First Mass Screening of the Human Population to Estimate the Bio-load of Mycobacterium avium Subspecies paratuberculosis in North India

Therapeutic management of Mycobacterium avium subspecies paratuberculosis infection with complete resolution of symptoms and disease in a patient with advanced inflammatory bowel syndrome

BACKGROUND

A 26-year-old male had a history of frequent bowel movements, mushy stool with mucus and loss of 25 kg body weight in 6 months was diagnosed as a case of inflammatory bowel disease (IBD). The patient did not respond to routine and standard treatment for IBD. His condition was steadily deteriorating, and he was in a very precarious state when he reported to us.

METHODS

Upon laboratory investigation by using IS900 specific PCR [which is specific for Mycobacterium avium subspecies paratuberculosis (MAP)], the blood and stool samples were found negative. However, the presence of low titer MAP-antibodies by indigenous ELISA were found followed by detection of the typical acid-fast MAP bacilli (with 3 + or 4 + grade) microscopically. The MAP stool culture was positive after 6 months incubation. The biotyping by IS1311 specific polymerase chain reaction restriction enzyme (PCR-RE) confirmed infection with 'Indian Bison Type Genotype', a dominant biotype infecting the domestic livestock population of India. Standard anti-MAP therapy was initiated under supervision of the treating physician. The drug of choice in prescribed treatment regimen included Isoniazid (5 mg/kg), Rifampicin (10 mg/kg), Ethambutol (15-25 mg/kg) once a day for 24 weeks and Clarithromycin (250 mg)/Levofloxacin (250 mg) twice a day for 6 weeks.

RESULTS

Following treatment, the patient started improving progressively with reduction in bowel movement frequency and gained body weight with an enhanced appetite propensity. Upon follow-up of the patient after 1 year of treatment, stool-microscopy and stool-culture were found negative for MAP. Till the recent past, the patient was further monitored for disease relapse, if any.

CONCLUSIONS

This patient has experienced a complete resolution of IBD using a combination of anti-MAP antibiotics. The initial detection of heavy shedding of acid-fast MAP bacilli and typical colony morphology with its characterization obtained from culturing of stool sample indicated the infection of MAP. Interestingly, the present case is one more example of the linkage of demonstrable MAP infection treated with anti-MAP therapy in the presence and then absence of disease in the human host.

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.

A national serosurvey to determine the prevalence of paratuberculosis in cattle in Bhutan following detection of clinical cases

Johne's disease is an economically important ruminant disease predominantly affecting cattle, sheep and goats. The economic losses are due to early culling, reduced growth rate, progressive weight loss and reduced production. It is caused by Mycobacterium avium subspecies paratuberculosis (MAP). Johne's disease was reported in cattle in Bhutan, based on clinical signs and histopathology; in the late 1990s samples from one mithun that was suspected to have died due to this disease was confirmed by molecular testing at the Faculty of Veterinary Science, University of Sydney, Australia. However, no detailed study on prevalence of JD has been attempted in Bhutan. Objective of this study was to conduct serosurveillance to determine the national prevalence of Johne's disease in cattle for the period 2013–2014 to provide the basis for planning a future control strategy. A national serosurvey was conducted wherein a two‐stage sampling procedure was used with 95% confidence and an error level of ±0.05. The sample size required for the survey was calculated using the software‐Survey Toolbox for Livestock Diseases, available as Epitools at http://www.ausvet.com.au. A total of 1123 serum samples were collected from an administrative structure of 52 villages, 40 sub‐districts and 15 districts. Serum samples were tested using commercially available antibody enzyme linked immunosorbent assay. Statistical analysis was performed using GraphPad Prism 5.0. Illustration such as maps was produced using QGIS version 2.18 ‘Las Palmas. The mean national apparent prevalence of Johne's disease was found to be 2.31 (26/1123) (95% CI: 0.80–4.50) with an estimated true prevalence was found to be 8.00 (95% CI: 2.00–17.00). Trongsa district had the highest prevalence (12.96) followed by Zhemgang (4.34), Lhuntse (4.25), Sarpang (3.89), Bumthang (3.60), Trashigang (2.67) and Haa (2.63). Prevalence for all other districts was 2.00 or below. Seropositive samples were reported from all over the country with varying levels of sero‐positivity. In the recent past many more cattle were imported from India to boost dairy production. Nevertheless, the wide distribution of seroreactive JD cattle all over the country is a concern for future control. Therefore, in future, a detailed study on the impact of cattle import with regard to disease incursion such as Johne's disease and other diseases should be undertaken.

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.

IFN-γ fails to overcome inhibition of selected macrophage activation events in response to pathogenic mycobacteria

According to most models of mycobacterial infection, inhibition of the pro-inflammatory macrophage immune responses contributes to the persistence of bacteria. Mycobacterium avium subsp. paratuberculosis (MAP) is a highly successful pathogen in cattle and sheep and is also implicated as the causative agent of Crohn's disease in humans. Pathogenic mycobacteria such as MAP have developed multiple strategies to evade host defence mechanisms including interfering with the macrophages' capacity to respond to IFN-γ, a feature which might be lacking in non-pathogenic mycobacteria such as M. smegmatis. We hypothesized that pre-sensitisation of macrophages with the pro-inflammatory cytokine IFN-γ would help in overcoming the inhibitory effect of MAP or its antigens on macrophage inflammatory responses. Herein we have compared a series of macrophage activation parameters in response to MAP and M. smegmatis as well as mycobacterial antigens. While IFN-γ did overcome the inhibition in immune suppressive mechanisms in response to MAP antigen as well as M. smegmatis, we could not find a clear role for IFN-γ in overcoming the inhibition of macrophage inflammatory responses to the pathogenic mycobacterium, MAP. We demonstrate that suppression of macrophage defence mechanisms by pathogenic mycobacteria is unlikely to be overcome by prior sensitization with IFN-γ alone. This indicates that IFN-γ signaling pathway-independent mechanisms may exist for overcoming inhibition of macrophage effector functions in response to pathogenic mycobacteria. These findings have important implications in understanding the survival mechanisms of pathogenic mycobacteria directed towards finding better therapeutics and vaccination strategies.

Comparative Evaluation of Different Test Combinations for Diagnosis of Mycobacterium avium Subspecies paratuberculosis Infecting Dairy Herds in India

A total of 355 cows were sampled (serum, n = 315; faeces, n = 355; milk, n = 209) from dairy farms located in the Punjab state of India. Faeces and serum/milk samples were screened by acid fast staining and “indigenous ELISA,” respectively. IS900 PCR was used to screen faeces and milk samples. Bio-load of MAP in dairy cows was 36.9, 15.6, 16.3, and 14.4%, using microscopy, serum ELISA, milk ELISA and milk PCR, respectively. Estimated kappa values between different test combinations: serum and milk ELISA, faecal microscopy and faecal PCR, milk ELISA and milk PCR, faecal PCR and serum ELISA were 0.325, 0.241, 0.682, and 0.677, respectively. Estimation of the relative sensitivity and specificity of different tests in the present study indicated that “serum ELISA” and “milk ELISA” were good screening tests, add “milk PCR” was “confirmatory test” for MAP infection. Combination of milk ELISA with milk PCR may be adopted as a model strategy for screening and diagnosis of JD in lactating/dairy cattle herds in Indian conditions.