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The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Mycobacterium avium ssp. paratuberculosis (MAP) is the bacterium responsible for causing Johne's disease (JD), which is endemic to dairy cattle and also implicated in the etiology of Crohn's disease. The difficulty in diagnosing asymptomatic cows for JD makes this disease hard to control. Johne's disease is considered a priority under the One Health approach to prevent the spread of the causative agent to humans. Environmental screening is a strategic approach aimed at identifying dairy herds with animals infected with MAP. It serves as the initial step toward implementing more intensive actions to control the disease. Quantitative PCR (qPCR) technology is widely used for diagnosis. Given that genome sequencing is now much more accessible than ever before, it is possible to target regions of the MAP genome that allow for the greatest diagnostic sensitivity and specificity. The aim of this study was to identify among the published qPCR assays targeting IS 900 the more cost-effective options to detect MAP and to validate them in the diagnostic context of JD. Mycobacterium avium ssp. paratuberculosis IS 900 is a prime target because it is a multicopy genetic element. A total of 136 publications have reported on the use of IS 900 qPCR assays over the past 3 decades. Among these records, 29 used the SYBR Green chemistry, and 107 used TaqMan technology. Aside from the 9 reports using commercial assays, 72 TaqMan reports cited previously published work, leaving us with 27 TaqMan qPCR designs. Upon closer examination, 5 TaqMan designs contained mismatches in primer or probe sequences. Additionally, others exhibited high similarity to environmental microorganisms or non-MAP mycobacteria. We assessed the performance of 6 IS 900 qPCR designs and their sensitivity when applied to clinical or environmental samples, which varied from 4 to 56 fold overall. Additionally, we provide recommendations for testing clinical and environmental samples, as certain strategies used previously should be avoided due to poor qPCR design (e.g., the presence of mismatches) or a lack of specificity. [ABSTRACT FROM AUTHOR]

Highly sensitive vertically aligned carbon nanotube arrays (VANTAs) interdigitated electrode (IDE) arrays are developed for electrochemical biosensing of two cytokines (i.e., interleukin‐10 (IL‐10) and interferon‐gamma (IFN‐γ)) that are useful for early detection Johne's disease (Bovine Paratuberculosis) in cattle. The high aspect ratio VANTA‐IDEs (50–60 µm in height) are grown through a chemical vapor deposition process from an iron (Fe) catalyst that is lithographically patterned on a silicon wafer with equal finger width and inter‐finger spacing of 25 µm. After functionalization with distinct antibodies the VANTA‐IDEs are capable of selective detection of both IL‐10 and IFN‐γ within an actual biological matrix (i.e., diluted bovine implant supernatant) over concentration ranges of 0.1 to 30 pg mL−1 (limit of detection – LOD: 0.0911 pg mL−1) and 50–500 pg mL−1 (LOD: 24.17 pg mL−1), respectively with a response time of <35 min. Results demonstrate important initial steps for rapid, pen‐side identification of cattle with stage‐I Mycobacterium avium subspecies paratuberculosis infection before physical symptoms of Johne's disease are present. Such a rapid pen‐side diagnostic test can be used on cattle at an auction or before they are introduced to a herd to ensure the larger population does not become infected with Johne's disease. [ABSTRACT FROM AUTHOR]

Simple Summary: Paratuberculosis (PTB) is a chronic disease that affects domestic and wild ruminants worldwide. This study was conducted in 12 diary caprine farms on the Canary Islands. The region counts with the fourth largest goat population in Spain and has "officially free" bovine tuberculosis status. Two sampling sessions were conducted, and 2774 serum samples were tested by an enzyme-linked immunosorbent assay. In the first session, a prevalence of 18.4% was obtained, varying from 2.5% up to 61.1%. In the second session, the effect of PTB vaccination was evaluated and both non-vaccinated (nV) and vaccinated (V) were included. Variable tendencies in antibody development were registered in farms with different initial seroprevalences. In farms in which up to 10% of the animals were positive, more adult goats had antibodies against PTB after vaccination. In farms with more than 10% of ELISA-positive animals, a heterogeneous response to vaccination was reported. We observed that in farms with higher initial prevalence, fewer goats that were V developed antibodies. Our work characterizes the caprine PTB situation on the Canary Islands and gives new insights on the effect of farm prevalence on the immune response to PTB vaccination, although further studies on a greater scale are needed. Paratuberculosis (PTB), caused by Mycobacterium avium subspecies paratuberculosis (MAP), is a chronic disease with economic impact on ruminant farming worldwide. The Canary Islands count with the fourth largest goat population in Spain and are "officially free" of bovine tuberculosis. Twelve farms were included with 2774 serum samples tested by an enzyme-linked immunosorbent assay (ELISA) for detection of anti-MAP antibodies in two sessions. In the first session, an overall apparent prevalence of 18.4% (2.5% up to 61.1%) was obtained. Farms with prevalences (0–10%], (10–20%] and >20% were identified, with differences in seroconversion in the same prevalence group between farms and age ranges. Non-vaccinated (nV) and vaccinated (V) animals were included in the second sampling session. Higher levels of antibodies were detected in V animals older than 12 months, with considerable variations between age ranges and farms. Our results describe the current PTB status of the Canary Islands' goat farming. Furthermore, new insights on the effect of the farm prevalence on seroconversion in V animals are provided, although further studies are needed to evaluate the multiple factors affecting the immune response to anti-MAP vaccination. [ABSTRACT FROM AUTHOR]

ABSTRACT: Mycobacterium avium ssp. paratuberculosis (MAP) is the bacterium responsible for causing Johne's disease (JD), which is endemic to dairy cattle and also implicated in the etiology of Crohn's disease. The difficulty in diagnosing asymptomatic cows for JD makes this disease hard to control. Johne's disease is considered a priority under the One Health approach to prevent the spread of the causative agent to humans. Environmental screening is a strategic approach aimed at identifying dairy herds with animals infected with MAP. It serves as the initial step toward implementing more intensive actions to control the disease. Quantitative PCR (qPCR) technology is widely used for diagnosis. Given that genome sequencing is now much more accessible than ever before, it is possible to target regions of the MAP genome that allow for the greatest diagnostic sensitivity and specificity. The aim of this study was to identify among the published qPCR assays targeting IS900 the more cost-effective options to detect MAP and to validate them in the diagnostic context of JD. Mycobacterium avium ssp. paratuberculosis IS900 is a prime target because it is a multicopy genetic element. A total of 136 publications have reported on the use of IS900 qPCR assays over the past 3 decades. Among these records, 29 used the SYBR Green chemistry, and 107 used TaqMan technology. Aside from the 9 reports using commercial assays, 72 TaqMan reports cited previously published work, leaving us with 27 TaqMan qPCR designs. Upon closer examination, 5 TaqMan designs contained mismatches in primer or probe sequences. Additionally, others exhibited high similarity to environmental microorganisms or non-MAP mycobacteria. We assessed the performance of 6 IS900 qPCR designs and their sensitivity when applied to clinical or environmental samples, which varied from 4 to 56 fold overall. Additionally, we provide recommendations for testing clinical and environmental samples, as certain strategies used previously should be avoided due to poor qPCR design (e.g., the presence of mismatches) or a lack of specificity.

Abstract Background Johne’s disease is a chronic wasting disease caused by the bacterium Mycobacterium avium subspecies paratuberculosis (MAP). Johne’s disease is highly contagious and MAP infection in dairy cattle can eventually lead to death. With no available treatment for Johne’s disease, genetic selection and improvements in management practices could help reduce its prevalence. In a previous study, the gene coding interleukin-10 receptor subunit alpha (IL10Rα) was associated with Johne’s disease in dairy cattle. Our objective was to determine how IL10Rα affects the pathogenesis of MAP by examining the effect of a live MAP challenge on a mammary epithelial cell line (MAC-T) that had IL10Rα knocked out using CRISPR/cas9. The wild type and the IL10Rα knockout MAC-T cell lines were exposed to live MAP bacteria for 72 h. Thereafter, mRNA was extracted from infected and uninfected cells. Differentially expressed genes were compared between the wild type and the IL10Rα knockout cell lines. Gene ontology was performed based on the differentially expressed genes to determine which biological pathways were involved. Results Immune system processes pathways were targeted to determine the effect of IL10Rα on the response to MAP infection. There was a difference in immune response between the wild type and IL10Rα knockout MAC-T cell lines, and less difference in immune response between infected and not infected IL10Rα knockout MAC-T cells, indicating IL10Rα plays an important role in the progression of MAP infection. Additionally, these comparisons allowed us to identify other genes involved in inflammation-mediated chemokine and cytokine signalling, interleukin signalling and toll-like receptor pathways. Conclusions Identifying differentially expressed genes in wild type and ILR10α knockout MAC-T cells infected with live MAP bacteria provided further evidence that IL10Rα contributes to mounting an immune response to MAP infection and allowed us to identify additional potential candidate genes involved in this process. We found there was a complex immune response during MAP infection that is controlled by many genes.

Infection of ruminants such as cattle with Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease, a disease characterized by chronic inflammation of the small intestine and diarrhoea. Infection with MAP is acquired via the faecal-to-oral route and the pathogen initially invades the epithelial lining of the small intestine. In this study we used an in vitro 3D mouse enteroid model to determine the influence of M cells in infection of the gut epithelia by MAP, in comparison with another bacterial intestinal pathogen of veterinary importance, Salmonella enterica serovar Typhimurium. The differentiation of M cells in the enteroid cultures was induced by stimulation with the cytokine receptor activator of nuclear factor-βB ligand (RANKL), and the effects on MAP and Salmonella uptake and intracellular survival were determined. The presence of M cells in the cultures correlated with increased uptake and intracellular survival of Salmonella, but had no effect on MAP. Interestingly neither pathogen was observed to preferentially accumulate within GP2- positive M cells. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Johne's disease is a chronic wasting disease caused by the bacterium Mycobacterium avium subspecies paratuberculosis (MAP). Johne's disease is highly contagious and MAP infection in dairy cattle can eventually lead to death. With no available treatment for Johne's disease, genetic selection and improvements in management practices could help reduce its prevalence. In a previous study, the gene coding interleukin-10 receptor subunit alpha (IL10Rα) was associated with Johne's disease in dairy cattle. Our objective was to determine how IL10Rα affects the pathogenesis of MAP by examining the effect of a live MAP challenge on a mammary epithelial cell line (MAC-T) that had IL10Rα knocked out using CRISPR/cas9. The wild type and the IL10Rα knockout MAC-T cell lines were exposed to live MAP bacteria for 72 h. Thereafter, mRNA was extracted from infected and uninfected cells. Differentially expressed genes were compared between the wild type and the IL10Rα knockout cell lines. Gene ontology was performed based on the differentially expressed genes to determine which biological pathways were involved. Results: Immune system processes pathways were targeted to determine the effect of IL10Rα on the response to MAP infection. There was a difference in immune response between the wild type and IL10Rα knockout MAC-T cell lines, and less difference in immune response between infected and not infected IL10Rα knockout MAC-T cells, indicating IL10Rα plays an important role in the progression of MAP infection. Additionally, these comparisons allowed us to identify other genes involved in inflammation-mediated chemokine and cytokine signalling, interleukin signalling and toll-like receptor pathways. Conclusions: Identifying differentially expressed genes in wild type and ILR10α knockout MAC-T cells infected with live MAP bacteria provided further evidence that IL10Rα contributes to mounting an immune response to MAP infection and allowed us to identify additional potential candidate genes involved in this process. We found there was a complex immune response during MAP infection that is controlled by many genes. [ABSTRACT FROM AUTHOR]

Introduction: As a contagious and chronic disease in the livestock industry, Paratuberculosis is a significant threat to dairy herds' genetic and economic resources. Due to intensive breeding and high production of dairy cattle, the incidence and prevalence are higher. Developing non-destructive diagnostic methods for the early detection and identification of healthy animals is paramount for breeding programs. Conventional methods are almost entirely destructive, have low accuracy, lack precision, and are time-consuming. Nearinfrared spectroscopy (NIRS) and aquaphotomics can detect changes in biofluids and thus have the potential to diagnose disease. This study aimed to investigate the diagnostic ability of NIRS and aquaphotomics for Paratuberculosis in dairy cattle. Methods: Blood plasma from dairy cattle was collected in the NIR range (1,300 nm to 1,600 nm) 60 days before and 100 days to 200 days after calving in two groups, positive and negative, using the same consecutive enzyme-linked immunosorbent assay test results three times as a reference test. Results: NIRS and aquaphotomics methods invite 100% accuracy, sensitivity, and specificity to detect Paratuberculosis using data mining by unsupervised method, Principal Component Analysis, and supervised methods: Soft Independent Modeling of Class Analogiest, Linear Discriminant Analysis, Quadratic Discriminant Analysis, Partial Least Square-Discriminant Analysis, and Support Vector Machine models. Discussion: The current study found that monitoring blood plasma with NIR spectra provides an opportunity to analyze antibody levels indirectly via changes in water spectral patterns caused by complex physiological changes, such as the amount of antibodies related to Paratuberculosis by aquagram. [ABSTRACT FROM AUTHOR]

Abstract Highly sensitive vertically aligned carbon nanotube arrays (VANTAs) interdigitated electrode (IDE) arrays are developed for electrochemical biosensing of two cytokines (i.e., interleukin‐10 (IL‐10) and interferon‐gamma (IFN‐γ)) that are useful for early detection Johne's disease (Bovine Paratuberculosis) in cattle. The high aspect ratio VANTA‐IDEs (50–60 µm in height) are grown through a chemical vapor deposition process from an iron (Fe) catalyst that is lithographically patterned on a silicon wafer with equal finger width and inter‐finger spacing of 25 µm. After functionalization with distinct antibodies the VANTA‐IDEs are capable of selective detection of both IL‐10 and IFN‐γ within an actual biological matrix (i.e., diluted bovine implant supernatant) over concentration ranges of 0.1 to 30 pg mL−1 (limit of detection – LOD: 0.0911 pg mL−1) and 50–500 pg mL−1 (LOD: 24.17 pg mL−1), respectively with a response time of

Abstract Current diagnostic methods for Johne’s disease in cattle allow reliable detection of infections with Mycobacterium avium ssp. paratuberculosis (MAP) not before animals are 2 years of age. Applying a flow cytometry-based approach (FCA) to quantify a MAP-specific interferon-gamma (IFN-γ) response in T cell subsets, the present study sought to monitor the kinetics of the cell-mediated immune response in experimentally infected calves. Six MAP-negative calves and six calves, orally inoculated with MAP at 10 days of age, were sampled every 4 weeks for 52 weeks post-inoculation (wpi). Peripheral blood mononuclear cells (PBMC) were stimulated with either purified protein derivatives (PPD) or whole cell sonicates derived from MAP (WCSj), M. avium ssp. avium or M. phlei for 6 days followed by labeling of intracellular IFN-γ in CD4+ and CD8+ T cells. No antigen-specific IFN-γ production was detectable in CD8+ cells throughout and the responses of CD4+ cells of MAP-infected and control calves were similar up to 12 wpi. However, the mean fluorescence intensity (MFI) for the detection of IFN-γ in CD4+ cells after WCSj antigen stimulation allowed for a differentiation of animal groups from 16 wpi onwards. This approach had a superior sensitivity (87.8%) and specificity (86.8%) to detect infected animals from 16 wpi onwards, i.e., in an early infection stage, as compared to the IFN-γ release assay (IGRA). Quantification of specific IFN-γ production at the level of individual CD4+ cells may serve, therefore, as a valuable tool to identify MAP-infected juvenile cattle.

Current diagnostic methods for Johne's disease in cattle allow reliable detection of infections with Mycobacterium avium ssp. paratuberculosis (MAP) not before animals are 2 years of age. Applying a flow cytometry-based approach (FCA) to quantify a MAP-specific interferon-gamma (IFN-γ) response in T cell subsets, the present study sought to monitor the kinetics of the cell-mediated immune response in experimentally infected calves. Six MAP-negative calves and six calves, orally inoculated with MAP at 10 days of age, were sampled every 4 weeks for 52 weeks post-inoculation (wpi). Peripheral blood mononuclear cells (PBMC) were stimulated with either purified protein derivatives (PPD) or whole cell sonicates derived from MAP (WCSj), M. avium ssp. avium or M. phlei for 6 days followed by labeling of intracellular IFN-γ in CD4+ and CD8+ T cells. No antigen-specific IFN-γ production was detectable in CD8+ cells throughout and the responses of CD4+ cells of MAP-infected and control calves were similar up to 12 wpi. However, the mean fluorescence intensity (MFI) for the detection of IFN-γ in CD4+ cells after WCSj antigen stimulation allowed for a differentiation of animal groups from 16 wpi onwards. This approach had a superior sensitivity (87.8%) and specificity (86.8%) to detect infected animals from 16 wpi onwards, i.e., in an early infection stage, as compared to the IFN-γ release assay (IGRA). Quantification of specific IFN-γ production at the level of individual CD4+ cells may serve, therefore, as a valuable tool to identify MAP-infected juvenile cattle. [ABSTRACT FROM AUTHOR]

Paratuberculosis (PTB), or Johne's disease, is a disease with worldwide distribution caused by Mycobacterium avium subsp. paratuberculosis (MAP) that leads to chronic enteritis, primarily in ruminants. Even subclinical infection significantly reduces the animals' performance, and consequences of the disease lead to high economic losses for the cattle industry. To estimate the economic burden of bovine PTB and to evaluate the benefits of a potential control program, accurate estimates of the production effects associated with the disease are required. Therefore, the aim of this scoping review was to provide a comprehensive overview of associations between MAP infection and production parameters in cattle. The studies were collected from three electronic databases. Of the total 1,605 identified studies, 1,432 did not meet the set criteria in the title and abstract screening and a further 106 were excluded during full-text review. Finally, data on 34 different production parameters were extracted from 67 publications. Results show that the magnitude of reported performance losses varies depending on several factors, such as the type of diagnostic test applied, disease status or number of lactations. Studies reported a reduction in milk yield, changes in milk quality (e.g., higher somatic cell count, lower amount of produced milk fat and protein), reduced fertility (e.g., prolonged calving interval and service period, higher abortion rate and calving difficulties), reduced weaning weight, slaughter weight and slaughter value, or a higher risk for mastitis. Results from the studies included in our review show a median decrease of milk yield per infected cow of -452 kg/lactation for raw and -405 kg/lactation for modeled data. Similarly, the amount of produced milk protein fell by a median of -14.41 kg/lactation for modeled data and the amount of produced milk fat by a median of -13.13 kg/lactation. The reviewed studies revealed a prolonged calving interval by around 30 days and a 1.5 to 3 times higher likeliness of culling per lactation in PTB positive animals. Results from this scoping review provide evidence-based inputs for the development of economic models aiming at the estimation of the costs and benefits associated with different disease control scenarios for PTB. [ABSTRACT FROM AUTHOR]

Aims This study aimed to identify specific genomic targets for the detection and strain typing of Map and analyse their sensitivity and specificity, and detect Map directly from faeces. Methods and results A comparative genomics approach was used to identify specific genomic targets for the detection and strain typing of Map. A Map specific qPCR using the primer pair 7132 that targets a DNA segregation ATPase protein was able to detect all strains of Map and is more sensitive than the current Johne's disease PCR assays with a sensitivity of 0.0002 fg µl−1. A strain specific qPCR using the Atsa primer pair that targets the arylsulfase gene was able to differentiate between Type S and Type C strains of Map and was more sensitive than the IS1311 PCR and REA with a sensitivity of 40 fg µl−1 and was specific for Type S Map. Both assays successfully detected Map directly from faeces. Conclusion This study developed and validated two genomics informed qPCR assays, 7132B Map and Atsa Type S and found both assays to be highly specific and sensitive for the detection of Map from culture and directly from faeces. This is the first time that a probe-based qPCR has been designed and developed for Map strain typing, which will greatly improve the response time during outbreak investigations. [ABSTRACT FROM AUTHOR]

Simple Summary: Paratuberculosis control programmes in countries with a relevant dairy industry differ largely in participation and progress. Despite over a century of experience with paratuberculosis control efforts, major knowledge gaps still exist, including the efficacy of control programmes and drivers and barriers influencing the uptake of control programmes amongst farmers. Biennially, the International Dairy Federation (IDF) brings together experts on paratuberculosis control to share the most recent knowledge and experiences regarding practical aspects of paratuberculosis control. Taken together, studies on control programmes presented at the 7th and 8th IDF ParaTB Fora and the 15th International Colloquium on Paratuberculosis (ICP) indicated a key finding that a reduction of the prevalence of Map infection had been achieved by various programmes. Important prerequisites for successful control were long-term stable funding, stakeholder commitment and incentives for farmers to participate. Focal topics to improve the control of Map were identified, including improved communication about the epidemiology of infection and its control, increased attention to intrauterine, calf-to-calf and adult-to-adult transmission, sound but easy-to-use surveillance schemes, measures to reduce between-herd transmission and breeding for resistance to Map infection. Research in parallel with these programmes was found to keep interest in Map control high among stakeholders and farmers and to enable programme improvement. While paratuberculosis control has been studied for over a century, knowledge gaps still exist regarding the uptake and efficacy of control programmes. This narrative review aims to summarise studies on control programmes presented at the IDF ParaTB Fora in 2021 and 2022 and the International Colloquium on Paratuberculosis in 2022. Studies were grouped by topic as follows: successful control, field studies, education and extension, voluntary and compulsory control programmes, and surveillance. Various Map control programmes resulted in a decreasing animal and herd level Map prevalence. Long-term stakeholder commitment, stable funding, involvement of herd veterinarians and incentives for farmers to participate were shown to be pivotal for long-term success. Control measures focused on vertical and calf-to-calf transmission may improve Map control in infected herds. Easy-to-capture visualisation of surveillance test results to inform participants on the progress of Map control in their herds was developed. The probability of freedom from disease and estimated within-herd prevalence were identified as good candidates for categorisation of herds to support low-risk trade of cattle. Results of the surveillance schemes may inform genetic selection for resistance to Map infection. In conclusion, successful paratuberculosis control is feasible at both the herd and country level provided that crucial prerequisites are met. [ABSTRACT FROM AUTHOR]

Simple Summary: Johne's disease is a chronic progressive gastrointestinal disease of ruminants. The diagnosis and control of this disease remains a challenge for cattle producers and herd veterinarians. Machine learning is a broad class of algorithms and statistical analysis belonging to the area of artificial intelligence. These techniques allow for the recognition of patterns in large datasets that are not found by traditional analytical and statistical methods. While artificial intelligence and machine learning have been used in human medicine and in various aspects of animal husbandry, they have only just started to be used in Johne's disease research. By using results from milk component tests and past Johne's individual test results, tree-based models, a type of machine learning, were used to predict future Johne's results. This type of predictive algorithm may help producers and veterinarians more reliably identify those animals most likely to yield a positive result. This will, in turn, help improve control efforts and reduce the testing burden for herds working towards disease control and eradication. Machine learning algorithms have been applied to various animal husbandry and veterinary-related problems; however, its use in Johne's disease diagnosis and control is still in its infancy. The following proof-of-concept study explores the application of tree-based (decision trees and random forest) algorithms to analyze repeat milk testing data from 1197 Canadian dairy cows and the algorithms' ability to predict future Johne's test results. The random forest models using milk component testing results alongside past Johne's results demonstrated a good predictive performance for a future Johne's ELISA result with a dichotomous outcome (positive vs. negative). The final random forest model yielded a kappa of 0.626, a roc AUC of 0.915, a sensitivity of 72%, and a specificity of 98%. The positive predictive and negative predictive values were 0.81 and 0.97, respectively. The decision tree models provided an interpretable alternative to the random forest algorithms with a slight decrease in model sensitivity. The results of this research suggest a promising avenue for future targeted Johne's testing schemes. Further research is needed to validate these techniques in real-world settings and explore their incorporation in prevention and control programs. [ABSTRACT FROM AUTHOR]

Wild and domestic ruminants become infected with Mycobacterium avium subsp. paratuberculosis (MAP) leads to chronic enteritis, known as Johne’s disease (JD). nA eight-year-old male wild goat (Capra aegagrus) that lived in the wildlife breeding center in Chaharmahal and Bakhtiari province with symptoms of prolonged diarrhea that did not respond to antibiotic treatment was referred to a veterinary center. After a while, the animal died. JD was diagnosed after laboratory diagnosis (by acid-fast staining). The present study reported the incidence of JD in a wild goat in Iran for the first time. The economic losses and animal health should be considered. Since 2020, the wild goat (Capra aegagrus) has been classified in the category Near Threatened (NT) near treated on the list (International Union for Conservation of Nature) IUCN. Therefore, protecting the health of these species is essential. The importance of carrier animals and reservoirs in wildlife should be given special attention. [ABSTRACT FROM AUTHOR]

This study aimed to diagnose Mycobacterium avium subsp. paratuberculosis (MAP) infections in sheep in the state of Pernambuco, Brazil. A total of 276 blood samples were analyzed using the enzyme-linked immunosorbent assay IDEXX Paratuberculosis Screening kit, and 261 fecal samples were submitted for bacterial culture and polymerase chain reaction tests. An animal-level sero-frequency of 0.72% (n = 2/276) and a farm-level sero-frequency of 20% (n = 2/10) were found. All fecal sample cultures were negative, and molecular analyses were also negative. To the best of our knowledge, this is the first study of MAP infection in sheep in the state of Pernambuco and one of the pioneers in the country. It is an asymptomatic disease that is difficult to diagnose in this species because the susceptibility of sheep to the organism is lower than that of other ruminant species. However, the sero-frequency found reveals that there is MAP exposure in sheep flocks in the region. In addition, serological monitoring can contribute to the observation of the organism's behavior in herds. Our results support the potential risk of MAP infection in sheep in the state of Pernambuco, Brazil. [ABSTRACT FROM AUTHOR]

Simple Summary: Paratuberculosis impacts animal welfare and the economic performance of dairy herds by causing reduced milk yield and carcass weight and premature culling. Due to the ability of the infectious agent Mycobacterium avium subsp. paratuberculosis (MAP) to survive in the environment for a long time, the limited diagnostic accuracy of tests, and the long incubation period, successful elimination of MAP from a cattle herd is doubted. This study describes measures applied to control the disease in a 450-head dairy herd and, as the result of these measures, the progress of prevalence reduction to a level where the infectious agent was not detectable anymore in any individual sample and from the liquid manure of the herd. MAP shedders were detected by the bacteriological cultivation of individual faecal samples from each cow in annual intervals and MAP shedders were removed from the herd in a timely manner. Calves were kept outside the barn of adult cows and hygienic measures to minimize their MAP exposure were established. The results demonstrate that the elimination of MAP might be possible within 10 years. Voluntary control programs are effective in controlling paratuberculosis in closed herds by providing adequate diagnostic, logistic, and financial support for farmers. This longitudinal case study provides an in-detail report of the process towards the elimination of Mycobacterium avium subsp. paratuberculosis (MAP) from a closed 450-head commercial dairy herd. In parallel, two diagnostic approaches were applied to all cows in annual intervals during 2012–2022: detection of MAP in individual faecal samples by bacteriological cultivation on solid medium and detection of MAP-specific antibodies by ELISA. For each annual sampling, the kappa coefficients for test agreement and the survival rates of MAP-positive and MAP-negative cows were calculated. Applying a multivariable linear regression model revealed a significantly lower fat-corrected 305-day milk yield for MAP-positive cows. The true prevalence of MAP shedders reduced from 24.2% in 2012 to 0.4% in 2019 and during 2020–2022, no MAP shedder was identified. Test agreement was generally low and bacteriological cultivation showed positive results earlier than the ELISA. In the first years of control, the survival of MAP shedders was longer than in the final stage. In conclusion, the elimination of MAP from a dairy herd might be feasible within a decade. Changes in the test agreement must be considered. Timely removal of MAP shedders, hygienic calf rearing, and colostrum supply are key for successful control. [ABSTRACT FROM AUTHOR]

Simple Summary: Johne's disease, caused by Mycobacterium avium subsp. paratuberculosis (MAP), is endemic in cattle herds in the UK and throughout the world. It is a wasting disease with a protracted incubation period, during which clinical signs are not apparent, and is responsible for considerable economic losses. Infection can be transmitted silently from animal to animal, and MAP can find its way into the food chain through the products of infected animals. Ante-mortem diagnosis of the disease is normally achieved through detection of the organism (by faecal culture or PCR) or serological tests, but agreement as to a positive diagnosis is often poor and the certainty of identifying all positive animals is low, particularly in early-stage infections. Mycobacterial cells contain high-molecular-weight lipids, mycolic acids (MAs), which are recognised by antibodies in active infections. Here, we show that a simple assay using different classes of single synthetic MAs can detect antibodies in serum from cattle with MAP infections and distinguish uninfected animals from animals positive both to faecal culture and a commercial serodiagnostic assay. It does so without interference from vaccination either for MAP (a Gudair vaccination) or for bovine TB (BCG vaccination). When the assay is optimised to distinguish negative samples from those positive only by faecal PCR, it identifies additional positives that are not seen using a commercial serodiagnostic assay; this suggests that, with further development, it may provide a method for detecting infections before the commercial serodiagnostic assay can. The problem: Ante-mortem diagnosis of Johne's disease, caused by Mycobacterium avium subsp. paratuberculosis (MAP), is normally achieved through faecal culture, PCR, or serological tests, but agreement as to which samples are positive for Johne's disease is often poor and sensitivities are low, particularly in early-stage infections. The potential solution: Mycobacterial cells contain very complex characteristic mixtures of mycolic acid derivatives that elicit antibodies during infection; this has been used to detect infections in humans. Here, we explore its application in providing an assay differentiating infected from vaccinated animals (DIVA assay) for Johne's disease in cattle. Method: Antibody responses to different classes of mycolic acid derivatives were measured using ELISA for serum from cattle positive for MAP by both faecal PCR and commercial serum ELISA, or just by PCR, and from animals from herds with no history of Johne's disease, bovine tuberculosis reactors, BCG-vaccinated, BCG-vaccinated and M. bovis-infected, and Gudair-vaccinated animals. Results: The best-performing antigens, ZAM295 and ST123—the latter a molecule present in the cells of MAP but not of Mycobacterium bovis—achieved a sensitivity of 75% and 62.5%, respectively, for serum from animals positive by both faecal PCR and a commercial MAP serum ELISA, at a specificity of 94% compared to 80 no-history negatives. Combining the results of separate assays with two antigens (ST123 and JRRR121) increased the sensitivity/specificity to 75/97.5%. At the same cut-offs, animals vaccinated with Gudair or BCG vaccines and bTB reactors showed a similar specificity. The specificity in BCG-vaccinated but M. bovis-infected animals dropped to 85%. Combining the results of two antigens gave a sensitivity/specificity of 37.5/97.5% for the full set of 80 PCR-positive samples, detecting 30 positives compared 16 for IDEXX. Conclusion: Serum ELISA using synthetic lipids distinguishes effectively between MAP-negative cattle samples and those positive by both PCR and a commercial MAP serodiagnostic, without interference by Gudair or BCG vaccination. It identified almost twice as many PCR positives as the commercial serodiagnostic, offering the possibility of earlier detection of infection. [ABSTRACT FROM AUTHOR]

Mycobacterial diseases impact millions in the human and veterinary fields each year. Their diagnosis is long and laborious, often only sensitive in the late stages of disease. This has created an unmet need for new diagnostics that are effective in the earlier stages of infection and are quick and easy to perform. This study details the optimization of LAMP assays for the detection of M. tuberculosis, M. bovis and M. avium subsp. paratuberculosis combined with phage-mediated lysis to meet the needs of a novel diagnostic—termed phage-LAMP. The optimized phage-LAMP assay had a limit of detection of less than 10 mycobacteria per ml and no cross-reaction was seen between assays. The phage-LAMP method was then tested on a small number of clinical blood samples from suspected TB patients and herds suspected of Johne's disease. The phage-LAMP assay could detect viable Mycobacterium tuberculosis and M. avium subsp. paratuberculosis in these samples. [ABSTRACT FROM AUTHOR]

Paratuberculosis (Johne's disease) is a chronic granulomatous small intestine disease caused by MAP. Diagnosing and isolating infected animals is the most important measure for controlling the disease. Therefore, this study aimed to molecularly identify mycobacterium isolated from ELISA-positive cows with Johne's disease by nested PCR from the samples from Markazi Province, Iran. For this purpose, 2938 samples were decontaminated and then cultured on the Herrold egg culture medium containing mycobactin and no mycobactin. After DNA extraction, PCR for 16S rRNA was first performed, followed by nested PCR on positive samples. Of 2938 samples, 87 were positive, and 26 were suspected. All positive isolates were observed in Ziehl-Neelsen staining in microscopic expansion. A 543-bp band was observed in 26 tested samples and mycobacterium strains in PCR for 16S rRNA, indicating the presence of mycobacterium in the above samples. Nested PCR was performed for all isolates and positive and negative control strains. A 398-bp band was obtained in the first stage, and a 298-bp fragment was obtained in the second stage, indicating the presence of MAP in the samples. Accordingly, nested PCR is suggested as a proper method for the quick and definitive diagnosis of disease cases.

Mycobacterial diseases impact millions in the human and veterinary fields each year. Their diagnosis is long and laborious, often only sensitive in the late stages of disease. This has created an unmet need for new diagnostics that are effective in the earlier stages of infection and are quick and easy to perform. This study details the optimization of LAMP assays for the detection of M. tuberculosis, M. bovis and M. avium subsp. paratuberculosis combined with phage-mediated lysis to meet the needs of a novel diagnostic—termed phage-LAMP. The optimized phage-LAMP assay had a limit of detection of less than 10 mycobacteria per ml and no cross-reaction was seen between assays. The phage-LAMP method was then tested on a small number of clinical blood samples from suspected TB patients and herds suspected of Johne’s disease. The phage-LAMP assay could detect viable Mycobacterium tuberculosis and M. avium subsp. paratuberculosis in these samples.

Paratuberculosis (PTB) is a chronic disease affecting ruminants caused by mycobacterium avium subspecies paratuberculosis (MAP), characterized by the iceberg phenomena, as many cases are subclinical and underdiagnosed. An early diagnosis is imperative; however, no reliable single test is available, leading to delayed culling. Furthermore, using more than one test increases the rate of positively diagnosed cases. The current study aimed to detect subclinical PTB in dairy cows in El-Minia governorate, Egypt, using ELISA jointly with the detection of MAP by PCR. The positive cases were also subjected to pathological examination to determine whether lesions were present and their severity. A total of 145 cows of different breeds (Baladi, Mixed, and Holestins) and ages were tested by ELISA and PCR. Our results showed that the positive PTB cases detected by ELISA and PCR were 17.24% and 20%, respectively. Holestins have a significantly higher infection rate 31.70% than Baladi and Mixed breeds. In contrast, the native (Baladi) breed has the lowest infection rate 11.47%. Moreover, PTB is more common in cows aging (age ≥ 1.5-

Mycobacterium avium subsp. paratuberculosis (MAP), the etiological agent of Johne's disease (JD) in ruminants, establishes a prolonged and often lifelong enteric infection. The implementation of control measures for bovine JD has faced obstacles due to the considerable expenses involved in disease surveillance and hindered by unreliable and inadequate diagnostic tests, emphasizing the need for an effective vaccine that can stimulate mucosal immunity in the gastrointestinal tract. Previous investigations have demonstrated that deletion of the BacA gene in MAP produces an attenuated strain that can transiently colonize the calf small intestine while retaining its capacity to stimulate systemic immune responses similar to wildtype MAP strains. This study assessed the efficacy of the BacA gene deletion MAP strain, referred to as the BacA vaccine, when administered orally to young calves. The research aimed to evaluate its effectiveness in controlling MAP intestinal infection and to investigate the immune responses elicited by mucosal vaccination. The study represents the first evaluation of an enteric modified live MAP vaccine in the context of an oral MAP challenge in young calves. Oral immunization with BacA reduced MAP colonization specifically in the ileum and ileocecal valve. This partially protective immune response was associated with an increased frequency of CD4+ and CD8+ T cells with a pro-inflammatory phenotype (IFNγ+/TNFα+) in vaccinated animals. Moreover, re-stimulated PBMCs from vaccinated animals showed increased expression of IFNγ, IP-10, IL-2, and IL-17 at 10- and 12-weeks post challenge. Furthermore, immunophenotyping of blood leukocytes revealed that vaccinated calves had increased levels of T cells expressing cell-surface markers consistent with long-term central memory. Overall, our findings provide new insights into the development and immunogenicity of a modified live MAP vaccine against bovine JD, demonstrating oral vaccination can stimulate host immune responses that can be protective against enteric MAP infection. [ABSTRACT FROM AUTHOR]

This document is a compilation of various research articles and studies related to the diagnosis and detection of Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of Johne's disease in dairy cattle. The articles discuss different methods and techniques used for the detection of MAP, including fecal culture, ELISA, PCR, and serology. The studies evaluate the sensitivity and specificity of these diagnostic tests and compare their effectiveness in detecting MAP in dairy herds. The document provides valuable information for researchers and veterinarians interested in the diagnosis and control of Johne's disease in cattle. [Extracted from the article]

Paratuberculosis (Johne's disease) is a chronic granulomatous small intestine disease caused by MAP. Diagnosing and isolating infected animals is the most important measure for controlling the disease. Therefore, this study aimed to molecularly identify mycobacterium isolated from ELISA- positive cows with Johne's disease by nested PCR from the samples from Markazi Province, Iran. For this purpose, 2938 samples were decontaminated and then cultured on the Herrold egg culture medium containing mycobactin and no mycobactin. After DNA extraction, PCR for 16S rRNA was first performed, followed by nested PCR on positive samples. Of 2938 samples, 87 were positive, and 26 were suspected. All positive isolates were observed in Ziehl-Neelsen staining in microscopic expansion. A 543-bp band was observed in 26 tested samples and mycobacterium strains in PCR for 16S rRNA, indicating the presence of mycobacterium in the above samples. Nested PCR was performed for all isolates and positive and negative control strains. A 398-bp band was obtained in the first stage, and a 298-bp fragment was obtained in the second stage, indicating the presence of MAP in the samples. Accordingly, nested PCR is suggested as a proper method for the quick and definitive diagnosis of disease cases. [ABSTRACT FROM AUTHOR]

IntroductionAs a contagious and chronic disease in the livestock industry, Paratuberculosis is a significant threat to dairy herds’ genetic and economic resources. Due to intensive breeding and high production of dairy cattle, the incidence and prevalence are higher. Developing non-destructive diagnostic methods for the early detection and identification of healthy animals is paramount for breeding programs. Conventional methods are almost entirely destructive, have low accuracy, lack precision, and are time-consuming. Near-infrared spectroscopy (NIRS) and aquaphotomics can detect changes in biofluids and thus have the potential to diagnose disease. This study aimed to investigate the diagnostic ability of NIRS and aquaphotomics for Paratuberculosis in dairy cattle. MethodsBlood plasma from dairy cattle was collected in the NIR range (1,300 nm to 1,600 nm) 60 days before and 100 days to 200 days after calving in two groups, positive and negative, using the same consecutive enzyme-linked immunosorbent assay test results three times as a reference test.ResultsNIRS and aquaphotomics methods invite 100% accuracy, sensitivity, and specificity to detect Paratuberculosis using data mining by unsupervised method, Principal Component Analysis, and supervised methods: Soft Independent Modeling of Class Analogiest, Linear Discriminant Analysis, Quadratic Discriminant Analysis, Partial Least Square–Discriminant Analysis, and Support Vector Machine models.DiscussionThe current study found that monitoring blood plasma with NIR spectra provides an opportunity to analyze antibody levels indirectly via changes in water spectral patterns caused by complex physiological changes, such as the amount of antibodies related to Paratuberculosis by aquagram.

Paratuberculosis (PTB), or Johne’s disease, is a disease with worldwide distribution caused by Mycobacterium avium subsp. paratuberculosis (MAP) that leads to chronic enteritis, primarily in ruminants. Even subclinical infection significantly reduces the animals’ performance, and consequences of the disease lead to high economic losses for the cattle industry. To estimate the economic burden of bovine PTB and to evaluate the benefits of a potential control program, accurate estimates of the production effects associated with the disease are required. Therefore, the aim of this scoping review was to provide a comprehensive overview of associations between MAP infection and production parameters in cattle. The studies were collected from three electronic databases. Of the total 1,605 identified studies, 1,432 did not meet the set criteria in the title and abstract screening and a further 106 were excluded during full-text review. Finally, data on 34 different production parameters were extracted from 67 publications. Results show that the magnitude of reported performance losses varies depending on several factors, such as the type of diagnostic test applied, disease status or number of lactations. Studies reported a reduction in milk yield, changes in milk quality (e.g., higher somatic cell count, lower amount of produced milk fat and protein), reduced fertility (e.g., prolonged calving interval and service period, higher abortion rate and calving difficulties), reduced weaning weight, slaughter weight and slaughter value, or a higher risk for mastitis. Results from the studies included in our review show a median decrease of milk yield per infected cow of −452 kg/lactation for raw and −405 kg/lactation for modeled data. Similarly, the amount of produced milk protein fell by a median of −14.41 kg/lactation for modeled data and the amount of produced milk fat by a median of −13.13 kg/lactation. The reviewed studies revealed a prolonged calving interval by around 30 days and a 1.5 to 3 times higher likeliness of culling per lactation in PTB positive animals. Results from this scoping review provide evidence-based inputs for the development of economic models aiming at the estimation of the costs and benefits associated with different disease control scenarios for PTB.

ABSTRACTTuberculostearic acid (TBSA) is a fatty acid unique to mycobacteria and some corynebacteria and has been studied due to its diagnostic value, biofuel properties, and role in membrane dynamics. In this study, we demonstrate that TBSA production can be abrogated either by addition of pivalic acid to mycobacterial growth cultures or by a bfaA gene knockout encoding a flavin adenine dinucleotide (FAD)-binding oxidoreductase. Mycobacterium avium subspecies paratuberculosis (Map) growth and TBSA production were inhibited in 0.5-mg/mL pivalic acid-supplemented cultures, but higher concentrations were needed to have a similar effect in other mycobacteria, including Mycobacterium smegmatis. While Map C-type strains, isolated from cattle and other ruminants, will produce TBSA in the absence of pivalic acid, the S-type Map strains, typically isolated from sheep, do not produce TBSA in any condition. A SAM-dependent methyltransferase encoded by bfaB and FAD-binding oxidoreductase are both required in the two-step biosynthesis of TBSA. However, S-type strains contain a single-nucleotide polymorphism in the bfaA gene, rendering the oxidoreductase enzyme vestigial. This results in the production of an intermediate, termed 10-methylene stearate, which is detected only in S-type strains. Fatty acid methyl ester analysis of a C-type Map bfaA knockout revealed the loss of TBSA production, but the intermediate was present, similar to the S-type strains. Collectively, these results demonstrate the subtle biochemical differences between two primary genetic lineages of Map and other mycobacteria as well as explain the resulting phenotype at the genetic level. These data also suggest that TBSA should not be used as a diagnostic marker for Map.IMPORTANCEBranched-chain fatty acids are a predominant cell wall component among species belonging to the Mycobacterium genus. One of these is TBSA, which is a long-chain middle-branched fatty acid used as a diagnostic marker for Mycobacterium tuberculosis. This fatty acid is also an excellent biolubricant. Control of its production is important for industrial purposes as well as understanding the biology of mycobacteria. In this study, we discovered that a carboxylic acid compound termed pivalic acid inhibits TBSA production in mycobacteria. Furthermore, Map strains from two separate genetic lineages (C-type and S-type) showed differential production of TBSA. Cattle-type strains of Mycobacterium avium subspecies paratuberculosis produce TBSA, while the sheep-type strains do not. This important phenotypic difference is attributed to a single-nucleotide deletion in sheep-type strains of Map. This work sheds further light on the mechanism used by mycobacteria to produce tuberculostearic acid.

ABSTRACT The objective of this work was to describe the clinical, pathological, and serological aspects of paratuberculosis in a bullock on dairy and beef farm in the municipality of Inhangapí, state of Pará. The animal was raised extensively and presented progressive weight loss, pale mucous membranes, and chronic diarrhea. A blood sample was collected for serology by the indirect ELISA technique. Due to the unfavorable prognosis, the animal was euthanized and necropsied. At necropsy, there was thickened and wrinkled intestinal mucosa, enlarged mesenteric lymph nodes and liquid intestinal contents with a brown color. Organ fragments were fixed in 10% buffered formaldehyde, embedded in paraffin wax, cut, and stained by hematoxylin and eosin and by Ziehl-Neelsen techniques. Histopathology showed intense granulomatous infiltration with Langhans giant cells in the lamina propria and submucosa of the small intestine, Peyer patches and mesenteric lymph nodes. Ziehl-Neelsen staining revealed many intralesional acid-fast bacilli. Antibody searching against Mycobacterium avium (subsp.) paratuberculosis was positive. The diagnosis of paratuberculosis was based on epidemiological, clinical, pathological, and serological data. This is the first report of clinical paratuberculosis, confirmed by pathology and serology, in a bullock in the state of Pará.

Introduction: Paratuberculosis, or Johne’s disease, is a chronic, granulomatous, gastrointestinal tract disease of goat and other ruminants caused by the bacterium Mycobacterium avium ssp. paratuberculosis (MAP). The clinical signs of disease in goat are pipestream diarrhea, weight loss, and edema due to hypoproteinemia caused by protein-losing enteropathy. Knowledge concerning genetics of susceptibility to MAP infection can contribute to disease control programs by facilitating genetic selection for a less susceptible population to reduce incidence of infection in the future. The opportunity for genetic improvement in susceptibility to infection is evidenced by estimates of heritability of MAP infection ranging from 0.03 to 0.28 (Kirkpatrick and Lett, 2018). Domestication and selection has significantly changed the behavioral and phenotypic traits in modern domestic animals. The selection of animals by humans left detectable signatures on the genome of modern goat. The identification of these signals can help us to improve the genetic characteristics of economically important traits in goat. Over the last decade, interest in detection of genes or genomic regions that are targeted by selection has been growing. Identifying signatures of selection can provide valuable insights about the genes or genomic regions that are or have been under selection pressure, which in turn leads to a better understanding of genotype-phenotype relationships. The aim of this study was to identify the selection signatures using the unbiased Theta method associated with resistance to Johne’s disease in two Italian goat breeds.Materials and Methods: The work described here is a case–control association study using the Illumina Caprine SNP50 BeadChip to unravel the genes involved in susceptibility of goats to Johne’s disease. Goats in herds with a high occurrence of Johne's disease were classified as healthy or infected based on the level of serum antibodies against MAP, and 331 animals were selected for the study. For the Siriana breed 174 samples (87 cases and 87 controls) were selected from 14 herds and for the Jonica breed 157 samples (77 cases and 80 controls) were selected from 10 herds. Cases were defined as animals serologically positive for MAP by ELISA with a sample to positive ratio (S/P) higher than 0.7 and MAP negative animals had a S/P lower than 0.6. Positive animals were tested twice with the ID Screen Paratuberculosis confirmation test. The 331 samples were genotyped using the Illumina GoatSNP50 BeadChip. SNP missing 5% of data, with MAF of

Paratuberculosis (PTB), caused by Mycobacterium avium subspecies paratuberculosis (MAP), is a chronic disease with economic impact on ruminant farming worldwide. The Canary Islands count with the fourth largest goat population in Spain and are “officially free” of bovine tuberculosis. Twelve farms were included with 2774 serum samples tested by an enzyme-linked immunosorbent assay (ELISA) for detection of anti-MAP antibodies in two sessions. In the first session, an overall apparent prevalence of 18.4% (2.5% up to 61.1%) was obtained. Farms with prevalences (0–10%], (10–20%] and >20% were identified, with differences in seroconversion in the same prevalence group between farms and age ranges. Non-vaccinated (nV) and vaccinated (V) animals were included in the second sampling session. Higher levels of antibodies were detected in V animals older than 12 months, with considerable variations between age ranges and farms. Our results describe the current PTB status of the Canary Islands’ goat farming. Furthermore, new insights on the effect of the farm prevalence on seroconversion in V animals are provided, although further studies are needed to evaluate the multiple factors affecting the immune response to anti-MAP vaccination.

Paratuberculosis, also known as Johne’s (Yo’-ness) disease, is a significant bacterial disease of large and small ruminants, including other animals, caused by Mycobacterium avium subspecies paratuberculosis (MAP). Due to its impact on animal health and severe economic loss, the disease is recognized and reported in developed countries as a significant disease of livestock importance. The paper aims to review the current information about paratuberculosis in Nigeria. About 95 research articles were downloaded from various online journals databases such as Scopus, Google Scholar, Research Gate, PubMed, and CABI abstracts based on the following keywords: Johne’s disease, paratuberculosis, Africa, prevalence, Nigeria, report, occurrence, and Mycobacterium avium subspecies paratuberculosis. In addition to the perusal of organization databases, 60 research articles were used in writing this review article. Few cases and suspected cases of paraTB were reported in Nigeria by the World Organization for Animal Health (OIE). Despite growing global concerns, Johne's disease can be considered an unreported disease of livestock animals in Nigeria based on the knowledge gap and lack of reports about this significant disease of livestock animals. Studies need to be carried out to address the knowledge gaps before the disease becomes endemic and causes severe economic and public health menace in Nigeria and, by extension, Sub-Saharan Africa.

Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne's disease in wild and domestic ruminants. Clinically, infected cattle show emaciation symptoms, diarrhea, and death. Asymptomatic subclinical cases can intermittently shed MAP through feces and milk and infect other cattle animals, thus increasing the risk of infection. The purpose of the present study was to detect the prevalence of this disease in dairy cattle. For this purpose, 348 samples were randomly collected from 15 cattle farms. All fecal samples were subjected to ZN staining and PCR of nucleotide sequences related to specific MAP gene fragments (IS900, F57) and were cultured in Harold's egg yolk culture medium after being disinfected with solution (0.0% HPC75). PCR testing of 116 fecal samples (33.3%, CI:95% 28.3-38.2), ZN staining of 23 samples (6.6%, CI: 95% 4-9.2), and fecal sample culture of only 15 samples (4.3%, CI:95% 2.3-6.3,) were infected with MAP. Comparison of test results showed poor agreement (kappa statistic: 0.19) between ZN staining and PCR results and poor agreement (kappa statistic: 0.13) between PCR test and fecal culture. This study highlights the advantages of PCR for detecting MAP in subclinically infected cattle compared to ZN staining and fecal culture. Therefore, it can be used for early detection and control of MAP in cattle and at-risk populations.

Mycobacterium avium subsp. paratuberculosis (MAP), the etiological agent of Johne’s disease (JD) in ruminants, establishes a prolonged and often lifelong enteric infection. The implementation of control measures for bovine JD has faced obstacles due to the considerable expenses involved in disease surveillance and hindered by unreliable and inadequate diagnostic tests, emphasizing the need for an effective vaccine that can stimulate mucosal immunity in the gastrointestinal tract. Previous investigations have demonstrated that deletion of the BacA gene in MAP produces an attenuated strain that can transiently colonize the calf small intestine while retaining its capacity to stimulate systemic immune responses similar to wildtype MAP strains. This study assessed the efficacy of the BacA gene deletion MAP strain, referred to as the BacA vaccine, when administered orally to young calves. The research aimed to evaluate its effectiveness in controlling MAP intestinal infection and to investigate the immune responses elicited by mucosal vaccination. The study represents the first evaluation of an enteric modified live MAP vaccine in the context of an oral MAP challenge in young calves. Oral immunization with BacA reduced MAP colonization specifically in the ileum and ileocecal valve. This partially protective immune response was associated with an increased frequency of CD4+ and CD8+ T cells with a pro-inflammatory phenotype (IFNγ+/TNFα+) in vaccinated animals. Moreover, re-stimulated PBMCs from vaccinated animals showed increased expression of IFNγ, IP-10, IL-2, and IL-17 at 10- and 12-weeks post challenge. Furthermore, immunophenotyping of blood leukocytes revealed that vaccinated calves had increased levels of T cells expressing cell-surface markers consistent with long-term central memory. Overall, our findings provide new insights into the development and immunogenicity of a modified live MAP vaccine against bovine JD, demonstrating oral vaccination can stimulate host immune responses that can be protective against enteric MAP infection.

Johne's disease (JD) is a chronic wasting disease caused by Mycobacterium avium subspecies paratuberculosis (MAP). MAP is responsible for large economic losses for the dairy sector and has been linked to human disease. Susceptibly to MAP is mainly limited to young animals and diagnostic tests are poor at detecting MAP in early stages of infection. Therefore, ascertaining the contribution of the dam to the risk of calf infection and the relative role of the different infection routes is important to inform disease control measures. This data article presents MAP exposures at time of calving on a cohort of 439 calves born between 2012 and 2013 from 6 UK dairy herds. Each calf participated in routine quarterly MAP milk ELISA testing using the IDEXX Porquire ELISA. Each animal was followed until testing MAP positive, being culled or end of follow up (January 2023). The dataset includes risk factors associated with transmission via colostrum route (MAP status of cow giving colostrum); transmission via the dam (MAP status of the dam) and transmission via fecal oral route (whether at birth the calf spent a long time in a dirty yard). Ascertainment of exposure to risk factors involved video recording and self-capture data forms from time of calving in the maternity area of the farms until calf left the area. The dataset provides a unique opportunity to examine MAP infection and its relationship with different exposures at time of birth, where cows were followed up during their entire lives.

Introduction1: Paratuberculosis, or Johne's disease, is a chronic, granulomatous, gastrointestinal tract disease of goat and other ruminants caused by the bacterium Mycobacterium avium ssp. paratuberculosis (MAP). The clinical signs of disease in goat are pipestream diarrhea, weight loss, and edema due to hypoproteinemia caused by protein-losing enteropathy. Knowledge concerning genetics of susceptibility to MAP infection can contribute to disease control programs by facilitating genetic selection for a less susceptible population to reduce incidence of infection in the future. The opportunity for genetic improvement in susceptibility to infection is evidenced by estimates of heritability of MAP infection ranging from 0.03 to 0.28 (Kirkpatrick and Lett, 2018). Domestication and selection has significantly changed the behavioral and phenotypic traits in modern domestic animals. The selection of animals by humans left detectable signatures on the genome of modern goat. The identification of these signals can help us to improve the genetic characteristics of economically important traits in goat. Over the last decade, interest in detection of genes or genomic regions that are targeted by selection has been growing. Identifying signatures of selection can provide valuable insights about the genes or genomic regions that are or have been under selection pressure, which in turn leads to a better understanding of genotype-phenotype relationships. The aim of this study was to identify the selection signatures using the unbiased Theta method associated with resistance to Johne's disease in two Italian goat breeds. Materials and Methods: The work described here is a case-control association study using the Illumina Caprine SNP50 BeadChip to unravel the genes involved in susceptibility of goats to Johne's disease. Goats in herds with a high occurrence of Johne's disease were classified as healthy or infected based on the level of serum antibodies against MAP, and 331 animals were selected for the study. For the Siriana breed 174 samples (87 cases and 87 controls) were selected from 14 herds and for the Jonica breed 157 samples (77 cases and 80 controls) were selected from 10 herds. Cases were defined as animals serologically positive for MAP by ELISA with a sample to positive ratio (S/P) higher than 0.7 and MAP negative animals had a S/P lower than 0.6. Positive animals were tested twice with the ID Screen Paratuberculosis confirmation test. The 331 samples were genotyped using the Illumina GoatSNP50 BeadChip. SNP missing 5% of data, with MAF of <1% and Hardy-Weinberg equilibrium p-values <10-6 were removed. The genotyping efficiency for samples was also verified, and samples with more than 5% missing data were removed. Grouping was done to infer selection signatures based on FST statistic. Bioinformatics inquiries were conducted employing the Ensembl database (Cunningham et al., 2022), specifically for caprine genes (assembly ARS1). The aim was to pinpoint potential candidate genes that have either been previously reported in, or are situated within the genomic regions encompassing the peak of absolute extreme FST values. In this context, regions corresponding to the top and bottom 0.01% of acquired positive and negative FST scores were earmarked as areas undergoing selection. The identification of genes was executed through the application of a 250 Kb window both upstream and downstream of each core SNP. Results and Discussion: By applying a threshold at the 99.90 percentile of the obtained Theta (θ) values, a total of 13 distinct genomic regions were identified in the Jonica breed. These regions were situated across chromosomes 1, 5, 7 (in 2 regions), 8, 9 (in 2 regions), 11, 16, 17, 18, and 20 (in 2 regions). Similarly, in the Siriana breed, genomic regions were pinpointed on chromosomes 3, 5 (in 2 regions), 10, 12, 16, 17, 18, 23, 24, and 29. Further exploration through bioinformatics tools brought to light the overlap of these genomic regions with genes associated with the immune system, disease resistance, bacterial infection resilience, response to oxidative stress, and tumor suppression. The study population size is relatively modest, predominantly due to the intricacy of procuring a substantial volume of blood samples from goats within commercial herds that have been diagnosed with JD and are poised for culling. It's worth noting that JD diagnosis and culling procedures are not infallible preventive measures. The gradual progression of the disease often leads to late-stage diagnosis, allowing subclinical goats to intermittently excrete MAP in the environment. As the infection and disease progress, the fecal shedding of MAP increases and contributes to its horizontal transmission. In combination with genetic improvement (innate protection), vaccination (acquired protection) will support eradicating this incurable disease. Conclusions: To conclude, the findings of this study hold potential significance as they offer valuable insights for identifying genomic regions and subsequently, the genes that influence Johne's disease in goats. Nonetheless, additional research endeavors are essential to enhance and validate these outcomes. Utilizing a more extensive sample size, incorporating whole-genome sequencing, and implementing high-density genotyping are imperative steps to further refine and strengthen these findings. [ABSTRACT FROM AUTHOR]

In many parts of the world, bovine tuberculosis eradication efforts are hampered by wildlife reservoirs of Mycobacterium bovis, which serve as a constant source of M. bovis for nearby cattle. The human tuberculosis vaccine, M. bovis BCG has been investigated for use in several wildlife species, including deer. In the US, white-tailed deer in Michigan have been the source of infection for over 82 cattle herds since M. bovis was discovered in free-ranging deer in 1995. The efficacy of BCG may be influenced by many factors, including prior exposure or infection with non-tuberculous mycobacteria, that is, species other than members of the M. tuberculosis complex. M. avium subspecies paratuberculosis (Map) infection is not uncommon in ruminants such as deer. Using natural exposure to Map and experimental infection with M. bovis, we demonstrate that Map infection increased BCG vaccine efficacy as measured by lesion severity scores. [ABSTRACT FROM AUTHOR]

Non-coding RNAs (ncRNA) have paved the way to new perspectives on the regulation of gene expression, not only in biology and medicine, but also in associated fields and technologies, ensuring advances in diagnostic means and therapeutic modalities. Critical in this multistep approach are the associations of long non-coding RNA (lncRNA) with diseases and their causal genes in their networks of interactions, gene enrichment and expression analysis, associated pathways, the monitoring of the involved genes and their functional roles during disease progression from one stage to another. Studies have shown that Johne's Disease (JD), caused by Mycobacterium avium subspecies partuberculosis (MAP), shares common lncRNAs, clinical findings, and other molecular entities with Crohn's Disease (CD). This has been a subject of vigorous investigation owing to the zoonotic nature of this condition, although results are still inconclusive. In this review, on one hand, the current knowledge of lncRNAs in cells is presented, focusing on the pathogenesis of gastrointestinal-related pathologies and MAP-related infections and, on the other hand, we attempt to dissect the associated genes and pathways involved. Furthermore, the recently characterized and novel lncRNAs share common pathologies with IBD and JD, including the expression, molecular networks, and dataset analysis results. These are also presented in an attempt to identify potential biomarkers pertinent to cattle and human disease phenotypes. [ABSTRACT FROM AUTHOR]

Background: Mycobacterium avium subspecies paratuberculosis (MAP) causes a chronic and progressive granulomatous enteritis and economic losses in dairy cattle in subclinical stages. Subclinical infection in cattle can be detected using serum MAP antibody enzyme-linked immunosorbent assay (ELISA) and fecal polymerase chain reaction (PCR) tests. Objectives: To investigate the differences in blood parameters, according to the detection of MAP using serum antibody ELISA and fecal PCR tests. Methods: We divided 33 subclinically infected adult cattle into three groups: seronegative and fecal-positive (SNFP, n = 5), seropositive and fecal-negative (SPFN, n = 10), and seropositive and fecal-positive (SPFP, n = 18). Hematological and serum biochemical analyses were performed. Results: Although the cows were clinically healthy without any manifestations, the SNFP and SPFP groups had higher platelet counts, mean platelet volumes, plateletcrit, lactate dehydrogenase levels, lactate levels, and calcium levels but lower mean corpuscular volume concentration than the SPFN group (p < 0.017). The red blood cell count, hematocrit, monocyte count, glucose level, and calprotectin level were different according to the detection method (p < 0.05). The SNFP and SPFP groups had higher red blood cell counts, hematocrit and calprotectin levels, but lower monocyte counts and glucose levels than the SPFN group, although there were no significant differences (p > 0.017). Conclusions: The cows with fecal-positive MAP status had different blood parameters from those with fecal-negative MAP status, although they were subclinically infected. These findings provide new insights into understanding the mechanism of MAP infection in subclinically infected cattle. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) can directly kill Gram-positive bacteria, Gram-negative bacteria, mycobacteria, fungi, enveloped viruses, and parasites. At sublethal concentrations, some AMPs and also conventional antibiotics can stimulate bacterial response increasing their resilience, also called the hormetic response. This includes stimulation of growth, mobility, and biofilm production. Here, we describe the discovery of AMPs that stimulate the growth of certain mycobacteria. Peptide 14 showed a growth stimulating effect on Mycobacteria tuberculosis (MTB), M. bovis, M. avium subsp. paratuberculosis (MAP), M. marinum, M. avium-intracellulare, M. celatum, and M. abscessus. The effect was more pronounced at low bacterial inocula. The peptides induce a faster transition from the lag phase to the log phase and keep the bacteria longer in the log phase before entering stationary phase when compared to nontreated controls. In some cases, an increase in the division rate was observed. An initial screen using MAP and a collection of 75 peptides revealed 13 peptides with a hormetic effect. For MTB, a collection of 25 artificial peptides were screened and 13 were found to reduce the time to positivity (TTP) by at least 5%, improving growth. A screen of 43 naturally occurring peptides, 11 fragments of naturally occurring peptides and 5 designed peptides, all taken from the database APD3, identified a further 44 peptides that also lowered TTP by at least 5%. Lasioglossin LL-III (Bee) and Ranacyclin E (Frog) were the most active natural peptides, and the human cathelicidin LL37 fragment GF-17 and a porcine cathelicidin protegrin-1 fragment were the most active fragments of naturally occurring peptides. Peptide 14 showed growth-stimulating activity between 10 ng/mL and 10 µg/mL, whereas the stability-optimised Peptide 14D had a narrow activity range of 0.1–1 µg/mL. Peptides identified in this study are currently in commercial use to improve recovery and culture for the diagnostics of mycobacteria in humans and animals. [ABSTRACT FROM AUTHOR]

ABSTRACT: For the control of Johne's disease (JD), management practices to minimize disease transmission must be implemented and maintained. Once infected, animals will enter a latent phase and will typically only manifest clinical symptoms years later. As young calves are the main susceptible group on farm, the observed effects of management practices geared toward minimizing their exposure to infective material may not be realized until years later. This delayed feedback limits the sustained implementation of JD control practices. Although quantitative research methods have demonstrated changes to management practices as well as their association with changes to JD prevalence, dairy farmers can offer insights into the current challenges relating to JD implementation and control. Thus, this study aims to use qualitative methods and in-depth interviews (n = 20) with Ontario dairy farmers who had previously been engaged in a Johne's control program to explore their motivations and barriers to the implementation of JD control practices and general herd biosecurity. A thematic analysis using inductive coding was completed generated the following 4 overarching themes: (1) the hows and whys of Johne's control, (2) barriers to general herd biosecurity, (3) barriers to Johne's control, and (4) overcoming barriers. Farmers no longer believed JD was an issue on their farm. Johne's was low on their list of concerns due to little public discourse, absence of animals displaying clinical signs, and no financial support for diagnostic testing. Producers who were still actively engaged in JD control cited animal and human health as their primary motivations. Financial support, targeted education, and promoting engagement through discourse may help encourage producers to reconsider their participation in JD control. Government and industry collaboration with producers may help to develop more effective biosecurity and disease control programs.

Machine learning algorithms have been applied to various animal husbandry and veterinary-related problems; however, its use in Johne’s disease diagnosis and control is still in its infancy. The following proof-of-concept study explores the application of tree-based (decision trees and random forest) algorithms to analyze repeat milk testing data from 1197 Canadian dairy cows and the algorithms’ ability to predict future Johne’s test results. The random forest models using milk component testing results alongside past Johne’s results demonstrated a good predictive performance for a future Johne’s ELISA result with a dichotomous outcome (positive vs. negative). The final random forest model yielded a kappa of 0.626, a roc AUC of 0.915, a sensitivity of 72%, and a specificity of 98%. The positive predictive and negative predictive values were 0.81 and 0.97, respectively. The decision tree models provided an interpretable alternative to the random forest algorithms with a slight decrease in model sensitivity. The results of this research suggest a promising avenue for future targeted Johne’s testing schemes. Further research is needed to validate these techniques in real-world settings and explore their incorporation in prevention and control programs.