverse outcomes. Individuals either homozygous or heterozygous for the T allele of DNA variant, rs4988235, located 14kb upstream from the LCT locus, are associated with having lactase persistence.

The aim of this study was to determine whether lactase persistence as evident by the T allele of rs4988235 is associated with Crohn's Disease (CD) in a New Zealand population.

Findings

Individuals homozygous for the T allele (T/T genotype) showed a significantly increased risk of having CD as compared with those homozygous for the C allele (OR = 1.61, 95% CI = 1.03-2.51). Additionally, a significant increase in the frequency of the T allele was observed in CD patients (OR = 1.30, 95% CI = 1.05-1.61, p = 0.013), indicating that the T allele encoding lactase persistence was associated with an increased risk of CD.

Conclusions

Our findings indicate that lactase persistence as evident by the presence of the T allele of rs4988235 is associated with risk of CD in this New Zealand Caucasian population.

Absence of Mycobacterium avium ss paratuberculosis-specific IS900 sequence in intestinal biopsy tissues of Indian patients with Crohn's disease

BACKGROUND AND OBJECTIVE

The role of Mycobacterium avium ss paratuberculosis (MAP) in the etiopathology of Crohn's disease (CD) remains controversial, because of conflicting reports demonstrating the presence of MAP-specific insertion sequence from intestinal biopsy tissues of patients clinically diagnosed for the disease. The present study was carried out to investigate the presence of MAP DNA in the intestinal tissues of CD patients to ascertain the relevance of MAP in Indian patients with CD.

METHODS

Patients diagnosed as CD at our institute were recruited. Healthy individuals without inflammatory bowel disease served as controls. Mucosal biopsy specimens were collected from ileum and colon in duplicates and subjected to histopathological examination and polymerase chain reaction (PCR) amplification. Total DNA (81 CD patients, 85 healthy individuals) and total RNA (12 CD patients, 12 healthy individuals) isolated from tissue specimens was used for amplification of MAP-specific IS900 by nested PCR.

RESULTS

MAP-specific IS900 DNA and RNA could not be detected by nested PCR in the intestinal tissues of any patient with CD.

CONCLUSION

Our results do not support the etiological role of MAP in the pathogenesis of CD in Indian patients.

Paratuberculose em caprinos e ovinos no Brasil

Este trabalho relata, pela primeira vez no Brasil, no Estado da Paraíba, paratuberculose em dois rebanhos com criação conjunta de caprinos e ovinos. Na Fazenda 1, de um rebanho de 33 caprinos e 13 ovinos, uma cabra adulta apresentou emagrecimento progressivo por aproximadamente um ano e fezes pastosas um mês antes da morte. Todos os animais do rebanho foram tuberculinizados com a prova comparativa. Um ovino (2,2%) teve resultado positivo à tuberculina aviar e em dois o teste foi inconclusivo. Na Fazenda 2, com 200 ovinos e 80 caprinos, foi afetada uma ovelha adulta que apresentou emagrecimento progressivo por aproximadamente um ano e fezes pastosas por aproximadamente 20 dias. Todos os ovinos com mais de 4 meses de idade e 23 caprinos foram tuberculinizados com tuberculina aviar; em 47 (25,4%) o resultado foi positivo, em 115 (61,5%) inconclusivo e em 25 (13,4%) negativo. Entre as cabras não houve nenhuma positiva à tuberculina aviar, mas em 11 (47,8%) o teste foi inconclusivo e em 12 (52,2%) foi negativo. Na necropsia dos dois animais com sinais clínicos os linfonodos mesentéricos estavam aumentados de tamanho e edemaciados. O ovino afetado da Fazenda 2, apresentou espessamento e enrugamento da mucosa do intestino, principalmente no íleo e válvula íleo-cecal. Microscopicamente o caprino e o ovino com sinais clínicos apresentaram lesões semelhantes, caracterizadas por granulomas com predominância de macrófagos espumosos, na lâmina própria e submucosa do intestino e linfonodos mesentéricos. O ovino positivo à tuberculina e um caprino negativo na Fazenda 1 foram eutanasiados e apresentaram discreto espessamento da mucosa do íleo. Na histologia foi observado infiltrado preferentemente linfocítico. Em todos os casos dentro de macrófagos e linfócitos havia bacilos ácool-ácidos resistentes, positivos na imunohistoquímica para Mycobacterium spp. Sugere-se a necessidade de estudar a prevalência de paratuberculose em rebanhos de caprinos e ovinos no Brasil, determinar medidas de controle e avaliar a possibilidade de transmissão para humanos.

Short communication: progression of Johne's disease curtailed by a probiotic

The naturally occurring inflammatory bowel disease Johne's, caused by Mycobacterium avium ssp. paratuberculosis (MAP), has many clinical manifestations in common with the human inflammatory bowel disease Crohn's disease. In addition, both lack preventive and curative therapies. Because a high percentage of Crohn's patients harbor MAP, it is not surprising that MAP is at the center of controversy as to its contribution. Special concern is being raised as to what role, if any, food animals play in transmission of MAP to humans. Because management practices, presently considered the best way to control the spread of MAP, have not and most likely will not eliminate MAP from food animals, other preventive or curative measures are needed. The results presented herein show that a unique bacterium, Dietzia ssp. C79793-74, used as a probiotic, was therapeutic for adult paratuberculosis animals, and resulted in a cure rate of 37.5%.

Detection of spatial and temporal spread of Mycobacterium avium subsp. paratuberculosis in the environment of a cattle farm through bio-aerosols

Environmental samples were collected to investigate the spatial and temporal spread of Mycobacterium avium subsp. paratuberculosis (MAP) in a dairy cattle barn before and after the introduction of two groups of MAP-shedding animals. Samples collected off the floor of the barn reflected the moment of sampling whereas samples collected by microfiber wipes at a minimal of 3m height contained the accumulated settled dust over a 3-week period. Samples were analysed by IS900 qPCR for the presence of MAP DNA and by culture for viable MAP bacteria. MAP DNA was detected in a large number of sites both before and after introduction cattle. MAP DNA was detected inside the barn in floor and dust samples from cubicles and slatted floors and in settled dust samples located above the slatted floors and in the ventilation ridge opening. Outside the barn MAP DNA was detected by PCR in samples reflecting the walking path of the farmer despite hygiene measures. No viable MAP was detected before the introduction of shedder cattle. Three weeks later viable MAP was found inside the barn at 7/49 locations but not outside. Fifteen weeks later viable MAP was also detected in environmental samples outside the barn. In conclusion, introduction of MAP shedding cattle lead to widespread contamination of the internal and external environment of a dairy barn, including the presence of viable MAP in settled dust particles suggesting potential transmission of MAP infection through bio-aerosols.

Investigation and diagnosis of nontuberculous mycobacteriosis in a captive herd of aoudad (Ammotragus lervia)

An epizootic of nontuberculous mycobacteriosis occurred in a captive herd of aoudad (Ammotragus lervia) over a period of 18 mo. Each of the affected animals was subject to a thorough postmortem examination that included histopathology, tissue concentration and acid-fast staining, aerobic and anaerobic bacterial culture, mycobacterial culture, and real-time polymerase chain reaction specific for Mycobacterium tuberculosis DNA. Histopathologic lesions consistent with pulmonary mycobacteriosis, including the presence of acid-fast bacteria, were identified in two captive adult male aoudad. M. avium was isolated in culture from the pulmonary parenchyma, and M. parafortuitum was isolated from a mesenteric lymph node of a third animal, an adult female, euthanized subsequent to an illness characterized by progressive dyspnea and tachypnea. M. intracellulare was isolated within the bronchial lymph node of a fourth aoudad, an adult female that was euthanized due to chronic weight loss. Diagnostic testing of the 34 individuals in the herd included collection of blood for an interferon-gamma assay, intradermal tuberculin testing, and radiometric fecal culture for M. avium subsp. paratuberculosis. On the basis of this investigation, mycobacteriosis associated with M. bovis, M. tuberculosis, and/or M. avium subsp. paratuberculosis was ruled out and nontuberculous mycobacteriosis was confirmed in this herd.

Absence of mycobacterium avium subsp. paratuberculosis in Crohn's patients

BACKGROUND

Mycobacterium avium subspecies paratuberculosis (MAP) has been suspected of involvement in Crohn's disease (CD). We investigated this potential association by testing whole blood from CD patients and healthy controls for the presence of MAP by culture and molecular methods. In addition, each blood sample was analyzed for polymorphisms in the NOD2/CARD15 gene previously associated with CD.

METHODS

Four 4-mL K(2)-EDTA tubes of whole blood were drawn from each subject (n = 260, 130 CD patients and 130 healthy controls). Two tubes of blood were cultured for MAP by the following methods: Mycobacterial Growth Indicator Tube, Herrold's Egg Yolk Agar, BACTEC 460, and Hungate. The remaining 2 tubes of blood were tested for MAP DNA and polymorphisms in the NOD2/CARD15 gene by polymerase chain reaction (PCR).

RESULTS

One healthy control patient was positive for MAP via PCR; however, no viable MAP was cultured from this individual. All blood cultures were negative for MAP. One CD patient's blood was culture-positive for M. tuberculosis complex. CD patients exhibited a higher rate of polymorphism in the NOD2/CARD15 gene than healthy control patients.

CONCLUSIONS

In this study MAP was not recovered from the blood of CD patients or healthy controls. However, CD patients showed higher mutation rates in the NOD2/CARD15 gene, compared with healthy controls, supporting the findings of other investigators. No correlation between these polymorphisms and MAP bacteremia in CD patients could be identified in this study.

Contamination of food products with Mycobacterium avium paratuberculosis: a systematic review

Although a causal link between Mycobacterium avium subspecies paratuberculosis (MAP) and Crohn's disease has not been proved, previous studies suggest that the potential routes of human exposure to MAP should be investigated. We conducted a systematic review of literature concerning the likelihood of contamination of food products with MAP and the likely changes in the quantity of MAP in dairy and meat products along their respective production chains. Relevant data were extracted from 65 research papers and synthesized qualitatively. Although estimates of the prevalence of Johne's disease are scarce, particularly for non-dairy herds, the available data suggest that the likelihood of contamination of raw milk with MAP in most studied regions is substantial. The presence of MAP in raw and pasteurized milk has been the subject of several studies which show that pasteurized milk is not always MAP-free and that the effectiveness of pasteurization in inactivating MAP depends on the initial concentration of the agent in raw milk. The most recent studies indicated that beef can be contaminated with MAP via dissemination of the pathogen in the tissues of infected animals. Currently available data suggests that the likelihood of dairy and meat products being contaminated with MAP on retail sale should not be ignored.