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21 pages, 3608 KiB

Open AccessFeature PaperArticle

Comparison of Machine Learning Tree-Based Algorithms to Predict Future Paratuberculosis ELISA Results Using Repeat Milk Tests

by Jamie Imada, Juan Carlos Arango-Sabogal, Cathy Bauman, Steven Roche and David Kelton

Animals 2024, 14(7), 1113; https://doi.org/10.3390/ani14071113 - 05 Apr 2024

Viewed by 646

Abstract

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 [...] Read more.

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. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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17 pages, 1096 KiB

Open AccessFeature PaperArticle

An ELISA Using Synthetic Mycolic Acid-Based Antigens with DIVA Potential for Diagnosing Johne’s Disease in Cattle

by Paul S. Mason, Thomas Holder, Natasha Robinson, Brendan Smith, Rwoa’a T. Hameed, Juma’a R. Al Dulayymi, Valerie Hughes, Karen Stevenson, Gareth J. Jones, H. Martin Vordermeier, Shawn Mc Kenna and Mark S. Baird

Animals 2024, 14(6), 848; https://doi.org/10.3390/ani14060848 - 09 Mar 2024

Viewed by 925

Abstract

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 [...] Read more.

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. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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20 pages, 971 KiB

Open AccessArticle

Molecular Diversity of Mycobacterium avium subsp. paratuberculosis in Four Dairy Goat Herds from Thuringia (Germany)

by Chris Pickrodt, Heike Köhler, Udo Moog, Elisabeth M. Liebler-Tenorio and Petra Möbius

Animals 2023, 13(22), 3542; https://doi.org/10.3390/ani13223542 - 16 Nov 2023

Cited by 1 | Viewed by 710

Abstract

This study investigated the intra- and inter-herd diversity of Mycobacterium avium subsp. paratuberculosis (MAP) isolates from four goat herds in Thuringia (Germany) that were affected by paratuberculosis for several years. The main focus was on the characterization and distribution of genotypes among animals [...] Read more.

This study investigated the intra- and inter-herd diversity of Mycobacterium avium subsp. paratuberculosis (MAP) isolates from four goat herds in Thuringia (Germany) that were affected by paratuberculosis for several years. The main focus was on the characterization and distribution of genotypes among animals and the environment of goat herd 1. This study included 196 isolates from the feces of 121 infected goats, various tissues from 13 clinically diseased goats, 29 environmental samples from herd 1, and additionally, 22 isolates of different origin from herds 2 to 4. The isolates, sampled between 2018 and 2022, were genotyped using short-sequence-repeat (SSR) analysis, mycobacterial-interspersed repetitive units–variable-number tandem repeat (MIRU–VNTR) analysis, and a single nucleotide polymorphism (SNP)-based assay for phylogenetic grouping. All the isolates belonged to the MAP-C group. In herd 1, one predominant genotype was determined, while two other genotypes were identified very rarely and only in fecal and environmental samples. One of three further genotypes was found in each of herds 2 to 4. The assignment of genotypes to different phylogenetic clades suggested six different infection strains. The results indicated no epidemiological links between the examined herds. Based on the current MAP genotyping data from Germany, possible sources of infection are MAP-contaminated barns previously used by infected cattle and the purchase of sub-clinically infected goats. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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14 pages, 2176 KiB

Open AccessArticle

Paratuberculosis, Animal Welfare and Biosecurity: A Survey in 33 Northern Italy Dairy Goat Farms

by Alessandra Gaffuri, Filippo Barsi, Edoardo Magni, Stefania Bergagna, Debora Dellamaria, Matteo Ricchi, Livia De Paolis, Giorgio Galletti, Norma Arrigoni, Valentina Lorenzi, Francesca Fusi, Alice Prosperi and Chiara Garbarino

Animals 2023, 13(14), 2346; https://doi.org/10.3390/ani13142346 - 18 Jul 2023

Cited by 1 | Viewed by 1608

Abstract

Paratuberculosis is a notable infectious disease of ruminants. Goats appear to be particularly susceptible. The survey aimed to investigate the spread of paratuberculosis in Italian goat farming and evaluate whether the presence of the disease could be influenced by welfare and biosecurity deficiencies. [...] Read more.

Paratuberculosis is a notable infectious disease of ruminants. Goats appear to be particularly susceptible. The survey aimed to investigate the spread of paratuberculosis in Italian goat farming and evaluate whether the presence of the disease could be influenced by welfare and biosecurity deficiencies. A serological survey for paratuberculosis in 33 dairy farms in northern Italy was conducted. Contextually, animal welfare and biosecurity were assessed, using a standardized protocol of 36 welfare indicators and 15 biosecurity indicators which assigns to each farm a welfare and biosecurity score from 0 (any application) to 100% (full application). An overall result of less than 60% was considered insufficient. Nineteen farms (58%) tested positive for paratuberculosis, with a mean intra-herd seroprevalence of 7.4%. Total welfare ranged from 39.56 to 90.7% (mean 68.64%). Biosecurity scores ranged from 10.04 to 90.01% (mean 57.57%). Eight farms (24%) showed poor welfare conditions (welfare score < 60%) and 19 (58%) an unsatisfactory biosecurity condition (biosecurity score < 60%). With respect to the explorative character of the study, an indicative association between seven welfare and biosecurity indicators and paratuberculosis seropositivity was identified. The presence of paratuberculosis in northern Italy dairy goat farms was confirmed. The welfare and biosecurity assessment protocol proved to be an accurate tool, capable of identifying critical points for managing health, welfare and productivity. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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14 pages, 1003 KiB

Open AccessArticle

High-Impact Risk Factors for Mycobacterium avium ssp. paratuberculosis in Dairy Herds in Germany

by Mette Krieger, Susanne Eisenberg, Karsten Donat and Amely Campe

Animals 2023, 13(12), 1889; https://doi.org/10.3390/ani13121889 - 06 Jun 2023

Cited by 2 | Viewed by 1043

Abstract

In a cross-sectional study, it was identified that three regions in Germany differed with respect to their herd-level prevalence for paratuberculosis in dairy cattle. In the study presented here, the same farms were analyzed to identify those components of biosecurity and farm management [...] Read more.

In a cross-sectional study, it was identified that three regions in Germany differed with respect to their herd-level prevalence for paratuberculosis in dairy cattle. In the study presented here, the same farms were analyzed to identify those components of biosecurity and farm management with the highest impact on Mycobacterium avium ssp. paratuberculosis (MAP) introduction and establishment in a farm. Hence, the data analyzes included 183, 170 and 104 herds from the study regions north, east and south, respectively. A herd was considered MAP-positive if at least one fecal environmental sample was positive. Twenty-six different possible risk factors from five different components of biosecurity and farm management were analyzed. We show that the average management of calf feeding increased the odds for a MAP-positive farm by 5.22 times (95% confidence interval (CI) = 1.25–21.83). With every 100-cow increase in farm size, the risk for a farm to test MAP-positive increased by 1.94 times (CI = 1.15–3.27), 1.14 times (CI = 1.02–1.27) and 5.53 times (CI = 0.44–68.97) in the north, east and south study regions, respectively. Furthermore, the purchase of cattle with an unknown MAP status increased the risk for a farm testing MAP-positive by 2.86-fold (CI = 1.45–5.67). Our results demonstrate that herd size, unknown MAP status of the purchased cattle and different aspects of calf feeding play an important role in the MAP status of a farm and should be in focus in regions with different MAP between-herd prevalence. Additionally, farm individual risk patterns should be identified during (veterinary) biosecurity consultancy. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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12 pages, 1734 KiB

Open AccessArticle

Presence of Non-Tuberculous Mycobacteria Including Mycobacterium avium subsp. paratuberculosis Associated with Environmental Amoebae

by Vincent Rochard, Thierry Cochard, Stéphanie Crapart, Vincent Delafont, Jean-Louis Moyen, Yann Héchard and Franck Biet

Animals 2023, 13(11), 1781; https://doi.org/10.3390/ani13111781 - 27 May 2023

Viewed by 1256

Abstract

One of the obstacles to eradicating paratuberculosis or Johne’s Disease (JD) seems to be the persistence of Mycobacterium avium subsp. paratuberculosis (Map) in the environment due to its ability to survive alone or vectorized. It has been shown that Map is [...] Read more.

One of the obstacles to eradicating paratuberculosis or Johne’s Disease (JD) seems to be the persistence of Mycobacterium avium subsp. paratuberculosis (Map) in the environment due to its ability to survive alone or vectorized. It has been shown that Map is widely distributed in soils and water. Previously, we isolated amoebae associated with Map strains in the environment of bovines from an infected herd. This work aims to verify our working hypothesis, which suggests that amoebae may play a role in the transmission of JD. In this study, we sampled water in the vicinity of herds infected with Map or Mycobacterium bovis (M. bovis) and searched for amoebae and mycobacteria. Live amoebae were recovered from all samples. Among these amoebae, four isolates associated with the presence of mycobacteria were identified and characterized. Map and other mycobacterial species were detected by qPCR and, in some cases, by culture. This study suggests that amoebae and Map may be found in the same environment and might represent a risk of exposure of animals to pathogenic mycobacteria. These data open up new perspectives on the control measures to be put in place to prevent contamination by Map. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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20 pages, 6499 KiB

Open AccessArticle

Morphological Assessment of Concomitant Lesions Detected in Goat Herds Naturally Infected with Paratuberculosis (Johne’s Disease)

by Elena Plamenova Stefanova, Óscar Quesada-Canales, Yania Paz-Sánchez, María José Caballero, María del Pino Quintana-Montesdeoca, Antonio Espinosa de los Monteros, Miguel Antonio Rivero, Ayoze Castro, Valentín Pérez and Marisa Andrada

Animals 2023, 13(10), 1693; https://doi.org/10.3390/ani13101693 - 19 May 2023

Cited by 1 | Viewed by 2936

Abstract

Paratuberculosis (PTB), caused by Mycobacterium avium subspecies paratuberculosis (MAP), causes significant financial losses in the ruminant industry. The aim of this study is to describe the concomitant pathological findings as well as PTB-induced lesions in 39 naturally infected goats (15 vaccinated and 24 [...] Read more.

Paratuberculosis (PTB), caused by Mycobacterium avium subspecies paratuberculosis (MAP), causes significant financial losses in the ruminant industry. The aim of this study is to describe the concomitant pathological findings as well as PTB-induced lesions in 39 naturally infected goats (15 vaccinated and 24 non-vaccinated). All animals exhibited MAP-induced microscopic lesions affecting target organs, although only 62% of those were detected grossly. Mainly concomitant inflammatory pathologies were recognized affecting the hemolymphatic, respiratory and gastrointestinal systems. Non-vaccinated animals exhibited both moderate and marked granulomatous enteritis in contrast with vaccinated ones which presented mild intestinal affection. Our results demonstrate that non-vaccinated animals presented pneumonia in all age groups studied (from 12 up to >48 months old). A significantly higher prevalence of ileocecal valve PTB lesions was detected in non-vaccinated animals with pneumonic lesions (p = 0.027). Furthermore, a reduction of gastrointestinal non-PTB processes was described in vaccinated goats. In conclusion, a PTB infected goat herd can be affected by a wide range of concomitant pathologies, mostly inflammatory in origin. Anatomic pathology is of crucial importance for correct herd diagnosis and histopathology is an indispensable tool for lesion detection. Additionally, anti-MAP vaccination could have a beneficial effect on the reduction of respiratory and gastrointestinal non-PTB diseases. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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18 pages, 2259 KiB

Open AccessArticle

Mycobacterium avium subsp. Paratuberculosis in Different Environmental Samples from a Dairy Goat Barn—Implications for Sampling Strategies for Paratuberculosis Diagnostic and Prevention

by Chris Pickrodt, Karsten Donat, Udo Moog and Heike Köhler

Animals 2023, 13(10), 1688; https://doi.org/10.3390/ani13101688 - 18 May 2023

Cited by 2 | Viewed by 1133

Abstract

Environmental samples are often used to classify the paratuberculosis status of cattle herds. The disease is caused by Mycobacterium avium subsp. paratuberculosis (MAP), predominantly through oral ingestion during infancy. In this explorative study, the presence of MAP was determined in the barn environment [...] Read more.

Environmental samples are often used to classify the paratuberculosis status of cattle herds. The disease is caused by Mycobacterium avium subsp. paratuberculosis (MAP), predominantly through oral ingestion during infancy. In this explorative study, the presence of MAP was determined in the barn environment of a paratuberculosis-infected vaccinated dairy goat herd. A total of 256 bedding, dust, feed, and water samples were collected at eight time points and examined using culture and qPCR. Detection rates of both methods were compared, and factors determining MAP confirmation were identified. MAP was cultured from 28 bedding and one dust sample, while MAP DNA was detected in all materials (117/256). Samples from high animal traffic areas and those collected during the indoor season were more likely to yield positive culture and qPCR results. Cultivation of MAP from kidding pens indicated this area as a possible infection site. Dust proved to be the most suitable material for detecting MAP DNA, as bedding was for MAP culture. Environmental sampling was demonstrated to be an effective way to detect MAP in a dairy goat herd. qPCR results could confirm herd infection, while culture results provided insight into crucial areas for MAP transmission. These findings should be considered when designing farm-specific paratuberculosis control plans. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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17 pages, 2909 KiB

Open AccessArticle

Differences in Faecal Microbiome Taxonomy, Diversity and Functional Potential in a Bovine Cohort Experimentally Challenged with Mycobacterium avium subsp. paratuberculosis (MAP)

by Chloe Matthews, Aaron M. Walsh, Stephen V. Gordon, Bryan Markey, Paul D. Cotter and Jim O' Mahony

Animals 2023, 13(10), 1652; https://doi.org/10.3390/ani13101652 - 16 May 2023

Viewed by 1471

Abstract

Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne’s disease in ruminants, a chronic enteritis which results in emaciation and eventual loss of the animal. Recent advances in metagenomics have allowed a more in-depth study of complex microbiomes, including that of [...] Read more.

Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne’s disease in ruminants, a chronic enteritis which results in emaciation and eventual loss of the animal. Recent advances in metagenomics have allowed a more in-depth study of complex microbiomes, including that of gastrointestinal tracts, and have the potential to provide insights into consequences of the exposure of an animal to MAP or other pathogens. This study aimed to investigate taxonomic diversity and compositional changes of the faecal microbiome of cattle experimentally challenged with MAP compared to an unexposed control group. Faecal swab samples were collected from a total of 55 animals [exposed group (n = 35) and a control group (n = 20)], across three time points (months 3, 6 and 9 post-inoculation). The composition and functional potential of the faecal microbiota differed across time and between the groups (p < 0.05), with the primary differences, from both a taxonomic and functional perspective, occurring at 3 months post inoculation. These included significant differences in the relative abundance of the genera Methanobrevibacter and Bifidobacterium and also of 11 other species (4 at a higher relative abundance in the exposed group and 7 at a higher relative abundance in the control group). Correlations were made between microbiome data and immunopathology measurements and it was noted that changes in the microbial composition correlated with miRNA-155, miR-146b and IFN-ɣ. In summary, this study illustrates the impact of exposure to MAP on the ruminant faecal microbiome with a number of species that may have relevance in veterinary medicine for tracking exposure to MAP. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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18 pages, 2210 KiB

Open AccessArticle

Effects of Silirum^®-Based Vaccination Programs on Map Fecal Shedding and Serological Response in Seven French Dairy Herds

by Fabien Corbiere, Dorra Guellouz, Christian Tasca, Laurent Foures, Emma Dubaux and Gilles Foucras

Animals 2023, 13(9), 1569; https://doi.org/10.3390/ani13091569 - 08 May 2023

Viewed by 1446

Abstract

(1) Background: paratuberculosis is an important disease in ruminants, causing worldwide economic losses to the livestock industry. Although vaccination is known not to prevent transmission of the causative agent Mycobacterium avium subsp. paratuberculosis (Map), it is considered an effective tool for paratuberculosis in [...] Read more.

(1) Background: paratuberculosis is an important disease in ruminants, causing worldwide economic losses to the livestock industry. Although vaccination is known not to prevent transmission of the causative agent Mycobacterium avium subsp. paratuberculosis (Map), it is considered an effective tool for paratuberculosis in infected herds. The objectives of this controlled field study were to evaluate the effects of the whole-cell heat-killed Silirum^® vaccine on Map fecal shedding and serological status in dairy herds infected with paratuberculosis. (2) Methods: The serological status (ELISA) and fecal shedding (qPCR) of 358 vaccinated cows were assessed over 3 years in 7 infected dairy herds in the Meuse department, France. Within each herd, cows from the last non-vaccinated birth cohort (n = 265) were used as controls. The probability and level of Map fecal shedding and the serological status were modeled using multivariable mixed general linear regression models. (3) Results: Overall, 34.7% of cows tested positive at least once on fecal qPCR, with significant differences between herds, but high shedding levels were observed in only 5.5% of cows. Compared to non-vaccinated seronegative cows, a statistically significant reduction in the probability of Map shedding was found only in cows vaccinated before 4 to 5 months of age that tested negative for Map antibodies throughout the study period (odds ratio = 0.5, 95% confidence interval: 0.3–0.9, p = 0.008), but no significant effect of vaccination on the amount of Map shedding could be evidenced. Finally, the younger the cows were when vaccinated, the less they tested positive on the serum ELISA. (4) Conclusions: a beneficial effect of vaccination on Map fecal shedding may exist in cows vaccinated before 4 to 5 months of age. The variability of the serum ELISA response in vaccinated cows remains to be investigated. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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13 pages, 1052 KiB

Open AccessArticle

Mycobacterium avium subsp. paratuberculosis in Sheep and Goats in Austria: Seroprevalence, Risk Factors and Detection from Boot Swab Samples

by Juliane Schrott, Eva Sodoma, Michael Dünser, Alexander Tichy and Johannes Lorenz Khol

Animals 2023, 13(9), 1517; https://doi.org/10.3390/ani13091517 - 30 Apr 2023

Cited by 2 | Viewed by 1581

Abstract

This study aimed to investigate the prevalence of Mycobacterium avium subsp. paratuberculosis (MAP) in small ruminants in Austria by testing 22,019 serum samples with ELISA for the presence of specific antibodies. Furthermore, detailed investigations in five MAP-infected goat herds were carried out by [...] Read more.

This study aimed to investigate the prevalence of Mycobacterium avium subsp. paratuberculosis (MAP) in small ruminants in Austria by testing 22,019 serum samples with ELISA for the presence of specific antibodies. Furthermore, detailed investigations in five MAP-infected goat herds were carried out by ELISA, qPCR and bacterial culture. The found animal-level apparent MAP seroprevalence was 2.0% for goats and 0.7% for sheep (calculated true prevalence 3.5% and 1.2%, respectively). Herd-level apparent MAP seroprevalence was 11.1% for goat herds and 8.9% for sheep flocks. Significant risk factors for seropositivity in goat herds were: herd size, animal trading, farmed as a dairy herd, Animal Health Service membership and cohabitation with farmed game. For sheep flocks, seroprevalence was significantly higher in flocks with animal trading and where cattle or goats were kept in the flock, respectively. The overall apparent within-herd MAP seroprevalence in the five goat farms investigated was 21.8% (11.7%–28.0%, calculated true seroprevalence 38.6%) and an overall rate of MAP shedding of 12.3% was detected (5.0%–24.7%). It was possible to identify MAP by culture using boot swab samples in each herd. The results indicated a moderate MAP infection rate in small ruminants in Austria. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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11 pages, 545 KiB

Open AccessArticle

Evaluation of Environmental Sampling for Detection of Mycobacterium avium subspecies paratuberculosis in the Pre-Weaned Calf Area and Calving Area of Infected Dairy Farms Enrolled in a Voluntary Johne’s Disease Control Programme

by Niamh L. Field, John F. Mee and Conor G. McAloon

Animals 2023, 13(4), 669; https://doi.org/10.3390/ani13040669 - 14 Feb 2023

Cited by 1 | Viewed by 1637

Abstract

One of the pillars of Johne’s disease control is to break the cycle of transmission from infectious adult animals to young susceptible animals. Many control programmes utilise a risk assessment and management plan (RAMP) to identify specific risks for transmission of infection on [...] Read more.

One of the pillars of Johne’s disease control is to break the cycle of transmission from infectious adult animals to young susceptible animals. Many control programmes utilise a risk assessment and management plan (RAMP) to identify specific risks for transmission of infection on individual farms and then recommend tailored biosecurity measures to mitigate the risk. It is important that infected farms in particular, practice effective biocontainment in the calving area and pre-weaned calf area. The objectives of this study were: (1) to determine what proportion of MAP-infected farms (PCR-positive) enrolled in a control programme had detectable MAP in their calf environment; (2) to compare RAMP scores and apparent within-herd prevalence (aWHP) of PCR-positive and PCR-negative farms; (3) to evaluate the correlation between RAMP scores, aWHP and levels of contamination based on PCR test Ct value. A novel environmental sampling protocol combining manure samples and boot swab samples was conducted in the calving area and pre-weaned calf area on 28 dairy farms with PCR-confirmed MAP infection. All samples were tested with PCR. Logistic regression modelling was used to evaluate the association between RAMP score and aWHP and PCR outcome. Overall, 46% of farms had positive PCR samples in either the calving area, pre-weaned calf area or both. The calving area was positive in 36% of farms and the pre-weaned calf area was positive in 21% of farms. There was a moderate, negative correlation (r = −0.45; p = 0.08) observed between RAMP scores and Ct value at the sample-level that slightly missed the required significance level. No significant association was identified between RAMP scores or aWHP and PCR test outcome (positive or negative). It was concluded that environmental sampling of the calving area and pre-weaned calf area has potential applications in the assessment of transmission risk on infected farms and could be used to monitor the efficacy of biosecurity measures over time. Further research conducted on a larger scale is required to support these results. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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12 pages, 841 KiB

Open AccessArticle

The Upregulation of Cathepsin G Is Associated with Resistance to Bovine Paratuberculosis

by Maria Canive, Gerard Badia-Bringué and Marta Alonso-Hearn

Animals 2022, 12(21), 3038; https://doi.org/10.3390/ani12213038 - 04 Nov 2022

Cited by 2 | Viewed by 1292

Abstract

An in silico genomic–transcriptomic combined approach allowed the identification of a polymorphism (cis-eQTL-rs41976219) in the Bos taurus genome associated with the CTSG mRNA expression in bovine blood samples, which suggests that individual genetic variation might modulate the CTSG transcriptional response. In the current [...] Read more.

An in silico genomic–transcriptomic combined approach allowed the identification of a polymorphism (cis-eQTL-rs41976219) in the Bos taurus genome associated with the CTSG mRNA expression in bovine blood samples, which suggests that individual genetic variation might modulate the CTSG transcriptional response. In the current study, a sandwich ELISA is used to measure the CTSG protein levels in supernatants of monocyte-derived macrophages (MDMs) isolated from cows with the AA (n = 5) and AC (n = 11) genotypes for the rs41976219 and infected ex vivo with MAP. Cows with the AC genotype have significantly higher CTSG protein levels (1.85 ng/mL) in the supernatants of enriched CD14+-MDMs after 2 h of infection when compared with infected CD14+-MDMs from cows with the AA genotype (1.68 ng/mL). Statistically significant differences in the intracellular MAP load at 7 d p.i. are observed between animals with the AA (2.16 log CFUs) and AC (1.44 log CFUs) genotypes. Finally, the association between the rs41976219 allelic variants and resistance to PTB is tested in a larger cattle population (n = 943) classified according to the presence (n = 442) or absence (n = 501) of PTB-associated lesions. The presence of the two minor alleles in the rs41976219 (CC) is more frequent among healthy cows than in cows with PTB-associated lesions in gut tissues (2.2% vs. 1.4%, OR = 0.61). In agreement with this, the CTSG levels in plasma samples of cows without lesions in gut tissues and with the CC (n = 8) genotype are significantly higher than in the plasmas of cows with the AA + AC (n = 36) genotypes. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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Review

Jump to: Research

27 pages, 904 KiB

Open AccessReview

Modeling Paratuberculosis in Laboratory Animals, Cells, or Tissues: A Focus on Their Applications for Pathogenesis, Diagnosis, Vaccines, and Therapy Studies

by Ana Jolly, Bárbara Fernández, Silvia Leonor Mundo and Natalia Elguezabal

Animals 2023, 13(22), 3553; https://doi.org/10.3390/ani13223553 - 17 Nov 2023

Viewed by 1330

Abstract

Paratuberculosis is a chronic granulomatous enteritis caused by Mycobacterium avium subsp. Paratuberculosis that affects a wide variety of domestic and wild animals. It is considered one of the diseases with the highest economic impact on the ruminant industry. Despite many efforts and intensive [...] Read more.

Paratuberculosis is a chronic granulomatous enteritis caused by Mycobacterium avium subsp. Paratuberculosis that affects a wide variety of domestic and wild animals. It is considered one of the diseases with the highest economic impact on the ruminant industry. Despite many efforts and intensive research, paratuberculosis control still remains controversial, and the existing diagnostic and immunoprophylactic tools have great limitations. Thus, models play a crucial role in understanding the pathogenesis of infection and disease, and in testing novel vaccine candidates. Ruminant animal models can be restricted by several reasons, related to space requirements, the cost of the animals, and the maintenance of the facilities. Therefore, we review the potential and limitations of the different experimental approaches currently used in paratuberculosis research, focusing on laboratory animals and cell-based models. The aim of this review is to offer a vision of the models that have been used, and what has been achieved or discovered with each one, so that the reader can choose the best model to answer their scientific questions and prove their hypotheses. Also, we bring forward new approaches that we consider worth exploring in the near future. Full article

(This article belongs to the Special Issue Mycobacterium avium Subspecies Paratuberculosis Infection in Ruminants—Agent, Disease, Diagnosis, and Control)

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