Full Text Available The Norwegian surveillance and control programme for paratuberculosis revealed 8 seroreactors in a single dairy cattle herd that had no clinical signs of Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis infection. Paratuberculosis had been a clinical problem in goats several years previously in this herd. All 45 cattle were culled and a thorough investigation of the infection status was conducted by the use of interferon-γ (IFN-γ immunoassay, measurement of antibodies, and pathological and bacteriological examination. In the IFN-γ immunoassay, 9 animals gave positive results, and 13 were weakly positive, while 19 animals were negative. In the serological test,10 animals showed positive reactions, and 5 were doubtful, while 30 animals gave negative reactions. There appeared to be a weak trend toward younger animals having raised IFN-γ and older animals having raised serological tests. Histopathological lesions compatible with paratuberculosis were diagnosed in 4 animals aged between 4 and 9 years. Three of these animals had positive serological reaction and one animal gave also positive results in the IFN-γ immunoassay. Infection was confirmed by isolation of M. a. paratuberculosis from 2 of these 4 animals. One single bacterial isolate examined by restriction fragment length polymorphism (RFLP had the same profile, B-C1, as a strain that had been isolated from a goat at the same farm several years previously. Despite many animals being positive in one or both of the immunological tests, indicative of a heavily infected herd, none of the animals showed clinical signs and only one cow was shown to be shedding bacteria. A cross-reaction with other mycobacteria might have caused some of the immunoreactions in these animals. It is also possible that the Norwegian red cattle breed is resistant to clinical infection with M. a. paratuberculosis.
McAloon, Conor G; Whyte, Paul; More, Simon J; O'Grady, Luke; Doherty, Michael L
Paratuberculosis is a challenging disease to control at farm level, in part due to the poor sensitivity of diagnostic tests and a prolonged incubation period. Simulation studies have highlighted on-farm management to be the most important factor in preventing on-farm spread. A risk assessment (RA) and management plan (MP) approach (collectively, RAMP) has been adopted around the world as the most appropriate method of controlling disease in infected farms. However, there are problems with RAMP that remain to be resolved. The RA relies heavily on farmer recollection and estimation resulting in subjectivity and substantial inter-observer variability. MPs consist of a series of qualitative, farm specific recommendations showing how management can be improved. However, MP assessment is generally conducted informally, and progress is monitored through 'end-point' diagnostic testing of adult animals and repeated risk assessments. Hazard analysis and critical control point (HACCP) has been developed as a proactive alternative to end-point testing. We hypothesise that farm-based HACCP systems may be a useful alternative to RAMP on farms where more intensive monitoring and evaluation of controls for paratuberculosis is required. Therefore, the objective of this methodological study was to develop a HACCP-based system for paratuberculosis control. Critical control points (CCPs) relating to peri-parturient area management, calving, new-born calf management and colostrum management were identified as areas where additional control could be exerted above existing methods. Novel monitoring systems were developed for each CCP, along with targets and corrective actions. This system is intended for use in high prevalence herds, or farms where more robust monitoring of key control points may be beneficial. It is currently being trialled on infected commercial dairy herds in Ireland. Copyright © 2015 Elsevier B.V. All rights reserved.
Kirkeby, Carsten; Græsbøll, Kaare; Hisham Beshara Halasa, Tariq
Background: Mycobacterium avium subsp. paratuberculosis (MAP) infections in cattle are generally challenging to detect and cost-effective test strategies are consequently difficult to identify. MAP-specific antibody ELISAs for milk and serum are relatively inexpensive, but their utility is influe......Background: Mycobacterium avium subsp. paratuberculosis (MAP) infections in cattle are generally challenging to detect and cost-effective test strategies are consequently difficult to identify. MAP-specific antibody ELISAs for milk and serum are relatively inexpensive, but their utility...
Mikkelsen, Heidi; Jungersen, Gregers; Nielsen, Søren Saxmose
Paratuberculosis is a chronic infection of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). It is possible to detect infection with paratuberculosis at different stages of disease by means of various diagnostic test strategies. The objective of the present study was to evalu......Paratuberculosis is a chronic infection of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). It is possible to detect infection with paratuberculosis at different stages of disease by means of various diagnostic test strategies. The objective of the present study...
Weber, M.F.; Nielen, M.; Velthuis, A.G.J.; Roermund, van H.J.W.
bulk milk quality assurance programme for Mycobacterium avium subsp. paratuberculosis (Map) in dairy herds was simulated with a stochastic simulation model (JohneSSim). The aim of this study was to evaluate the epidemiological and economic effects of preventive management measures and various test
More, S J; Cameron, A R; Strain, S; Cashman, W; Ezanno, P; Kenny, K; Fourichon, C; Graham, D
As part of a broader control strategy within herds known to be infected with Mycobacterium avium ssp. paratuberculosis (MAP), individual animal testing is generally conducted to identify infected animals for action, usually culling. Opportunities are now available to quantitatively compare different testing strategies (combinations of tests) in known infected herds. This study evaluates the effectiveness, cost, and cost-effectiveness of different testing strategies to identify infected animals at a single round of testing within dairy herds known to be MAP infected. A model was developed, taking account of both within-herd infection dynamics and test performance, to simulate the use of different tests at a single round of testing in a known infected herd. Model inputs included the number of animals at different stages of infection, the sensitivity and specificity of each test, and the costs of testing and culling. Testing strategies included either milk or serum ELISA alone or with fecal culture in series. Model outputs included effectiveness (detection fraction, the proportion of truly infected animals in the herd that are successfully detected by the testing strategy), cost, and cost-effectiveness (testing cost per true positive detected, total cost per true positive detected). Several assumptions were made: MAP was introduced with a single animal and no management interventions were implemented to limit within-herd transmission of MAP before this test. In medium herds, between 7 and 26% of infected animals are detected at a single round of testing, the former using the milk ELISA and fecal culture in series 5 yr after MAP introduction and the latter using fecal culture alone 15 yr after MAP introduction. The combined costs of testing and culling at a single round of testing increases with time since introduction of MAP infection, with culling costs being much greater than testing costs. The cost-effectiveness of testing varied by testing strategy. It was also
St-Jean, G; Jernigan, A D
Paratuberculosis is a chronic, debilitating, fatal condition that usually is clinically undetectable until the onset of copious diarrhea. Paratuberculosis is caused by an acid-fast organism, M. paratuberculosis. Successful eradication of paratuberculosis depends on the early detection of infected animals, thereby allowing removal of carrier animals from the herd. Treatment for paratuberculosis is therefore rarely indicated or undertaken; however, treatment may be considered for animals of exceptional genetic value or companion animals. Antimicrobials reviewed in this article for the treatment of paratuberculosis include isoniazid, rifampin, streptomycin, amikacin, clofazimine, and dapsone. Treatment of paratuberculosis requires daily medication for extended periods and results in palliation of the disease rather than a definitive cure. The treatment for paratuberculosis recommended by the authors is isoniazid at 20 mg/kg administered orally every 24 hours for the rest of the animal's life. When the animal has acute onset of diarrhea, rifampin at 20 mg/kg every 24 hours is also administered orally. In severe, imminently life-threatening cases, an aminoglycoside should be administered concurrently for 3 to 8 weeks. This protocol (isoniazid, rifampin, and an aminoglycoside) will help ensure that Mycobacteria organisms are sensitive to at least two of the antibiotics. Rifampin treatment can be discontinued if clinical signs of paratuberculosis disappear and the cost of therapy is judged excessive. The combined therapeutic approach has been used in three animals, and the results are presented in this article. Because isoniazid, rifampin, and some aminoglycosides are not approved for use in food animals in the United States of America, the meat or milk from treated animals should not be used for human consumption.
Nielsen, S.S.; Weber, M.F.; Kudahl, Anne Margrethe Braad
in the design of certification, surveillance, and control strategies for paratuberculosis in cattle herds. A detailed comparison is made between the Dutch JohneSSim and the Danish PTB-Simherd, using the same context of a set of control strategies in a typical Dutch/Danish herd. The conclusion is that while...
Beaver, A; Sweeney, R W; Hovingh, E; Wolfgang, D R; Gröhn, Y T; Schukken, Y H
Mycobacterium avium ssp. paratuberculosis (MAP), the causative agent of ruminant Johne's disease, presents a particular challenge with regard to infection mitigation on dairy farms. Diagnostic testing strategies to identify and quantify MAP and associated antibodies are imperfect, and certain facets of the relationship between diagnostic tests remain to be explored. Additional repeated-measures data from known infected animals are needed to complement the body of cross-sectional research on Johne's disease-testing methods. Statistical models that accurately account for multiple diagnostic results while adjusting for the effects of individual animals and herds over time can provide a more detailed understanding of the interplay between diagnostic outcomes. Further, test results may be considered as continuous wherever possible so as to avoid the information loss associated with dichotomization. To achieve a broader understanding of the relationship between diagnostic tests, we collected a large number of repeated fecal and milk samples from 14 infected cows, in addition to bulk milk samples, from 2 low-prevalence dairy herds in the northeast United States. Predominately through the use of mixed linear modeling, we identified strong associations between milk ELISA optical density, fecal quantitative PCR, and fecal culture in individual animals while concurrently adjusting for variables that could alter these relationships. Notably, we uncovered subtleties in the predictive abilities of fecal shedding level on milk ELISA results, with animals categorized as disease progressors reaching higher ELISA optical density levels. Moreover, we observed that spikes in fecal shedding could predict subsequent high ELISA values up to 2 mo later. We also investigated the presence of MAP in individual milk samples via PCR and noted an association between poor udder hygiene and MAP positivity in milk, suggesting some level of environmental contamination. The paucity of positive milk
Nielsen, Søren Saxmose; Weber, M.F.; Kudahl, Anne Margrethe Braad
Stochastic simulation models are widely accepted as a means of assessing the impact of changes in daily management and the control of different diseases, such as paratuberculosis, in dairy herds. This paper summarises and discusses the assumptions of four stochastic simulation models and their use...... the models are somewhat different in their underlying principles and do put slightly different values on the different strategies, their overall findings are similar. Therefore, simulation models may be useful in planning paratuberculosis strategies in dairy herds, although as with all models caution...
Verdugo, Cristobal; Toft, Nils; Nielsen, Søren
estimates. Bayesian posterior probabilities were computed in order to compare prevalence between the years. A total of 665,700 samples were included in the study, from 221,914, 224,040, and 220,466 cows sourced from 1138, 1112, and 1059 herds in years 2011, 2012, and 2013, respectively. In that period, HTP...... estimates of 0.92 (95% posterior probability interval (PPI), 0.87-0.96), 0.78 (95% PPI, 0.74-0.83), and 0.75 (95% PPI, 0.71-0.78) were recorded, respectively. Low TP were observed, with population mean estimates of 0.08 (95% PPI, 0.07-0.08), 0.07 (95% PPI, 0.07-0.08), and 0.07 (95% PPI, 0.......06-0.07) for the three consecutive years. Statistically-important differences were recorded for HTP and population mean TP estimates between years, indicating a trend for a decreasing level of MAP infection at both herd and animal level. Model results showed that MAP infection was widespread among the Dairy cattle herds...
Full Text Available A total of 355 cows were sampled (serum, n=315; faeces, n=355; milk, n=209 from dairy farms located in the Punjab state of India. Faeces and serum/milk samples were screened by acid fast staining and “indigenous ELISA,” respectively. IS900 PCR was used to screen faeces and milk samples. Bio-load of MAP in dairy cows was 36.9, 15.6, 16.3, and 14.4%, using microscopy, serum ELISA, milk ELISA and milk PCR, respectively. Estimated kappa values between different test combinations: serum and milk ELISA, faecal microscopy and faecal PCR, milk ELISA and milk PCR, faecal PCR and serum ELISA were 0.325, 0.241, 0.682, and 0.677, respectively. Estimation of the relative sensitivity and specificity of different tests in the present study indicated that “serum ELISA” and “milk ELISA” were good screening tests, add “milk PCR” was “confirmatory test” for MAP infection. Combination of milk ELISA with milk PCR may be adopted as a model strategy for screening and diagnosis of JD in lactating/dairy cattle herds in Indian conditions.
Nielsen, Søren Saxmose; Hansen, Kira Frello; Kvist, Louise
potentially important for MAP transmission control. The objective of this study was therefore to assess the dam's infection progress and the within-herd test-prevalence as predictors of MAP infection in Danish dairy cattle. MAP specific antibody ELISA records from 95,025 dam-offspring pairs were combined...... with test-prevalence estimates from 939 Danish Holstein herds. The odds of testing ELISA-positive given the within-herd test-prevalence and the time-period a dam had had MAP specific antibodies were estimated for the offspring. Both dams and offspring were tested as adults, and parity-group was used...
van Hulzen, K J E; Heuven, H C M; Nielen, M; Hoeboer, J; Santema, W J; Koets, A P
A better understanding of the biodiversity of Mycobacterium avium subsp. paratuberculosis (MAP) offers more insight in the epidemiology of paratuberculosis and therefore may contribute to the control of the disease. The aim of this study was to investigate the genetic diversity in bovine MAP isolates using PCR-based methods detecting genetic elements called Variable-Number Tandem Repeats (VNTRs) and Mycobacterial Interspersed Repetitive Units (MIRUs) to determine if multiple MAP strains can coexist on farms with endemic MAP infection. For 52 temporal isolates originating from infected cattle from 32 commercial dairy herds with known trading history, MIRU-VNTR analysis was applied at 10 loci of which six showed variation. Within the group of 52 isolates, 17 different MIRU-VNTR patterns were detected. One MIRU-VNTR pattern was found in 29 isolates, one pattern in four isolates, one pattern in three isolates, two times one MIRU-VNTR pattern was found occurring in two isolates, and 12 patterns were found only once. Eleven herds provided multiple isolates. In five herds a single MIRU-VNTR pattern was detected among multiple isolates whereas in six herds more than one pattern was found. This study confirms that between dairy farms as well as within dairy farms, infected animals shed MAP with different MIRU-VNTR patterns. Analysis of trading history and age within herds indicated that cows born within the same birth cohort can be infected with MAP strains exhibiting variations in the number of MIRU-VNTR repeats. These data indicate that such multiple genotypes of MAP can coexist within one herd. Copyright © 2010 Elsevier B.V. All rights reserved.
Weber, M.F.; Roermund, van H.J.W.; Vernooij, J.C.M.; Kalis, C.H.J.; Stegeman, J.A.
The rate and structure of cattle transfers between 206 Dutch cattle herds with a 'Mycobacterium avium subsp. paratuberculosis (Map)-free' status by November 2002, were analyzed over a 3-year period (November 1999-November 2002). Of the 206 'Map-free' herds, 184 were closed herds during the period
Cho, J; Tauer, L W; Schukken, Y H; Gómez, M I; Smith, R L; Lu, Z; Grohn, Y T
Johne's disease, or paratuberculosis, is a chronic infectious enteric disease of ruminants, caused by infection with Mycobacterium avium ssp. paratuberculosis (MAP). Given the absence of a fail-safe method of prevention or a cure, Johne's disease can inflict significant economic loss on the US dairy industry, with an estimated annual cost of over $200 million. Currently available MAP control strategies include management measures to improve hygiene, culling MAP serologic- or fecal-positive adult cows, and vaccination. Although the 2 first control strategies have been reported to be effective in reducing the incidence of MAP infection, the changes in herd management needed to conduct these control strategies require significant effort on the part of the dairy producer. On the other hand, vaccination is relatively simple to apply and requires minor changes in herd management. Despite these advantages, only 5% of US dairy operations use vaccination to control MAP. This low level of adoption of this technology is due to limited information on its cost-effectiveness and efficacy and some important inherent drawbacks associated with current MAP vaccines. This study investigates the epidemiological effect and economic values of MAP vaccines in various stages of development. We create scenarios for the potential epidemiological effects of MAP vaccines, and then estimate economically justifiable monetary values at which vaccines become economically beneficial to dairy producers such that a net present value (NPV) of a farm's net cash flow can be higher than the NPV of a farm using no control or alternative nonvaccine controls. Any vaccination with either low or high efficacy considered in this study yielded a higher NPV compared with a no MAP control. Moreover, high-efficacy vaccines generated an even higher NPV compared with alternative controls, making vaccination economically attractive. Two high-efficacy vaccines were particularly effective in MAP control and NPV
Kirkeby, Carsten Thure; Græsbøll, Kaare; Nielsen, Søren Saxmose
Paratuberculosis (PTB) is a chronic disease which may lead to reduced milk yield, lower animal welfare and death in cattle. The causative agent is Mycobacterium avium subsp. paratuberculosis (MAP). The economic consequences are particularly important incentives in the control and eradication...... of the infection. One strategy to control PTB in a herd is to purchase animals from farms with a low risk of MAP infection. We wanted to investigate the epidemiological and economic consequences of buying livestock from different supplier farms of low, medium or high risk, as well as farms with unknown status. We...
Kudahl, A B; Nielsen, S S; Ostergaard, S
Effect of time for culling cows infected with Mycobacterium avium ssp. paratuberculosis on prevalence and profitability was identified through simulations. Seven test-and-cull strategies with different culling criteria and no attempts to close infection routes were compared with strategies with (1) no control and (2) closure of infection routes and no culling. The effects on true prevalence and gross margin were evaluated in a herd with typical reproduction management (heat detection rate of 38%). This was repeated in a herd with poor reproduction management (heat detection rate of 28%), because poor reproduction leads to lack of replacement animals, which was hypothesized to affect the economic effects of culling. Effects of varying prices of milk, replacement heifers, and hourly wages were also evaluated. The simulated results predicted that immediate culling after the first positive antibody ELISA test would be the most effective culling strategy to reduce prevalence. However, closing transmission routes was even more effective in reducing the prevalence. In the first 3 to 6 yr, all test-and-cull strategies reduced gross margin by US$5 to 55/stall per year. These losses were fully compensated by increased gross margin in yr 6 to 19. In the short run (7 yr with typical reproduction and 10 yr with poor reproduction), it was most profitable to cull test-positive cows when their milk yield decreased below 85% of that expected according to their parity and lactation stage, especially in herds with poor reproduction management. However, this strategy only stabilized the prevalence and did not reduce it. In the long term (>7 yr from implementation of a strategy), it was most profitable to cull cows immediately or as soon as possible after testing positive the first time. Varying milk prices did not affect the ranking between the different culling strategies. Increased market price (20%) of replacement heifers made all culling strategies less profitable and made culling
Nielsen, Søren Saxmose; Toft, Nils
Detection of bulk tank milk (BTM) antibodies using ELISA (BTM-ELISA) may constitute an inexpensive test for surveillance of Mycobacterium avium subsp. paratuberculosis (MAP) infection in dairy cattle herds provided that the test is accurate and consistent. The objectives of this study were...... Danish Holstein herds over a period of one year. All samples were tested using a commercial indirect ELISA for detection of MAP specific antibodies. The individual cow's results were dichotomised and used to estimate the within-herd antibody prevalence at each test-date. These prevalences were...... to 0.60 when corrected for the within-herd antibody prevalence. Although the test-results were relatively consistent and correlated with the within-herd prevalence, the magnitude of the test-values makes it difficult to use the BTM-ELISA for surveillance of MAP infections in practice....
Avaliação sorológica e de fatores de risco para a infecção por Mycobacterium avium subsp. paratuberculosis em rebanhos leiteiros da Microrregião de Garanhuns, Pernambuco Serological evaluation and risk factors for Mycobacterium avium subsp. paratuberculosis infection in dairy herds of Microregion Garanhuns, Pernambuco
Luenda de M. e Sá
Full Text Available Objetivou-se com esse trabalho realizar um inquérito epidemiológico da infecção por Mycobacterium avium subsp. paratuberculosis (MAP em bovinos leiteiros da microrregião de Garanhuns, Pernambuco, Brasil. Para este estudo foram coletadas amostras sanguíneas de 408 animais, provenientes de 19 rebanhos localizados em 15 municípios. O exame sorológico foi realizado por Ensaio Imunoenzimático (ELISA indireto para detecção de anticorpos frente ao MAP. Em todas as propriedades, foi aplicado um questionário investigativo para análise dos fatores de risco, e as coordenadas geográficas coletadas por um aparelho de Global Position System (GPS para realização da distribuição espacial. A prevalência da infecção por MAP foi de 2,7% (11/408; I.C. 1,4-4,9. O número de focos foi 47,4% (9/19. Na análise de regressão logística foi identificado como fator de risco a taxa anual de nascimentos superior a 51 bezerros/ano (OR 3,8; I.C. 1,1-13,1. Desta forma, conclui-se que a infecção por MAP encontra-se presente nos rebanhos bovinos leiteiros da microrregião estudada e que medidas de controle baseadas nos fatores de risco identificados devem ser implementadas com o objetivo de reduzir o número de focos da infecção.The present study aimed to conduct an epidemiological investigation of Mycobacterium avium subsp. paratuberculosis (MAP infection in dairy cattle of the Garanhuns microregion, in Pernambuco, Brazil. Blood samples were collected from 408 animals from 19 herds located in 15 cities. Serological tests were performed by indirect immunoenzymatic assay (ELISA for antibodies against MAP. In all farms, a questionnaire to investigate risk factors was used, and Global Position System (GPS receivers were used to collect geographic coordinates to show the spatial distribution of the animals. The prevalence of MAP infected cattle was 2.7% (11/408; I.C. 1.4-4.9. The rate of infection was 47.4% (9/19. An annual birth rate over 51 calves
Mycobacterium avium subsp. paratuberculosis (MAP) infection in ruminants leads to a chronic and progressive enteric disease (Johne’s disease) that results in loss of intestinal function, poor body condition, and eventual death. Transmission is primarily through a fecal-oral route in neonates but con...
The study of host immune responses to Mycobacterium avium subsp. paratuberculosis (MAP) is complicated by a number of factors, including the protracted nature of the disease and the stealthy nature of the pathogen. Improved tools for the measurement of immunologic responses in ruminant species, par...
Kudahl, Anne Margrethe Braad; Nielsen, Søren Saxmose; Østergaard, Søren
Effect of time for culling cows infected with Mycobacterium avium ssp. paratuberculosis on prevalence and profitability was identified through simulations. Seven test-and-cull strategies with different culling criteria and no attempts to close infection routes were compared with strategies with (1...... would be the most effective culling strategy to reduce prevalence. However, closing transmission routes was even more effective in reducing the prevalence. In the first 3 to 6 yr, all test-and-cull strategies reduced gross margin by US$5 to 55/stall per year. These losses were fully compensated...... the ranking between the different culling strategies. Increased market price (20%) of replacement heifers made all culling strategies less profitable and made culling based on a milk yield criterion the most profitable culling strategy for a longer period (11 to 13 yr). A 20% reduction in heifer price made...
Khol, J L; Wassertheurer, M; Sodoma, E; Revilla-Fernández, S; Damoser, J; Osterreicher, E; Dünser, M; Kleb, U; Baumgartner, W
Mycobacterium avium ssp. paratuberculosis (MAP) causes Johne's disease (JD) in ruminants and is shed into the milk of infected cows, which contributes to the controversial discussion about a possible link between MAP and Crohn's disease in humans. The aim of the study was to investigate the risk for the entry of MAP in the food chain via milk from dairy farms with subclinical JD. Therefore, the occurrence of MAP in the milk of a dairy herd with a low prevalence of JD was studied in single and bulk tank milk samples over a period of 23 mo and compared with MAP shedding into feces. Milk, fecal, and blood samples were taken from all cows older than 1.5 yr of age at the beginning and the end of the trial and analyzed for MAP or specific antibodies. In addition, 63 cows (33 MAP infected and 30 MAP noninfected) were selected for monthly sampling. Raw and pasteurized bulk tank milk samples were collected on a monthly basis. The milk samples were tested for MAP by real-time quantitative PCR (qPCR), and the fecal samples were tested for bacterial shedding by qPCR or solid culture. Based on the results of the herd investigations, the prevalence of cows shedding MAP was around 5%; no cases of clinical JD were observed during the study period. The results of the ELISA showed high variation, with 2.1 to 5.1% positive milk samples and 14.9 to 18.8% ELISA-positive blood samples. Monthly milk sampling revealed low levels of MAP shedding into the individual milk samples of both MAP-infected and noninfected cows, with only 13 cows shedding the bacterium into milk during the study period. Mycobacterium avium ssp. paratuberculosis was not detected by qPCR in any raw or pasteurized bulk tank milk sample throughout the study. A significant positive association could be found between MAP shedding into milk and feces. From the results of the present study, it can be concluded that MAP is only shed via milk in a small proportion of cows with subclinical JD for a limited period of time and
Hulzen, van K.J.E.; Heuven, H.C.M.; Nielen, M.; Hoeboer, J.; Santema, W.J.; Koets, A.P.
A better understanding of the biodiversity of Mycobacterium avium subsp. paratuberculosis (MAP) offers more insight in the epidemiology of paratuberculosis and therefore may contribute to the control of the disease. The aim of this study was to investigate the genetic diversity in bovine MAP
Souriau, Armel; Freret, Sandrine; Foret, Benjamin; Willemsen, Peter T J; Bakker, Douwe; Guilloteau, Laurence A
Currently Mycobacterium avium subsp. paratuberculosis (MAP) infection is diagnosed through indirect tests based on the immune response induced by the infection. The antigens commonly used in IFN-γ release assays (IGRA) are purified protein derivative tuberculins (PPD). However, PPDs, lack both specificity (Sp) and sensitivity (Se) in the early phase of infection. This study investigated the potential of 16 MAP recombinant proteins and five lipids to elicit the release of IFN-γ in goats from herds with or without a history of paratuberculosis. Ten recombinant proteins were selected as potential candidates for the detection of MAP infection in young goats. They were found to detect 25 to 75% of infected shedder (IS) and infected non-shedder (INS) kids younger than 10months of age. In comparison, PPD was shown to detect only 10% of INS and no IS kids. For seven antigens, Se (21-33%) and Sp (≥90%) of IGRA were shown to be comparable with PPD at 20months old. Only three antigens were suitable candidates to detect IS adult goats, although Se was lower than that obtained with PPD. In paratuberculosis-free herds, IGRA results were negative in 97% of indoor goats and 86% of outdoor goats using the 10 antigens. However, 22 to 44% of one-year-old outdoor goats were positive suggesting that they may be infected. In conclusion, this study showed that ten MAP recombinant proteins are potential candidates for early detection of MAP infected goats. Combining these antigens could form a possible set of MAP antigens to optimize the Se of caprine IGRA. Copyright © 2017 Elsevier Ltd. All rights reserved.
Whist, A C; Liland, K H; Jonsson, M E; Sæbø, S; Sviland, S; Østerås, O; Norström, M; Hopp, P
Surveillance programs for animal diseases are critical to early disease detection and risk estimation and to documenting a population's disease status at a given time. The aim of this study was to describe a risk-based surveillance program for detecting Mycobacterium avium ssp. paratuberculosis (MAP) infection in Norwegian dairy cattle. The included risk factors for detecting MAP were purchase of cattle, combined cattle and goat farming, and location of the cattle farm in counties containing goats with MAP. The risk indicators included production data [culling of animals >3 yr of age, carcass conformation of animals >3 yr of age, milk production decrease in older lactating cows (lactations 3, 4, and 5)], and clinical data (diarrhea, enteritis, or both, in animals >3 yr of age). Except for combined cattle and goat farming and cattle farm location, all data were collected at the cow level and summarized at the herd level. Predefined risk factors and risk indicators were extracted from different national databases and combined in a multivariate statistical process control to obtain a risk assessment for each herd. The ordinary Hotelling's T(2) statistic was applied as a multivariate, standardized measure of difference between the current observed state and the average state of the risk factors for a given herd. To make the analysis more robust and adapt it to the slowly developing nature of MAP, monthly risk calculations were based on data accumulated during a 24-mo period. Monitoring of these variables was performed to identify outliers that may indicate deviance in one or more of the underlying processes. The highest-ranked herds were scattered all over Norway and clustered in high-density dairy cattle farm areas. The resulting rankings of herds are being used in the national surveillance program for MAP in 2014 to increase the sensitivity of the ongoing surveillance program in which 5 fecal samples for bacteriological examination are collected from 25 dairy herds
Sergeant, E.S.G.; Nielsen, Søren S.; Toft, Nils
of this study was to develop a method to estimate the probability of low within-herd prevalence of paratuberculosis for Danish dairy herds. A stochastic simulation model was developed using the R(R) programming environment. Features of this model included: use of age-specific estimates of test......-sensitivity and specificity; use of a distribution of observed values (rather than a fixed, low value) for design prevalence; and estimates of the probability of low prevalence (Pr-Low) based on a specific number of test-positive animals, rather than for a result less than or equal to a specified cut-point number of reactors....... Using this model, five herd-testing strategies were evaluated: (1) milk-ELISA on all lactating cows; (2) milk-ELISA on lactating cows 4 years old; (4) faecal culture on all lactating cows; and (5) milk-ELISA plus faecal culture in series on all lactating cows. The five testing strategies were evaluated...
Wolf, R; Barkema, H W; De Buck, J; Orsel, K
Mycobacterium avium ssp. paratuberculosis (MAP), the causative agent of Johne's disease, is present on most dairy farms in Alberta, causing economic losses and presenting a potential public health concern. The objective of this cross-sectional study was to identify risk factors for Alberta dairy herds being MAP-positive based on environmental samples (ES). Risk assessments were conducted and ES were collected on 354 Alberta dairy farms (62% of eligible producers) voluntarily participating in the Alberta Johne's Disease Initiative. In univariate logistic regression, risk factors addressing animal and pen hygiene, as well as the use of feeding equipment to remove manure and manure application on pastures, were all associated with the number of positive ES. Furthermore, based on factor analysis, risk factors were clustered and could be summarized as 4 independent factors: (1) animal, pen, and feeder contamination; (2) shared equipment and pasture contamination; (3) calf diet; and (4) cattle purchase. Using these factor scores as independent variables in multivariate logistic regression models, a 1-unit increase in animal, pen, and feeder contamination resulted in 1.31 times higher odds of having at least 1 positive ES. Furthermore, a 1-unit increase in cattle purchase also resulted in 1.31 times the odds of having at least 1 positive ES. Finally, a 100-cow increase in herd size resulted in an odds ratio of 2.1 for having at least 1 positive ES. In conclusion, cleanliness of animals, pens, and feeders, as well as cattle purchase practices, affected risk of herd infection with MAP. Therefore, improvements in those management practices should be the focus of effective tools to control MAP on dairy farms. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Pesqueira, M N; Yus, E; Factor, C; Mato, I; Sanjuán, M L; Eiras, C; Arnaiz, I; Diéguez, F J
The objective of this study was to determine the correlation between the results obtained with the ELISA technique for antibodies to Mycobacterium avium ssp. paratuberculosis in serum and bulk tank milk at the herd level. For this purpose, 203 samples of bulk tank milk were analyzed with 2 commercial ELISA from dairy herds with a prevalence of seropositive animals that was also determined. In regard to the reference test (results in blood serum), the sensitivity of the bulk tank milk test to detect high-positive herds (≥10% seroprevalence) ranged from 85.7 to 71.4%. The specificity to detect herds with no seropositive animals ranged from 70.5 to 53%. In a quantitative approach, Pearson correlation coefficients, reported as a measure of the linear association between herd seroprevalences and transformed optical density values recorded in bulk tank milk, were 0.39 and 0.54 for the studied ELISA. Although the test results were relatively fairly correlated with the within-herd prevalence, the practical utility of bulk tank milk testing for Mycobacterium avium ssp. paratuberculosis seems limited, especially regarding specificity. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Fecteau, Marie-Eve; Whitlock, Robert H; Buergelt, Claus D; Sweeney, Raymond W
This study investigated the susceptibility of 1- to 2-year-old cattle to Mycobacterium avium subsp. paratuberculosis (MAP) on pasture previously grazed by infected cattle. The exposure of yearling cattle to pastures contaminated with MAP resulted in infection with MAP, showing that age resistance to infection can be overcome by pressure of infection.
Mikkelsen, Heidi; Aagaard, Claus; Nielsen, Søren Saxmose
of the study were to evaluate immunogenicity and specificity of 14 novel recombinant antigens for use in the IFN-γ assay and to assess the consistency of IFN-γ responses. The antigens used were 4 ESAT-6 family members, 4 latency proteins, 4 secreted proteins including Ag85B, 3 other antigens and PPDj......Early stage Mycobacterium avium subsp. paratuberculosis (MAP) infection can be detected by measuring antigen specific cell mediated immune responses by the interferon gamma (IFN-γ) assay. Available IFN-γ assay use purified protein derivate of Johnin (PPDj) leading to low specificity. The objectives...... of the infected and non-infected herds were significantly (Passay using PPDj did not correlate with the results using the novel antigens since 5 of the 17 animals that were positive to PPDj were...
Mikkelsen, Heidi; Nielsen, Søren Saxmose; Jungersen, Gregers
time interval from blood sampling to culture. The objective of the study was to assess options for use of day-old blood samples for early-stage diagnosis of MAP infections. Bovine interleukin 12 (IL-12) can induce, and IL-10 reduce, IFN-γ production. Therefore, addition of IL-12 and anti-IL-10 could...... result in production of IFN-γ in samples previously exposed to MAP antigens. Whole blood samples were collected from heifers in a Danish dairy herd known to be infected with MAP. The samples were collected on three sample dates, and on each date the blood samples were stimulated with PPDj and recombinant......The interferon gamma (IFN-γ) test measuring specific cell-mediated immune responses in whole blood can be used for diagnosis at an early stage of Mycobacterium avium subsp. paratuberculosis (MAP) infection. A major obstacle for the practical use of IFN-γ testing is the recommended maximum 8 hour...
Elzo, M A; Rae, D O; Lanhart, S E; Hembry, F G; Wasdin, J G; Driver, J D
The objective of this research was to assess the association between 4 cow reproductive and weight traits, and 2 preweaning calf traits and ELISA scores for paratuberculosis (0 = negative, 1 = suspect, 2 = weak-positive, and 3 = positive) in a multibreed herd of cows ranging from 100% Angus (A) to 100% Brahman (B). Cow data were 624 gestation lengths (GL), 358 records of time open (TO), 605 calving intervals (CI), and 1240 weight changes from November to weaning in September (WC) from 502 purebred and crossbred cows. Calf data consisted of 956 birth weights (BWT), and 923 weaning weights adjusted to 205 d of age (WW205) from 956 purebred and crossbred calves. Traits were analyzed individually using multibreed mixed models that assumed homogeneity of variances across breed groups. Covariances among random effects were assumed to be zero. Fixed effects were year, age of cow, sex of calf, year x age of cow interaction (except WC), age of cow x sex of calf interaction (only for WC), and covariates for B fraction of sire and cow, heterosis of cow and calf, and ELISA score. Random effects were sire (except for TO and CI), dam, and residual. Regression estimates of cow and calf traits on ELISA scores indicated that lower cow fertility (longer TO), lower ability of cows to maintain weight (negative WC), lower calf BWT, and lower calf WW205 were associated with higher cow ELISA scores. Further research on the effects of subclinical paratuberculosis in beef cattle at regional and national levels seems advisable considering the large potential economic cost of this disease.
Nielsen, Søren Saxmose
the exposure of susceptible animals to the milk and faeces of infected animals. However, cost-effectiveness may depend on labour costs, and strategic use of diagnostics may have certain appeals through the information provided. Current bulk tank milk tests are not deemed to have a role in MAP control, whereas......Bovine paratuberculosis can be costly to farmers who, as a consequence, may be interested in control of the causative agent, Mycobacterium avium subsp. paratuberculosis (MAP). Between-herd spread is primarily due to movement of MAP-infected livestock, and within-herd transmission most often occurs...
Immunopathological changes and apparent recovery from infection revealed in cattle in an experimental model of Johne's disease using a lyophilised culture of Mycobacterium avium subspecies paratuberculosis.
Begg, Douglas J; Plain, Karren M; de Silva, Kumudika; Gurung, Ratna; Gunn, Alison; Purdie, Auriol C; Whittington, Richard J
Johne's disease (JD) or paratuberculosis is an economically significant, chronic enteropathy of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). Experimental models of JD in cattle are logistically challenging due to the need for long term monitoring, because the clinical disease can take years to manifest. Three trials were undertaken, the largest involving 20 cattle exposed orally to a low dose of C strain MAP and 10 controls studied for 4.75 years. Frequent blood and faecal sampling was used to monitor immunological and infection parameters, and intestinal biopsies were performed at two time points during the subclinical disease phase. Although clinical disease was not seen, there was evidence of infection in 35% of the animals and at necropsy 10% had histopathological lesions consistent with JD, similar to the proportions expected in naturally infected herds. Faecal shedding occurred in two distinct phases: firstly there was intermittent shedding <∼9 months post-exposure that did not correlate with disease outcomes; secondly, in a smaller cohort of animals, this was followed by more consistent shedding of increasing quantities of MAP, associated with intestinal pathology. There was evidence of regression of histopathological lesions in the ileum of one animal, which therefore had apparently recovered from the disease. Both cattle with histopathological lesions of paratuberculosis at necropsy had low MAP-specific interferon-gamma responses at 4 months post-exposure and later had consistently shed viable MAP; they also had the highest loads of MAP DNA in faeces 4.75 year s post-exposure. In a trial using a higher dose of MAP, a higher proportion of cattle developed paratuberculosis. The information derived from these trials provides greater understanding of the changes that occur during the course of paratuberculosis in cattle. Copyright © 2018 Elsevier B.V. All rights reserved.
Nielsen, Liza Rosenbaum
SUMMARY In this study within-herd prevalence of Salmonella Dublin was investigated in three age groups (calves, young stock, adult cows) during five herd visits at 3-month intervals of 14 endemically infected dairy herds. A total of 10162 paired faecal cultures and antibody measurements were used...... stock and adult cows than in calves. Hierarchical mixed-model results showed that seroprevalence was associated with the bacteriological status in calves and cows, but not in young stock. These results can be used to develop and validate theoretical infection dynamics models and to design effective...... control programmes for Salmonella Dublin in dairy herds....
Gurung, Ratna B; Begg, Douglas J; Purdie, Auriol C; Bach, Horacio; Whittington, Richard J
Evasion of host defense mechanisms and survival inside infected host macrophages are features of pathogenic mycobacteria including Mycobacterium avium subspecies paratuberculosis, the causative agent of Johne's disease in ruminants. Protein tyrosine phosphatase A (PtpA) has been identified as a secreted protein critical for survival of mycobacteria within infected macrophages. The host may mount an immune response to such secreted proteins. In this study, the humoral immune response to purified recombinant M. avium subsp. paratuberculosis PtpA was investigated using sera from a cohort of sheep infected with M. avium subsp. paratuberculosis and compared with uninfected healthy controls. A significantly higher level of reactivity to PtpA was observed in sera collected from M. avium subspecies paratuberculosis infected sheep when compared to those from uninfected healthy controls. PtpA could be a potential candidate antigen for detection of humoral immune responses in sheep infected with M. avium subspecies paratuberculosis. Copyright © 2014 Elsevier B.V. All rights reserved.
Available diagnostic assays for Mycobacterium avium subsp paratuberculosis (MAP) have poor sensitivities and cannot detect early stages of the infection, therefore, there is need to find new diagnostic markers for early infection detection and disease stages. We analyzed longitudinal IFN- gamma, ELI...
Fecteau, Marie-Eve; Pitta, Dipti W; Vecchiarelli, Bonnie; Indugu, Nagaraju; Kumar, Sanjay; Gallagher, Susan C; Fyock, Terry L; Sweeney, Raymond W
Johne's disease (JD) is a chronic, intestinal infection of cattle, caused by Mycobacterium avium subsp. paratuberculosis (MAP). It results in granulomatous inflammation of the intestinal lining, leading to malabsorption, diarrhea, and weight loss. Crohn's disease (CD), a chronic, inflammatory gastrointestinal disease of humans, has many clinical and pathologic similarities to JD. Dysbiosis of the enteric microbiota has been demonstrated in CD patients. It is speculated that this dysbiosis may contribute to the intestinal inflammation observed in those patients. The purpose of this study was to investigate the diversity patterns of fecal bacterial populations in cattle infected with MAP, compared to those of uninfected control cattle, using phylogenomic analysis. Fecal samples were selected to include samples from 20 MAP-positive cows; 25 MAP-negative herdmates; and 25 MAP-negative cows from a MAP-free herd. The genomic DNA was extracted; PCR amplified sequenced on a 454 Roche platform, and analyzed using QIIME. Approximately 199,077 reads were analyzed from 70 bacterial communities (average of 2,843 reads/sample). The composition of bacterial communities differed between the 3 treatment groups (P Permanova test). Taxonomic assignment of the operational taxonomic units (OTUs) identified 17 bacterial phyla across all samples. Bacteroidetes and Firmicutes constituted more than 95% of the bacterial population in the negative and exposed groups. In the positive group, lineages of Actinobacteria and Proteobacteria increased and those of Bacteroidetes and Firmicutes decreased (P < 0.001). Actinobacteria was highly abundant (30% of the total bacteria) in the positive group compared to exposed and negative groups (0.1-0.2%). Notably, the genus Arthrobacter was found to predominate Actinobacteria in the positive group. This study indicates that MAP-infected cattle have a different composition of their fecal microbiota than MAP-negative cattle.
Full Text Available Johne's disease (JD is a chronic, intestinal infection of cattle, caused by Mycobacterium avium subsp. paratuberculosis (MAP. It results in granulomatous inflammation of the intestinal lining, leading to malabsorption, diarrhea, and weight loss. Crohn's disease (CD, a chronic, inflammatory gastrointestinal disease of humans, has many clinical and pathologic similarities to JD. Dysbiosis of the enteric microbiota has been demonstrated in CD patients. It is speculated that this dysbiosis may contribute to the intestinal inflammation observed in those patients. The purpose of this study was to investigate the diversity patterns of fecal bacterial populations in cattle infected with MAP, compared to those of uninfected control cattle, using phylogenomic analysis. Fecal samples were selected to include samples from 20 MAP-positive cows; 25 MAP-negative herdmates; and 25 MAP-negative cows from a MAP-free herd. The genomic DNA was extracted; PCR amplified sequenced on a 454 Roche platform, and analyzed using QIIME. Approximately 199,077 reads were analyzed from 70 bacterial communities (average of 2,843 reads/sample. The composition of bacterial communities differed between the 3 treatment groups (P < 0.001; Permanova test. Taxonomic assignment of the operational taxonomic units (OTUs identified 17 bacterial phyla across all samples. Bacteroidetes and Firmicutes constituted more than 95% of the bacterial population in the negative and exposed groups. In the positive group, lineages of Actinobacteria and Proteobacteria increased and those of Bacteroidetes and Firmicutes decreased (P < 0.001. Actinobacteria was highly abundant (30% of the total bacteria in the positive group compared to exposed and negative groups (0.1-0.2%. Notably, the genus Arthrobacter was found to predominate Actinobacteria in the positive group. This study indicates that MAP-infected cattle have a different composition of their fecal microbiota than MAP-negative cattle.
Johne’s disease is a chronic infection of the small intestine caused by Mycobacterium avium subspecies paratuberculosis (MAP), an intracellular bacterium. The events of pathogen survival within the host cell(s), chronic inflammation and the progression from asymptomatic subclinical stage to an advan...
S. V. Singh
Full Text Available A total of 829 serum samples belonging to domestic livestock (Cattle, buffaloes, goat and sheep and driven from different parts of North India between 2005 to 2008, were screened to estimate the seroprevalence of Mycobacterium avium subspecies paratuberculosis (MAP infection using 'indigenous absorbed ELISA kit'. Seroprevalence of MAP in the domestic livestock was 23.1%. Prevalence was higher in large ruminants (24.1% as compared to small ruminants (22.5%. Highest seropositivity was in cattle (26.9%, followed by goats (23.9%, buffaloes (20.2%, and sheep (19.0%. In cattle region-wise, 25.8, 29.1 and 30.7% animals were positive from Mathura (UP, Rohtak (Haryana, and Bareilly (UP regions, respectively. In buffaloes, the highest prevalence was found at Bareilly (26.6% followed by Rohtak (20.0% and Bhaghpat (18.4% regions. In goats, 19.6, 37.5, 40.0 and 21.9% animals were positive from Mathura (farm herd, Etawah, Agra and Ajmer (farmers herd regions, respectively. In sheep, prevalence of MAP was 25.5 and 16.3% in Mathura and Mannavanur regions, respectively. In sheep, prevalence was higher in Northern region as compared to the Southern region of the country. The present study showed that the prevalence of MAP in domestic livestock was moderately higher; therefore there is an urgent need to control the disease at National level in order to improve per animal productivity in the country.
Correlation of antigen-specific IFN-γ responses of fresh blood samples from Mycobacterium avium subsp. paratuberculosis infected heifers with responses of day-old samples co-cultured with IL-12 or anti-IL-10 antibodies
Mikkelsen, Heidi; Aagaard, Claus; Nielsen, Søren Saxmose
Paratuberculosis is a chronic infection of the intestine of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). Early stage MAP infection can be detected by measuring cell-mediated immune responses using the interferon gamma (IFN-γ) assay. Whole blood samples are cultured...... to enhance IFN-γ responses of cultures stimulated with Johnin purified protein derivative (PPDj). Here we examined the correlation of IFN-γ production in response to PPDj and 15 recombinant antigens in day-old blood samples from heifers 10–21 months of age from a MAP infected herd with addition of either...... overnight with specific MAP antigens followed by quantification of IFN-γ by ELISA. It is recommended that the time interval from sampling to culture does not exceed eight hours but addition of the co-stimulating cytokine interleukin 12 (IL-12) or anti-IL-10 antibodies to culture have been demonstrated...
Pooley, Hannah B.; de Silva, Kumudika; Purdie, Auriol C.; Begg, Douglas J.; Whittington, Richard J.
ABSTRACT Determining the viability of bacteria is a key outcome of in vitro cellular infection assays. Currently, this is done by culture, which is problematic for fastidious slow-growing bacteria such as Mycobacterium avium subsp. paratuberculosis, where it can take up to 4 months to confirm growth. This study aimed to identify an assay that can rapidly quantify the number of viable M. avium subsp. paratuberculosis cells in a cellular sample. Three commercially available bacterial viability assays along with a modified liquid culture method coupled with high-throughput quantitative PCR growth detection were assessed. Criteria for assessment included the ability of each assay to differentiate live and dead M. avium subsp. paratuberculosis organisms and their accuracy at low bacterial concentrations. Using the culture-based method, M. avium subsp. paratuberculosis growth was reliably detected and quantified within 2 weeks. There was a strong linear association between the 2-week growth rate and the initial inoculum concentration. The number of viable M. avium subsp. paratuberculosis cells in an unknown sample was quantified based on the growth rate, by using growth standards. In contrast, none of the commercially available viability assays were suitable for use with samples from in vitro cellular infection assays. IMPORTANCE Rapid quantification of the viability of Mycobacterium avium subsp. paratuberculosis in samples from in vitro cellular infection assays is important, as it allows these assays to be carried out on a large scale. In vitro cellular infection assays can function as a preliminary screening tool, for vaccine development or antimicrobial screening, and also to extend findings derived from experimental animal trials. Currently, by using culture, it takes up to 4 months to obtain quantifiable results regarding M. avium subsp. paratuberculosis viability after an in vitro infection assay; however, with the quantitative PCR and liquid culture method
Kaevska, Marija; Videnska, Petra; Sedlar, Karel; Bartejsova, Iva; Kralova, Alena; Slana, Iva
The aim of this study was to determine possible differences in the faecal microbiota of dairy cows infected with Mycobacterium avium subsp. paratuberculosis (Johne's disease) in comparison with noninfected cows from the same herds. Faecal samples from cows in 4 herds were tested for M. avium subsp. paratuberculosis by real-time PCR, and faecal bacterial populations were analysed by 454 pyrosequencing of the 16S rRNA gene. The most notable differences between shedding and nonshedding cows were an increase in the genus Psychrobacter and a decrease in the genera Oscillospira, Ruminococcus, and Bifidobacterium in cows infected with M. avium subsp. paratuberculosis. The present study is the first to report the faecal microbial composition in dairy cows infected with M. avium subsp. paratuberculosis.
Paisley Larry G
Full Text Available Monte Carlo simulation models were used to evaluate the feasibility and potential results of a proposed national survey of the prevalence of bovine paratuberculosis (PTB in dairy herds in Norway. The expected herd prevalence was assumed to be 0.2% in the simulations. Infected herds were classified as detected if 1 animal was sero-positive. With a sample size of 6000 herds at least 1 truly infected herd was detected in 99% of the iterations. The low sensitivity of the ELISA test, the assumed low herd prevalence, the typical low within-herd prevalence of PTB and the small herd sizes in Norway all present problems in detection of the disease. The results showed that the ratio between false-positive herds and true positive herds detected had a median of 70:1. At the assumed herd prevalence of 0.2% and a cost/test of 70 NOK the median cost of detecting 1 infected herd was approximately 900,000 NOK. If 2 positive reactors were needed to classify a herd "infected" the median cost of detecting 1 infected herd was 5,055,000 NOK. Our results suggest that a randomized national prevalence survey would not be feasible, due to the low probability of detecting infected herds and because of the high number of false-positive reactions that would be expected.
Butot, Sophie; Jagadeesan, Balamurugan; Bakker, Douwe; Donaghy, John
ABSTRACT The efficiency of direct steam injection (DSI) at 105°C for 3 s to inactivate Mycobacterium avium subsp. paratuberculosis in milk at a pilot-plant scale was investigated. Milk samples were artificially contaminated with M. avium subsp. paratuberculosis and also with cow fecal material naturally infected with M. avium subsp. paratuberculosis. We also tested milk artificially contaminated with Mycobacterium smegmatis as a candidate surrogate to compare thermal inactivation between M. smegmatis and M. avium subsp. paratuberculosis. Following the DSI process, no viable M. avium subsp. paratuberculosis or M. smegmatis was recovered using culture methods for both strains. For pure M. avium subsp. paratuberculosis cultures, a minimum reduction of 5.6 log10 was achieved with DSI, and a minimum reduction of 5.7 log10 was found with M. smegmatis. The minimum log10 reduction for wild-type M. avium subsp. paratuberculosis naturally present in feces was 3.3. In addition, 44 dairy and nondairy powdered infant formula (PIF) ingredients used during the manufacturing process of PIF were tested for an alternate source for M. avium subsp. paratuberculosis and were found to be negative by quantitative PCR (qPCR). In conclusion, the results obtained from this study indicate that a >7-fold-log10 reduction of M. avium subsp. paratuberculosis in milk can be achieved with the applied DSI process. IMPORTANCE M. avium subsp. paratuberculosis is widespread in dairy herds in many countries. M. avium subsp. paratuberculosis is the causative agent of Johne's disease in cattle, and infected animals can directly or indirectly (i.e., fecal contamination) contaminate milk. Despite much research and debate, there is no conclusive evidence that M. avium subsp. paratuberculosis is a zoonotic bacterium, i.e., one that causes disease in humans. The presence of M. avium subsp. paratuberculosis or its DNA has been reported in dairy products, including pasteurized milk, cheese, and infant formula
Ahlstrom, Christina; Barkema, Herman W; Stevenson, Karen; Zadoks, Ruth N; Biek, Roman; Kao, Rowland; Trewby, Hannah; Haupstein, Deb; Kelton, David F; Fecteau, Gilles; Labrecque, Olivia; Keefe, Greg P; McKenna, Shawn L B; De Buck, Jeroen
Mycobacterium avium subsp. paratuberculosis (MAP), the causative bacterium of Johne's disease in dairy cattle, is widespread in the Canadian dairy industry and has significant economic and animal welfare implications. An understanding of the population dynamics of MAP can be used to identify introduction events, improve control efforts and target transmission pathways, although this requires an adequate understanding of MAP diversity and distribution between herds and across the country. Whole genome sequencing (WGS) offers a detailed assessment of the SNP-level diversity and genetic relationship of isolates, whereas several molecular typing techniques used to investigate the molecular epidemiology of MAP, such as variable number of tandem repeat (VNTR) typing, target relatively unstable repetitive elements in the genome that may be too unpredictable to draw accurate conclusions. The objective of this study was to evaluate the diversity of bovine MAP isolates in Canadian dairy herds using WGS and then determine if VNTR typing can distinguish truly related and unrelated isolates. Phylogenetic analysis based on 3,039 SNPs identified through WGS of 124 MAP isolates identified eight genetically distinct subtypes in dairy herds from seven Canadian provinces, with the dominant type including over 80% of MAP isolates. VNTR typing of 527 MAP isolates identified 12 types, including "bison type" isolates, from seven different herds. At a national level, MAP isolates differed from each other by 1-2 to 239-240 SNPs, regardless of whether they belonged to the same or different VNTR types. A herd-level analysis of MAP isolates demonstrated that VNTR typing may both over-estimate and under-estimate the relatedness of MAP isolates found within a single herd. The presence of multiple MAP subtypes in Canada suggests multiple introductions into the country including what has now become one dominant type, an important finding for Johne's disease control. VNTR typing often failed to
Palmer, Mitchell V; Stoffregen, William C; Carpenter, Jeremy G; Stabel, Judith R
Paratuberculosis is an economically important disease of dairy cattle caused by Mycobacterium avium subsp. paratuberculosis (Map). The role of nonruminant, nondomestic animals in the epidemiology of paratuberculosis in cattle is unclear. To examine nonruminant, nondomestic animals for the presence of Map, 25 feral cats, nine mice (species unknown), eight rabbits (Sylvilagus floridanus), six raccoons (Procyon lotor), and three opossums (Didelphis virginiana) were collected from a mid-western dairy with known Map-infected cattle. Mycobacterium avium subsp. paratuberculosis was isolated from the mesenteric lymph node from seven of 25 (28%) feral cats. Ileum was culture-positive for three of these seven cats, and an isolation of Map was also made from the ileum of one of nine (11%) mice. Tissue samples from other species were negative as determined by Map culture; microscopic lesions consistent with paratuberculosis were not seen in any animal. Restriction fragment polymorphism analysis of isolates from cats and dairy cattle suggest interspecies transmission. The means by which interspecies transmission occurred may be through ingestion of Map-contaminated feces or waste milk or through ingestion of Map-infected prey. Shedding of Map from infected cats was not evaluated. The epidemiologic role of Map-infected feral cats on dairy farms requires further investigation.
Souriau, Armel; Freret, Sandrine; Foret, Benjamin; Willemsen, Peter T.J.; Bakker, Douwe; Guilloteau, Laurence A.
Currently Mycobacterium avium subsp. paratuberculosis (MAP) infection is diagnosed through indirect tests based on the immune response induced by the infection. The antigens commonly used in IFN-γ release assays (IGRA) are purified protein derivative tuberculins (PPD). However, PPDs, lack both
Fernández, Bárbara; Gilardoni, Liliana Rosa; Jolly, Ana; Colavecchia, Silvia Beatriz; Paolicchi, Fernando Alberto; Mundo, Silvia Leonor
Johne's Disease or Paratuberculosis is a chronic granulomatous enteritis disease affecting ruminants. Detection of subclinically infected animals is difficult, hampering the control of this disease. The aim of this work was to evaluate the performance of detection of IgG isotypes in a PPA-ELISA to improve the recognition of cattle naturally infected with Map in different stages. A total of 108 animals from Tuberculosis-free herds were grouped as follows: exposed (n = 30), subclinically infected (n = 26), clinically infected (n = 14), and healthy controls (n = 38). Receiver-operating characteristic (ROC) curves of isotypes/PPA-ELISAs were constructed and areas under the curves were compared to evaluate the performance of each test. Our study demonstrated that the conventional PPA-ELISA (detecting IgG) is the best to identify clinically infected animals with high sensitivity (92.9%) and specificity (100%). Meanwhile, IgG2/PPA-ELISA improved the number of subclinically infected cattle detected as compared with conventional IgG/PPA-ELISA (53.8 versus 23.1%). In addition, it had the maximum sensitivity (65.0%, taking into account all Map-infected cattle). In conclusion, the combination of IgG and IgG2/PPA-ELISAs may improve the identification of Map-infected cattle in different stages of disease. The usefulness of IgG2 detection in serological tests for Johne's Disease diagnosis should be further evaluated.
Jungersen, Gregers; Huda, A.; Hansen, J.J.
A group of 252 cattle without clinical signs of paratuberculosis (paraTB) in 10 herds infected with paraTB and a group of 117 cattle in 5 herds without paraTB were selected. Whole-blood samples were stimulated with bovine, avian, and johnin purified protein derivative (PPD) and examined for gamma...... interferon (IFN-gamma) release. For diagnosis of paraTB, satisfactory estimated specificities (95 to 99%) could be obtained by johnin PPD stimulation irrespective of interpretation relative to bovine PPD or no-antigen stimulation alone, but numbers of test positives in the infected herds varied from 64...
The early immune response to Mycobacterium avium subsp. paratuberculosis (MAP) in cattle is characterized by a Th1-like immune response effective in controlling bacterial proliferation during the subclinical stage of infection. In young calves nearly 60% of circulating lymphocytes are gamma delta T ...
Infection of the host with Mycobacterium avium subsp. paratuberculosis (MAP) results in a chronic and progressive enteritis that traverses both subclinical and clinical stages. The mechanism(s) for the shift from asymptomatic subclinical disease state to advanced clinical disease are not fully under...
Stege, H.; Jensen, Tim Kåre; Møller, Kristian
shedding of L. intracellularis was assessed by real time-PCR and sero-conversion by an indirect immunofluorescence antibody test (IFAT). Clinical disease was not reported but infection was present in all herds and the PCR assay indicated infection in 75% of pigs examined. Most L. intracellularis infected....... Relative to the bacterial shedding, the onset of sero-conversion was a little delayed, in general, most pigs had sero-converted 2 weeks after the first shedding. Once sero-converted, 92% of the pigs remained sero-positive over the entire survey period....
Kirkeby, Carsten Thure; Græsbøll, Kaare; Nielsen, Søren Saxmose
of the infection. One strategy to control PTB in a herd is to purchase animals from farms with a low risk of MAP infection. We wanted to investigate the epidemiological and economic consequences of buying livestock from different supplier farms of low, medium or high risk, as well as farms with unknown status. We...... one, five or ten infected animals annually into an initially infection-free herd was also modeled. Our findings show that once infected, a farm can relatively safely purchase animals from other low and medium-risk farms without experiencing an increase in the prevalence, highlighting the importance...... of certification programmes. Furthermore, farms free of MAP are highly susceptible and cannot purchase more than a small number of animals per year without having a high risk of being infected. The probability of spontaneous fadeout after 10 years was 82% when introducing a single infected animal into an initially...
Olsen, Abbey; Frankena, Klaas; Bødker, Rene
fitted the observed spatial pattern. Results: During the investigated period (2011-2013), an increase in annual herd prevalence was noted (2011-25.6%; 2012-28.4%; 2013-29.3%). The spatial analysis suggested significant clustering of positive and negative herds. Presence of streams, wetlands and pastures...... on farms showed a significant association with the presence of infection in cattle herds. Buying animals from positive herds was a risk factor on conventional farms. Additionally, risk of being infected with Fasciola hepatica was higher in non-dairy herds of medium size (>= 30 and ... to dairy and large (>= 100) cattle herds. The observed spatial pattern could be reproduced by predictions of the risk factor model. Conclusions: This study showed an increase in annual herd level prevalence (2011 to 2013) indicating that an increasing proportion of herds are infected with Fasciola hepatica...
Jeroen De Buck
Full Text Available The sensitivity of current diagnostics for Johne's disease, a slow, progressing enteritis in ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP, is too low to reliably detect all infected animals in the subclinical stage. The objective was to identify individual metabolites or metabolite profiles that could be used as biomarkers of early MAP infection in ruminants. In a monthly follow-up for 17 months, calves infected at 2 weeks of age were compared with aged-matched controls. Sera from all animals were analyzed by 1H nuclear magnetic resonance spectrometry. Spectra were acquired, processed, and quantified for analysis. The concentration of many metabolites changed over time in all calves, but some metabolites only changed over time in either infected or non-infected groups and the change in others was impacted by the infection. Hierarchical multivariate statistical analysis achieved best separation between groups between 300 and 400 days after infection. Therefore, a cross-sectional comparison between 1-year-old calves experimentally infected at various ages with either a high- or a low-dose and age-matched non-infected controls was performed. Orthogonal Projection to Latent Structures Discriminant Analysis (OPLS DA yielded distinct separation of non-infected from infected cattle, regardless of dose and time (3, 6, 9 or 12 months after infection. Receiver Operating Curves demonstrated that constructed models were high quality. Increased isobutyrate in the infected cattle was the most important agreement between the longitudinal and cross-sectional analysis. In general, high- and low-dose cattle responded similarly to infection. Differences in acetone, citrate, glycerol and iso-butyrate concentrations indicated energy shortages and increased fat metabolism in infected cattle, whereas changes in urea and several amino acids (AA, including the branched chain AA, indicated increased protein turnover. In conclusion, metabolomics
Wong, Danilo Lo Fo; Dahl, J.; Stege, H.
Our objective was to find herd factors associated with pigs testing seropositive for Salmonella. Data were collected from 359 finishing-pig herds in Germany, Denmark, Greece, The Netherlands and Sweden, between 1996 and 1998. Pigs fed non-pelleted feed (dry or wet) had 2- and 2.5-times lower odds...... recruiting from more than three supplier herds had three-times higher odds to test seropositive than pigs in herds which breed their own replacement stock or recruit from a maximum of three supplier herds....
Gussmann, Maya; Kirkeby, Carsten; Græsbøll, Kaare; Farre, Michael; Halasa, Tariq
Intramammary infections (IMI) in dairy cattle lead to economic losses for farmers, both through reduced milk production and disease control measures. We present the first strain-, cow- and herd-specific bio-economic simulation model of intramammary infections in a dairy cattle herd. The model can be used to investigate the cost-effectiveness of different prevention and control strategies against IMI. The objective of this study was to describe a transmission framework, which simulates spread of IMI causing pathogens through different transmission modes. These include the traditional contagious and environmental spread and a new opportunistic transmission mode. In addition, the within-herd transmission dynamics of IMI causing pathogens were studied. Sensitivity analysis was conducted to investigate the influence of input parameters on model predictions. The results show that the model is able to represent various within-herd levels of IMI prevalence, depending on the simulated pathogens and their parameter settings. The parameters can be adjusted to include different combinations of IMI causing pathogens at different prevalence levels, representing herd-specific situations. The model is most sensitive to varying the transmission rate parameters and the strain-specific recovery rates from IMI. It can be used for investigating both short term operational and long term strategic decisions for the prevention and control of IMI in dairy cattle herds. Copyright © 2018 Elsevier Ltd. All rights reserved.
Rossi, G; Grohn, Y T; Schukken, Y H; Smith, R L
Endemic diseases can be counted among the most serious sources of losses for livestock production. In dairy farms in particular, one of the most common diseases is Johne's disease, caused by Mycobacterium avium ssp. paratuberculosis (MAP). Infection with MAP causes direct costs because it affects milk production, but it has also been suspected to increase the risk of clinical mastitis (CM) among infected animals. This might contribute to further costs for farmers. We asked whether MAP infection represents a risk factor for CM and, in particular, whether CM occurrences were more common in MAP-infected animals. Our results, obtained by survival analysis, suggest that MAP-infected cows had an increased probability of experiencing CM during lactation. These results highlight the need to account for the interplay of infectious diseases and other health conditions in economic and epidemiological modeling. In this case, accounting for MAP-infected cows having an increased CM occurrence might have nonnegligible effects on the estimated benefit of MAP control. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Bach, Eviatar; Raizman, Eran A; Vanderwal, Rich; Soto, Paolete; Chaffer, Marcelo; Keefe, Greg; Pogranichniy, Roman; Bach, Horacio
Mycobacterium avium subsp. paratuberculosis (MAP) is the etiological agent of Johne's disease. To survive within host macrophages, the pathogen secretes a battery of proteins to interfere with the immunological response of the host. One of these proteins is tyrosine phosphate A (PtpA), which has been identified as a secreted protein critical for survival of its close relative M. tuberculosis within infected macrophages. In this study, the immune response to recombinant PtpA used as an antigen was investigated in a cohort of ∼1000 cows infected with MAP compared to negative control animals using ELISA. The sera from MAP-infected cows had significantly higher levels of antibodies against PtpA when compared to uninfected cows. The data presented here indicate that the antibodies produced against PtpA are sensitive enough to detect infected animals before the appearance of the disease symptoms. The use of PtpA as an antigen can be developed as an early diagnostic test. Moreover, PtpA is a candidate antigen for detection of humoral immune responses in cows infected with MAP. Copyright © 2018 Elsevier B.V. All rights reserved.
This study aimed to determine the seroprevalence of antibodies for Mycobacterium avium subspecies paratuberculosis (MAP) in dairy cattle in the Jimma zone of Ethiopia in 2011. A random sample of 29 herds was selected, and all mature cattle within these herds had a blood sample taken. Serum was tested in duplicate, ...
Shoor Vir Singh
Full Text Available Examination of samples of stool from a 61 year old male patient, presenting with the clinical symptoms of Crohn’s disease (CD, revealed massive shedding of acid fast bacilli with the morphology of Mycobacterium avium paratuberculosis (MAP, the causative agent of Johne’s disease in cattle. MAP was cultured from the stool. Biotyping of the bacterium isolated from cultures of stool demonstrated it was the Indian Bison biotype of MAP, the dominant biotype infecting livestock and humans in India. Based on this finding and because the patient was unresponsive to standard therapy used in India to treat patients with gastrointestinal inflammatory disorders, the patient was placed on a regimen of multi-antibiotic therapy, currently used to treat tuberculosis and CD. After one year of treatment, the patient’s health was restored, concurrent with cessation of shedding of MAP in his stool. This patient is the first case shown to shed MAP from the stool who was cured of infection with antibiotics and who was concurrently cured of clinical signs of CD.
Zarei, Mehdi; Ghorbanpour, Masoud; Tajbakhsh, Samaneh; Mosavari, Nader
Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease, a chronic enteritis in cattle and other domestic and wild ruminants. The presence of MAP in tissues other than intestines and associated lymph nodes, such as meat and liver, is a potential public health concern. In the present study, the relationship between the results of rapid diagnostic tests of the Johne's disease, such as serum ELISA, rectal scraping PCR, and acid-fast staining, and the presence of MAP in liver was evaluated. Blood, liver, and rectal scraping samples were collected from 200 slaughtered cattle with unknown Johne's disease status. ELISA was performed to determine the MAP antibody activity in the serum. Acid-fast staining was performed on rectal scraping samples, and PCR was performed on rectal scraping and liver samples. PCR-positive liver samples were used for mycobacterial culture. Overall, the results of this study demonstrated that MAP can be detected and cultured from liver of slaughtered cattle and rapid diagnostic tests of Johne's disease have limited value in detecting cattle with MAP infection in liver. These findings show that the presence of MAP in liver tissue may occur in cows with negative results for rapid diagnostic tests and vice versa. Hence, liver might represent another possible risk of human exposure to MAP. Given concerns about a potential zoonotic role for MAP, these results show the necessity to find new methods for detecting cattle with MAP disseminated infection.
Mortensen, Sten; Stryhn, Henrik; Søgaard, Rikke
In 1992, the porcine reproductive and respiratory syndrome virus (PRRSV) of European type (PRRSV-EU) was introduced in Denmark. By 1996, the virus had spread to approximately 25% of the Danish herds. In January 1996, a modified-live vaccine based on the American type of the virus (PRRSV-US) was u......In 1992, the porcine reproductive and respiratory syndrome virus (PRRSV) of European type (PRRSV-EU) was introduced in Denmark. By 1996, the virus had spread to approximately 25% of the Danish herds. In January 1996, a modified-live vaccine based on the American type of the virus (PRRSV......-US) was used in replacement boars for Danish artificial insemination (AI) centres and from July 1996, the vaccine was used in PRRSV-EU infected herds for prevention of disease. Soon after vaccine introduction, PRRSV non-infected herds experienced outbreaks of disease due to infection with PRRSV...... in the case herds). The data were analysed using a Cox-regression model. The hazard of infection increased significantly with exposure from PRRSV-US-infected neighbouring herds, purchase of animals from herds incubating PRRSV-US infection, increasing herd size and purchase of semen from boars at PRRSV...
Theonys Diógenes Freitas
Full Text Available The aim of this investigation was to conduct an epidemiological study and identify risk factors associated with the occurrence of paratuberculosis (Johne’s disease in dairy goats within the semiarid region of Paraíba State. The study was done during the period of March 2009 to July 2011, during which 727 female goats from 86 flocks from the city of Monteiro, Paraíba were investigated. For the serological diagnosis of Mycobacterium avium subsp. paratuberculosis (Map infection indirect ELISA tests (screening and confirmatory were performed. Of the 727 animals used six (0.82% were seropositive at the confirmatory test after screening, and of the 86 flocks six (6.97% presented at least one seropositive animal. In positive flocks the frequency of reactive animals ranged from 5.26% to 16.60%. Risk factors identified were production system (weaning and reproduction (odds ratio = 36.0; 95% CI = 2.6 –486.1; p < 0,001 and absence of technical infrastructure (odds ratio = 54.0; 95% CI = 4.5 –642.9; p < 0,001. It was concluded that Mycobacterium avium subsp. paratuberculosis is present in dairy goat flocks in the region; however, its influence on decrease productivity as well as the risk of transmission to humans through animal products must totally evaluated. Based on the analysis of risk factors, improvements are recommended for the technical infrastructure and the management of breeding goats.
Godden, S M; Wells, S; Donahue, M; Stabel, J; Oakes, J M; Sreevatsan, S; Fetrow, J
In summer 2007, a randomized controlled field trial was initiated on 6 large Midwest commercial dairy farms to investigate the effect of feeding heat-treated (HT) colostrum on transmission of Mycobacterium avium ssp. paratuberculosis (MAP) and on future milk production and longevity within the herd. On each farm, colostrum was collected daily from fresh cows, pooled, divided into 2 aliquots, and then 1 aliquot was heat-treated in a commercial batch pasteurizer at 60°C for 60min. A sample from each batch of colostrum was collected for PCR testing (MAP-positive vs. MAP-negative). Newborn heifer calves were removed from the dam within 30 to 60min of birth and systematically assigned to be fed 3.8 L of either fresh (FR; n=434) or heat-treated (HT; n=490) colostrum within 2h of birth. After reaching adulthood (>2 yr old), study animals were tested once annually for 3 yr (2010, 2011, 2012) for infection with MAP using serum ELISA and fecal culture. Lactation records describing milk production data and death or culling events were collected during the 3-yr testing period. Multivariable model logistic and linear regression was used to investigate the effect of feeding HT colostrum on risk for testing positive to MAP during the 3-yr testing period (positive/negative; logistic regression) and on first and second lactation milk yield (kg/cow; linear regression), respectively. Cox proportional hazards regression was used to investigate the effect of feeding HT colostrum on risk and time to removal from the herd. Fifteen percent of all study animals were fed PCR-positive colostrum. By the end of the 3-yr testing period, no difference was noted in the proportion of animals testing positive for MAP, with either serum ELISA or fecal culture, when comparing the HT group (10.5%) versus the FR group (8.1%). There was no effect of treatment on first- (HT=11.797kg; FR=11,671kg) or second-lactation (HT=11,013kg; FR=11,235kg) milk production. The proportion of cows leaving the herd by
Andreasen, Margit; Nielsen, Jens; Bækbo, Poul
Sixteen litters of seven pigs from each of nine Danish farrow-to-finish herds were followed to investigate the serological patterns caused by natural infection with Mycoplasma hyponeumoniae, Pasteurella multocida toxin and Actinobacillus pleuroneumoniae serotypes 2, 5-7, 12. In seven of the herds......, pigs were followed as two separate cohorts started 4 weeks apart, and in two herds only one cohort was followed. A total of 999 pigs were included in the study. The pigs were blood sampled at weaning and subsequently every fourth week until slaughter. All pigs were examined for antibodies against M....... hyopneumoniae (enzyme-linked immunosorbent assay), P. multocida toxin (enzyme-linked immunosorbent assay) and A. pleuropneumoniae serotypes 2, 5-7, 12 (complement-fixation tests). The most-common pattern (28%) of seroconversion was that of pigs first seroconverting to A. pleuropneumoniae serotype 2, followed...
Anna Rita, Attili; Victor, Ngu Ngwa; Silvia, Preziuso; Luciana, Pacifici; Anastasia, Domesi; Vincenzo, Cuteri
In order to fulfil the seroprevalence gap on Mycobacterium avium subsp. paratuberculosis infection in ovine dairy farms of Marche region (central Italy), a stratified study was carried out on 2086 adult female sheep randomly chosen from 38 herds selected in Ancona and Macerata provinces. 73.7% flocks resulted infected by a commercial ELISA test (Pourquier, France), with a mean seroprevalence of 6.29% of sampled sheep in both provinces. A higher number of MAP seropositive ewes was recorded in the large herds' consistence than in the small and medium herds' consistence (P = 0.0269), and a greater percentage of infected sheep was obtained among female at early/late than in peak lactation stage (P = 0.0237). MAP infection was confirmed in 12.6% of infected farms by faecal culture. The true sheep-level seroprevalence was 15.1% ± 7.3%. PMID:21876850
Gussmann, Maya Katrin; Kirkeby, Carsten Thure; Græsbøll, Kaare
Intramammary infections (IMI) in dairy cattle lead to economic losses for farmers, both through reduced milk production and disease control measures. We present the first strain-, cow- and herd-specific bio-economic simulation model of intramammary infections in a dairy cattle herd. The model can...... various within-herd levels of IMI prevalence, depending on the simulated pathogens and their parameter settings. The parameters can be adjusted to include different combinations of IMI causing pathogens at different prevalence levels, representing herd-specific situations. The model is most sensitive...
A role for gamma delta T cells in protection against mycobacterial infections including Johne’s disease (JD) has been suggested. In neonatal calves where the risk to infection with Mycobacterium avium subsp. paratuberculosis (MAP) is high, the majority of circulating CD3+ lymphocytes are gamma delta...
Nielsen, Liza Rosenbaum; Kudahl, Anne Braad; Østergaard, Søren
for the individual animals in each of the six age groups in the herd. The hygiene level was highly influential on the probability that the infection spread within the herd, duration of infection and epidemic size. The herd susceptibility level was also influential, but not likely to provide sufficient prevention...... of the six age-groups; 2) S. Dublin incidence and number of animals in each infection state; and 3) S. Dublin related morbidity and mortality in the acutely infected animals. The effects of introducing one infectious heifer on the risk of spread of S. Dublin within the herd and on the duration of infection...... and control of infection on its own. Herd size did not affect the probability of infection spread upon exposure, but the larger the herd the more important were management and housing practices that improve hygiene and reduce susceptibility to shorten durations of infection in the herd and to increase...
Eisenberg Susanne WF
Full Text Available Abstract A challenge experiment was performed to investigate whether administration of Mycobacterium avium subsp. paratuberculosis (MAP via the respiratory route leads to MAP infection in calves. Eighteen calves from test negative dams were randomly allocated to four groups. Six calves were challenged with MAP nasally and six calves were challenged by transtracheal injection; three orally challenged calves served as positive controls, and three non challenged calves as negative controls. The challenge was performed as a nine-fold trickle dose, 107 CFU in total. Blood and faecal samples were collected frequently. Calves were euthanized three months post-challenge and extensively sampled. Blood samples were tested for the presence of antibodies and interferon gamma producing cells by ELISA. Faecal and tissue samples were cultured in a liquid culture system and the presence of MAP was confirmed by IS900 realtime PCR. Fourteen out of fifteen calves had no MAP antibody response. The negative controls remained negative; all positive controls became infected. Two nasally challenged calves showed a Purified Protein Derivative Avian (PPDA specific interferon gamma response. In all nasally challenged calves, MAP positive intestinal samples were detected. In three calves of the nasal group MAP positive retropharyngeal lymph nodes or tonsils were detected. In all calves of the transtracheal group MAP positive intestinal tissues were detected as well and three had a MAP positive tracheobronchial lymph node. These findings indicate that inhalation of MAP aerosols can result in infection. These experimental results may be relevant for transmission under field conditions since viable MAP has been detected in dust on commercial dairy farms.
Full Text Available Abstract Background Inflammatory Bowel Disease (IBD, which includes both Crohn’s disease (CD and ulcerative colitis (UC, is caused by a complex interplay involving genetic predisposition, environmental factors and an infectious agent. Mycobacterium avium subsp. paratuberculosis (MAP is a promising pathogen candidate since it produces a chronic intestinal inflammatory disease in ruminants that resembles CD in humans. MAP is a ubiquitous microorganism, although its presence in the food chain, especially in milk from infected animals, is what made us think that there could be an association between lactase persistence (LP and IBD. The LCT mutation has brought adaptation to dairy farming which in turn would have increased exposure of the population to infection by MAP. NOD2 gene mutations are highly associated to CD. Methods In our study, CD and UC patients and controls from the North of Spain were genotyped for the lactase gene (LCT and for three NOD-2 variants, R702W, G908R and Cins1007fs. MAP PCR was carried out in order to assess MAP infection status and these results were correlated with LCT and NOD2 genotypes. Results As for LP, no association was found with IBD, although UC patients were less likely to present the T/T−13910 variant compared to controls, showing a higher C-allele frequency and a tendency to lactase non-persistence (LNP. NOD2 mutations were associated to CD being the per-allele risk higher for the Cins1007fs variant. MAP infection was more extended among the healthy controls (45.2% compared to CD patients (21.38% and UC patients (19.04% and this was attributed to therapy. The Asturian CD cohort presented higher levels of MAP prevalence (38.6% compared to the Basque CD cohort (15.5%, differences also attributed to therapy. No interaction was found between MAP infection and LCT or NOD2 status. Conclusions We conclude that LP is not significantly associated with IBD, but that MAP infection and NOD2 do show not mutually
Alyssa N Malone
Full Text Available Johne's disease is an infectious chronic inflammatory bowel disease in ruminants. The key factor for the management of this disease is an early positive diagnosis. Unfortunately, most diagnostics detect animals with Johne's disease in the clinical stage with positive serology and/or positive fecal cultures. However, for effective management of the disease within herds, it is important to detect infected animals as early as possible. This might only be possible with the help of parameters not specific for Johne's disease but that give an early indication for chronic infections such as weight development. Here we report our findings on the development of total body weight and weight gain during the first six months of goats experimentally infected to induce Johne's disease. Twenty dairy goat kids age 2 to 5 days were included in this study. Goats were divided into two groups: a negative control group and a positive infected group. The weight was obtained weekly throughout the study. Goats of the positive group were infected at the age of seven weeks. We detected significant changes in weight gain and total body weight as early as one week after infection. Differences are significant throughout the six month time period. Weight as a non-specific parameter should be used to monitor infection especially in studies on Johne's disease using the goat model. Our study suggests that goats with Johne's disease have a reduced weight gain and reduced weight when compared with healthy goats of the same age.
Kudahl, Anne Braad; Nielsen, Søren Saxmose; Østergaard, Søren
Long-term effects of paratuberculosis on within-herd prevalence and on-farm economy of implementing risk-based control strategies were compared with alternative strategies by using a herd-simulation model. Closing transmission routes is essential for effective control of paratuberculosis. However...
Full Text Available Paratuberculosis is a chronic infection that in dairy cattle causes reduced milk yield, weight loss, and ultimately fatal diarrhea. Subclinical animals can excrete bacteria (Mycobacterium avium ssp. paratuberculosis, MAP in feces and infect other animals. Farmers identify the infectious animals through a variety of test-strategies, but are challenged by the lack of perfect tests. Frequent testing increases the sensitivity but the costs of testing are a cause of concern for farmers. Here, we used a herd simulation model using milk ELISA tests to evaluate the epidemiological and economic consequences of continuously adapting the sampling interval in response to the estimated true prevalence in the herd. The key results were that the true prevalence was greatly affected by the hygiene level and to some extent by the test-frequency. Furthermore, the choice of prevalence that will be tolerated in a control scenario had a major impact on the true prevalence in the normal hygiene setting, but less so when the hygiene was poor. The net revenue is not greatly affected by the test-strategy, because of the general variation in net revenues between farms. An exception to this is the low hygiene herd, where frequent testing results in lower revenue. When we look at the probability of eradication, then it is correlated with the testing frequency and the target prevalence during the control phase. The probability of eradication is low in the low hygiene herd, and a test-and-cull strategy should probably not be the primary strategy in this herd. Based on this study we suggest that, in order to control MAP, the standard Danish dairy farm should use an adaptive strategy where a short sampling interval of three months is used when the estimated true prevalence is above 1%, and otherwise use a long sampling interval of one year.
Elze, J; Liebler-Tenorio, E; Ziller, M; Köhler, H
The objective of this study was to identify the most reliable approach for prevalence estimation of Mycobacterium avium ssp. paratuberculosis (MAP) infection in clinically healthy slaughtered cattle. Sampling of macroscopically suspect tissue was compared to systematic sampling. Specimens of ileum, jejunum, mesenteric and caecal lymph nodes were examined for MAP infection using bacterial microscopy, culture, histopathology and immunohistochemistry. MAP was found most frequently in caecal lymph nodes, but sampling more tissues optimized the detection rate. Examination by culture was most efficient while combination with histopathology increased the detection rate slightly. MAP was detected in 49/50 animals with macroscopic lesions representing 1.35% of the slaughtered cattle examined. Of 150 systematically sampled macroscopically non-suspect cows, 28.7% were infected with MAP. This indicates that the majority of MAP-positive cattle are slaughtered without evidence of macroscopic lesions and before clinical signs occur. For reliable prevalence estimation of MAP infection in slaughtered cattle, systematic random sampling is essential.
Paratuberculosis is a chronic intestinal disease of ruminant animals caused by Mycobacterium avium subsp. paratuberculosis (MAP). A hallmark of paratuberculosis is a transition from a cell-mediated Th1 type response to a humoral Th2 response with the progression of disease from a subclinical to clin...
Full Text Available Abstract Background The Swedish salmonella control programme covers the entire production chain, from feed to food. All salmonella serotypes are notifiable. On average, less than 20 cases of salmonella in food-producing animals are reported every year. In some situations, the cases would be expected to cluster geographically. The aim of this study was to illustrate the geographic distribution of the salmonella cases detected in pigs, cattle and sheep. Methods Data on all herds with pigs, cattle and sheep found to be infected with salmonella during the time period from 1993 to 2010 were obtained from the Swedish Board of Agriculture. Using the ArcGIS software, various maps were produced of infected herds, stratified on animal species as well as salmonella serotype. Based on ocular inspection of all maps, some were collapsed and some used separately. Data were also examined for temporal trends. Results No geographical clustering was observed for ovine or porcine cases. Cattle herds infected with Salmonella Dublin were mainly located in the southeast region and cattle herds infected with Salmonella Typhimurium in the most southern part of the country. Some seasonal variation was seen in cattle, but available data was not sufficient for further analyses. Conclusions Analyses of data on salmonella infected herds revealed some spatial and temporal patterns for salmonella in cattle. However, despite using 18 years' of data, the number of infected herds was too low for any useful statistical analyses.
Zhang, K; Wu, K; Liu, J; Ge, S; Xiao, Y; Shang, Y; Ning, Z
Atypical porcine pestivirus (APPV) have been detected in swine herds from the USA, Germany, the Netherlands, Spain and most recently in Austria, suggesting a wide geographic distribution of this novel virus. Here, for the first time, we reported APPV infection in swine herds in China. Newborn piglets from two separate swine herds in Guangdong province were found showing typical congenital tremors in July and August 2016. RT-PCR, sequencing and phylogenetic analysis showed APPV infection occurred. Phylogenetic analysis showed that Chinese APPV strains, GD1 and GD2, formed independent branch from the USA, Germany and the Netherlands. Nucleotide identities between members of the APPV ranged between 83.1% and 83.5%, and this showed APPV is highly diverse. It is apparent that this provides the first molecular evidence of APPV infection in swine herds in China. © 2017 Blackwell Verlag GmbH.
Nathues, Heiko; Woeste, Henrike; Doehring, Stefanie; Fahrion, Anna S; Doherr, Marcus G; Beilage, Elisabeth grosse
Mycoplasma hyopneumoniae is the etiologic agent of enzootic pneumonia mainly occurring in fattening pigs. It is assumed that horizontal transmission of the pathogen during nursery and growing phase starts with few suckling pigs vertically infected by the sow. The aim of the present study was the exploration of the herd prevalence of M. hyopneumoniae infections in suckling pigs followed by an investigation of various herd specific factors for their potential of influencing the occurrence of this pathogen at the age of weaning. In this cross-sectional study, 125 breeding herds were examined by taking nasal swabs from 20 suckling pigs in each herd. In total, 3.9% (98/2500) of all nasal swabs were tested positive for M. hyopneumoniae by real-time PCR. Piglets tested positive originated from 46 different herds resulting in an overall herd prevalence of 36.8% (46/125) for M. hyopneumoniae infection in pigs at the age of weaning. While the herds were epidemiologically characterized, the risk for demonstration of M. hyopneumoniae was significantly increased, when the number of purchased gilts per year was more than 120 (OR: 5.8), and when the number of farrowing pens per compartment was higher than 16 (OR: 3.3). In herds with a planned and segregated production, where groups of sows entered previously emptied farrowing units, the risk for demonstration of M. hyopneumoniae in piglets was higher in herds with two or four weeks between batches than in herds with one or three weeks between batches (OR: 2.7). In this cross-sectional study, several risk factors could be identified enhancing the probability of breeding herds to raise suckling pigs already infected with M. hyopneumoniae at the time of weaning. Interestingly, some factors (farrowing rhythm, gilt acclimatisation issues) were overlapping with those also influencing the seroprevalences among sows or the transmission of the pathogen between older age groups. Taking the multifactorial character of enzootic pneumonia
Whittington, R J; Begg, D J; de Silva, K; Purdie, A C; Dhand, N K; Plain, K M
Paratuberculosis (Johne's disease) is an economically significant condition caused by Mycobacterium avium subsp. paratuberculosis. However, difficulties in diagnosis and classification of individual animals with the condition have hampered research and impeded efforts to halt its progressive spread in the global livestock industry. Descriptive terms applied to individual animals and herds such as exposed, infected, diseased, clinical, sub-clinical, infectious and resistant need to be defined so that they can be incorporated consistently into well-understood and reproducible case definitions. These allow for consistent classification of individuals in a population for the purposes of analysis based on accurate counts. The outputs might include the incidence of cases, frequency distributions of the number of cases by age class or more sophisticated analyses involving statistical comparisons of immune responses in vaccine development studies, or gene frequencies or expression data from cases and controls in genomic investigations. It is necessary to have agreed definitions in order to be able to make valid comparisons and meta-analyses of experiments conducted over time by a given researcher, in different laboratories, by different researchers, and in different countries. In this paper, terms are applied systematically in an hierarchical flow chart to enable classification of individual animals. We propose descriptive terms for different stages in the pathogenesis of paratuberculosis to enable their use in different types of studies and to enable an independent assessment of the extent to which accepted definitions for stages of disease have been applied consistently in any given study. This will assist in the general interpretation of data between studies, and will facilitate future meta-analyses.
Full Text Available Information on the distribution and related epidemiological characteristics of herpesvirus infections, and in particular referring to Bovine Herpesvirus 1 (BoHV1 and Bubaline Herpesvirus 1 (BuHV1 in buffaloes, have to date not been reported. Different studies based on serological surveys and viral isolation describe the circulation of both infections in this species. The specific etiological attribution of the infections in sero-surveys can be uncertain because of antigenic cross-reactivity of these ruminant α-herpesvirus and therefore depends on the diagnostic techniques employed. For this , we proceeded in verifying the diffusion of the two infections in a buffalo population of Central Italy. The sample size for the number of herds to test was defined considering an expected prevalence > 20% and the number of heads to be tested within each herd was established using an expected prevalence of > 25% (absolute precision of 5%, with 95% confidence level. The 155 herds to test were those with no IBR vaccination history. A maximum of 15 random blood samples were collected within the >3 year age category. The same sampling criteria was adopted when cows were present on buffalo farms to study the possible role of this species. Through the combined use of gB-gE Elisa tests, we assigned a specific infection status, for the BuHV1 infection status (gB-pos/gE-neg, as confirmed by an experimental infection conducted by us inoculating buffaloes with the BuHV1 “strain Metzler”, and for the BoHV1 status (gBpos/ gE-pos as that observed for the infection in bovines. Prevalence of infection, based on the Elisa status of each animal, were estimated for the whole sample and within each herd. Furthermore, the selected farms were investigated for their numeric consistency, presence of bovines, occurrence of typical clinical herpesvirus disorders occurring during the year prior to sampling. The association of these factors with the infection status was verified
Rademaker, Jan L W; Vissers, Marc M M; Te Giffel, Meike C
The effectiveness of high-temperature, short holding time (HTST) pasteurization and homogenization with respect to inactivation of Mycobacterium avium subsp. paratuberculosis was evaluated quantitatively. This allowed a detailed determination of inactivation kinetics. High concentrations of feces from cows with clinical symptoms of Johne's disease were used to contaminate raw milk in order to realistically mimic possible incidents most closely. Final M. avium subsp. paratuberculosis concentrations varying from 10(2) to 3.5 x 10(5) cells per ml raw milk were used. Heat treatments including industrial HTST were simulated on a pilot scale with 22 different time-temperature combinations, including 60 to 90 degrees C at holding (mean residence) times of 6 to 15 s. Following 72 degrees C and a holding time of 6 s, 70 degrees C for 10 and 15 s, or under more stringent conditions, no viable M. avium subsp. paratuberculosis cells were recovered, resulting in >4.2- to >7.1-fold reductions, depending on the original inoculum concentrations. Inactivation kinetic modeling of 69 quantitative data points yielded an E(a) of 305,635 J/mol and an lnk(0) of 107.2, corresponding to a D value of 1.2 s at 72 degrees C and a Z value of 7.7 degrees C. Homogenization did not significantly affect the inactivation. The conclusion can be drawn that HTST pasteurization conditions equal to 15 s at > or =72 degrees C result in a more-than-sevenfold reduction of M. avium subsp. paratuberculosis.
Rademaker, Jan L. W.; Vissers, Marc M. M.; te Giffel, Meike C.
The effectiveness of high-temperature, short holding time (HTST) pasteurization and homogenization with respect to inactivation of Mycobacterium avium subsp. paratuberculosis was evaluated quantitatively. This allowed a detailed determination of inactivation kinetics. High concentrations of feces from cows with clinical symptoms of Johne's disease were used to contaminate raw milk in order to realistically mimic possible incidents most closely. Final M. avium subsp. paratuberculosis concentrations varying from 102 to 3.5 × 105 cells per ml raw milk were used. Heat treatments including industrial HTST were simulated on a pilot scale with 22 different time-temperature combinations, including 60 to 90°C at holding (mean residence) times of 6 to 15 s. Following 72°C and a holding time of 6 s, 70°C for 10 and 15 s, or under more stringent conditions, no viable M. avium subsp. paratuberculosis cells were recovered, resulting in >4.2- to >7.1-fold reductions, depending on the original inoculum concentrations. Inactivation kinetic modeling of 69 quantitative data points yielded an Ea of 305,635 J/mol and an lnk0 of 107.2, corresponding to a D value of 1.2 s at 72°C and a Z value of 7.7°C. Homogenization did not significantly affect the inactivation. The conclusion can be drawn that HTST pasteurization conditions equal to 15 s at ≥72°C result in a more-than-sevenfold reduction of M. avium subsp. paratuberculosis. PMID:17496131
Khol, Johannes Lorenz; Braun, Anna Lena; Slana, Iva; Kralik, Petr; Wittek, Thomas
Johne's disease (paratuberculosis) is caused by Mycobacterium avium subsp. paratuberculosis (MAP) and can lead to severe economic losses in the affected cattle herds. The transmission of the disease occurs mainly orally, by the ingestion of MAP, which is shed in the feces and milk of infected animals. Calves show a high susceptibility for the infection compared to adult animals. The use of milk replacers can, therefore, contribute to the prevention of the transmission of the disease to calves in MAP-positive herds by preventing the ingestion of the bacterium with milk from infected animals. The objective of this study was to test milk replacers for calves for the presence of MAP by bacteriological culture and PCR. Therefore, commercially available milk replacers for calves were purchased from 15 different companies. All of the products were tested for MAP by solid culture and real time quantitative PCR (qPCR) targeting IS900 and F57. During the present study, MAP could not be detected by qPCR or solid culture in commercially available milk replacers for calf rearing. The results of the present study underpins that the use of milk replacers for calf rearing might contribute to the reduction of MAP intake by calves in JD positive herds. Additional studies, including more products with a higher diversity, are needed to further elucidate the presence or absence of MAP in milk replacers for calves. Copyright © 2017 Elsevier B.V. All rights reserved.
Scanu, Antonio M.; Bull, Tim J.; Cannas, Sara; Sanderson, Jeremy D.; Sechi, Leonardo A.; Dettori, Giuseppe; Zanetti, Stefania; Hermon-Taylor, John
Mycobacterium avium subsp. paratuberculosis causes Johne's disease, a systemic infection and chronic inflammation of the intestine that affects many species, including primates. Infection is widespread in livestock, and human populations are exposed. Johne's disease is associated with immune dysregulation, with involvement of the enteric nervous system overlapping with features of irritable bowel syndrome in humans. The present study was designed to look for an association between Mycobacteri...
Nielsen, Torben Dahl; Kudahl, Anne Braad; Østergaard, S.
and dynamic simulation model. The model incorporated six age groups (neonatal, pre-weaned calves, weaned calves, growing heifers, breeding heifers and cows) and five infection stages (susceptible, acutely infected, carrier, super shedder and resistant). The effects of introducing one S. Dublin infectious......Salmonella Dublin affects production and animal health in cattle herds. The objective of this study was to quantify the gross margin (GM) losses following introduction and spread of S. Dublin within dairy herds. The GM losses were estimated using an age-structured stochastic, mechanistic...... with poorer management and herd size, e.g. average annual GM losses were estimated to 49 euros per stall for the first year after infection, and to 8 euros per stall annually averaged over the 10 years after herd infection for a 200 cow stall herd with very good management. In contrast, a 200 cow stall herd...
Maura E Casey
Full Text Available Johne’s disease, caused by infection with Mycobacterium avium subsp. paratuberculosis, (MAP, is a chronic intestinal disease of ruminants with serious economic consequences for cattle production in the United States and elsewhere. During infection, MAP bacilli are phagocytosed and subvert host macrophage processes, resulting in subclinical infections that can lead to immunopathology and dissemination of disease. Analysis of the host macrophage transcriptome during infection can therefore shed light on the molecular mechanisms and host-pathogen interplay associated with Johne’s disease. Here we describe results of an in vitro study of the bovine monocyte-derived macrophage (MDM transcriptome response during MAP infection using RNA-seq. MDM were obtained from seven age- and sex-matched Holstein-Friesian cattle and were infected with MAP across a six-hour infection time course with non-infected controls. We observed 245 and 574 differentially expressed genes in MAP-infected versus non-infected control samples (adjusted P value ≤ 0.05 at 2 and 6 hours post-infection, respectively. Functional analyses of these differentially expressed genes, including biological pathway enrichment, highlighted potential functional roles for genes that have not been previously described in the host response to infection with MAP bacilli. In addition, differential expression of pro- and anti-inflammatory cytokine genes, such as those associated with the IL-10 signaling pathway, and other immune-related genes that encode proteins involved in the bovine macrophage response to MAP infection emphasize the balance between protective host immunity and bacilli survival and proliferation. Systematic comparisons of RNA-seq gene expression results with Affymetrix® microarray data generated from the same experimental samples also demonstrated that RNA-seq represents a superior technology for studying host transcriptional responses to intracellular infection.
Mai, H M; Irons, P C; Kabir, J; Thompson, P N
Brucellosis and campylobacteriosis are economically important diseases affecting bovine reproductive efficiency in Nigeria. A questionnaire-based survey was conducted in 271 cattle herds in Adamawa, Kaduna and Kano states of northern Nigeria using multistage cluster sampling. Serum from 4745 mature animals was tested for Brucella antibodies using the Rose-Bengal plate test and positives were confirmed in series-testing protocol using competitive enzyme-linked immunosorbent assay. Preputial scrapings from 602 bulls were tested using culture and identification for Campylobacter fetus. For each disease, a herd was classified as positive if one or more animals tested positive. For each herd, information on potential managemental and environmental risk factors was collected through a questionnaire administered during an interview with the manager, owner or herdsman. Multiple logistic regression models were used to model the odds of herd infection for each disease. A zero-inflated Poisson model was used to model the count of Brucella-positive animals within herds, with the number tested as an exposure variable. The presence of small ruminants (sheep and/or goats) on the same farm, and buying-in of >3 new animals in the previous year or failure to practice quarantine were associated with increased odds of herd-level campylobacteriosis and brucellosis, as well as increased within-herd counts of Brucella-positive animals. In addition, high rainfall, initial acquisition of animals from markets, practice of gynaecological examination and failure to practice herd prophylactic measures were positively associated with the odds of C. fetus infection in the herd. Herd size of >15, pastoral management system and presence of handling facility on the farm were associated with increased odds, and gynaecological examination with reduced odds of herd-level Brucella seropositivity. Furthermore, the zero-inflated Poisson model showed that borrowing or sharing of bulls was associated with
Doherty Michael L
Full Text Available Abstract Background Infection with bovine herpesvirus-1 (BHV-1 causes a wide range of disease manifestations, including respiratory disease and abortion, with world-wide distribution. The primary objective of the present study was to describe aspects of BHV-1 infection and control on Irish farms, including herd-level seroprevalence (based on pooled sera and vaccine usage. Methods The characteristics of a diagnostic indirect BHV-1 antibody ELISA test when used on serum pools were evaluated using laboratory replicates for use in the seroprevalence study. The output from this indirect ELISA was expressed as a percentage positivity (PP value. A proposed cut off (PCO PP was applied in a cross-sectional study of a stratified random sample of 1,175 Irish dairy and beef cattle herds in 2009, using serum pools, to estimate herd seroprevalence. The study was observational, based primarily on the analysis of existing samples, and only aggregated results were reported. For these reasons, ethical approval was not required. Bulk milk samples from a subset of 111 dairy herds were analysed using the same ELISA. Information regarding vaccine usage was determined in a telephone survey. Results A PCO PP of 7.88% was determined to give 97.1% sensitivity and 100% specificity relative to the use of the ELISA on individual sera giving maximization of the prevalence independent Youden's index, on receiver operating characteristics analysis of replicate results. The herd-level BHV-1 seroprevalence was 74.9% (95% CI - 69.9%-79.8%, with no significant difference between dairy and beef herds. 95.5% agreement in herd classification was found between bulk milk and serum pools. Only 1.8 percent of farmers used BHV-1 marker vaccine, 80% of which was live while 75% of vaccinated herds were dairy. A significant association was found between herd size (quartiles and seroprevalence (quartiles. Conclusions The results from this study indicate BHV-1 infection is endemic, although
Melvang, Heidi Mikkelsen; Hassan, Sufia Butt; Thakur, Aneesh
Mycobacterium avium subsp. paratuberculosis (Map) is the cause of paratuberculosis, a chronic enteritis of ruminants that is widespread worldwide. We investigated the effect of post-exposure vaccination with Map specific peptides in a goat model aiming at developing a Map vaccine that will neither...... unique to Map from selected proteins (n =68). For vaccination, 23 MAP peptides (20 µg each) were selected and formulated with Montanide ISA 61 VG adjuvant. At age three weeks 10 goats were orally inoculated with 4x10E9 live Map and assigned to two groups of 5 goats each: 5 vaccinated (V) at 14 and 18...... weeks post inoculation (PI) and 5 unvaccinated (C). At termination 32 weeks PI, Map burdens in 15 intestinal tissues and lymph nodes were determined by IS900 qPCR. Of the 75 tissue samples from the 5 C goats only 5 samples were IS900 qPCR negative. In contrast, only 9 samples in total from 5 V goats...
Full Text Available Abstract In a number of countries, tuberculosis (due to infection with Mycobacterium bovis is a significant health problem of captive deer. This paper describes outbreaks of bovine tuberculosis in sika deer (Cervus nippon on two farms in Ireland and the methods used to control the disease. On Farm A, infection was first detected during 1993. The infection was eradicated using a programme of test and removal, in association with segregation of young animals. A second outbreak (also due to infection with M. bovis, but a different RFLP profile was detected in 2002. In the latter outbreak, infection was particularly prevalent in two groups of young deer. M. bovis with the same RFLP profile was also isolated in a badger found dead on the farm. Control was achieved by test and removal in association with herd management changes. In Herd B, infection was first detected in 1995, and subsequently eradicated using test and removal alone. In Herd A, re-infection remains an ongoing risk. Control rather than eradication of infection may more realistic in the short-to medium-term.
Bovine viral diarrhea virus (BVDV) continues to have significant economic impact on the cattle industry worldwide. The virus is primarily maintained in the cattle population due to persistently infected animals. Herd surveillance along with good vaccination programs and biosecurity practices are the...
Shook, G.E.; Kirk, R.L.B.; Welcome, Frank L.; Schukken, Y.H.; Ruegg, P.L.
We examined consistency of the relationship between intramammary infection (IMI) and somatic cell score (SCS) across several classes of cow, herd, and sampling time variables. Microbial cultures of composite milk samples were performed by New York Quality Milk Production Services from 1992 to
Shook, G. E.; Kirk, R. L.Bamber; Welcome, Frank L.; Schukken, Y. H.; Ruegg, P. L.
We examined consistency of the relationship between intramammary infection (IMI) and somatic cell score (SCS) across several classes of cow, herd, and sampling time variables. Microbial cultures of composite milk samples were performed by New York Quality Milk Production Services from 1992 to 2004.
Mweu, Marshal M.; Nielsen, Søren S.; Hisham Beshara Halasa, Tariq
-herd sources of new herd infections coupled with the spatiotemporal distribution of the infection, may aid in effective targeting of control efforts. Thus, the objectives of this study were: (1) to describe the spatiotemporal patterns of infection with S. agalactiae in the population of Danish dairy herds from...
Kirkeby, Carsten Thure; Gussmann, Maya Katrin; Græsbøll, Kaare
Introduction. Mastitis, or intramammary infection (IMI), is one of the most significant diseases in dairy herds worldwide. It is caused by environmental and contagious bacteria. Simulation models have proven useful for evaluating the effect of different control strategies. However, previous...... published models are not cow-specific and therefore not so detailed in the simulation of host-pathogen interactions. If a simulation model is to be used by dairy farmers as a decision-making tool, it needs to be cow-specific because daily management decisions are made on cow level. Furthermore, as IMI......, contagious or mixed), the model should be able to reflect this diversity. Our objective was thus to create a pathogen-, cow- and herd-specific bio-economic simulation model that could simulate multiple pathogens and strains at the same time within a dairy herd. This model should be able to simulate realistic...
Kumar, Subbiah Krishna; Palanivel, K M; Sukumar, K; Ronald, B Samuel Masilamoni; Selvaraju, G; Ponnudurai, G
A cross-sectional study was carried out to identify risk factors for bovine viral diarrhea virus (BVDV) infection in 62 randomly selected dairy herds which were tested for BVD serum antibodies by using an indirect ELISA kit (IDEXX). Results from the chi-square test analysis were interpreted by analyzing by chi-square test. A sum of 500 sera samples were screened and 66 animals (13.20%) showed positive for BVDV antibody. Within herd, BVD seroprevalence was 12-65%. This study concluded that epidemiological risk factors like location, herd size, housing patterns like, tail to tail system, roofing pattern, distance between the manure pit and farm, and distance between farms were significantly associated with BVDV serological status (P < 0.05).
Uttenthal, Åse; Larsen, Lars Erik; Philipsen, J.S.
Using specific ELISAs, antibody levels of four different isotypes to bovine respiratory syncytial virus (BRSV) were determined in calves, following experimental BRSV infection. Most calves experienced an increase in the specific IgM and IgG1 titres about 6-10 days after infection with BRSV. The Ig......M titre was transient showing positive titres for only 5-10 days, while specific IgG1 was present for a longer time. IgA was detected concomitantly with IgM but at a lower level. Production of IgG2 anti-BRSV antibodies was detected from 3 weeks after infection. In two closed herds, repeated blood......, another herd with acute BRSV was followed by weekly blood samples in six calves; in both herds IgM and IgG1 was detected shortly after the appearance of clinical signs. Serum samples from 50 Danish dairy herds (453 samples) were tested for immunoglobulins of the isotypes IgG1, IgG2 and IgM. The presence...
Mweu, Marshal M; Nielsen, Søren S; Halasa, Tariq; Toft, Nils
Several decades after the inception of the five-point plan for the control of contagious mastitis pathogens, Streptococcus agalactiae (S. agalactiae) persists as a fundamental threat to the dairy industry in many countries. A better understanding of the relative importance of within- and between-herd sources of new herd infections coupled with the spatiotemporal distribution of the infection, may aid in effective targeting of control efforts. Thus, the objectives of this study were: (1) to describe the spatiotemporal patterns of infection with S. agalactiae in the population of Danish dairy herds from 2000 to 2009 and (2) to estimate the annual herd-level baseline and movement-related incidence risks of S. agalactiae infection over the 10-year period. The analysis involved registry data on bacteriological culture of all bulk tank milk samples collected as part of the mandatory Danish S. agalactiae surveillance scheme as well as live cattle movements into dairy herds during the specified 10-year period. The results indicated that the predicted risk of a herd becoming infected with S. agalactiae varied spatiotemporally; the risk being more homogeneous and higher in the period after 2005. Additionally, the annual baseline risks yielded significant yet distinctive patterns before and after 2005 - the risk of infection being higher in the latter phase. On the contrary, the annual movement-related risks revealed a non-significant pattern over the 10-year period. There was neither evidence for spatial clustering of cases relative to the population of herds at risk nor spatial dependency between herds. Nevertheless, the results signal a need to beef up within-herd biosecurity in order to reduce the risk of new herd infections. Copyright © 2013 Elsevier B.V. All rights reserved.
Kirkeby, Carsten Thure; Græsbøll, Kaare; Nielsen, Søren Saxmose
We describe a new mechanistic bioeconomic model for simulating the spread of Mycobacterium avium subsp. paratuberculosis (MAP) within a dairy cattle herd. The model includes age-dependent susceptibility for infection; age-dependent sensitivity for detection; environmental MAP build up in five...... control actions from the Danish MAP control program, it was not economically attractive since the expenses for the control actions outweigh the benefits. Furthermore, the three most popular control actions against the spread of MAP on the farm were found to be costly and inefficient in lowering...
Olsen, Abbey; Frankena, Klaas; Bødker, Rene
Background: Fasciola hepatica, a trematode parasite (liver fluke), infects a wide range of host species causing fasciolosis. The disease is prevalent world-wide and causes considerable economic losses to the livestock industry. Fasciolosis is regarded as an emerging food-borne zoonosis. To promote...... awareness among farmers and to implement strategies to control the infection, this study examined the prevalence, spatial distribution and risk factors for Fasciola hepatica infection in Danish cattle herds. Methods: A retrospective population based study was performed using meat inspection data...... of approximately 1.5 million cattle slaughtered in the period 2011 to 2013. Annual cumulative prevalence of recorded liver fluke findings was calculated for each year. Global and local spatial cluster analysis was used to identify and map spatial patterns of Fasciola hepatica positive and negative herds to explore...
Chai, Chunxia; Wang, Qiao; Cao, Sanjie; Zhao, Qin; Wen, Yiping; Huang, Xiaobo; Wen, Xintian; Yan, Qiguai; Ma, Xiaoping; Wu, Rui
Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic flavivirus causing viral encephalitis in humans and reproductive disorder in swine. JEV is prevalent throughout China in human; however, spatiotemporal analysis of JEV in Chinese swine herds has not been reported previously. Herein, we present serological and molecular epidemiological results and estimates of prevalence of JEV infections among swine herds in various regions of China. The results suggest that JEV infections are widespread and genotype I and III strains co-exist in the same regions. Therefore, there is an urgent need to monitor JEV infection status among swine herds in China.
Chai, Chunxia; Wang, Qiao; Cao, Sanjie; Zhao, Qin; Wen, Yiping; Huang, Xiaobo; Wen, Xintian; Yan, Qiguai; Ma, Xiaoping
Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic flavivirus causing viral encephalitis in humans and reproductive disorder in swine. JEV is prevalent throughout China in human; however, spatiotemporal analysis of JEV in Chinese swine herds has not been reported previously. Herein, we present serological and molecular epidemiological results and estimates of prevalence of JEV infections among swine herds in various regions of China. The results suggest that JEV infections are widespread and genotype I and III strains co-exist in the same regions. Therefore, there is an urgent need to monitor JEV infection status among swine herds in China. PMID:28693301
Kelton David F
Full Text Available Abstract Background Johne's disease is a chronic inflammatory bowel disease (IBD of ruminants caused by Mycobacterium avium ssp. paratuberculosis (MAP. Since this pathogen has been implicated in the pathogenesis of human IBDs, the goal of this study was to assess whether single nucleotide polymorphism (SNPs in several well-known candidate genes for human IBD are associated with susceptibility to MAP infection in dairy cattle. Methods The bovine candidate genes, interleukin-10 (IL10, IL10 receptor alpha/beta (IL10RA/B, transforming growth factor beta 1 (TGFB1, TGFB receptor class I/II (TGFBR1/2, and natural resistance-associated macrophage protein 1 (SLC11A1 were sequenced for SNP discovery using pooled DNA samples, and the identified SNPs were genotyped in a case-control association study comprised of 242 MAP negative and 204 MAP positive Holstein dairy cattle. Logistic regression was used to determine the association of SNPs and reconstructed haplotypes with MAP infection status. Results A total of 13 SNPs were identified. Four SNPs in IL10RA (984G > A, 1098C > T, 1269T > C, and 1302A > G were tightly linked, and showed a strong additive and dominance relationship with MAP infection status. Haplotypes AGC and AAT, containing the SNPs IL10RA 633C > A, 984G > A and 1185C > T, were associated with an elevated and reduced likelihood of positive diagnosis by serum ELISA, respectively. Conclusions SNPs in IL10RA are associated with MAP infection status in dairy cattle. The functional significance of these SNPs warrants further investigation.
Full Text Available Abstract Background Enzyme-linked immunosorbent assay (ELISA is often used to test wildlife samples for Mycobacterium avium subsp. paratuberculosis (MAP infection. However, commercially available kits are only validated for use with domestic ruminant species. A literature review was performed to document the current use of MAP serum ELISA in wild and semi-domestic ruminants. We then modified and evaluated a commercial ELISA kit (IDEXX Mycobacterium paratuberculosis Antibody Test Kit for use with species for which it was not originally developed: elk (Cervus elaphus, bison (Bison bison and caribou (Rangifer tarandus. We tested the affinity of different conjugates for immunoglobulin G (IgG isolated from these species, performed checkerboard tests to determine the optimal dilutions of samples and conjugates, and established cut-off values using two different methods: a Receiver Operational Curve on a panel of known samples for elk, and an alternate method involving a panel of unknown serum samples for the three species. Results We found that the anti-bovine conjugate included in the IDEXX ELISA kit has limited affinity for elk, bison, and caribou IgG. Protein G showed good affinity for IgG of all three species, while anti-deer conjugate also bound elk and caribou IgG. Using Protein G with elk serum, a cut-off sample-to-positive (S/P value of 0.22 was selected, resulting in a sensitivity and specificity of 73% and 90%, respectively, whereas, using an anti-deer conjugate with elk serum, an S/P cut-off value of 0.29 gave a sensitivity of 68%, with 100% specificity. Cut-off values for bison and caribou using the Protein G conjugate were 0.17 and 0.25 respectively. Conclusions Due to incomplete reporting and a lack of test validation, it is difficult to critically appraise results of many sero-surveys that have previously been done for MAP in wildlife. Commercial ELISA kits may have limited or no capacity to detect antibodies from species other than for
Ajay Vir Singh
Full Text Available Mycobacterium avium subspecies paratuberculosis (MAP has emerged as a major health problem for domestic livestock and human beings. Reduced per animal productivity of domestic livestock seriously impacts the economics of dairy farming globally. High to very high bioload of MAP in domestic livestock and also in the human population has been reported from north India. Presence of live MAP bacilli in commercial supplies of raw and pasteurized milk and milk products indicates its public health significance. MAP is not inactivated during pasteurization, therefore, entering into human food chain daily. Recovery of MAP from patients with inflammatory bowel disease or Crohn's disease and animal healthcare workers suffering with chronic gastrointestinal problems indicate a close association of MAP with a number of chronic and other diseases affecting human health. Higher bioload of MAP in the animals increases the risk of exposure to the human population with MAP. This review summarizes the current status of MAP infection in animals as well as in human beings and also highlights the prospects of effective management and control of disease in animals to reduce the risk of exposure to human population.
Full Text Available A longitudinal study was performed in a Swedish dairy herd where Neospora caninum had been isolated from a stillborn calf. Starting in autumn 1994, blood samples from all female animals in the herd were collected once yearly until 1999. The sera were analysed for presence of IgG1 antibodies to N. caninum by the iscom ELISA, and by an avidity ELISA to establish the timing of infection. In addition, data on reproductive performance were compiled. During the study the percentage of seropositive female animals increased from 63% to 87%. In 1994 a large number of young animals tested seropositive although their dams were seronegative, indicating that a transmission of the parasite other than the vertical had recently occurred. Low avidity values supported this assumption. The annual abortion rate increased from a mean of 2% before the initiation of the study to 9% in 1994–1998. During the same time, as judged by the avidity data, a large proportion of the animals shifted from being recently to being chronically infected. The source of the external infection in the herd could not be identified.
Mikkelsen, Heidi; Tollefsen, S.; Olsen, I.
Paratuberculosis in ruminants is caused by an infection with Mycobacterium avium subspecies paratuberculosis (MAP) and is a chronic disease characterized by granulomatous enteritis. Available vaccines against paratuberculosis consist of variations of whole bacteria with adjuvant showing various...... efficacies. The main problem with available vaccines is their interference with surveillance and diagnosis of bovine tuberculosis and paratuberculosis. Our ultimate aim is to develop a subunit vaccine consisting of selected MAP peptides, which allow differentiation of infected from vaccinated animals. Here......, 118 peptides were identified by in silico analysis and synthesized chemically. Peptides were tested for reactivity and immunogenicity with T-cell lines generated from PBMCs isolated from MAP infected goats and with blood samples from MAP infected calves. Immunogenicity of peptides was evaluated using...
Full Text Available In November 2008, a total of 19,910 bulk tank milk (BTM samples were obtained from dairy farms from all over Germany, corresponding to about 20% of all German dairy herds, and analysed for antibodies against the bovine lungworm Dictyocaulus viviparus by use of the recombinant MSP-ELISA. A total number of 3,397 (17.1%; n = 19,910 BTM samples tested seropositive. The prevalences in individual German federal states varied between 0.0% and 31.2% positive herds. A geospatial map was drawn to show the distribution of seropositive and seronegative herds per postal code area. ELISA results were further analysed for associations with land-use and climate data. Bivariate statistical analysis was used to identify potential spatial risk factors for dictyocaulosis. Statistically significant positive associations were found between lungworm seropositive herds and the proportion of water bodies and grassed area per postal code area. Variables that showed a statistically significant association with a positive BTM test were included in a logistic regression model, which was further refined by controlled stepwise selection of variables. The low Pseudo R(2 values (0.08 for the full model and 0.06 for the final model and further evaluation of the model by ROC analysis indicate that additional, unrecorded factors (e.g. management factors or random effects may substantially contribute to lungworm infections in dairy cows. Veterinarians should include lungworms in the differential diagnosis of respiratory disease in dairy cattle, particularly those at pasture. Monitoring of herds through BTM screening for antibodies can help farmers and veterinarians plan and implement appropriate control measures.
Schunn, Anne-Marie; Conraths, Franz J.; Staubach, Christoph; Fröhlich, Andreas; Forbes, Andrew; Strube, Christina
In November 2008, a total of 19,910 bulk tank milk (BTM) samples were obtained from dairy farms from all over Germany, corresponding to about 20% of all German dairy herds, and analysed for antibodies against the bovine lungworm Dictyocaulus viviparus by use of the recombinant MSP-ELISA. A total number of 3,397 (17.1%; n = 19,910) BTM samples tested seropositive. The prevalences in individual German federal states varied between 0.0% and 31.2% positive herds. A geospatial map was drawn to show the distribution of seropositive and seronegative herds per postal code area. ELISA results were further analysed for associations with land-use and climate data. Bivariate statistical analysis was used to identify potential spatial risk factors for dictyocaulosis. Statistically significant positive associations were found between lungworm seropositive herds and the proportion of water bodies and grassed area per postal code area. Variables that showed a statistically significant association with a positive BTM test were included in a logistic regression model, which was further refined by controlled stepwise selection of variables. The low Pseudo R2 values (0.08 for the full model and 0.06 for the final model) and further evaluation of the model by ROC analysis indicate that additional, unrecorded factors (e.g. management factors) or random effects may substantially contribute to lungworm infections in dairy cows. Veterinarians should include lungworms in the differential diagnosis of respiratory disease in dairy cattle, particularly those at pasture. Monitoring of herds through BTM screening for antibodies can help farmers and veterinarians plan and implement appropriate control measures. PMID:24040243
Barkema, H W; Orsel, K; Nielsen, S S
In the last decades, many regional and country-wide control programmes for Johne's disease (JD) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were...... programmes are typically evaluated in a limited number of herds and the duration of the study is less than 5 year, making it difficult to adequately assess the efficacy of control programmes. In this manuscript, we identify the most important gaps in knowledge hampering JD prevention and control programmes......, including vaccination and diagnostics. Secondly, we discuss directions that research should take to address those knowledge gaps....
Bauman, Cathy A; Jones-Bitton, Andria; Menzies, Paula; Jansen, Jocelyn; Kelton, David
A cross-sectional study was undertaken (October 2010 to August 2011) to determine the risk factors for dairy goat herds and dairy sheep flocks testing positive for paratuberculosis (PTB) in Ontario, Canada. A questionnaire was administered to 50 producers during a farm visit in which concurrently, 20 randomly selected, lactating animals over the age of 2 years underwent sampling for paratuberculosis testing. Only 1 of 50 farms (2.0%) was closed to animal movement, whereas 96.6% of dairy goat farms and 94.1% of sheep farms purchased livestock from other producers. Only 10.3% of dairy goat, and no dairy sheep farms used artificial insemination. Manure was spread on grazing pastures by 65.5% and 70.6% of dairy goat and dairy sheep farms, respectively. Because of the high true-prevalence of paratuberculosis infection detected, no risk factor analysis could be performed. This study demonstrates that biosecurity practices conducive to transmission of PTB are highly prevalent in Ontario small ruminant dairy farms.
Krüger, C; Köhler, H; Liebler-Tenorio, E M
Mycobacterium avium subsp. paratuberculosis (MAP) causes lesions in naturally and experimentally infected ruminants which greatly differ in severity, cellular composition and number of mycobacteria. Morphologically distinct lesions are already found during the clinically inapparent phase of infection. The complex local host response and number of MAP were characterized at the initial sites of lesions, organized gut-associated lymphoid tissue, in experimentally infected goats. Tissues were collected at 3, 6, 9 and 12 month post-inoculation (mpi) from goat kids that had orally received 10 times 10mg of bacterial wet mass of MAP (JII-1961). The cellular composition of lesions in Peyer's patches in the jejunum and next to the ileocecal valve was evaluated in 21 MAP-inoculated goats, where lesions were compared with unaltered tissue of six control goats. CD68+, CD4+, CD8+, γδ T lymphocytes, B lymphocytes and plasma cells, MHC class II+ and CD25+ cells were demonstrated by immunohistochemistry in serial cryostat sections. At 3 mpi, extensive granulomatous infiltrates predominated, consisting of numerous epitheloid cells admixed with many CD4 and γδ T lymphocytes. Only single MAP were detected. This indicates a strong cellular immune reaction able to control MAP infection. γδ T lymphocytes were markedly increased in this type of lesion which may reflect their important role early in the pathogenesis of paratuberculosis. At 9 and 12 mpi, divergent lesions were observed which may reflect different outcomes of host-pathogen interactions. In five goats, minimal granulomatous lesions were surrounded by extensive lymphoplasmacytic infiltrates and no MAP were detected by immunohistochemistry. This was interpreted as effective host response that was able to eliminate MAP locally. In three goats, decreased numbers of lymphocytes, but extensive granulomatous infiltrates with numerous epitheloid cells containing increased numbers of mycobacteria were seen. This shift of the
Full Text Available Fasciolosis is generally a subclinical infection of dairy cows and can cause marked economic losses. This study investigated the prevalence and spatial distribution of fasciolosis in dairy cow herds in Ireland using an in-house antibodydetection enzyme-linked immunosorbent assay applied to bulk tank milk (BTM samples collected during the autumn of 2012. A total of 5,116 BTM samples were collected from 4,602 different herds, with 514 farmers submitting BTM samples in two consecutive months. Analysis of the BTM samples showed that 82% (n = 3,764 of the dairy herds had been exposed to Fasciola hepatica. A total of 108 variables, including averaged climatic data for the period 1981-2010 and contemporary meteorological data for the year 2012, such as soil, subsoil, land cover and habitat maps, were investigated for a possible role as predictor of fasciolosis. Using mainly climatic variables as the major predictors, a model of the predicted risk of fasciolosis was created by Random Forest modelling that had 95% sensitivity and 100% specificity. The most important predictors in descending order of importance were: average of annual total number of rain-days for the period 1981-2010, total rainfall during September, winter and autumn of 2012, average of annual total number of wet-days for the period 1981- 2010 and annual mean temperature of 2012. The findings of this study confirm the high prevalence of fasciolosis in Irish dairy herds and suggest that specific weather and environmental risk factors support a robust and precise distribution model.
Wedderkopp, A.; Stroger, U.; Bitsch, V.
-negative to test-positive in each area was correlated with the incidence of S. Dublin outbreaks in the corresponding county (r = 0.48, n = 19; P third test rounds was not constant (Pr \\t\\ = 0.0001). The study demonstrated that the probability...... of being test-negative in the third test round was 0.926 for a herd with 2 previous test-negative results. It was concluded that the investigated ELISA method was in general accordance with the cases of clinical S. Dublin infection recorded. and that the method has a potential for national screening...
Smith, R L; Al-Mamun, M A; Gröhn, Y T
The cost of paratuberculosis to dairy herds, through decreased milk production, early culling, and poor reproductive performance, has been well-studied. The benefit of control programs, however, has been debated. A recent stochastic compartmental model for paratuberculosis transmission in US dairy herds was modified to predict herd net present value (NPV) over 25 years in herds of 100 and 1000 dairy cattle with endemic paratuberculosis at initial prevalence of 10% and 20%. Control programs were designed by combining 5 tests (none, fecal culture, ELISA, PCR, or calf testing), 3 test-related culling strategies (all test-positive, high-positive, or repeated positive), 2 test frequencies (annual and biannual), 3 hygiene levels (standard, moderate, or improved), and 2 cessation decisions (testing ceased after 5 negative whole-herd tests or testing continued). Stochastic dominance was determined for each herd scenario; no control program was fully dominant for maximizing herd NPV in any scenario. Use of the ELISA test was generally preferred in all scenarios, but no paratuberculosis control was highly preferred for the small herd with 10% initial prevalence and was frequently preferred in other herd scenarios. Based on their effect on paratuberculosis alone, hygiene improvements were not found to be as cost-effective as test-and-cull strategies in most circumstances. Global sensitivity analysis found that economic parameters, such as the price of milk, had more influence on NPV than control program-related parameters. We conclude that paratuberculosis control can be cost effective, and multiple control programs can be applied for equivalent economic results. Copyright © 2017 Elsevier B.V. All rights reserved.
Collins, M.T.; Kenefick, K.B.; Sockett, D.C.; Lambrecht, R.S.; McDonald, J.; Jorgensen, J.B.
A commercial radiometric medium, BACTEC 12B, was modified by addition of mycobactin, egg yolk suspension, and antibiotics (vancomycin, amphotericin B, and nalidixic acid). Decontaminated bovine fecal specimens were filter concentrated by using 3-microns-pore-size, 13-mm-diameter polycarbonate filters, and the entire filter was placed into the radiometric broth. Comparison of the radiometric technique with conventional methods on 603 cattle from 9 Mycobacterium paratuberculosis-infected herds found that of 75 positive specimens, the radiometric technique detected 92% while conventional methods detected 60% (P less than 0.0005). Only 3.9% of radiometric cultures were contaminated. To measure the effect of filter concentration of specimens on the detection rate, 5 cattle with minimal and 5 with moderate ileum histopathology were sampled weekly for 3 weeks. M. paratuberculosis was detected in 33.3% of nonfiltered specimens and 76.7% of filtered specimens (P less than 0.005). Detection rates were directly correlated with the severity of disease, and the advantage of specimen concentration was greatest on fecal specimens from cattle with low-grade infections. Detection times were also correlated with infection severity: 13.4 +/- 5.9 days with smear-positive specimens, 27.9 +/- 8.7 days with feces from cows with typical subclinical infections, and 38.7 +/- 3.8 days with fecal specimens from cows with low-grade infections. Use of a cocktail of vancomycin, amphotericin B, and nalidixic acid for selective suppression of nonmycobacterial contaminants was better than the commercial product PANTA (Becton Dickinson Microbiologic Systems, Towson, Md.) only when specimens contained very low numbers of M. paratuberculosis
Pruvot, M; Kutz, S; Barkema, H W; De Buck, J; Orsel, K
Mycobacterium avium subsp. paratuberculosis (MAP) and Neospora caninum (NC) are two pathogens causing important production limiting diseases in the cattle industry. Significant impacts of MAP and NC have been reported on dairy cattle herds, but little is known about the importance, risk factors and transmission patterns in western Canadian cow-calf herds. In this cross-sectional study, the prevalence of MAP and NC infection in southwest Alberta cow-calf herds was estimated, risk factors for NC were identified, and the reproductive impacts of the two pathogens were assessed. Blood and fecal samples were collected from 840 cows on 28 cow-calf operations. Individual cow and herd management information was collected by self-administered questionnaires and one-on-one interviews. Bayesian estimates of the true prevalence of MAP and NC were computed, and bivariable and multivariable statistical analysis were done to assess the association between the NC serological status and ranch management risk factors, and the clinical effects of the two pathogens. Bayesian estimates of true prevalence indicated that 20% (95% probability interval: 8-38%) of herds had at least one MAP-positive cow, with a within-herd prevalence in positive herds of 22% (8-45%). From the Bayesian posterior distributions of NC prevalence, the median herd-level prevalence was 66% (33-95%) with 10% (4-21%) cow-level prevalence in positive herds. Multivariable analysis indicated that introducing purchased animals in the herd might increase the risk of NC. The negative association of NC with proper carcass disposal and presence of horses on ranch (possibly in relation to herd monitoring and guarding activities), may suggest the importance of wild carnivores in the dynamics of this pathogen in the study area. We also observed an association between MAP and NC serological status and the number of abortions. Additional studies should be done to further examine specific risk factors for MAP and NC, assess the
Lundberg, Å; Nyman, A-K; Aspán, A; Börjesson, S; Unnerstad, H Ericsson; Waller, K Persson
Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis are common causes of bovine mastitis. To study these pathogens in early lactation, a 12-mo longitudinal, observational study was carried out in 13 herds with suboptimal udder health. The aims of the study were to investigate the occurrence of these pathogens and to identify if presence of the 3 pathogens, and of genotypes within the pathogens, differed with respect to herd, season, and parity. Quarter milk samples, collected at calving and 4 d in milk (DIM), were cultured for the 3 pathogens. Genotyping of staphylococcal and streptococcal isolates was performed using spa typing and pulsed-field gel electrophoresis, respectively. For each of the 3 pathogens, cows with an udder infection at calving or 4 DIM were allocated to 1 of 4 infection types: cleared (pathogen present only at calving), persistent (pathogen present in the same quarter at calving and 4 DIM), new (pathogen present only at 4 DIM), or cleared/new (pathogen present in 1 quarter at calving and in another quarter at 4 DIM). Associations between season or parity and overall occurrence of pathogens or infection types were determined using univariable mixed-effect logistic-regression models and the Fisher's exact test, respectively. The most commonly occurring pathogen was Staph. aureus, followed by Strep. dysgalactiae and Strep. uberis. Persistent infections were the most common infection type among Staph. aureus-infected cows, whereas cleared infections were the most common among Strep. dysgalactiae- and Strep. uberis-positive cows. The proportion of cows with persistent Staph. aureus infections and the proportion of cows having a Strep. uberis infection at calving or 4 DIM were higher in the multiparous cows than in primiparous cows. Infections with Strep. dysgalactiae were less common during the early housing season than during the late housing or pasture seasons, whereas persistent Strep. uberis
Gilardoni, Liliana R; Paolicchi, Fernando A; Mundo, Silvia L
Paratuberculosis (PTB), or Johne's disease, is a chronic infectious granulomatous enteritis of ruminants, caused by Mycobacterium avium subspecies paratuberculosis (Map). It is characterized by diarrhea and progressive cachexia, which may cause the death of the animal. Calves are the most susceptible to infection. Infected animals excrete Map mainly by the feces. PTB is endemic worldwide, with high prevalence levels, strong economic impact and public health relevance because of its possible association with Crohn's disease. Although the current reference diagnostic test is identification of Map in the bacterial culture, there are different diagnostic tests to identify infected individuals and/or herds. The sensitivity and specificity of these tests vary according to the stage of the disease in the animals to be evaluated. The correct choice and application of each of these diagnostic tests will ensure their success and may allow to establish a control program. The aim of this work is to review and discuss the different diagnostic tests used in the detection of Map-infected animals, focusing on their advantages and disadvantages.
Virtanen, S; Nikunen, S; Korkeala, H
Altogether, 369 pathogenic Yersinia enterocolitica isolates from 1,118 fecal samples collected from 22 pig farms of different production types were characterized by biotyping, serotyping, and genotyping using multiple-locus variable-number tandem repeats analysis. We investigated the distribution of the different genotypes at the farm level and their association with different farm conditions. Pigs were found to carry and transmit Y. enterocolitica between farms, because the same genotypes were found on farms that had previously transported the pigs between them. The purchase of new animals for the farms associated significantly with the number of different multiple-locus variable-number tandem repeats analysis types of Y. enterocolitica found within a farm. Some genotypes seemed to persist on farms for years. The results of this study show that pigs purchased from infected herds transmit Y. enterocolitica infection between farms. Certain pig farms may act as long-term sources of infection.
Full Text Available Abstract Background The primary aims of this study were to determine the incidence of Giardia infections in dairy herds on farms in the New York City Watershed region and to evaluate risk factors associated with infections. Because co-infections of Giardia and Cryptosporidium spp. are common in this population, we also evaluated the effect of herd infection status on Giardia infections. Methods Farms were grouped into three cohorts based on their prior infection status with Giardia and/or Cryptosporidium spp. The sampling plan included collecting fecal samples from all calves below 30 days of age and proportional sampling of calves, young stock, and adults. A total of 10,672 fecal samples were collected and analyzed for the presence of Giardia cysts using zinc sulfate flotation. Herds enrolled in the study were sampled seasonally for a study period of two years. The probability of shedding cysts past a certain age and the factors that influenced the likelihood of shedding were evaluated using survival analysis. Linear regression was used to evaluate factors that were associated with the intensity of shedding. Results The majority of Giardia infections occurred in calves within their first 180 days of age, with the most number of calves shedding Giardia cysts between 11 and 20 days of age. The incidence of shedding of Giardia cysts ranged from 0.0004 per animal day for cattle in the low risk cohort to 0.0011 per animal day for cattle in the high risk cohort. The likelihood of shedding was influenced by the prior infection status of the herd and the season of collection. Infected animals shed on average 9,658 cysts/gram and the intensity of shedding Giardia cysts varied significantly with the age (p Conclusion Giardia infections are common in dairy herds in the New York City watershed, particularly in calves less than 6 months of age. Seasonality may be an important factor in the perpetuation of infections based on changes in management practices
Piepers, S.; Peeters, K.; Opsomer, G.; Barkema, H.W.; Frankena, K.; Vliegher, de S.
Risk factors for intramammary infections caused by coagulase-negative staphylococci, contagious major pathogens and environmental major pathogens in early lactating heifers were evaluated at the herd, heifer and quarter levels. In total, 764 quarters of 191 dairy heifers in 20 randomly selected
Jolly, Ana; Lompardía, Silvina; Hajos, Silvia E; Mundo, Silvia L
Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne's disease (JD), a chronic granulomatous enteritis in ruminants. Understanding the protective immune response following infection is crucial to improve the diagnosis and the development of vaccines against this disease. The goal of this work was to assess whether specific antibodies were able to modulate the macrophage response to MAP infection by evaluating apoptosis and TNF-α secretion in an in vitro model. Sera from healthy (n=2), MAP-infected (n=3) and lipoarabinomannan (LAM)-immunized (n=3) bovines were evaluated. LAM was chosen as immunogen due to its relevant role in mycobacterial pathogenesis. We demonstrated by two different techniques (Acridine Orange/Ethidium Bromide microscopy and Annexin V/7-Amino-Actinomycin D flow cytometry) that the immune sera from both, MAP-infected and LAM-immunized bovines, significantly increased macrophage apoptosis in infected cultures. Comparable levels of apoptosis were detected when MAP was pre-incubated with purified specific antibodies instead of whole serum. Furthermore, this effect was accompanied by a significantly higher secretion of TNF-α. These results strongly suggest that specific antibodies could limit the impact of MAP on the apoptosis of bovine cells. This work would contribute to elucidate the role of the specific antibody response in bovine JD and its prevention. Copyright © 2015 Elsevier B.V. All rights reserved.
Therefore, alternative diagnostic tests such as PCR, are needed for quick detection of infected animals. In this study, the conventional enrichment and isolation procedure and two IS900-based PCR methods for detection of Mycobactrium avium subsp. paratuberculosis in clinical samples from zoo animals and cattle were ...
Derakhshani, Hooman; De Buck, Jeroen; Mortier, Rienske; Barkema, Herman W; Krause, Denis O; Khafipour, Ehsan
Current diagnostic tests for Johne's disease (JD), a chronic granulomatous inflammation of the gastrointestinal tract of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP), lack the sensitivity to identify infected animals at early (asymptomatic) stages of the disease. The objective was to determine the pattern of MAP-associated dysbiosis of intestinal microbiota as a potential biomarker for early detection of infected cattle. To that end, genomic DNA was extracted from ileal mucosa and fecal samples collected from 28 MAP-positive and five control calves. High-throughput Illumina sequencing of the V4 hypervariable region of the 16S rRNA gene was used for community profiling of ileal mucosa-associated (MAM) or fecal microbiota. The PERMANOVA analysis of unweighted UniFrac distances revealed distinct clustering of ileal MAM (P = 0.049) and fecal microbiota (P = 0.068) in MAP-infected vs. control cattle. Microbiota profile of MAP-infected animals was further investigated by linear discriminant analysis effective size (LEfSe); several bacterial taxa within the phylum Proteobacteria were overrepresented in ileal MAM of control calves. Moreover, based on reconstructed metagenomes (PICRUSt) of ileal MAM, functional pathways associated with MAP infection were inferred. Enrichment of lysine and histidine metabolism pathways, and underrepresentation of glutathione metabolism and leucine and isoleucine degradation pathways in MAP-infected calves suggested potential contributions of ileal MAM in development of intestinal inflammation. Finally, simultaneous overrepresentation of families Planococcaceae and Paraprevotellaceae, as well as underrepresentation of genera Faecalibacterium and Akkermansia in the fecal microbiota of infected cattle, served as potential biomarker for identifying infected cattle during subclinical stages of JD. Collectively, based on compositional and functional shifts in intestinal microbiota of infected cattle, we inferred that
Full Text Available Current diagnostic tests for Johne's disease (JD, a chronic granulomatous inflammation of the gastrointestinal tract of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP, lack the sensitivity to identify infected animals at early (asymptomatic stages of the disease. The objective was to determine the pattern of MAP-associated dysbiosis of intestinal microbiota as a potential biomarker for early detection of infected cattle. To that end, genomic DNA was extracted from ileal mucosa and fecal samples collected from 28 MAP-positive and five control calves. High-throughput Illumina sequencing of the V4 hypervariable region of the 16S rRNA gene was used for community profiling of ileal mucosa-associated (MAM or fecal microbiota. The PERMANOVA analysis of unweighted UniFrac distances revealed distinct clustering of ileal MAM (P = 0.049 and fecal microbiota (P = 0.068 in MAP-infected versus control cattle. Microbiota profile of MAP infected animals was further investigated by linear discriminant analysis effective size (LEfSe; several bacterial taxa within the phylum Proteobacteria were overrepresented in ileal MAM of control calves. Moreover, based on reconstructed metagenomes (PICRUSt of ileal MAM, functional pathways associated with MAP infection were inferred. Enrichment of lysine and histidine metabolism pathways, and underrepresentation of glutathione metabolism and leucine and isoleucine degradation pathways in MAP-infected calves suggested potential contributions of ileal MAM in development of intestinal inflammation. Finally, simultaneous overrepresentation of families Planococcaceae and Paraprevotellaceae, as well as underrepresentation of genera Faecalibacterium and Akkermansia in the fecal microbiota of infected cattle, served as potential biomarker for identifying infected cattle during subclinical stages of JD. Collectively, based on compositional and functional shifts in intestinal microbiota of infected cattle, we
Derakhshani, Hooman; De Buck, Jeroen; Mortier, Rienske; Barkema, Herman W.; Krause, Denis O.; Khafipour, Ehsan
Current diagnostic tests for Johne's disease (JD), a chronic granulomatous inflammation of the gastrointestinal tract of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP), lack the sensitivity to identify infected animals at early (asymptomatic) stages of the disease. The objective was to determine the pattern of MAP-associated dysbiosis of intestinal microbiota as a potential biomarker for early detection of infected cattle. To that end, genomic DNA was extracted from ileal mucosa and fecal samples collected from 28 MAP-positive and five control calves. High-throughput Illumina sequencing of the V4 hypervariable region of the 16S rRNA gene was used for community profiling of ileal mucosa-associated (MAM) or fecal microbiota. The PERMANOVA analysis of unweighted UniFrac distances revealed distinct clustering of ileal MAM (P = 0.049) and fecal microbiota (P = 0.068) in MAP-infected vs. control cattle. Microbiota profile of MAP-infected animals was further investigated by linear discriminant analysis effective size (LEfSe); several bacterial taxa within the phylum Proteobacteria were overrepresented in ileal MAM of control calves. Moreover, based on reconstructed metagenomes (PICRUSt) of ileal MAM, functional pathways associated with MAP infection were inferred. Enrichment of lysine and histidine metabolism pathways, and underrepresentation of glutathione metabolism and leucine and isoleucine degradation pathways in MAP-infected calves suggested potential contributions of ileal MAM in development of intestinal inflammation. Finally, simultaneous overrepresentation of families Planococcaceae and Paraprevotellaceae, as well as underrepresentation of genera Faecalibacterium and Akkermansia in the fecal microbiota of infected cattle, served as potential biomarker for identifying infected cattle during subclinical stages of JD. Collectively, based on compositional and functional shifts in intestinal microbiota of infected cattle, we inferred that
Salgado, M; Steuer, P; Troncoso, E; Collins, M T
Mycobacterium avium subsp. paratuberculosis (MAP) causes paratuberculosis, or Johne's disease, in animals. Diagnosis of MAP infection is challenging because of the pathogen's fastidious in vitro growth requirements and low-level intermittent shedding in feces during the preclinical phase of the infection. Detection of these "low-shedders" is important for effective control of paratuberculosis as these animals serve as sources of infection for susceptible calves. Magnetic separation technology, used in combination with culture or molecular methods for the isolation and detection of pathogenic bacteria, enhances the analytical sensitivity and specificity of detection methods. The aim of the present study was to evaluate peptide-mediated magnetic separation (PMS) capture technology coupled with IS900 PCR using the Roche real-time PCR system (PMS-PCR), in comparison with fecal culture using BACTEC-MGIT 960 system, for detection of MAP in bovine fecal samples. Among the 351 fecal samples 74.9% (263/351) were PMS-PCR positive while only 12.3% (43/351) were MGIT culture-positive (p=0.0001). All 43 MGIT culture-positive samples were also positive by PMS-PCR. Mean PMS-PCR crossing-point (Cp) values for the 13 fecal samples with the highest number of MAP, based on time to detection, (26.3) were significantly lower than for the 17 fecal samples with technology provided results in a shorter time and yielded a higher number of positive results than MGIT culture. Earlier and faster detection of animals shedding MAP by PMS-PCR should significantly strengthen control efforts for MAP-infected cattle herds by helping to limit infection transmission at earlier stages of the infection. Copyright © 2013 Elsevier B.V. All rights reserved.
Küpper, J; Brandt, H; Donat, K; Erhardt, G
The objective of this study was to estimate genetic manifestation of Mycobacterium avium ssp. paratuberculosis (MAP) infection in German Holstein cows. Incorporated into this study were 11,285 German Holstein herd book cows classified as MAP-positive and MAP-negative animals using fecal culture results and originating from 15 farms in Thuringia, Germany involved in a paratuberculosis voluntary control program from 2008 to 2009. The frequency of MAP-positive animals per farm ranged from 2.7 to 67.6%. The fixed effects of farm and lactation number had a highly significant effect on MAP status. An increase in the frequency of positive animals from the first to the third lactation could be observed. Threshold animal and sire models with sire relationship were used as statistical models to estimate genetic parameters. Heritability estimates of fecal culture varied from 0.157 to 0.228. To analyze the effect of prevalence on genetic parameter estimates, the total data set was divided into 2 subsets of data into farms with prevalence rates below 10% and those above 10%. The data set with prevalence above 10% show higher heritability estimates in both models compared with the data set with prevalence below 10%. For all data sets, the sire model shows higher heritabilities than the equivalent animal model. This study demonstrates that genetic variation exists in dairy cattle for paratuberculosis infection susceptibility and furthermore, leads to the conclusion that MAP detection by fecal culture shows a higher genetic background than ELISA test results. In conclusion, fecal culture seems to be a better trait to control the disease, as well as an appropriate feature for further genomic analyses to detect MAP-associated chromosome regions. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Albarrak, S M; Waters, W R; Stabel, J R; Hostetter, J M
A role for γδ T cells in protection against mycobacterial infections including Johne's disease (JD) has been suggested. In neonatal calves where the risk to infection with Mycobacterium avium subsp. paratuberculosis (MAP) is high, the majority of circulating CD3 + lymphocytes are γδ TCR + . Bovine γδ T cells are divided into two major subsets based on the surface expression of workshop cluster 1 (WC1). The WC1 + subset, the predominant subset in periphery, is further divided into WC1.1 + and WC1.2 + subpopulations. The ability of γδ T cells to produce IFN-γ prior to CD4 + αβ T cell activation could be crucial to the outcome of MAP infection. In the current study, cattle were naturally infected with MAP and were classified as either in the subclinical or clinical stage of infection. Compared to the control non-infected group, γδ T cell frequency in circulating lymphocytes was significantly lower in the clinical group. The observed decline in frequency was restricted to the WC1.2 + subset, and was not associated with preferential migration to infection sites (distal-ileum). γδ T cells proliferated significantly in recall responses to stimulation with purified protein derivative from MAP (PPD-J) only in subclinically infected cattle. These responses were a heterogeneous mixture of WC1.1 and WC1.2 subsets. Proliferation and IFN-γ production by the WC1.1 + γδ T cell subset was significantly higher in the subclinical group compared to the control and clinical groups. Our data indicates differences in MAP-specific ex-vivo responses of peripheral WC1 + γδ T cells of cattle with the subclinical or clinical form of JD. Copyright © 2017 Elsevier B.V. All rights reserved.
Magombedze, Gesham; Eda, Shigetoshi; Stabel, Judy
Mycobacterium avium subsp. paratuberculosis (MAP) is an intracellular bacterial pathogen that causes Johne’s disease (JD) in cattle and other animals. The hallmark of MAP infection in the early stages is a strong protective cell-mediated immune response (Th1-type), characterized by antigen-specific γ-interferon (IFN-γ). The Th1 response wanes with disease progression and is supplanted by a non-protective humoral immune response (Th2-type). Interleukin-10 (IL-10) is believed to play a critical role in the regulation of host immune responses to MAP infection and potentially orchestrate the reversal of Th1/Th2 immune dominance during disease progression. However, how its role correlates with MAP infection remains to be completely deciphered. We developed mathematical models to explain probable mechanisms for IL-10 involvement in MAP infection. We tested our models with IL-4, IL-10, IFN-γ, and MAP fecal shedding data collected from calves that were experimentally infected and followed over a period of 360 days in the study of Stabel and Robbe-Austerman (2011). Our models predicted that IL-10 can have different roles during MAP infection, (i) it can suppress the Th1 expression, (ii) can enhance Th2 (IL-4) expression, and (iii) can suppress the Th1 expression in synergy with IL-4. In these predicted roles, suppression of Th1 responses was correlated with increased number of MAP. We also predicted that Th1-mediated responses (IFN-γ) can lead to high expression of IL-10 and that infection burden regulates Th2 suppression by the Th1 response. Our models highlight areas where more experimental data is required to refine our model assumptions, and further test and investigate the role of IL-10 in MAP infection. PMID:26619346
Full Text Available Mycobacterium avium subsp. paratuberculosis (MAP is an intracellular bacterial pathogen that causes Johne's disease (JD in cattle and other animals. The hallmark of MAP infection in the early stages is a strong protective cell-mediated immune response (Th1-type, characterized by antigen-specific γ-interferon (IFN-γ. The Th1 response wanes with disease progression and is supplanted by a non-protective humoral immune response (Th2-type. Interleukin-10 (IL-10 is believed to play a critical role in the regulation of host immune responses to MAP infection and potentially orchestrate the reversal of Th1/Th2 immune dominance during disease progression. However, how its role correlates with MAP infection remains to be completely deciphered. We developed mathematical models to explain probable mechanisms for IL-10 involvement in MAP infection. We tested our models with IL-4, IL-10, IFN-γ, and MAP fecal shedding data collected from calves that were experimentally infected and followed over a period of 360 days in the study of Stabel and Robbe-Austerman (2011. Our models predicted that IL-10 can have different roles during MAP infection, (i it can suppress the Th1 expression, (ii can enhance Th2 (IL-4 expression, and (iii can suppress the Th1 expression in synergy with IL-4. In these predicted roles, suppression of Th1 responses was correlated with increased number of MAP. We also predicted that Th1-mediated responses (IFN-γ can lead to high expression of IL-10 and that infection burden regulates Th2 suppression by the Th1 response. Our models highlight areas where more experimental data is required to refine our model assumptions, and further test and investigate the role of IL-10 in MAP infection.
Baggesen, Dorte Lau; Wegener, Henrik Caspar; Bager, Flemming
As a part of a nationwide programme to survey and control salmonella in pig herds, a microbiological survey of 1363 pig herds was performed in Denmark. A total of 13 468 slaughter pigs were examined at slaughter by culture of 5 g of caecal contents. Overall, 30 different serotypes of Salmonella...
Full Text Available Abstract Background At the end of 2011, a new orthobunyavirus, tentatively named Schmallenberg virus (SBV, was discovered in Germany. This virus has since been associated with clinical signs of decreased milk production, watery diarrhoea and fever in dairy cows, and subsequently also with congenital malformations in calves, lambs and goat kids. In affected countries, initial surveillance for the infection was based on examination of malformed progeny. These suspicions were followed up by real-time reverse transcription polymerase chain reaction (RT-PCR on brain tissue. For epidemiological purposes, a serological assay was, however, needed. Results A virus neutralisation test (VNT was developed and optimized, and subsequently evaluated. This VNT has a specificity of >99% and the sensitivity is likely also very close to 100%. The assay is highly repeatable and reproducible. The final assay was used to test for antibodies in cows, ewes and does from herds known to be infected or suspected to be so. Targets for sampling in these herds were the mothers of malformed offspring. In herds with an RT-PCR confirmed SBV infection, more than 94% (190 out of 201 of the ewes and 99% (145 out of 146 of the cows were seropositive. In herds with suspicion of SBV infection based on birth of malformed offspring only (no or negative RT-PCR, more than 90% (231 out of 255 of the ewes and 95% (795 out of 834 of the cows were seropositive. In goats, on the other hand, only a low number of seropositives was found: overall 36.4%, being 16 out of 44 goats tested. Conclusions Given the characteristics of this VNT, it can be used at a relative high throughput for testing of animals for export, surveillance, screening and research purposes, but can also be used as a confirmation test for commercially available enzyme-linked immunosorbent assays (ELISA’s and for (relative quantification of antibodies. Suspicions of SBV infections that were confirmed by RT-PCR were almost
Sørensen, J.T.; Enevoldsen, Carsten; Houe, H.
A dynamic, stochastic model simulating the technical and economic consequences of bovine virus diarrhoea virus (BVDV) infections for a dairy cattle herd for use on a personal computer was developed. The production and state changes of the herd were simulated by state changes of the individual cows...... and heifers. All discrete events at the cow level were triggered stochastically. Each cow and heifer was characterized by state variables such as stage of lactation, parity, oestrous status, decision for culling, milk production potential, and immune status for BVDV. The model was controlled by 170 decision...... variables describing biologic and management variables including 21 decision variables describing the effect of BVDV infection on the production of the individual animal. Two markedly different scenarios were simulated to demonstrate the behaviour of the developed model and the potentials of the applied...
Khare, Sangeeta; Drake, Kenneth L; Lawhon, Sara D; Nunes, Jairo E S; Figueiredo, Josely F; Rossetti, Carlos A; Gull, Tamara; Everts, Robin E; Lewin, Harris A; Adams, Leslie Garry
It has long been a quest in ruminants to understand how two very similar mycobacterial species, Mycobacterium avium ssp. paratuberculosis (MAP) and Mycobacterium avium ssp. avium (MAA) lead to either a chronic persistent infection or a rapid-transient infection, respectively. Here, we hypothesized that when the host immune response is activated by MAP or MAA, the outcome of the infection depends on the early activation of signaling molecules and host temporal gene expression. To test our hypothesis, ligated jejuno-ileal loops including Peyer's patches in neonatal calves were inoculated with PBS, MAP, or MAA. A temporal analysis of the host transcriptome profile was conducted at several times post-infection (0.5, 1, 2, 4, 8 and 12 hours). When comparing the transcriptional responses of calves infected with the MAA versus MAP, discordant patterns of mucosal expression were clearly evident, and the numbers of unique transcripts altered were moderately less for MAA-infected tissue than were mucosal tissues infected with the MAP. To interpret these complex data, changes in the gene expression were further analyzed by dynamic Bayesian analysis. Bayesian network modeling identified mechanistic genes, gene-to-gene relationships, pathways and Gene Ontologies (GO) biological processes that are involved in specific cell activation during infection. MAP and MAA had significant different pathway perturbation at 0.5 and 12 hours post inoculation. Inverse processes were observed between MAP and MAA response for epithelial cell proliferation, negative regulation of chemotaxis, cell-cell adhesion mediated by integrin and regulation of cytokine-mediated signaling. MAP inoculated tissue had significantly lower expression of phagocytosis receptors such as mannose receptor and complement receptors. This study reveals that perturbation of genes and cellular pathways during MAP infection resulted in host evasion by mucosal membrane barrier weakening to access entry in the ileum
de Silva, Kumudika; Plain, Karren; Purdie, Auriol; Begg, Douglas; Whittington, Richard
Paratuberculosis is an insidious, chronic disease of ruminants that has significant animal welfare implications and reduces on-farm profitability globally. Not all animals exposed to the causative pathogen, Mycobacterium avium subspecies paratuberculosis (MAP), succumb to disease and this unique, long-term trial was designed to track animals that were resilient. The advantages of understanding immune protection include the management option to retain resilient individuals in a herd/flock and the potential for deliberate manipulation of the host immune response using novel vaccines. Twenty sheep experimentally exposed to MAP and 10 controls were monitored for 2.5 years during which the condition progressed, resembling natural disease development. Cellular and humoral immune parameters and faecal MAP shedding were examined regularly and disease outcomes were classified at necropsy, based on the presence of viable MAP and histopathological lesions in intestinal tissues, either at the termination of the trial or when animals were culled due to weight loss. There were distinct characteristics, such as an early strong IFNγ response, that differentiated resilient sheep from susceptible individuals prior to the onset of clinical disease. Faecal MAP shedding and serum antibody level, commonly used to diagnose disease, were more ambiguous. The former was transient in the majority of resilient animals and therefore should not be used for diagnosis of MAP infection in younger animals. Remarkably, the serum antibody level in some resilient animals was higher than the usual positive-negative cut-off for disease diagnosis at multiple samplings throughout the trial. Consequently the antibody response in resistance to paratuberculosis requires further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.
Nielsen, Gitte Blach; Nielsen, Jens Peter; Haugegaard, John
During the last decade, the clinical manifestation of Porcine Circovirus type 2 (PCV2) infections has mostly changed from postweaning multisystemic wasting syndrome and high mortality to sub-clinical infections manifested only through impaired production parameters. However, co-infection with other...... respiratory pathogens often results in a larger effect on production, sometimes with clinical signs. Little is known about the impact of a moderate level PCV2 infection without co-infections, particularly in terms of feed conversion ratio and antimicrobial consumption. The purpose of the study was to evaluate...... the effect of vaccination against PCV2 in a sub-clinically infected, high-health finishing herd in terms of viral load in serum, feed conversion ratio and antimicrobial treatments. The study was conducted as a randomised clinical field trial with a parallel group design. Vaccination against PCV2...
Full Text Available Johne's disease is a chronic wasting disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP, resulting in inflammation of intestines and persistent diarrhea. The initial host response against MAP infections is mainly regulated by the Th1 response, which is characterized by the production of IFN-γ. With the progression of disease, MAP can survive in the host through the evasion of the host's immune response by manipulating the host immune response. However, the host response during subclinical phases has not been fully understood. Immune regulatory genes, including Th17-derived cytokines, interferon regulatory factors, and calcium signaling-associated genes, are hypothesized to play an important role during subclinical phases of Johne's disease. Therefore, the present study was conducted to analyze the expression profiles of immune regulatory genes during MAP infection in whole blood. Different expression patterns of genes were identified depending on the infection stages. Downregulation of IL-17A, IL-17F, IL-22, IL-26, HMGB1, and IRF4 and upregulation of PIP5K1C indicate suppression of the Th1 response due to MAP infection and loss of granuloma integrity. In addition, increased expression of IRF5 and IRF7 suggest activation of IFN-α/β signaling during subclinical stages, which induced indoleamine 2,3-dioxygenase mediated depletion of tryptophan metabolism. Increased expression of CORO1A indicate modulation of calcium signaling, which enhanced the survival of MAP. Taken together, distinct host gene expression induced by MAP infection indicates enhanced survival of MAP during subclinical stages.
Full Text Available We describe a new mechanistic bio-economic model for simulating the spread of Mycobacterium avium ssp. paratuberculosis (MAP within a dairy cattle herd. The model includes age-dependent susceptibility for infection; age-dependent sensitivity for detection; environmental MAP build-up in five separate areas of the farm; in utero infection; infection via colostrum and waste milk, and it allows for realistic culling (i.e. due to other diseases by including a ranking system. We calibrated the model using a unique dataset from Denmark, including 102 random farms with no control actions against spread of MAP. Likewise, four control actions recommended in the Danish MAP control program were implemented in the model based on reported management strategies in Danish dairy herds in a MAP control scheme. We tested the model parameterization in a sensitivity analysis. We show that a test-and-cull strategy is on average the most cost-effective solution to decrease the prevalence and increase the total net revenue on a farm with low hygiene, but not more profitable than no control strategy on a farm with average hygiene. Although it is possible to eradicate MAP from the farm by implementing all four control actions from the Danish MAP control program, it was not economically attractive since the expenses for the control actions outweigh the benefits. Furthermore, the three most popular control actions against the spread of MAP on the farm were found to be costly and inefficient in lowering the prevalence when used independently.
Full Text Available The etiology of type 1 diabetes mellitus (T1DM is still unknown; numerous studies are performed to unravel the environmental factors involved in triggering the disease. SLC11A1 is a membrane transporter that is expressed in late endosomes of antigen presenting cells involved in the immunopathogenic events leading to T1DM. Mycobacterium avium subsp. paratuberculosis (MAP has been reported to be a possible trigger in the development of T1DM.Fifty nine T1DM patients and 79 healthy controls were genotyped for 9 polymorphisms of SLC11A1 gene, and screened for the presence of MAP by PCR. Differences in genotype frequency were evaluated for both T1DM patients and controls. We found a polymorphism in the SLC11A1 gene (274C/T associated to type 1 diabetic patients and not to controls. The presence of MAP DNA was also significantly associated with T1DM patients and not with controls.The 274C/T SCL11A1 polymorphism was found to be associated with T1DM as well as the presence of MAP DNA in blood. Since MAP persists within macrophages and it is also processed by dendritic cells, further studies are necessary to evaluate if mutant forms of SLC11A1 alter the processing or presentation of MAP antigens triggering thereby an autoimmune response in T1DM patients.
Condas, Larissa A Z; De Buck, Jeroen; Nobrega, Diego B; Carson, Domonique A; Naushad, Sohail; De Vliegher, Sarne; Zadoks, Ruth N; Middleton, John R; Dufour, Simon; Kastelic, John P; Barkema, Herman W
Non-aureus staphylococci (NAS), the microorganisms most frequently isolated from bovine milk worldwide, are a heterogeneous group of numerous species. To establish their importance as a group, the distribution of individual species needs to be determined. In the present study, NAS intramammary infection (IMI) was defined as a milk sample containing ≥1,000 cfu/mL in pure or mixed culture that was obtained from a cohort of cows assembled by the Canadian Bovine Mastitis Research Network. Overall, 6,213 (6.3%) of 98,233 quarter-milk samples from 5,149 cows and 20,305 udder quarters were associated with an NAS IMI. Of the 6,213 phenotypically identified NAS isolates, 5,509 (89%) were stored by the Canadian Bovine Mastitis Research Network Mastitis Pathogen Collection and characterized using partial sequencing of the rpoB housekeeping gene, confirming 5,434 isolates as NAS. Prevalence of each NAS species IMI was estimated using Bayesian models, with presence of a specific NAS species as the outcome. Overall quarter-level NAS IMI prevalence was 26%. The most prevalent species causing IMI were Staphylococcus chromogenes (13%), Staphylococcus simulans (4%), Staphylococcus haemolyticus (3%), Staphylococcus xylosus (2%), and Staphylococcus epidermidis (1%). The prevalence of NAS IMI as a group was highest in first-parity heifers and was evenly distributed throughout cows in parities ≥2. The IMI prevalence of some species such as S. chromogenes, S. simulans, and S. epidermidis differed among parities. Overall prevalence of NAS IMI was 35% at calving, decreased over the next 10 d, and then gradually increased until the end of lactation. The prevalence of S. chromogenes, Staphylococcus gallinarum, Staphylococcus cohnii, and Staphylococcus capitis was highest at calving, whereas the prevalence of S. chromogenes, S. haemolyticus, S. xylosus, and S. cohnii increased during lactation. Although the overall prevalence of NAS IMI was similar across barn types, the prevalence of S
Bovine paratuberculosis: a review of the advantages and disadvantages of different diagnostic tests Paratuberculosis bovina: una revisión sobre las ventajas y desventajas de las diferentes pruebas diagnósticas
Liliana R. Gilardoni
Full Text Available Paratuberculosis (PTB, or Johne's disease, is a chronic infectious granulomatous enteritis of ruminants, caused by Mycobacterium avium subspecies paratuberculosis (Map. It is characterized by diarrhea and progressive cachexia, which may cause the death of the animal. Calves are the most susceptible to infection. Infected animals excrete Map mainly by the feces. PTB is endemic worldwide, with high prevalence levels, strong economic impact and public health relevance because of its possible association with Crohn's disease. Although the current reference diagnostic test is identification of Map in the bacterial culture, there are different diagnostic tests to identify infected individuals and/or herds. The sensitivity and specificity of these tests vary according to the stage of the disease in the animals to be evaluated. The correct choice and application of each of these diagnostic tests will ensure their success and may allow to establish a control program. The aim of this work is to review and discuss the different diagnostic tests used in the detection of Map-infected animals, focusing on their advantages and disadvantages.La paratuberculosis (PTBC o enfermedad de Johne es una enteritis granulomatosa crónica de rumiantes, causada por Mycobacterium avium subsp. paratuberculosis (Map. Se caracteriza por producir diarrea y caquexia progresiva, la cual conduce a la muerte del animal. Los terneros son los animales más proclives a la infección. Los animales infectados excretan Map, principalmente por las heces. La PTBC es una enfermedad endémica a nivel mundial, con altos niveles de prevalencia, fuerte impacto económico e importancia en salud pública, debido a su posible asociación con la enfermedad de Crohn. Aunque la prueba de referencia diagnóstica es la identificación de Map en cultivo bacteriológico, existen diferentes pruebas diagnósticas para detectar animales o rodeos infectados. La sensibilidad y especificidad de estas pruebas
Nielsen, Liza Rosenbaum; Dohoo, Ian
Salmonella Dublin infections reduce gross margins and compromise animal health and welfare in dairy cattle herds. Despite on-going control efforts in several countries the duration and risk factors of a persistent infection have been difficult to study due to a lack of suitable data. This study...
Pribylova-Dziedzinska, Radka; Slana, Iva; Lamka, Jiri; Pavlik, Ivo
There is no European legislation concerning paratuberculosis that requires that imported animals be kept in quarantine and commonly they are directly released into areas with other animals. In this study, detection of latent infection of paratuberculosis in healthy mouflons previously diagnosed as paratuberculosis-free, but originating from a real time quantitative PCR- (qPCR-) positive herd, occurred after their transport to a new farm. During a twelve-day quarantine period, all mouflons irregularly shed Mycobacterium avium subsp. paratuberculosis (MAP) in faeces, and in a small number of cases also in milk. After the animals were released from quarantine, MAP was detected for a further two days, after which, testing was negative, except in one case. Therefore, the stress connected with transport, novel environment, dietary change, or limited area with high density of animals might have contributed to the induction of paratuberculosis and the shedding of MAP from the animals, previously diagnosed as MAP-negative. According to these results, the keeping of imported animals in quarantine and their examination for MAP presence not only before the transport but also afterwards should be recommended. The designation of a particular area of a farm as a quarantine enclosure could help to mitigate the impact of stress caused by a confined space with a high density of animals.
Tkachuk, Victoria L; Krause, Denis O; McAllister, Tim A; Buckley, Katherine E; Reuter, Tim; Hendrick, Steve; Ominski, Kim H
Mycobacterium avium subsp. paratuberculosis causes Johne's disease (JD) in ruminants, with substantial economic impacts on the cattle industry. Johne's disease is known for its long latency period, and difficulties in diagnosis are due to insensitivities of current detection methods. Eradication is challenging as M. avium subsp. paratuberculosis can survive for extended periods within the environment, resulting in new infections in naïve animals (W. Xu et al., J. Environ. Qual. 38:437-450, 2009). This study explored the use of a biosecure, static composting structure to inactivate M. avium subsp. paratuberculosis. Mycobacterium smegmatis was also assessed as a surrogate for M. avium subsp. paratuberculosis. Two structures were constructed to hold three cattle carcasses each. Naturally infected tissues and ground beef inoculated with laboratory-cultured M. avium subsp. paratuberculosis and M. smegmatis were placed in nylon and plastic bags to determine effects of temperature and compost environment on viability over 250 days. After removal, samples were cultured and growth of both organisms was assessed after 12 weeks. After 250 days, M. avium subsp. paratuberculosis was still detectable by PCR, while M. smegmatis was not detected after 67 days of composting. Furthermore, M. avium subsp. paratuberculosis remained viable in both implanted nylon and plastic bags over the composting period. As the compost never reached a homogenous thermophilic (55 to 65°C) state throughout each structure, an in vitro experiment was conducted to examine viability of M. avium subsp. paratuberculosis after exposure to 80°C for 90 days. Naturally infected lymph tissues were mixed with and without compost. After 90 days, M. avium subsp. paratuberculosis remained viable despite exposure to temperatures typically higher than that achieved in compost. In conclusion, it is unlikely composting can be used as a means of inactivating M. avium subsp. paratuberculosis associated with cattle
Tkachuk, Victoria L.; Krause, Denis O.; McAllister, Tim A.; Buckley, Katherine E.; Reuter, Tim; Hendrick, Steve
Mycobacterium avium subsp. paratuberculosis causes Johne's disease (JD) in ruminants, with substantial economic impacts on the cattle industry. Johne's disease is known for its long latency period, and difficulties in diagnosis are due to insensitivities of current detection methods. Eradication is challenging as M. avium subsp. paratuberculosis can survive for extended periods within the environment, resulting in new infections in naïve animals (W. Xu et al., J. Environ. Qual. 38:437-450, 2009). This study explored the use of a biosecure, static composting structure to inactivate M. avium subsp. paratuberculosis. Mycobacterium smegmatis was also assessed as a surrogate for M. avium subsp. paratuberculosis. Two structures were constructed to hold three cattle carcasses each. Naturally infected tissues and ground beef inoculated with laboratory-cultured M. avium subsp. paratuberculosis and M. smegmatis were placed in nylon and plastic bags to determine effects of temperature and compost environment on viability over 250 days. After removal, samples were cultured and growth of both organisms was assessed after 12 weeks. After 250 days, M. avium subsp. paratuberculosis was still detectable by PCR, while M. smegmatis was not detected after 67 days of composting. Furthermore, M. avium subsp. paratuberculosis remained viable in both implanted nylon and plastic bags over the composting period. As the compost never reached a homogenous thermophilic (55 to 65°C) state throughout each structure, an in vitro experiment was conducted to examine viability of M. avium subsp. paratuberculosis after exposure to 80°C for 90 days. Naturally infected lymph tissues were mixed with and without compost. After 90 days, M. avium subsp. paratuberculosis remained viable despite exposure to temperatures typically higher than that achieved in compost. In conclusion, it is unlikely composting can be used as a means of inactivating M. avium subsp. paratuberculosis associated with cattle
Full Text Available Mycobacterium avium subspecies paratuberculosis (MAP is the aetiological agent of Johne's disease (JD, a chronic enteritis in ruminants that causes substantial economic loses to agriculture worldwide. Current diagnostic assays are hampered by low sensitivity and specificity that seriously complicate disease control; a new generation of diagnostic and prognostic assays are therefore urgently needed. Circulating microRNAs (miRNAs have been shown to have significant potential as novel biomarkers for a range of human diseases, but their potential application in the veterinary sphere has been less well characterised. The aim of this study was therefore to apply RNA-sequencing approaches to serum from an experimental JD infection model as a route to identify novel diagnostic and prognostic miRNA biomarkers. Sera from experimental MAP-challenged calves (n = 6 and age-matched controls (n = 6 were used. We identified a subset of known miRNAs from bovine serum across all samples, with approximately 90 being at potentially functional abundance levels. The majority of known bovine miRNAs displayed multiple isomiRs that differed from the canonical sequences. Thirty novel miRNAs were identified after filtering and were found within sera from all animals tested. No significant differential miRNA expression was detected when comparing sera from MAP-challenged animals to their age-matched controls at six-month's post-infection. However, comparing sera from pre-infection bleeds to six-month's post-infection across all 12 animals did identify increased miR-205 (2-fold and decreased miR-432 (2-fold within both challenged and control groups, which suggests changes in circulating miRNA profiles due to ageing or development (P<0.00001. In conclusion our study has identified a range of novel miRNA in bovine serum, and shown the utility of small RNA sequencing approaches to explore the potential of miRNA as novel biomarkers for infectious disease in cattle.
The present invention provides one or more immunogenic polypeptides for use in a preventive or therapeutic vaccine against latent or active infection in a human or animal caused by a Mycobacterium species, e.g. Mycobacterium avium subsp. paratuberculosis. Furthermore a single or multi-phase vaccine...... comprising the one or more immunogenic polypeptides is provided for administration for the prevention or treatment of infection with a Mycobacterium species, e.g. Mycobacterium avium subsp. paratuberculosis. Additionally, nucleic acid vaccines, capable of in vivo expression of the multi-phase vaccine...
Full Text Available Mycobacterium avium subsp. paratuberculosis (MAP is the etiologic agent of paratuberculosis. The disease affects cows and other ruminants and causes high economic losses, mainly for dairy production. MAP may also have a role in the development of Crohn’s disease in humans. Infected animals shed viable MAP with milk and faeces and humans may assume MAP via the consumption of contaminated milk and dairy products. Current methods of milk pasteurization are not sufficient to kill all MAP cells present in milk and MAP has been found in raw or pasteurized milk and isolated from cheese. The aim of this paper is to review the current knowledge about MAP in dairy production. We analyzed studies on milk contamination, effect of pasteurization and methods for identification of MAP that can be applied to dairy products.
Tikofsky, L L; Zadoks, R N
Group G streptococci in animals usually belong to the species Streptococcus canis and are most commonly found in dogs and cats. Occasionally, Strep. canis is detected in milk from dairy cows. An outbreak of Strep. canis mastitis in a dairy herd is described. Based on results from bacterial culture and ribotyping, a cat with chronic sinusitis was the most likely source of the outbreak. Subsequent cow-to-cow transmission of Strep. canis was facilitated by poor udder health management, including use of a common udder cloth and failure to use postmilking teat disinfection. Infected cows had macroscopically normal udders and milk, but significantly higher somatic cell counts than Strep. canis-negative herd mates. The outbreak was controlled through antibiotic treatment of lactating cows, early dry-off with dry cow therapy, culling of infected animals, and implementation of standard mastitis prevention measures. Cure was significantly more likely in dry-treated cows (87.5%) and cows treated during lactation (67%) than in untreated cows (9%). Whereas mastitis due to group G streptococci or Strep. canis in dairy cows is usually limited to sporadic cases of environmental (canine or feline) origin, this case study shows that crossing of the host species barrier by Strep. canis may result in an outbreak of mastitis if management conditions are conducive to contagious transmission. In such a situation, measures that are successful in control of Strep. agalactiae can also be used to control Strep. canis mastitis.
Alonso, Carmen; Murtaugh, Michael P; Dee, Scott A; Davies, Peter R
Porcine reproductive and respiratory syndrome virus (PRRSV) is the most economically significant pathogen in the US swine industry. Aerosol transmission among herds is a major concern in pig dense regions and filtration of incoming air, in combination with standard biosecurity procedures, has been demonstrated to prevent transmission of PRRSV into susceptible herds. To quantify the impact of air filtration on reducing risk of PRRSV outbreaks, we compared the incidence rate of new PRRSV introductions in 20 filtered and 17 non-filtered control sow herds in a swine dense region of North America during a 7 year study period. Events of novel virus introduction were ascertained by phylogenetic analysis of PRRSV ORF5 gene sequences. Putative new viruses were defined as exogenous (introduced) based on ORF5 nucleotide sequence differences compared to previous farm isolates. The influence of sequence difference cut-off values ranging from 2 to 10% on case definition and relative risk were evaluated. Non-filtered farms incurred about 0.5 outbreaks per year, with a seasonal increase in risk in cooler periods. Baseline risk, prior to filtration, in treatment farms was approximately 0.75 per year, approximately 50% higher than in control farms. Air filtration significantly reduced risk of PRRSV introduction events to 0.06-0.22 outbreaks per year, depending on the cut-off values used to classify a virus isolate as new to the herd. Overall, air filtration led to an approximately 80% reduction in risk of introduction of novel PRRSV, indicating that on large sow farms with good biosecurity in swine-dense regions, approximately four-fifths of PRRSV outbreaks may be attributable to aerosol transmission. Copyright © 2013 Elsevier B.V. All rights reserved.
Kowalczyk, Sławomir J; Czopowicz, Michał; Weber, Corinna N; Müller, Elisabeth; Nalbert, Tomasz; Bereznowski, Andrzej; Kaba, Jarosław
Fasciola hepatica and Ostertagia ostertagi infections are widespread in cattle population of Europe, however data on their prevalence in Poland are only fragmentary. Therefore, the cross-sectional study was carried out to determine the herd-level seroprevalence of F. hepatica and O. ostertagi infection in dairy cattle population in the central and north-eastern provinces Poland, and to identify basic local risk factors for these infections. In total, 598 herds were enrolled, 394 (65.9%) in the north-eastern province and 204 (34.1%) in the central province. In each herd the questionnaire survey was conducted and bulk-tank milk (BTM) sample was collected and screened using two indirect immunoenzymatic tests. Optical density ratio (ODR) was regarded as the quantitative proxy of exposure to either of the two parasites. Both Fasciola and Ostertagia ELISA ODR in the north-eastern province was significantly higher than ODR in the central province. At the cut-off value of ODR = 0.27 the true herd-level seroprevalence of F. hepatica was 79.6% (95% CI: 74.0%, 84.3%) in the north-eastern province and 13.0% (95% CI: 5.3%, 21.7%) in the central province. At the cut-off of ODR = 0.50151 of 188 herds (80.3%, 95% CI: 74.1%, 85.4%) were seropositive for O. ostertagi in the north-eastern province and only 70 of 136 herds (51.5%, 95% CI: 43.1%, 59.7%) were seropositive in the central province. Location of a herd in the north-eastern province, longer grazing period practiced in a herd and > 50%-share of grazing grass in roughage were all positively related to the increase in exposure to both parasites. Moreover, the use of hay or haylage as main roughage proved to be positively related to the increase in exposure to F. hepatica. F. hepatica and O. ostertagi are widespread in cattle population in Poland, however their occurrence at a herd-level varies between different regions of Poland. This diversity can only partly be explained by different herd management, and appears
Fernandes, Leise Gomes; Nogueira, Adriana Hellmeister de Campos; De Stefano, Eliana; Pituco, Edviges Maristela; Ribeiro, Cláudia Pestana; Alves, Clebert José; Oliveira, Tainara Sombra; Clementino, Inácio José; de Azevedo, Sérgio Santos
Serological surveys based on a planned sampling on bovine viral diarrhea virus (BVDV) infection in Brazilian cattle herds are scarce. A cross-sectional study was carried out to determine herd- and animal-level seroprevalences and to identify risk factors associated with herd-level seroprevalence for BVDV infection in the State of Paraíba, Northeastern Brazil, from September 2012 to January 2013. The state was divided into three sampling strata, and for each stratum, the prevalence of herds infected with BVDV and the prevalence of seropositive animals was estimated by a two-stage sampling survey. In total, 2443 animals were sampled from 478 herds. A virus-neutralization test was used for BVDV antibody detection. A herd was considered positive when at least one seropositive animal was detected. The herd- and animal-level prevalences in the State of Paraíba were 65.5% (95% confidence interval (CI) = 61.1-69.7%) and 39.1% (95% CI = 33.1-45.6%), respectively. The frequency of seropositive animals per herd ranged from 10 to 100% (median of 50%). The risk factors identified were as follows: more than six calves aged ≤12 months (odds ratio (OR) = 3.72; 95% CI = 2.08-6.66), animal purchasing (OR = 1.66; 95% CI = 1.08-2.55), pasture rental (OR = 2.15; 95% CI = 1.35-3.55), and presence of veterinary assistance (OR = 2.04; 95% CI = 1.10-3.79). Our findings suggest that the implementation of control and prevention measures among farmers, with the aim of preventing dissemination of the agent in the herds, is necessary. Special attention should be given to addressing the identified risk factors, such as sanitary control prior to animal purchasing and to discourage the pasture rental, as well as to encourage the vaccination in the herds.
Widagdo Sri Nugroho
Full Text Available Johne’s disease (JD or partuberculosis is a chronic granulomatous enteritis in ruminants caused by infection of Mycobacterium avium paratuberculosis subspecies (MAP. The disease has been detected serologically in Indonesia. It’s potential to spread to other herds and could create great economic losses. The objectives of current study were to detect MAP in milk and faeces of dairy cows as well as to evaluate the association between farm management factors and presence of the bacteria in dairy cows in Bogor. The sample size was calculated using the formula to detect disease with the prevalence assumed to be 5% using 95% significant level. Milk and faeces samples were taken from 62 dairy cows which were suspected as suffering from MAP infection. Detection of MAP was done by isolation in Herrold’ egg yolk medium with mycobactin J (HEYMj, acid-fast bacilli Ziehl-Neelsen staining, PCR IS900 and F57. Biochemical test to confirm M. tuberculosis presence was also conducted. Fifteen isolates of Mycobacterium sp. were found from the faeces samples but not from the corresponding milk samples. However, conventional PCR conducted on the isolate as well as the milk samples, gave negative results. Biochemical test proved that all Mycobacterium sp. isolates were not M. tuberculosis. This study indicated the prevalence of MAP in Bogor was less than 5%. These findings should be continued by observational study to achieve the comprehensive information at the cattle and herd level. Bovine Tuberculosis monitoring should be done also to protect dairy herd and food safety for the community.
Gilardoni, Liliana Rosa; Fernández, Bárbara; Morsella, Claudia; Mendez, Laura; Jar, Ana María; Paolicchi, Fernando Alberto; Mundo, Silvia Leonor
The aim of this study was to standardize a diagnosis procedure to detect Mycobacterium avium subsp. paratuberculosis (Map) DNA in raw cow milk samples under field conditions. A procedure that combines both immunomagnetic separation and IS900-PCR detection (IMS-IS1 PCR) was employed on milk samples from 265 lactating Holstein cows from Map infected and uninfected herds in Argentina. IMS-IS1 PCR results were analyzed and compared with those obtained from milk and fecal culture and serum ELISA. The extent of agreement between both tests was determined by the Kappa test. IMS-IS1 PCR showed a detection limit of 10(1) CFU of Map/mL of milk, when 50:50 mix of monoclonal and polyclonal antibodies were used to coat magnetic beads. All of the 118 samples from the Map uninfected herds were negative for the set of the tests. In Map infected herds, 80 out of 147 cows tested positive by milk IMS-IS1 PCR (55%), of which 2 (1.4%) were also positive by milk culture, 15 (10%) by fecal culture, and 20 (14%) by serum ELISA. Kappa statistics (95% CI) showed a slight agreement between the different tests (<0.20), and the proportions of agreement were ≤0.55. The IMS-IS1 PCR method detected Map in milk of the cows that were not positive in other techniques. This is the first report dealing with the application of IMS-IS1 PCR in the detection of Map in raw milk samples under field conditions in Argentina. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.
Full Text Available This paper describes paratuberculosis in an isolated breeding herd of 25 high-yield dairy cows of the Red Holstein breed. The animals were examined clinically and then given the test for ldelayed type hypersensitivity and their blood serum was examined for the presence of specific antibodies against Mycobacterium avium subsp. paratuberculosis (Map. The clinical examination revealed that two cows exhibited symptoms of the disease that indicated an advanced stage of paratuberculosis. The following parameters were examined in the blood of the cows that showed clinical signs of the disease: leukocytes and erythrocytes count, concentrations of total proteins, albumin, iron, sodium, potassium, and activity of creatine kinase. The analysis of the red blood cell count revealed certain digressions that indicated the existence of hypochromic microcytic anaemia. The number of leukocytes was within the physiological values, but the neutrophil-lymphocyte ratio was disrupted and stood at almost 1:1. The results of the biochemical analyses of the blood serum of diseased cows indicated hypoproteinaemia, hypoalbuminaemia, hypoferremia, hyposodiumaemia, hypokalemia, and increased activities of creatine kinase enzymes. A suspect reaction on the site of application of avian tuberculin was determined in two animals. Animals with clinical signs of the disease reacted negative to the test of delayed type hypersensitivity. The presence of specific antibodies against the cause of paratuberculosis was proven in four animals (16%, including two animals with clinical signs of the disease and one that had a suspect reaction on the site of application of avian tuberculin. Furthermore, one animal that died exhibited macroscopic and microscopic changes regarding the intensity and distribution of lesions, the type of cellular infiltrate, and the number of present acidresistent bacteria, and the changes were characterized as diffuse changes of multibacillary type. The cause of
Lorenzen, Ellen; Kjær, Torben Egil; Lorenzen, Niels
as well as selective breeding, i.e. the more non-susceptible individuals in a population, the lower the risk of disease among susceptible individuals. Thus as part of a recent field trial with a VHS-DNA-vaccine vaccinated as well as naïve fish from a Danish fish farm were brought to the laboratory......Abstract for Scofda meeting 4-5.11.09 Studies on herd-immunity effect and primary versus secondary infection of VHSV by Ellen Lorenzen, Torben Eigil Kjær & Niels Lorenzen, National Veterinary Laboratory, Århus The phenomenon of “herd-immunity” is one of the basal principles behind vaccination...... at a size of 24g to be subjected to an experimental challenge with VHSV. The setup included 7 aquaria with 100 fish in each: 2 aquaria with 100 vaccinated fish (+VHS-challenge), 2 aquaria with 100 naïve fish (+ VHS-challenge), 2 aquaria with 50 vaccinated + 50 naïve fish (+VHS-challenge), and 1 aquarium...
Full Text Available Abstract Background The prevalence of pleurisies recorded at slaughter is increasing in Sweden, and acute outbreaks of actinobacillosis that require antimicrobial treatments have become more frequent. As an increased use of antimicrobials may result in the development of antimicrobial resistance it is essential to develop alternative measures to control the disease. Vaccinations present an appealing alternative to antimicrobial treatments. The aim of this work was to evaluate the potential of two different vaccination strategies in a specialized fattening herd affected by actinobacillosis. Methods The study was conducted in a specialized fattening herd employing age segregated rearing in eight units. The herd suffered from infections caused by Actinobacillus pleuropneumoniae serotype 2, confirmed by necropsy and serology. The study included 54 batches of pigs grouped into five periods. Batches of pigs of the second period were vaccinated against actinobacillosis twice, and pigs in the fourth period were vaccinated three times. Batches of pigs of the first, third and fifth period were not vaccinated. Concentrations of serum antibodies to A. pleuropneumoniae and serum amyloid A (SAA were analysed and production data were recorded. Results Despite vaccinating, medical treatments were required to reduce the impact of the disease. The mean incidence of individual treatments for respiratory diseases during the rearing period ranged from 0 to 4.7 ± 1.8%, and was greatest during the triple vaccination period (period IV; p A. pleuropneumoniae serotype 2 in the absence of a SAA-response. The prevalence of pleuritis decreased from 25.4 ± 6.5% in the first period to 5.0 ± 3.7% in the fifth period (p Conclusions The vaccine did not effectively prevent clinical expression of A. pleuropneumoniae infections, but seroconversion to A. pleuropneumoniae in the absence of a SAA-response in a large number pigs indicated that the vaccine had activated the immune
Gonzalez-Garcia, M. A.; Arenas-Casas, A.; Carbonero-Martinez, A.; Borge-Rodriguez, C.; Garcia-Bocanegra, I.; Maldonado, J. L.; Gomez-Pacheco, J. M.; Perea-Remujo, J. A.
An epidemiological and serological survey of bovine herpes virus 1 (BHV1) infection was conducted in Andalusia from January to April of 2000. A total of 4,035 blood samples were collected from 164 herds. A questionnaire, which included variables potentially associated with infection, was filled out for each herd. Serum samples were obtained to identify specific BHV1 antibodies and were tested using a blocking ELISA test. The observed crude odds ratio (OR) (estimate of the chance of a particular event occurring in an exposed group in relation to its rate of occurrence in a nonexposed group) for vaccination is 9.8 (95 % confidence interval: 8.3-11.7). The vaccinated group comprised large dairy farms. This study can only be considered as representative of unvaccinated, small to medium size dairy farms and beef farms in Andalusia. True sero prevalence of the BHV1 virus in non vaccinated bovine populations in Andalusia reached 45.7% of individuals and 70.4% of herds. Risk factors for BHV1 infection in bovine Andalusian non vaccinated herds are nonexistence of specific cattle infrastructure (OR: 3.07), beef crossbreeding (OR: 7.90), affiliation with Livestock Health Defence Associations (OR: 2.57), a history of reproductive disorders (OR: 8.39), external replacement (OR: 2.74), proximity to an urban area (OR: 6.11) and herd size (41.98). To control for confounding effects, a binomial logistic regression model was developed. From this regression, BHV1 infections are concentrated in large herds, with external replacement, located close to urban areas. This is the first published report on BHV1 prevalence in the South of Spain. (Author) 14 refs.
Mundo, Silvia Leonor; Gilardoni, Liliana Rosa; Hoffman, Federico José; Lopez, Osvaldo Jorge
Paratuberculosis is an infectious, chronic, and incurable disease that affects ruminants, caused by Mycobacterium avium subsp. paratuberculosis. This bacterium is shed primarily through feces of infected cows but can be also excreted in colostrum and milk and might survive pasteurization. Since an association of genomic sequences of M. avium subsp. paratuberculosis in patients with Crohn's disease has been described; it is of interest to rapidly detect M. avium subsp. paratuberculosis in milk for human consumption. IS900 insertion is used as a target for PCR amplification to identify the presence of M. avium subsp. paratuberculosis in biological samples. Two target sequences were selected: IS1 (155 bp) and IS2 (94 bp). These fragments have a 100% identity among all M. avium subsp. paratuberculosis strains sequenced. M. avium subsp. paratuberculosis was specifically concentrated from milk samples by immunomagnetic separation prior to performing PCR. The amplicons were characterized using DNA methylase Genotyping, i.e., the amplicons were methylated with 6-methyl-adenine and digested with restriction enzymes to confirm their identity. The methylated amplicons from 100 CFU of M. avium subsp. paratuberculosis can be visualized in a Western blot format using an anti-6-methyl-adenine monoclonal antibody. The use of DNA methyltransferase genotyping coupled to a scintillation proximity assay allows for the detection of up to 10 CFU of M. avium subsp. paratuberculosis per ml of milk. This test is rapid and sensitive and allows for automation and thus multiple samples can be tested at the same time.
Bull, Tim J; Gilbert, Sarah C; Sridhar, Saranya; Linedale, Richard; Dierkes, Nicola; Sidi-Boumedine, Karim; Hermon-Taylor, John
Mycobacterium avium subspecies paratuberculosis causes systemic infection and chronic intestinal inflammation in many species including primates. Humans are exposed through milk and from sources of environmental contamination. Hitherto, the only vaccines available against Mycobacterium avium subspecies paratuberculosis have been limited to veterinary use and comprised attenuated or killed organisms. We developed a vaccine comprising a fusion construct designated HAV, containing components of two secreted and two cell surface Mycobacterium avium subspecies paratuberculosis proteins. HAV was transformed into DNA, human Adenovirus 5 (Ad5) and Modified Vaccinia Ankara (MVA) delivery vectors. Full length expression of the predicted 95 kDa fusion protein was confirmed. Vaccination of naïve and Mycobacterium avium subspecies paratuberculosis infected C57BL/6 mice using DNA-prime/MVA-boost or Ad5-prime/MVA-boost protocols was highly immunogenic resulting in significant IFN-gamma ELISPOT responses by splenocytes against recombinant vaccine antigens and a range of HAV specific peptides. This included strong recognition of a T-cell epitope GFAEINPIA located near the C-terminus of the fusion protein. Antibody responses to recombinant vaccine antigens and HAV specific peptides but not GFAEINPIA, also occurred. No immune recognition of vaccine antigens occurred in any sham vaccinated Mycobacterium avium subspecies paratuberculosis infected mice. Vaccination using either protocol significantly attenuated pre-existing Mycobacterium avium subspecies paratuberculosis infection measured by qPCR in spleen and liver and the Ad5-prime/MVA-boost protocol also conferred some protection against subsequent challenge. No adverse effects of vaccination occurred in any of the mice. A range of modern veterinary and clinical vaccines for the treatment and prevention of disease caused by Mycobacterium avium subspecies paratuberculosis are needed. The present vaccine proved to be highly
Full Text Available Sub clinical mastitis may cause more losses than clinical mastitis. Farmers can take advantage of employing several tools, California Mastitis Test (CMT and Somatic Cell Count (SCC among the others, to determine the presence of a sub clinical mastitis in their herds. The aim of the present study was to evaluate the microbiological quality of milk produced in some extensive goat herds in Sardinia through a clinical check to determine the infection status of the udder, CMT, SCC and microbiological milk tests. CMT has been confirmed to be a useful, practical and economical tool to detect sub clinical mastitis in goats. Farmers should be encouraged to use this as a first step in order to avoid prospective losses in their herds.
Frey, C F; Eicher, R; Raue, K; Strube, C; Bodmer, M; Hentrich, B; Gottstein, B; Marreros, N
Infections with helminth parasites can negatively affect performance of dairy cows. Knowledge on infection intensity, spatial distributions and risk factors are key to develop targeted treatment strategies. Canada and most EU countries have conducted large investigations, but respective data for Switzerland were missing. We now performed a bulk tank milk serosurvey for Ostertagia ostertagi, Fasciola hepatica, and Dictyocaulus viviparus on a total of 1036 voluntarily participating dairy herds that were sampled at confinement periods, i.e. in winter 2014/15 or 2015/16, respectively. All samples were analyzed with commercial ELISAs for antibodies (AB) against O. ostertagi and F. hepatica, and those of the first sampling period additionally with an in-house ELISA for AB against D. viviparus. Testing for the latter parasite was not done in the second year of the study, as the sampling period might have missed infections due to the short lived nature of specific antibodies. The possible influence of geographic, climatic, and farm management variables on AB levels were assessed for each parasite using scanning cluster and multiple regression analysis. Overall seroprevalence for O. ostertagi was 95.5% (95% C.I.: 94.0-96.6), with a mean optical density ratio (ODR) of 0.83, for F. hepatica 41.3% (95% C.I.: 38.3-44.4), and for D. viviparus 2.9% (95% C.I.: 1.6-4.7). There were no significant differences between the two sampling periods. For all parasites, significant geographic clusters of higher AB levels could be established. Furthermore, AB levels against all three parasites were positively correlated with each other, indicating either cross-reactions or co-infections. For O. ostertagi, herd size and percentage of pasture in the ration were positively correlated with AB levels. For F. hepatica, altitude above sea level (a.s.l.) positively, and milk production per cow and year was negatively correlated with AB levels. This work provides baseline data for further
Gioffré, A; Echeverría-Valencia, G; Arese, A; Morsella, C; Garbaccio, S; Delgado, F; Zumárraga, M; Paolicchi, F; Cataldi, A; Romano, M I
Johne's disease or paratuberculosis is widespread in almost all countries and remains difficult to eradicate. Nowadays, diagnosis of Mycobacterium avium subsp. paratuberculosis (MPTB) infection is one of the main concerns. In this work, we evaluated the expression, biochemical properties and antigenicity of the Apa antigen, encoded by the gene annotated as MAP1569, in the MPTB genome. We confirmed its expression in MPTB and its glycosylation by the ConA binding assay. Although the MPTB-Apa is not an immunodominant antigen, MPTB-infected cattle showed a strong humoral response to recombinant Apa by Western blot and ELISA. Milk was also a suitable sample to be tested by ELISA. We comparatively analysed the humoral cross-reactivity to the Apa from MPTB (MPTB-Apa) and the orthologue from Mycobacterium tuberculosis (MT-Apa, identical to that from Mycobacterium bovis) in both infected and control cows. Response of M. bovis- and MPTB-infected animals against MT-Apa was similar (P=0.6985) but the response of the M. bovis-infected ones to MPTB-Apa was differential, being significantly diminished (PApa stimulation in the IFNgamma release assay, we found no significant differences when compared infected herds with non-infected ones (P=0.34). This antigen, in contrast to bovine Purified Protein Derivative (PPDb), was strongly represented in avian PPD (PPDa), as shown by the recognition of BALB/c mice hyperimmune sera against MPTB-Apa by Dot-blot immunoassay. We therefore demonstrated the antigenicity of Apa in MPTB-infected animals and a differential response to the recombinant antigen when compared to M. bovis-infected animals. These traits herein described, added to the usefulness of milk samples to detect IgG anti-Apa, could be important for routine screening in dairy cattle, considering a multiantigenic approach to overcome the lack of immunodominance.
Koets, A.; Rutten, V.; Hoek, van A.; Mil, van F.; Muller, K.; Bakker, D.; Gruys, E.; Eden, van W.
Bovine paratuberculosis is caused by the infection of young calves with Mycobacterium avium subsp. paratuberculosis, resulting in a chronic granulomatous infection of predominantly the ileum. After an incubation period of 2 to 5 years, the disease becomes progressive in some of the chronically
Hisham Beshara Halasa, Tariq; Frankena, K.; Olsen, A.
Liver fluke infection, also known as fasciolosis, is a world-wide prevalent zoonotic parasitic disease infecting a wide range of host species and is caused by Fasciola hepatica. Despite of the substantial economic and animal welfare effects of the disease, knowledge on its prevalence and the fact......Liver fluke infection, also known as fasciolosis, is a world-wide prevalent zoonotic parasitic disease infecting a wide range of host species and is caused by Fasciola hepatica. Despite of the substantial economic and animal welfare effects of the disease, knowledge on its prevalence...
Full Text Available The aim of the study was to evaluate the presence of Mycoplasma bovis infection and co-infections with other Mycoplasma spp. infections in cattle. The tested population was one in the eastern region of Poland containing 66 dairy cows and 23 calves showing different clinical signs and suffering from pneumonia, mastitis, and arthritis. The incidence of M. bovis in co-infections with other Mycoplasma spp. was examined using serological traditional mycoplasma culture methods, and the molecular methods - PCR and polymerase chain reaction/denaturing gradient gel electrophoresis (PCR/DGGE. The PCR/DGGE method for detecting Mycoplasma spp. in cattle was used for the first time in Poland. The seroprevalence of M. bovis in the affected cattle herds in the eastern region of Poland was 47.8% in calves and 19.7% in dairy cows. The direct detection and identification of M. bovis from nasopharyngeal swabs by PCR revealed that 56.5% of calves were positive, but all of the dairy cows were negative. The PCR/DGGE identified eight (34.8% instances of M. arginini and eight (26.1% instances of M. bovirhinis co-infecting with M. bovis in ten calves. The seroprevalence of M. bovis in the tested population was 33.7%. Any future attempts to control mycoplasma infections require an insight into the current epidemiological situation of M. bovis infection and its relationship to other mycoplasmas in causing clinical disease in cattle. Using these diagnostic methods we have demonstrated that mycoplasmal infections are often caused by multiple species of Mycoplasma and not just the primary M. bovis pathogen.
Andreasen, Margit; Mousing, Jan; Thomsen, Lars Krogsgård
approximately 4 weeks of age), and sera were analyzed for antibodies to Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae serotypes 2, 5-7 and 12. Mixed analysis of covariance analyzed the relationship between the average daily weight gain and a categorical variable defining seroconversion as none...... most pigs included in the study were subclinically infected, or because a temporary negative influence of the infections is hidden due to an increased growth in the period following infection. In conclusion. at least in these eight herds, seroresponses to M. hyopneumoniae and A. pleuropneumoniae could...
Casal, Carmen; Alvarez, Julio; Bezos, Javier; Quick, Harrison; Díez-Guerrier, Alberto; Romero, Beatriz; Saez, Jose L; Liandris, Emmanouil; Navarro, Alejandro; Perez, Andrés; Domínguez, Lucas; de Juan, Lucía
The official technique for diagnosis of bovine tuberculosis (bTB) worldwide is the tuberculin skin test, based on the evaluation of the skin thickness increase after the intradermal inoculation of a purified protein derivative (PPD) in cattle. A number of studies performed on experimentally infected or sensitized cattle have suggested that the relative sensitivity of the cervical test (performed in the neck) may vary depending on the exact location in which the PPD is injected. However, quantitative evidence on the variation of the test accuracy associated to changes in the site of inoculation in naturally infected animals (the population in which performance of the test is most critical for disease eradication) is lacking. Here, the probability of obtaining a positive reaction (>2 or 4 millimeters and/or presence of local clinical signs) after multiple inoculations of bovine PPD in different cervical and scapular locations was assessed in animals from five bTB-infected herds (818 cattle receiving eight inoculations) using a hierarchical Bayesian logistic regression model and adjusting for the potential effect of age and sex. The effect of the inoculation site was also assessed qualitatively in animals from four officially tuberculosis free (OTF) herds (two inoculations in 210 animals and eight inoculations in 38 cattle). Although no differences in the qualitative outcome of the test were observed in cattle from OTF herds, a statistically important association between the test outcome and the inoculation site in animals from infected herds was observed, with higher probabilities of positive results when the test was performed in the neck anterior area. Our results suggest that test sensitivity may be maximized by considering the area of the neck in which the test is applied, although lack of effect of the inoculation site in the specificity of the test should be confirmed in a larger sample. Copyright © 2015 Elsevier B.V. All rights reserved.
Kriz, Petr; Kaevska, Marija; Slana, Iva; Bartejsova, Iva; Pavlik, Ivo
This study was performed on 40 finished pigs from one herd naturally infected with Mycobacterium avium subsp. avium. The aim was to investigate the presence and amount of M. a. avium in samples of lymph nodes and diaphragm tissues collected during routine postmortem inspection using the triplex quantitative real time PCR (qPCR) method. We collected, in total, 107 samples: various lymph nodes affected by gross tuberculosis (TB)-like lesions from 17 pig carcasses, as well as samples of head and mesenteric lymph nodes from 23 carcasses without TB-like lesions. Samples of diaphragm tissues were collected from all carcasses. M. a. avium was detected in one or more tissue samples collected from half of the slaughtered pigs tested. Samples of diaphragm tissues of three pigs with detected TB-like lesions contained M. a. avium (10(2) to 10(3) cells per g of sample); the organism was not detected in diaphragm tissues from pigs without TB-like lesions. The qPCR method may be useful for quantification of M. a. avium in pigs for the purposes of foodborne risk assessment.
MicroRNA 27a-3p Regulates Antimicrobial Responses of Murine Macrophages Infected by Mycobacterium avium subspecies paratuberculosis by Targeting Interleukin-10 and TGF-β-Activated Protein Kinase 1 Binding Protein 2
Full Text Available Mycobacterium avium subspecies paratuberculosis (MAP persistently survive and replicate in mononuclear phagocytic cells by adopting various strategies to subvert host immune response. Interleukin-10 (IL-10 upregulation via inhibition of macrophage bactericidal activity is a critical step for MAP survival and pathogenesis within the host cell. Mitogen-activated protein kinase p38 signaling cascade plays a crucial role in the elevation of IL-10 and progression of MAP pathogenesis. The contribution of microRNAs (miRNAs and their influence on the activation of macrophages during MAP pathogenesis are still unclear. In the current study, we found that miRNA-27a-3p (miR-27a expression is downregulated during MAP infection both in vivo and in vitro. Moreover, miR-27a is also downregulated in toll-like receptor 2 (TLR2-stimulated murine macrophages (RAW264.7 and bone marrow-derived macrophage. ELISA and real-time qRT-PCR results confirm that overexpression of miR-27a inhibited MAP-induced IL-10 production in macrophages and upregulated pro-inflammatory cytokines, while miR-27a inhibitor counteracted these effects. Luciferase reporter assay results revealed that IL-10 and TGF-β-activated protein kinase 1 binding protein 2 (TAB 2 are potential targets of miR-27a. In addition, we demonstrated that miR-27a negatively regulates TAB 2 expression and diminishes TAB 2-dependent p38/JNK phosphorylation, ultimately downregulating IL-10 expression in MAP-infected macrophages. Furthermore, overexpression of miR-27a significantly inhibited the intracellular survival of MAP in infected macrophages. Our data show that miR-27a augments antimicrobial activities of macrophages and inhibits the expression of IL-10, demonstrating that miR-27a regulates protective innate immune responses during MAP infection and can be exploited as a novel therapeutic target in the control of intracellular pathogens, including paratuberculosis.
Use of whole-genome sequencing and evaluation of the apparent sensitivity and specificity of antemortem tuberculosis tests in the investigation of an unusual outbreak of Mycobacterium bovis infection in a Michigan dairy herd.
Bruning-Fann, Colleen S; Robbe-Austerman, Suelee; Kaneene, John B; Thomsen, Bruce V; Tilden, John D; Ray, Jean S; Smith, Richard W; Fitzgerald, Scott D; Bolin, Steven R; O'Brien, Daniel J; Mullaney, Thomas P; Stuber, Tod P; Averill, James J; Marks, David
OBJECTIVE To describe use of whole-genome sequencing (WGS) and evaluate the apparent sensitivity and specificity of antemortem tuberculosis tests during investigation of an unusual outbreak of Mycobacterium bovis infection in a Michigan dairy herd. DESIGN Bovine tuberculosis (bTB) outbreak investigation. ANIMALS Cattle, cats, dog, and wildlife. PROCEDURES All cattle in the index dairy herd were screened for bTB with the caudal fold test (CFT), and cattle ≥ 6 months old were also screened with a γ-interferon (γIFN) assay. The index herd was depopulated along with all barn cats and a dog that were fed unpasteurized milk from the herd. Select isolates from M bovis-infected animals from the index herd and other bTB-affected herds underwent WGS. Wildlife around all affected premises was examined for bTB. RESULTS No evidence of bTB was found in any wildlife examined. Within the index herd, 53 of 451 (11.8%) cattle and 12 of 21 (57%) cats were confirmed to be infected with M bovis. Prevalence of M bovis-infected cattle was greatest among 4- to 7-month-old calves (16/49 [33%]) followed by adult cows (36/203 [18%]). The apparent sensitivity and specificity were 86.8% and 92.7% for the CFT and 80.4% and 96.5% for the γIFN assay when results for those tests were interpreted separately and 96.1% and 91.7% when results were interpreted in parallel. Results of WGS revealed that M bovis-infected barn cats and cattle from the index herd and 6 beef operations were infected with the same strain of M bovis. Of the 6 bTB-affected beef operations identified during the investigation, 3 were linked to the index herd only by WGS results; there was no record of movement of livestock or waste milk from the index herd to those operations. CONCLUSIONS AND CLINICAL RELEVANCE Whole-genome sequencing enhanced the epidemiological investigation and should be used in all disease investigations. Performing the CFT and γIFN assay in parallel improved the antemortem ability to detect M bovis-infected
Expression of inflammatory cytokine and inducible nitric oxide synthase genes in the small intestine and mesenteric lymph node tissues of pauci- and multibacillary sheep naturally infected with Mycobacterium avium ssp. paratuberculosis.
Sonawane, Ganesh G; Tripathi, Bhupendra Nath
Paratuberculosis (Johne's disease) is a chronic infectious granulomatous enteritis, primarily affecting ruminants, and caused by Mycobacterium avium ssp. paratuberculosis (MAP). The disease is widely prevalent throughout the world with significant economic losses. MAP has also been implicated with human Crohn's disease. There exists a strong correlation between the immune response and development of various types of pathologies in ruminants. The polarization of the immune response, which is critical to clinical outcome of the paratuberculosis infection, is controlled by the differential expression of certain cytokines and inducible nitric oxide synthase (iNOS) in Johne's disease. In previous studies, the role of different cytokines (Th1 and Th2) has been occasionally studied in sheep paratuberculosis. In the present study, we studied differential expression of interferon (IFN)-γ, interleukin (IL)-1α, IL-10, transforming growth factor (TGF)-β, iNOS, and TRAF1 genes in MAP-infected sheep and established relationship with distinct pathologies. Tissue sections (small intestine, ileocecal junction, and mesenteric lymph nodes) were collected from sheep suspected for Johne's disease and appropriately preserved for RNA extraction, polymerase chain reaction (PCR) analysis, and histopathology. Pathologic grading was done on the basis of nature and extent of cellular infiltration, granuloma formation and abundance of acid-fast bacilli. Six sheep each with pauci (PB)- and multibacillary (MB) lesions and six healthy control sheep were selected for cytokine studies. MAP in tissue extracted genomic DNA of sheep was quantified by a quantitative PCR assay. Tissue extracted RNA was reversed transcribed to prepare c-DNA from which quantitative reverse transcription PCR (qRT-PCR) was performed to amplify IFN-γ, IL-1β, IL-10, TGF-β, β-actin, TRAF1, and iNOS with Quantitect SYBR Green Master Mix. qRT-PCR data were analyzed using 2 -ΔΔCT method using β-actin gene as a control
Beaver, A.; Ruegg, P. L.; Gröhn, Y. T.; Schukken, Y. H.
Johne's disease, a granulomatous enteritis of ruminant animals, is a hidden threat on dairy farms, adversely affecting animal welfare as well as herd productivity. Control programs in the United States advocate for specific management practices to temper the spread of the causal organism
Berninger, Mary Lou; O'Hearn, Emily; Lomkin, Richanne; Newens, Ken; Havas, Karyn A
Vesicular stomatitis (VS) is a vesicular disease of horses, cattle, and pigs in the Western Hemisphere caused by viruses in the genus Vesiculovirus. Disease manifests as vesicles and erosions on the oral mucosa, teats, prepuce, and coronary band, and is similar in presentation to foot-and-mouth disease. Laboratory confirmation is therefore required. Conventional assays include competitive (c)ELISA and complement fixation (CF). The cELISA provides more accurate herd-level detection of VSV-exposed cattle, but may lack the ability to capture fluctuating antibody levels in individual animals. The CF assay can confirm newly infected animals because of its ability to detect antigen-antibody complexes, thus is considered to be indicative of IgM. We evaluated the immune status of 2 herds affected by VSV in 2014 by testing sera collected in June 2015. Two conventional assays were compared to a novel IgM-IgG ELISA. When sampled in 2015, both herds had detectable VSV-specific antibodies; 18% and 36% of animals tested by cELISA and 2% and 8% of animals tested by CF were positive. The novel IgM-IgG assay exhibited fair agreement (adjusted kappa score of 48) with the conventional assays, and should be evaluated further to assess its ability to replace the 2 separate assays with a single assay system, or for its ability to replace the CF assay as a more sensitive method for defining newly exposed animals.
Nathues, H; Chang, Y M; Wieland, B; Rechter, G; Spergser, J; Rosengarten, R; Kreienbrock, L; Grosse Beilage, E
The aim of the present study was to identify potential risk factors for the occurrence of enzootic pneumonia (EP) in herds situated in a region of high pig density, where a majority of herds is endemically infected with Mycoplasma hyopneumoniae. Between 2006 and 2010, overall 100 herds were enrolled in a case-control study. Data were collected through personal interview with the farmers, clinical examination of pigs and their environments, and serological testing for M. hyopneumoniae, swine influenza virus and porcine reproductive and respiratory syndrome virus. There were 40 case herds (coughing index high, seroprevalence high) with a mean coughing index of 4.3 and a seroprevalence of 86.6%. There were two control groups. Control group I consisted of 25 herds (coughing index low, seroprevalence low) with mean values of 0.7 and 11.2%, and 35 herds were allocated to control group II (coughing index low, seroprevalence high) where the mean coughing index was 0.9 and seroprevalence 86.3%. Case herds and control II herds had an increased age of piglets at weaning compared to control I herds. Any contact between fattening pigs of different age during restocking of compartments increased the risk for the occurrence of EP in a herd. Finally, farms that use living animals for the exposure to gilts during the acclimatization and farms that had increased number of weaned piglets per sow and year were less likely to test positive for M. hyopneumoniae and less likely to develop clinical symptoms of EP in fattening pigs. © 2012 Blackwell Verlag GmbH.
Mughini-Gras, L; Angeloni, G; Salata, C; Vonesch, N; D'Amico, W; Campagna, G; Natale, A; Zuliani, F; Ceglie, L; Monne, I; Vascellari, M; Capello, K; DI Martino, G; Inglese, N; Palù, G; Tomao, P; Bonfanti, L
We determined the hepatitis E virus (HEV) seroprevalence and detection rate in commercial swine herds in Italy's utmost pig-rich area, and assessed HEV seropositivity risk in humans as a function of occupational exposure to pigs, diet, foreign travel, medical history and hunting activities. During
Mughini-Gras, L|info:eu-repo/dai/nl/413306046; Angeloni, Giorgia; Salata, C; Vonesch, N; D'Amico, W; Campagna, G; Natale, Alda; Zuliani, Federica; Ceglie, Letizia; Monne, Isabella; Vascellari, M; Capello, Katia; DI Martino, G; Inglese, N; Palù, G; Tomao, P; Bonfanti, L.
We determined the hepatitis E virus (HEV) seroprevalence and detection rate in commercial swine herds in Italy's utmost pig-rich area, and assessed HEV seropositivity risk in humans as a function of occupational exposure to pigs, diet, foreign travel, medical history and hunting activities. During
Full Text Available Paratuberculosis or Johne’s disease is an infectious disease in ruminants (cattle, buffalo, sheep and goat caused by Mycobacterium avium subspecies paratuberculosis (MAP and characterized by granulomatous enteritis manifestation. The disease occurs worldwidely and causes great economic losses on domestic livestock industries. Calves are commonly infected soon after birth, with incubation period of either some months or years. Clinical signs observed from 2 to 10 years old of infected cattle are chronic diarrhea and progressive emaciation. Transmission of MAP to calves can occur by nursing the infected dam or got contaminated by fecal material. The pathogens can also be excreted in colostrum or milk, that is why calf can be infected since neonatal period. Infection in progress leads to cause thickening of the intestinal wall, granulomatous and mesenterical lymphnode, which diffusion lesions in the intestine are characterized by the macroscopical finding. In Indonesia, paratuberculosis had been reported in dairy cattle (in West Java with seroprevalence of 1.67% (3/180. From the serological positive reactors demonstrated MAP of 0.55% (1/180 by fecal cuture examination. Some samples of cattle and buffaloes from North Sumatera were also found positive paratuberculosis antibody against MAP detected by Complement Fixation Test (CFT at average of 4% (2/50. The presence of positive reactors of paratuberculosis in dairy cattle, beef cattle and buffaloes in Indonesia must be anticipated. These animals are carriers and can shed pathogens, although they do not show clinical signs. It is likely that paratuberculosis can not be detected by conventional diagnostic techniques, therefore, sensitive and early diagnosis techniques must be developed.
Grant, Irene R; Foddai, Antonio C G; Tarrant, James C; Kunkel, Brenna; Hartmann, Faye A; McGuirk, Sheila; Hansen, Chungyi; Talaat, Adel M; Collins, Michael T
When advising farmers on how to control Johne's disease in an infected herd, one of the main recommendations is to avoid feeding waste milk to calves and instead feed calf milk replacer (CMR). This advice is based on the assumption that CMR is free of viable Mycobacterium avium ssp. paratuberculosis (MAP) cells, an assumption that has not previously been challenged. We tested commercial CMR products (n = 83) obtained from dairy farms around the United States by the peptide-mediated magnetic separation (PMS)-phage assay, PMS followed by liquid culture (PMS-culture), and direct IS900 quantitative PCR (qPCR). Conventional microbiological analyses for total mesophilic bacterial counts, coliforms, Salmonella, coagulase-negative staphylococci, streptococci, nonhemolytic Corynebacterium spp., and Bacillus spp. were also performed to assess the overall microbiological quality of the CMR. Twenty-six (31.3%) of the 83 CMR samples showed evidence of the presence of MAP. Seventeen (20.5%) tested positive for viable MAP by the PMS-phage assay, with plaque counts ranging from 6 to 1,212 pfu/50 mL of reconstituted CMR (average 248.5 pfu/50 mL). Twelve (14.5%) CMR samples tested positive for viable MAP by PMS-culture; isolates from all 12 of these samples were subsequently confirmed by whole-genome sequencing to be different cattle strains of MAP. Seven (8.4%) CMR samples tested positive for MAP DNA by IS900 qPCR. Four CMR samples tested positive by both PMS-based tests and 5 CMR samples tested positive by IS900 qPCR plus one or other of the PMS-based tests, but only one CMR sample tested positive by all 3 MAP detection tests applied. All conventional microbiology results were within current standards for whole milk powders. A significant association existed between higher total bacterial counts and presence of viable MAP indicated by either of the PMS-based assays. This represents the first published report of the isolation of viable MAP from CMR. Our findings raise concerns
Full Text Available Mycobacterium avium subspecies paratuberculosis (MAP is a member of the M avium complex (MAC. It differs genetically from other MAC in having 14 to 18 copies of IS900 and a single cassette of DNA involved in the biosynthesis of surface carbohydrate. Unlike other MAC, MAP is a specific cause of chronic inflammation of the intestine in many animal species, including primates. The disease ranges from pluribacillary to paucimicrobial, with chronic granulomatous inflammation like leprosy in humans. MAP infection can persist for years without causing clinical disease. The herd prevalence of MAP infection in Western Europe and North America is reported in the range 21% to 54%. These subclinically infected animals shed MAP in their milk and onto pastures. MAP is more robust than tuberculosis, and the risk that is conveyed to human populations in retail milk and in domestic water supplies is high. MAP is harboured in the ileocolonic mucosa of a proportion of normal people and can be detected in a high proportion of full thickness samples of inflamed Crohn’s disease gut by improved culture systems and IS900 polymerase chain reaction if the correct methods are used. MAP in Crohn’s disease is present in a protease-resistant nonbacillary form, can evade immune recognition and probably causes an immune dysregulation. As with other MAC, MAP is resistant to most standard antituberculous drugs. Treatment of Crohn’s disease with combinations of drugs more active against MAC such as rifabutin and clarithromycin can bring about a profound improvement and, in a few cases, apparent disease eradication. New drugs as well as effective MAP vaccines for animals and humans are needed. The problems caused by MAP constitute a public health issue of tragic proportions for which a range of remedial measures are urgently needed.
The demography of bovine infections caused by Mycobacterium avium subspecies paratuberculosis (MAP) in Ireland is poorly defined. The objective of this study was to describe the demographics of cattle positive to MAP on faecal culture, based on submissions to the Cork Regional Veterinary Laboratory (Cork RVL) from 1994 to 2006. The study focused on all available faecal samples from adult cattle with non-responsive chronic diarrhoea that were submitted by private veterinary practitioners to Cork RVL for MAP culture. For each MAP-positive by faecal culture animal, data were collated from Cork RVL and Cattle Movement Monitoring Scheme (CMMS) records. Johne's disease (JD) was confirmed in 110 animals from 86 herds by the Cork RVL between 1994 and 2006, with a rate of positive cases between 15% and 18% over last four years of the study. Two breeds (Holstein/Friesian or Limousin) made up 78% of submissions. Movements were assessed for the 57 study animals with available movement information, 90% died within one year of the test and 26% tested positive in the herd they were born into. The study provides preliminary information about movement trends and demographics of animals with MAP positive submissions. Although the study area is restricted, it includes the most intensive (and economically-important) dairy region in Ireland. The demographics of JD infection from the study area are in agreement with international reports. Further work is required to determine demographic trends, incidence and prevalence of JD throughout Ireland. It is hoped this work may contribute to the development of a surveillance strategy for MAP by regional veterinary laboratories. PMID:21851736
Tim J Bull
Full Text Available BACKGROUND: Mycobacterium avium subspecies paratuberculosis causes systemic infection and chronic intestinal inflammation in many species including primates. Humans are exposed through milk and from sources of environmental contamination. Hitherto, the only vaccines available against Mycobacterium avium subspecies paratuberculosis have been limited to veterinary use and comprised attenuated or killed organisms. METHODS: We developed a vaccine comprising a fusion construct designated HAV, containing components of two secreted and two cell surface Mycobacterium avium subspecies paratuberculosis proteins. HAV was transformed into DNA, human Adenovirus 5 (Ad5 and Modified Vaccinia Ankara (MVA delivery vectors. Full length expression of the predicted 95 kDa fusion protein was confirmed. PRINCIPAL FINDINGS: Vaccination of naïve and Mycobacterium avium subspecies paratuberculosis infected C57BL/6 mice using DNA-prime/MVA-boost or Ad5-prime/MVA-boost protocols was highly immunogenic resulting in significant IFN-gamma ELISPOT responses by splenocytes against recombinant vaccine antigens and a range of HAV specific peptides. This included strong recognition of a T-cell epitope GFAEINPIA located near the C-terminus of the fusion protein. Antibody responses to recombinant vaccine antigens and HAV specific peptides but not GFAEINPIA, also occurred. No immune recognition of vaccine antigens occurred in any sham vaccinated Mycobacterium avium subspecies paratuberculosis infected mice. Vaccination using either protocol significantly attenuated pre-existing Mycobacterium avium subspecies paratuberculosis infection measured by qPCR in spleen and liver and the Ad5-prime/MVA-boost protocol also conferred some protection against subsequent challenge. No adverse effects of vaccination occurred in any of the mice. CONCLUSIONS/SIGNIFICANCE: A range of modern veterinary and clinical vaccines for the treatment and prevention of disease caused by Mycobacterium avium
Tikofsky, L L; Zadoks, R N
Group G streptococci in animals usually belong to the species Streptococcus canis and are most commonly found in dogs and cats. Occasionally, Strep. canis is detected in milk from dairy cows. An outbreak of Strep. canis mastitis in a dairy herd is described. Based on results from bacterial culture and ribotyping, a cat with chronic sinusitis was the most likely source of the outbreak. Subsequent cow-to-cow transmission of Strep. canis was facilitated by poor udder health management, including...
Grøndahl-Hansen, Jan; Barfod, Kristen; Klausen, Joan
The objective was to develop an enzyme-linked immunosorbent assay (ELISA) for simultaneous detection of antibodies against Actinobacillus pleuropneumoniae (Ap) serotypes 2, 6 and 12. The assay was designated MIX-ELISA. Lipopolysaccharide (LPS) from Ap serotypes 2, 6 and 12 was purified using hot...... of the assay indicate that screening of herds for Ap infection can be performed using this ELISA. Efficient serological surveillance can be achieved by using such mixed antigen ELISAs coated with size-selected LPS-antigens from the most prevalent serotypes....... phenol-water extraction followed by fractionation by size-exclusion chromatography. A mixture of fractions containing molecules with molecular weight above 50 kDa from all three serotypes was used as antigen. The MIX-ELISA was evaluated with sera from pigs experimentally infected with the serotypes 1, 2...
Vigre, Håkan; Josefsen, Mathilde Hartmann; Seyfarth, Anne Mette
either at farm or slaughter. Three sample matrices were collected; dust samples (5 environmental swabs), nasal swabs (10 pools with 5 animals per pool) and air samples (1 filter). Based on the assumption that MRSA occurred in all 48 herds the overall herd sensitivity was 58% for nasal swabs, 33% for dust....... In our example, the prevalence of infected pigs in each herd was estimated from the pooled samples of nasal swabs. Logistic regression was used to estimate the effect of animal prevalence on the probability to detect MRSA in the dust and air samples at herd level. The results show a significant increase...
Michele A. Miller
Full Text Available This case report shows that Mycobacterium avium subsp. paratuberculosis (MAP infection can cause clinical disease in domestic dogs, and should be considered as a differential diagnosis for gastrointestinal inflammatory conditions. A male dachshund presented with lethargy and pain. Enlarged mesenteric lymph nodes were found on abdominal ultrasound examination. Cytological examination of lymph node aspirates was consistent with granulomatous inflammation, which was culture-confirmed as MAP. Although we were unable to confirm the source of infection, the dog’s history included exposure to sheep in the Western Cape.
Broeders, D.; Chen, D.; Minderhoud, P.; Schudel, W.
This paper uses unique and detailed transaction data to analyse herding behavior among pension funds. We distinguish between weak, semi strong and strong herding behaviour. Weak herding occurs if pension funds have similar rebalancing strategies. Semi strong herding arises when pension funds react
Jungersen, Gregers; Mikkelsen, Heidi; Grell, Susanne N.
Although the interferon-gamma (IFN-γ) assay for measurements of cell-mediated immune (CMI) responses to paratuberculosis PPD (johnin) has been available for close to 20 years, the assay has not yet emerged as the long desired test to identify infected animals at an early time point. Among other...
Johne’s disease in ruminants is a chronic infection of the intestines caused by Mycobacterium avium subsp. paratuberculosis. Economic losses associated with Johne’s disease arise due to premature culling, reduced production of milk and wool and mortalities. The disease is characterised by a long inc...
Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne’s disease in domestic animals and has been implicated in Crohn’s disease in humans. Cows infected with Johne’s disease shed large quantities of MAP into soil. Further, MAP has been isolated from surface water, is resi...
Full Text Available Abstract Background Bovine respiratory syncytial virus (BRSV and bovine corona virus (BCV affects cattle worldwide. Our objective was to evaluate the effects of these infections on general health and reproduction parameters measurable on herd level and to explore the association between antibody status and some herd characteristics. Methods We collected a pooled milk sample from five primiparous cows from 79 Swedish dairy herds in September 2006. The samples were analysed for immunoglobulin G antibodies to BCV and BRSV with indirect enzyme-linked immunosorbent assays. Herd level data from 1 September 2005 to 30 August 2006 were accessed retrospectively. The location of the herds was mapped using a geographical information system. Results Ten herds were antibody negative to both viruses and were compared with 69 herds positive to BCV or BRSV or both. Positive herds had a higher (P = 0.001 bulk tank milk somatic cell count (BMSCC compared with negative herds. The medians for all other analyzed health and reproductive parameters were consistently in favour of the herds negative to both viruses although the differences were not statistically significant. A higher proportion (P = 0.01 of herds used professional technicians for artificial insemination, rather than farm personnel, amongst the 33 herds negative to BCV compared with the 46 positive herds. Conclusions Our result shows that herds that were antibody positive to BCV and/or BRSV had a higher BMSCC compared with herds negative to BCV and BRSV. There was also tendency that negative herds had a better general herd health compared with positive. A higher proportion amongst the BCV negative herds used external technicians for AI instead of farm personnel, indicating that it is possible to avoid infection although having regular visits. Negative herds were located in close proximity to positive herds, indicating that local spread and airborne transmission between herds might not be of great
Mycobacterium avium subsp. paratuberculosis: presencia en los alimentos y su relación con la enfermedad de Crohn Mycobacterium avium subsp. paratuberculosis in food and its relationship with Crohn's disease
subsp. paratuberculosis has been linked in men to a chronic inflammation of the intestine, named Crohn's disease. There is clinical and experimental evidence to link M. avium subsp. paratuberculosis with Crohn's disease by PCR, positive bacteriological culture from mother milk, blood and affected tissues by in situ hybridization. The milk and sub-products might be one of the possible infection sources and it has been suggested that M. avium subsp. paratuberculosis could resist pasteurization. Several works showed that this mycobacteria could be present in retail milk of countries such as United Kingdom, USA, Czech Republic, and recently in Argentina. M. avium subsp. paratuberculosis was associated with different dairy products and water for human consumption. Therefore, it is possible that these food sources may have a role for transmission. New investigations should emphasize the role of contaminated food and water in human infection around the world and determine the possible zoonotic role of M. avium subsp. paratuberculosis.
Oliver-Ferrando, Salvador; Segalés, Joaquim; López-Soria, Sergio; Callén, Antonio; Merdy, Olivier; Joisel, François; Sibila, Marina
This study sought to evaluate the effect of sow vaccination against Porcine circovirus 2 (PCV2) on reproductive parameters during two consecutive reproductive cycles. The study was performed in a PCV2 subclinical infected breeding herd (PCV2 circulation but absence of major reproductive problems). Ninety-four pregnant sows were primo-immunized with a commercial PCV2 vaccine and ninety-seven were injected with phosphate-buffered saline at 6 and 3 weeks before the first studied farrowing, and then boosted at 2 weeks before the second one. Blood samples were taken throughout the study to assess PCV2 DNA load and antibodies. At farrowing, main reproductive parameters and piglet vitality index were registered. In addition, in those litters with more than three mummified or stillborn piglets, microscopic examination and PCV2 antigen detection in foetal myocardium was done. Vaccinated sows showed significantly higher antibody levels compared to the non-vaccinated counterparts. PCV2 DNA was only detected at farrowing in 2 (4.2%) non-vaccinated sows. Vaccinated sows had 1.3 more live-born piglets per litter at the second cycle than non-vaccinated counterparts. Piglets from vaccinated sows had significantly higher (+ 12.7%) vitality score than the ones born from non-vaccinated sows. No PCV2 compatible lesions neither PCV2 antigen were detected in the tested foetal hearts. The present study represents a first attempt to demonstrate that PCV2 sow vaccination may have a positive influence on prolificacy and vitality of the offspring in a subclinical infected breeding herd. However, since reproductive outcomes at farm level may be affected by a number of factors, further studies would be needed to confirm this association.
Dimareli-Malli, Z; Mazaraki, K; Stevenson, K; Tsakos, P; Zdragas, A; Giantzi, V; Petridou, E; Heron, I; Vafeas, G
In this study the suitability of different solid media was investigated for the isolation of Mycobacterium avium subsp. paratuberculosis (Map) in order to identify the optimum single or combination of media to permit the isolation of all strain types from small ruminants. A subset of these Map strains was then further characterized by molecular typing methods to assess the genetic diversity of Map strains in the study area (Northern Greece). Map strains were isolated from tissues and faeces of infected goats (n=52) and sheep (n=8) and were analysed for polymorphisms in IS1311 to classify the strain type as Type C or S. The study found that M7H11 supplemented with mycobactin j, OADC and new born calf serum (M7H11+Mj) is the best single choice of medium for the primary isolation of Map of both Type C and S from small ruminants. The combination of M7H11+Mj and Herrolds egg yolk medium supplemented with mycobactin j and sodium pyruvate allowed the detection of all Map isolates in this study. Nineteen Map isolates were characterised by pulsed-field gel electrophoresis and the isolates demonstrated significant genetic diversity. Twelve different SnaBI and 16 distinct SpeI profiles were detected of which 25 have not been described previously and are new profiles. The combination of both enzyme profiles gave 13 different multiplex profiles. Ten different multiplex profiles were detected in goats and three in sheep. One ovine isolate gave the same multiplex profile as a caprine isolate and two different profiles were found within a single goat herd. Copyright © 2013 Elsevier Ltd. All rights reserved.
Tolosa, T; Verbeke, J; Ayana, Z; Piepers, S; Supré, K; De Vliegher, S
A cross-sectional study on clinical mastitis, intramammary infection (IMI) and blind quarters was conducted on 50 smallholder dairy farms in Jimma, Ethiopia. A questionnaire was performed, and quarters of 211 cows were sampled and bacteriologically cultured. Risk factors at the herd, cow, and quarter level for clinical mastitis and (pathogen-specific) intramammary infection were studied using multilevel modeling. As well, factors associated with quarters being blind were studied. Eleven percent of the cows and 4% of the quarters had clinical mastitis whereas 85% of the cows and 51% of the quarters were infected. Eighteen percent of the cows had one or more blind quarter(s), whereas 6% of the quarters was blind. Non-aureus staphylococci were the most frequently isolated pathogens in both clinical mastitis cases and IMI. The odds of clinical mastitis was lower in herds where heifers were purchased in the last year [odds ratio (OR) with 95% confidence interval: 0.11 (0.01-0.90)], old cows (>4 years) [OR: 0.45 (0.18-1.14)], and quarters not showing teat injury [OR: 0.23 (0.07-0.77)]. The odds of IMI caused by any pathogen was higher in herds not practicing teat drying before milking (opposed to drying teats with 1 towel per cow) [OR: 1.68 (1.05-2.69)], cows in later lactation (>180 DIM opposed to ≤90 DIM) [OR: 1.81 (1.14-2.88)], cows with a high (>3) body condition score (BCS) [OR: 1.57 (1.06-2.31)], right quarters (opposed to a left quarter position) [OR: 1.47 (1.10-1.98)], and quarters showing teat injury [OR: 2.30 (0.97-5.43)]. Quarters of cows in herds practicing bucket-fed calf feeding (opposed to suckling) had higher odds of IMI caused by Staphylococcus aureus [OR: 6.05 (1.31-27.90)]. Except for BCS, IMI caused by non-aureus staphylococci was associated with the same risk factors as IMI caused by any pathogen. No access to feed and water immediately after milking [OR: 2.41 (1.26-4.60)], higher parity [OR: 3.60 (1.20-10.82)] and tick infestation [OR: 2.42 (1
May 4, 2018 ... of both water and biofilm samples from 31 cold water ... temperatures ranging from 15 to 45°C and salinities .... et al., 2005) couple with specific growth requirements such as ..... paratuberculosis in muscle: lymphatic and organ.
Nielsen, Gitte Blach; Nielsen, Jens Peter; Haugegaard, John
During the last decade, the clinical manifestation of Porcine Circovirus type 2 (PCV2) infections has mostly changed from postweaning multisystemic wasting syndrome and high mortality to sub-clinical infections manifested only through impaired production parameters. However, co-infection with oth...
Analysis of Biobanked Serum from a Mycobacterium avium subsp paratuberculosis Bovine Infection Model Confirms the Remarkable Stability of Circulating miRNA Profiles and Defines a Bovine Serum miRNA Repertoire.
Ronan G Shaughnessy
Full Text Available Johne's Disease (JD is a chronic enteritis of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP. Current disease control strategies are hampered by the lack of sensitive and specific diagnostic modalities. Therefore, novel diagnostic and prognostic tools are needed, and circulating microRNAs (miRNAs may hold potential in this area. The aims of this study were twofold: (i to address the stability of miRNA in bovine sera from biobanked samples, and (ii to assess the potential of miRNAs as biomarkers for JD disease progression. To address these aims we used bovine sera from an experimental MAP infection model that had been stored at -20°C for over a decade, allowing us to also assess the stability of miRNA profiles in biobanked serum samples through comparison with fresh sera. Approximately 100-200 intact miRNAs were identified in each sample with 83 of these being consistently detected across all 57 samples. The miRNA profile of the biobanked sera stored at -20°C for over 10 years was highly similar to the profile of <1 year-old sera stored at -80°C, with an overlap of 73 shared miRNAs. IsomiR analysis also indicated a distinct bovine serum-specific isomiR profile as compared to previously reported bovine macrophage miRNA profiles. To explore the prognostic potential of miRNA profiles cattle defined as seropositive for anti-MAP antibodies (n = 5 were compared against seronegative cattle (n = 7. No significant differential expressed miRNAs were detected at either the early (6 months or late (43, 46 and 49 months intervals (FDR≤0.05, fold-change≥1.5 across seropositive or seronegative animals. However, comparing pre-infection sera to the early and late time-points identified increased miR-29a and miR-92b abundance (2-fold that may be due to blood-cell population changes over time (P<0.001. In conclusion our study has demonstrated that bovine circulating miRNAs retain their integrity under long-term sub-optimal storage
Greiner, Matthias; Dekker, Aldo
Small herds may present a problem in surveillance for infectious animal diseases because typical levels of a within-herd design prevalence are not directly applicable. We suggest a definition of small herds as those smaller than 2/(within-herd design prevalence) on the basis that such herds would...... be expected to have less than two (i.e. only one) infected animals. Consequently, the probability of detecting small herds cannot be improved by choosing a larger sample size within the herd. We derive necessary sample sizes of herds and the probability ("confidence") of detecting disease within a stratum...... conservative (lower) estimates of the confidence for a given sample size and should therefore be preferred....
Grant, Irene R.; Ball, Hywel J.; Rowe, Michael T.
An immunomagnetic separation (IMS) technique was developed to facilitate selective isolation of Mycobacterium paratuberculosis cells from milk. Rabbit polyclonal antibodies against radiation-killed intact M. paratuberculosis cells were produced and used to coat sheep anti-rabbit immunoglobulin G (IgG) type M-280 Dynabeads. The rabbit anti-M. paratuberculosis IgG-coated beads (IMB) reacted strongly with laboratory strains of M. paratuberculosis as determined by slide agglutination, and microsc...
Lyons, E T; Tolliver, S C; Collins, S S
Two closed horse herds (Old Lot 4 and Field 24), infected since 1966 with Population B small strongyles resistant to thiabendazole (TBZ) and phenothiazine (PTZ), were terminated in February, March, and May, 2005. At necropsy, only the large endoparasites were identified and counted. The number of horses on pasture was 14 (239 days of age to 23 years old) for Old Lot 4 and two (3 to 20 years old) for Field 24. The time of the last antiparasitic treatment, relative to the year (2005) of necropsy, was 26 years for Old Lot 4 and 9 years for Field 24 horses. Gasterophilus intestinalis third instars (three to 113 specimens/horse) were found in all 16 horses and second instars (one to two) in two horses. Gasterophilus nasalis third instars (one to three) were recovered from five horses. Parascaris equorum infections (23 to 144) were in four horses (239 days to 4 years old). Strongylus vulgaris were present in the large intestine (one to 155) of 13 horses from 239 days to 23 years old and in the cranial mesenteric artery (two to 79) in 10 horses from 239 days to 23 years old. Strongylus edentatus were in the large intestine (two to 101) of 12 horses, ranging in age from 2.5 to 23 years old and in the ventral abdominal wall (one to 53) of six horses from 239 days to 21 years old. Specimens (seven to 872) of Anoplocephala perfoliata were in all horses. Oxyuris equi (one to 129) were recovered from seven horses (330 days to 23 years old). Thelazia lacrymalis (one to 85) infected the eyes of five horses (317 days to 11 years old).
Full Text Available Torque teno viruses (TTVs are a large group of vertebrate-infecting small viruses with circular single-stranded DNA, classified in the Anelloviridae family. In swine, two genetically distinct species, Torque teno sus virus 1a (TTSuV1a and 1b (TTSuV1b are currently grouped into the genus Iotatorquevirus. More recently, a novel Torque teno sus virus species, named Torque teno sus virus k2b (TTSuVk2b, has been included with Torque teno sus virus k2a (TTSuVk2a into the genus Kappatorquevirus. In the present study, TTSuV1 (TTSuV1a and TTSuV1b, TTSuVk2a and TTSuVk2b prevalence was evaluated in 721 serum samples of healthy pigs from Sardinian farms, insular Italy. This is the largest study to date on the presence of TTSuV in healthy pigs in Italy. The global prevalence of infection was 83.2% (600/721, being 62.3% (449/721, 60.6% (437/721, and 11.5% (83/721 the prevalence of TTSuV1, TTSuVk2a and TTSuVk2b, respectively. The rate of co-infection with two and/or three species was also calculated, and data show that co-infections were significantly more frequent than infections with single species, and that TTSuV1+TTSuVk2a double infection was the prevalent combination (35.4%. Quantitative results obtained using species-specific real time-qPCR evidenced the highest mean levels of viremia in the TTSuV1 subgroup, and the lowest in the TTSuVk2b subgroup. Interestingly, multiple infections with distinct TTSuV species seemed to significantly affect the DNA load and specifically, data highlighted that double infection with TTSuVk2a increased the viral titers of TTSuV1, likewise the co-infection with TTSuVk2b increased the titers of TTSuVk2a.
Blois, Sylvain; Mallus, Francesca; Liciardi, Manuele; Pilo, Cristian; Camboni, Tania; Macera, Lisa; Maggi, Fabrizio; Manzin, Aldo
Torque teno viruses (TTVs) are a large group of vertebrate-infecting small viruses with circular single-stranded DNA, classified in the Anelloviridae family. In swine, two genetically distinct species, Torque teno sus virus 1a (TTSuV1a) and 1b (TTSuV1b) are currently grouped into the genus Iotatorquevirus. More recently, a novel Torque teno sus virus species, named Torque teno sus virus k2b (TTSuVk2b), has been included with Torque teno sus virus k2a (TTSuVk2a) into the genus Kappatorquevirus. In the present study, TTSuV1 (TTSuV1a and TTSuV1b), TTSuVk2a and TTSuVk2b prevalence was evaluated in 721 serum samples of healthy pigs from Sardinian farms, insular Italy. This is the largest study to date on the presence of TTSuV in healthy pigs in Italy. The global prevalence of infection was 83.2% (600/721), being 62.3% (449/721), 60.6% (437/721), and 11.5% (83/721) the prevalence of TTSuV1, TTSuVk2a and TTSuVk2b, respectively. The rate of co-infection with two and/or three species was also calculated, and data show that co-infections were significantly more frequent than infections with single species, and that TTSuV1+TTSuVk2a double infection was the prevalent combination (35.4%). Quantitative results obtained using species-specific real time-qPCR evidenced the highest mean levels of viremia in the TTSuV1 subgroup, and the lowest in the TTSuVk2b subgroup. Interestingly, multiple infections with distinct TTSuV species seemed to significantly affect the DNA load and specifically, data highlighted that double infection with TTSuVk2a increased the viral titers of TTSuV1, likewise the co-infection with TTSuVk2b increased the titers of TTSuVk2a.
Although most commonly associated with the infection of domestic livestock, the replication of pestiviruses, in particular bovine viral diarrhea virus (BVDV), occurs in a wide range of free ranging cervids including white-tailed deer, mule deer, fallow deer, elk, red deer, roe deer, eland and moused...
Thakur, Aneesh; Aagaard, Claus; Riber, Ulla
Effective control of paratuberculosis is hindered by lack of a vaccine preventing infection, transmission and without diagnostic interference with tuberculosis. We have developed a novel multi-stage recombinant subunit vaccine in which a fusion of four early expressed MAP antigens is combined...... characterized by a significant containment of bacterial burden in gut tissues compared to non-vaccinated animals. There was no cross-reaction with bovine tuberculosis in vaccinated animals. This novel multi-stage vaccine has the potential to become a marker vaccine for paratuberculosis....
Munyua, Peninah; Corman, Victor Max; Bitek, Austine; Osoro, Eric; Meyer, Benjamin; Müller, Marcel A; Lattwein, Erik; Thumbi, S M; Murithi, Rees; Widdowson, Marc-Alain; Drosten, Christian; Njenga, M Kariuki
AbstractHigh seroprevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) among camels has been reported in Kenya and other countries in Africa. To date, the only report of MERS-CoV seropositivity among humans in Kenya is of two livestock keepers with no known contact with camels. We assessed whether persons exposed to seropositive camels at household level had serological evidence of infection. In 2013, 760 human and 879 camel sera were collected from 275 and 85 households respectively in Marsabit County. Data on human and animal demographics and type of contact with camels were collected. Human and camel sera were tested for anti-MERS-CoV IgG using a commercial enzyme-linked immunosorbent assay (ELISA) test. Human samples were confirmed by plaque reduction neutralization test (PRNT). Logistic regression was used to identify factors associated with seropositivity. The median age of persons sampled was 30 years (range: 5-90) and 50% were males. A quarter (197/760) of the participants reported having had contact with camels defined as milking, feeding, watering, slaughtering, or herding. Of the human sera, 18 (2.4%) were positive on ELISA but negative by PRNT. Of the camel sera, 791 (90%) were positive on ELISA. On univariate analysis, higher prevalence was observed in female and older camels over 4 years of age ( P MERS-CoV infection among camel pastoralists in Marsabit County. The high seropositivity suggests that MERS-CoV or other closely related virus continues to circulate in camels and highlights ongoing potential for animal-to-human transmission.
Crohn’s disease (CD) is a chronic granulomatous inflammation of the intestine. The etiology is still unknown. One hypothesis is that CD is caused by infection with Mycobacterium avium subspecies paratuberculosis (MAP) in genetically predisposed individuals. MAP causes a similar disease in ruminants,...
Understanding the pathogenic mechanisms and host responses to Johne’s disease, a chronic enteritis of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP), is complicated by the multifaceted disease progression, late-onset host reaction, and the lack of ex vivo infection models ...
Cohen, Matan J; Brezis, Mayer; Block, Colin; Diederich, Adele; Chinitz, David
During the 2009 outbreak of novel influenza AH1N1, insufficient data were available to adequately inform decision makers about benefits and risks of vaccination and disease. We hypothesized that individuals would opt to mimic their peers, having no better decision anchor. We used Game Theory, decision analysis, and transmission models to simulate the impact of subjective risks and preference estimates on vaccination behavior. We asked 95 students to provide estimates of risk and health state valuations with regard to AH1N1 infection, complications, and expectations of vaccine benefits and risks. These estimates were included in a sequential chain of models: a dynamic epidemic model, a decision tree, and a population-level model. Additionally, participants' intentions to vaccinate or not at varying vaccination rates were documented. The model showed that at low vaccination rates, vaccination dominated. When vaccination rates increased above 78%, nonvaccination was the dominant strategy. We found that vaccination intentions did not correspond to the shift in strategy dominance and segregated to 3 types of intentions: regardless of what others do 29/95 (31%) intended to vaccinate while 27/95 (28%) did not; among 39 of 95 (41%) intention was positively associated with putative vaccination rates. Some people conform to the majority's choice, either shifting epidemic dynamics toward herd immunity or, conversely, limiting societal goals. Policy leaders should use models carefully, noting their limitations and theoretical assumptions. Behavior drivers were not explicitly explored in this study, and the discrepant results beg further investigation. Models including real subjective perceptions with empiric or subjective probabilities can provide insight into deviations from expected rational behavior and suggest interventions in order to provide better population outcomes.
Griffith, Brad; Douglas, David C.; Walsh, Noreen E.; Young, Donald D.; McCabe, Thomas R.; Russell, Donald E.; White, Robert G.; Cameron, Raymond D.; Whitten, Kenneth R.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.
Documentation of the natural range of variation in ecological, life history, and physiological characteristics of caribou (Rangifer tarandus) of the Porcupine caribou herd is a necessary base for detecting or predicting any potential effects of industrial development on the performance (e.g., distribution, demography, weight-gain of individuals) of the herd. To demonstrate an effect of development, post-development performance must differ from pre-development performance while accounting for any natural environmental trends.We had 2 working hypotheses for our investigations: 1) performance of the Porcupine caribou herd was associated with environmental patterns and habitat quality, and 2) access to important habitats was a key influence on demography.We sought to document the range of natural variation in habitat conditions, herd size, demography (defined here as survival and reproduction), sources and magnitude of mortality, distribution, habitat use, and weight gain and loss, and to develop an understanding of the interactions among these characteristics of the herd.In addition, we investigated ways that we could use this background information, combined with auxiliary information from the adjacent Central Arctic caribou herd, to predict the direction and magnitude of any potential effects of industrial oil development in the 1002 Area of the Arctic National Wildlife Refuge on Porcupine caribou herd calf survival on the herd's calving grounds during June.
Cappuccio, Javier; Dibarbora, Marina; Lozada, Inés; Quiroga, Alejandra; Olivera, Valeria; Dángelo, Marta; Pérez, Estefanía; Barrales, Hernán; Perfumo, Carlos; Pereda, Ariel; Pérez, Daniel R
Swine farms provide a dynamic environment for the evolution of influenza A viruses (IAVs). The present report shows the results of a surveillance effort of IAV infection in one commercial swine farm in Argentina. Two cross-sectional serological and virological studies (n=480) were carried out in 2011 and 2012. Virus shedding was detected in nasal samples from pigs from ages 7, 21 and 42-days old. More than 90% of sows and gilts but less than 40% of 21-days old piglets had antibodies against IAV. In addition, IAV was detected in 8/17 nasal swabs and 10/15 lung samples taken from necropsied pigs. A subset of these samples was further processed for virus isolation resulting in 6 viruses of the H1N2 subtype (δ2 cluster). Pathological studies revealed an association between suppurative bronchopneumonia and necrotizing bronchiolitis with IAV positive samples. Statistical analyses showed that the degree of lesions in bronchi, bronchiole, and alveoli was higher in lungs positive to IAV. The results of this study depict the relevance of continuing long-term active surveillance of IAV in swine populations to establish IAV evolution relevant to swine and humans. Copyright © 2016 Elsevier Ltd. All rights reserved.
McKenna, S L B; Ritter, C; Dohoo, I; Keefe, G P; Barkema, H W
In herds with typical moderate to low within-herd prevalence, testing for Mycobacterium avium ssp. paratuberculosis (MAP), the infectious agent of Johne's disease, will be more cost-effective if individual fecal samples are cultured in composite pools. However, sensitivity to classify a pool containing 1 or more positive individual samples as positive may depend on pool size and number of individual positive samples within a pool. Fecal samples collected from 994 dairy cows sampled at slaughter were cultured to detect MAP. Culturing was done both individually and as composite pooled samples using the TREK ESP Culture System II broth medium (Thermo Fisher Scientific, Trek Diagnostic Systems Inc., Cleveland, OH). Composite samples consisted of pools containing feces from 3, 5, 8, 10, or 15 cows. The number of individual fecal culture-positive cows within each pool ranged from 0 to 4. Culture of individual fecal samples detected MAP in 36 (3.6%) of the 994 cows. Individual samples that were detected within the first 50 d by TREK ESP Culture System II were more likely to lead to a positive pool result. In total, 840 pooled fecal samples were examined for presence of MAP, and of those, 272 pools actually contained feces from fecal culture-positive cows. The crude sensitivity (proportion of pools that contained at least 1 fecal-positive cow that tested positive) for pools of 3, 5, 8, 10, and 15 was 47, 67, 44, 59, and 39%, respectively. Across pools, an increase of the number of fecal culture-positive samples from 1 to 2 enhanced overall crude sensitivity from 44 to 71%. However, sensitivity did not further increase for pools with 3 or 4 fecal culture-positive samples (63 and 60%, respectively). Additionally, a simulation analysis assessing probability of pooled fecal samples being positive in herds of 50 and 100 cows was conducted. The simulation assumed that 1, 2, or 5 cows per herd were MAP fecal culture-positive and that pools of 5 and 10 were used. This low
Agerholm, J.S.; Willadsen, C. M.; Nielsen, Thomas Krogh
Diagnostic findings in 218 aborted bovine foetuses are reported. The materials were examined in a matched case-control study of 69 Danish dairy herds with a sudden increase in the number of abortions and a corresponding 69 control herds. Foetuses aborted during the subsequent 6-month period were...... examined to identify the cause of abortion if possible. A total of 186 specimens were submitted from case herds and 32 from control herds. A likely cause of abortion was diagnosed in 73 foetuses. The most common cause was bovine viral diarrhoea virus (BVDV: 13%) followed by Neospora caninum infection (10......%), mycosis (5%) and Bacillus licheniformis infection (4%). Foetal and/or placental lesions were found in a further 27 cases. Only BVDV infection and neosporosis were diagnosed in more than one foetus per herd and only protozoal associated abortions occurred significantly more frequently in the case, rather...
It has been shown that Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) activates the Mitogen Activated Protein Kinase (MAPK) p38 pathway, yet it is unclear which components of M. paratuberculosis are involved in the process. Therefore, a set of 42 M. paratuberculosis recombinan...
Okura, Hisako; Toft, Nils; Nielsen, Søren Saxmose
Presence of Mycobacterium avium subsp. paratuberculosis (MAP) in milk for human consumption is a concern due to its possible relationship with Crohn’s disease in humans. Pasteurization effectively reduces the MAP load by four to five logs, but the efficacy depends on the MAP concentration, which...... depends on the prevalence among contributing herds and individuals. Considerable variation of MAP in bulk tank milk (BTM) and individual cow’s milk (IM) is reported, but factors associated with MAP occurrence in milk at farm level have not been described. This study systematically reviewed published...... studies aiming at estimating the occurrence of MAP in on-farm BTM and IM by meta-analysis. A total of 692 articles were identified through electronic databases and initially screened using title and abstract. The quality of the 61 potentially relevant articles was assessed using full text and 31 articles...
Bauman, Cathy A.; Jones-Bitton, Andria; Menzies, Paula
). Using 3-test latent class Bayesian models, true farm-level prevalence was estimated to be 83.0% [95% probability interval (PI): 62.6% to 98.1%] for dairy goats and 66.8% (95% PI: 41.6% to 91.4%) for dairy sheep. The within-farm true prevalence for dairy goats was 35.2% (95% PI: 23.0% to 49......A cross-sectional study was undertaken (October 2010 to August 2011) to estimate the prevalence of paratuberculosis in the small ruminant dairy industries in Ontario, Canada. Blood and feces were sampled from 580 goats and 397 sheep (lactating and 2 y of age or older) that were randomly selected...... from 29 randomly selected dairy goat herds and 21 convenience -selected dairy sheep flocks. Fecal samples were analyzed using bacterial culture (BD BACTEC MGIT 960) and polymerase chain reaction (Tetracore); serum samples were tested with the Prionics Parachek enzyme-linked immunosorbent assay (ELISA...
Kudahl, Anne Braad
Infection with Salmonella Dublin in the dairy herd and effects of the infection and relevant control measures are currently being modeled into the dairy herd simulation model called Simherd. The aim is to compare the effects of different control strategies against Salmonella Dublin on both within...... of the simulations will therefore be used for decision support in the national surveillance and eradication program against Salmonella Dublin. Basic structures of the model are programmed and will be presented at the workshop. The model is in a phase of face-validation by a group of Salmonella......-herd- prevalence and economy by simulations. The project Dublin on both within-herd- prevalence and economy by simulations. The project is a part of a larger national project "Salmonella 2007 - 2011" with the main objective to reduce the prevalence of Salmonella Dublin in Danish Dairy herds. Results...
Debien, Elaine; Hélie, Pierre; Buczinski, Sébastien; Lebœuf, Anne; Bélanger, Denise; Drolet, Richard
The objectives of this study were to determine the main causes of mortality, with a special focus on caseous lymphadenits as a cause of death or wasting in caprine herds from Quebec. Goats (n = 152) from 13 herds were submitted for necropsy; the cause of mortality, and the presence, location, and cause of abscesses (if present) were recorded. Proportional mortalities were distributed as: Clostridium perfringens type D enterotoxemia (17.1%), pneumonia (13.8%), paratuberculosis (10.5%), listeriosis (6.6%), pregnancy toxemia (5.3%), caprine arthritis-encephalitis (4.6%), and caseous lymphadenitis (3.9%). Caseous lymphadenitis was diagnosed in 24.3% of the submitted goats, but was not a major cause of wasting or mortality. Abscesses were localized internally in 54.1% of the cases. Paratuberculosis was diagnosed in 29 goats (16 as cause of death) and was considered a major cause of wasting and/or mortality.
Elise M. Yamasaki
Full Text Available A paratuberculose ou doença de Johne é uma enterite granulomatosa causada por Mycobacterium avium subsp. paratuberculosis (Map e comumente afeta ruminantes domésticos, no entanto, pode infectar várias espécies de mamíferos. Está presente nos cinco continentes e é considerada endêmica em algumas regiões pela Organização Internacional de Epizootias (OIE. Pertence à lista de enfermidades notificáveis, que compreende as doenças transmissíveis de importância sócio-econômica e/ou em saúde-pública, cujo controle é necessário para o comércio internacional de animais e alimentos de origem animal. A importância da doença de Johne não se restringe somente aos preju��zos econômicos causados à indústria animal, mas também na possível participação do Map na íleocolite granulomatosa que afeta seres humanos, conhecida como doença de Crohn. No Brasil, a paratuberculose já foi descrita em diversas espécies de ruminantes e em vários estados. Embora os relatos naturais da enfermidade sejam pontuais, acredita-se na possibilidade da transmissão interespecífica e na disseminação do agente através da compra e venda de animais infectados. O objetivo deste artigo foi reunir as informações disponíveis referentes aos aspectos epidemiológicos, clínico-patológicos e laboratoriais da paratuberculose em bovinos, bubalinos, caprinos e ovinos no Brasil, e salientar a necessidade de implementação de medidas de controle sanitário da enfermidade no país, o que possibilitaria a melhoria da qualidade e valorização dos produtos de origem animal no mercado internacional.Paratuberculosis also known as Johne's disease, is a granulomatous enteritis caused by Mycobacterium avium subsp. paratuberculosis (MAP, an acid-fast bacillus that preferentially resides within host intestinal macrophages. The condition is most commonly seen in domestic ruminants, however MAP can also infect other mammalian species. Paratuberculosis shows a
Full Text Available The objectives of this study were to 1 screen all sow herds in a region for M. hyopneumoniae, 2 to effectuate an eradication programme in all those herds which were shown to be infected with M. hyopneumoniae, and 3 to follow the success of the screening and the eradication programmes. The ultimate goal was to eradicate M. hyopneumoniae from all member herds of a cooperative slaughterhouse (153 farrowing herds + 85 farrowing-to-finishing herds + 150 specialised finishing herds before year 2000. During 1998 and 1999, a total of 5067 colostral whey and 755 serum samples (mean, 25 samples/herd were collected from sow herds and analysed for antibodies to M. hyopneumoniae by ELISA. Antibodies were detected in 208 (3.6% samples. Two farrowing herds (1.3% and 20 farrowing-to-finishing herds (23.5% were shown to be infected with M. hyopneumoniae. A programme to eradicate the infection from these herds was undertaken. During March 2000, a survey was made to prove the success of the screening and the eradication programmes. In total, 509 serum samples were collected randomly from slaughtered finishing pigs. Antibodies to M. hyopneumoniae were not detected in 506 of the samples, whereas 3 samples were considered suspicious or positive. Accordingly, 3 herds were shown to be infected. One of the herds was previously falsely classified as non-infected. Two of the herds were finishing herds practising continuous flow system (CF. Unlike finishing herds which practice all-in/all-out management routines on herd level, CF herds do not get rid of transmissible diseases spontaneously between batches, for which reason a screening was made in the rest of the CF herds (total n = 7. Consequently, 2 more infected herds were detected. In addition to the results of the survey, a decreasing prevalence of lung lesions at slaughter (from 5.2% to 0.1% and lack of clinical breakdowns indicated that all member herds were finally free from M. hyopneumoniae in the end of year 2000.
Klausen, Joan; Huda, A.; Ekeroth, Lars
concurrently from six dairy herds infected with MAP and from two dairy herds without history of infection with MAP. A cut-off value of 7 OD% was used in the ELISAs. At this cut-off value, all six culture-positive herds were positive in the serum ELISA but one was negative in the milk ELISA. All six culture......-positive herds were positive in the CFT. In the two culture-negative herds, the serum and the milk ELISA deemed all serum samples negative at this cut-off value, whereas four serum samples from one of these herds were positive in the CFT. The highest cut-off value enabling the milk ELISA to record all six...... culture-positive herds as positive was 4 OD%. The highest cut-off value enabling the serum ELISA to record all six culture-positive herds as positive was 17 OD%. Individual-sample relative sensitivities of the ELISAs ranged from 49 to 64% and relative specificities were 80-96% at the cut-off values of 4...
Stabel, J R; Hurd, S; Calvente, L; Rosenbusch, R F
The 2002 NAHM's Dairy Survey indicated that 87.2% of dairy farms in the United States feed waste milk to their neonatal calves. Although cost-effective, this practice can lead to increased calf morbidity and mortality due to ingestion of pathogenic agents. In an effort to reduce the risk of infection, dairy producers are implementing on-farm pasteurization of the waste milk as a control procedure before feeding the milk to calves. In the present study, the efficacy of a commercial high-temperature, short-time (HTST) on-farm pasteurizer unit to destroy Mycobacterium paratuberculosis, Salmonella enterica spp., and Mycoplasma spp. in raw milk was evaluated. Replicate experiments were run for 3 isolates of M. paratuberculosis, 3 serovars of Salmonella (derby, dublin, typhimurium); and 4 species of Mycoplasma (bovis, californicum, canadense, serogroup 7) at 2 different levels of experimental inoculation. In addition, HTST pasteurization experiments were performed on colostrum experimentally inoculated with M. paratuberculosis. After culture of the pasteurized milk samples, no viable M. paratuberculosis, Salmonella, or Mycoplasma were recovered, regardless of species, strain, or isolate. Pasteurization of colostrum was also effective in the destruction of M. paratuberculosis but resulted in an average 25% reduction in colostral immunoglobulin. These results suggest that HTST pasteurization is effective in generating a safer product to feed to young calves.
Grant, I R; Ball, H J; Neill, S D; Rowe, M T
The thermal inactivation of 11 strains of Mycobacterium paratuberculosis at pasteurization temperatures was investigated. Cows' milk inoculated with M. paratuberculosis at two levels (10(7) and 10(4) CFU/ml) was pasteurized in the laboratory by (i) a standard holder method (63.5 degrees C for 30 min) and (ii) a high-temperature, short-time (HTST) method (71.7 degrees C for 15 s). Additional heating times of 5, 10, 15, 20, and 40 min at 63.5 degrees C were included to enable the construction of a thermal death curve for the organism. Viability after pasteurization was assessed by culture on Herrold's egg yolk medium containing mycobactin J (HEYM) and in BACTEC Middlebrook 12B radiometric medium supplemented with mycobactin J and sterile egg yolk emulsion. Confirmation of acid-fast survivors of pasteurization as viable M. paratuberculosis cells was achieved by subculture on HEYM to indicate viability coupled with PCR using M. paratuberculosis-specific 1S900 primers. When milk was initially inoculated with 10(6) to 10(7) CFU of M. paratuberculosis per ml, M. paratuberculosis cells were isolated from 27 of 28 (96%) and 29 of 34 (85%) pasteurized milk samples heat treated by the holder and HTST methods, respectively. Correspondingly, when 10(3) to 10(4) CFU of M. paratuberculosis per ml of milk were present before heat treatment, M. paratuberculosis cells were isolated from 14 of 28 (50%) and 19 of 33 (58%) pasteurized milk samples heat treated by the holder and HTST methods, respectively. The thermal death curve for M. paratuberculosis was concave in shape, exhibiting a rapid initial death rate followed by significant "tailing." Results indicate that when large numbers of M. paratuberculosis cells are present in milk, the organism may not be completely inactivated by heat treatments simulating holder and HTST pasteurization under laboratory conditions. PMID:8593064
Ronald J. Erskine
Full Text Available Enzootic bovine leukosis is a contagious disease of cattle caused by the retrovirus, bovine leukemia virus (BLV and is the most common cause of malignant neoplasm in cattle. In order to facilitate surveillance of this disease in dairy herds, we developed a method to combine ELISA of milk collected during routine production testing with a prescribed sampling of cows that is independent of the proportion of cows within each lactation. In 113 Michigan dairy herds, milk samples from ten cows in each of the 1st, 2nd, 3rd, and ≥4th lactations were analyzed for anti-Bovine Leukemia Virus (BLV antibodies by milk ELISA. For each herd, a BLV herd profile (BHP was calculated as the simple average of the percent of BLV-positive cows within each of the four lactation groups. The mean BHP for all herds was 32.8%, with means of 18.5, 28.8, 39.2, and 44.8% of 1st, 2nd, 3rd, and ≥4th lactation animals infected, respectively. In eight herds, we determined the correlation between the BHP, and true herd prevalence by testing the entire lactating herd (r=0.988, P<0.0001. The BHP allows discrimination of lactation-specific BLV prevalence within a dairy herd, to help identify risk factors and management plans that may be important in transmission of BLV.
Hoorfar, Jeffrey; Wedderkopp, A.
We investigated the ability of an antibody-specific, O antigen-based ELISA to document Salmonella typhimurium herd infections by screening of milk samples. Three cattle populations, 20 herds with no history of salmonellosis, 8 herds with history of S typhimurium epsiodes within the previous 7...... months, and 220 herds of unknown disease status, were tested. A herd was considered ELISA positive if at least 5% of the cows had OD values > 0.3. Among the 20 herds without history of salmonellosis, only 2 herds were ELISA positive, whereas all 8 herds with a known history of salmonellosis were ELISA...... positive (herd specificity, 0.9 and herd sensitivity, 1.0). A sig nificant correlation (P history of salmonellosis. It was concluded that ELISA testing of individual milk sam ples can be used for surveillance...
Lyashchenko, Konstantin P; Greenwald, Rena; Esfandiari, Javan; O'Brien, Daniel J; Schmitt, Stephen M; Palmer, Mitchell V; Waters, W Ray
Bovine tuberculosis (TB) in cervids remains a significant problem affecting farmed herds and wild populations. Traditional skin testing has serious limitations in certain species, whereas emerging serological assays showed promising diagnostic performance. The recently developed immunochromatographic dual-path platform (DPP) VetTB assay has two antigen bands, T1 (MPB83 protein) and T2 (CFP10/ESAT-6 fusion protein), for antibody detection. We evaluated the diagnostic accuracy of this test by using serum samples collected from groups of white-tailed deer experimentally inoculated with Mycobacterium bovis, M. avium subsp. paratuberculosis, or M. bovis BCG Pasteur. In addition, we used serum samples from farmed white-tailed deer in herds with no history of TB, as well as from free-ranging white-tailed deer culled during field surveillance studies performed in Michigan known to have bovine TB in the wild deer population. The DPP VetTB assay detected antibody responses in 58.1% of experimentally infected animals within 8 to 16 weeks postinoculation and in 71.9% of naturally infected deer, resulting in an estimated test sensitivity of 65.1% and a specificity of 97.8%. The higher seroreactivity found in deer with naturally acquired M. bovis infection was associated with an increased frequency of antibody responses to the ESAT-6 and CFP10 proteins, resulting in a greater contribution of these antigens, in addition to MPB83, to the detection of seropositive animals, compared with experimental M. bovis infection. Deer experimentally inoculated with either M. avium subsp. paratuberculosis or M. bovis BCG Pasteur did not produce cross-reactive antibodies that could be detected by the DPP VetTB assay. The present findings demonstrate the relatively high diagnostic accuracy of the DPP VetTB test for white-tailed deer, especially in the detection of naturally infected animals.
Marsot, Maud; Béral, Marina; Scoizec, Axelle; Mathevon, Yoann; Durand, Benoit; Courcoul, Aurélie
Although officially free of bovine tuberculosis (bTB), France has been experiencing a slight increase in the incidence and geographical spread of the infection. Eradication of bTB requires determining the infection risk factors. Although several studies identifying bTB risk factors have been conducted in the United Kingdom and Spain, no information is currently available regarding bTB risk factors in French cattle. The objective of this work was thus to study the factors associated with the risk of bTB in cattle herds in three French administrative divisions (départements of Ardennes, Côte d'Or and Dordogne). A case-control study was conducted to compare herds having experienced a bTB outbreak between 2012 and early 2014 with randomly selected control herds of the three study départements. A questionnaire of farming practices, inter-herd contacts (e.g. at pasture or via vehicles or materials), and the presence of other domestic species was carried out in the selected herds. Data on other variables of interest included animal movements between farms and potential contacts between cattle and wildlife (e.g. badger and wild boar abundances) were also collected. Multivariable logistic regression and multimodel inference methods were used to assess risk factors related to bTB. A total of 216 herds (72 cases and 144 controls) were analyzed. The two main risk factors were the presence of a recent neighboring outbreak, being defined as a neighboring herd at pasture reported as infected in the past two years (odds ratio (OR)=3.6; population attributable fraction (PAF)=30.7%) and the presence of a farm building for cattle housing or for feed storage located at more than 300-m from inhabited areas (OR=2.3; PAF=27.6%). Another risk factor was related to sharing water points at pasture with a recent neighboring outbreak. Results illustrated the multifactorial nature of bTB dynamics. The risk factors related to recently infected neighboring herds could be attributable to
Hoorfar, Jeffrey; Bitsch, V.
A total of 2585 serum samples from 62 dairy herds located in four different regions of Denmark were tested in an O-antigen (0:1,4,5,12)-based ELISA for the detection of antibodies against Salmonella typhimurium. Ten closed herds from an island with no reported occurrence of salmonellosis for seve......A total of 2585 serum samples from 62 dairy herds located in four different regions of Denmark were tested in an O-antigen (0:1,4,5,12)-based ELISA for the detection of antibodies against Salmonella typhimurium. Ten closed herds from an island with no reported occurrence of salmonellosis...... for several years, and 12 herds from a salmonella enzootic area which had had clinical outbreaks of S typhimurium were used to define a herd ELISA cut-off value. When herds with at least 5 per cent of the serum samples having an optical density of >0.5 were considered ELISA-positive, all 10 herds from...... the salmonellosis-free island were ELISA-negative, and all but one of the 12 S typhimurium-infected herds were ELISA-positive, which resulted in a herd test sensitivity of 0.92 and herd test specificity of 1.0. Eleven of the 12 S typhimurium-infected herds were negative in a blocking ELISA based on a monoclonal...
Rhind Susan M
Full Text Available Abstract Background Johne's disease is a chronic inflammatory disease of the gut caused by infection with Mycobacterium avium subspecies paratuberculosis (MAP. Symptoms include wasting, diarrhoea, loss of condition and eventual death. Three forms of Johne's disease have been described in sheep – paucibacillary, multibacillary and asymptomatic. The paucibacillary form is characterized by an inflammatory, Th1-type immune response. The multibacillary form of the disease, which disseminates the infection, is characterized by macrophage infiltration mediated by a Th2-type immune response, and asymptomatic animals have no clinical symptoms or pathology but are infected with MAP. What determines these three forms of the disease is unknown. To further understand these differences, we used real-time RT-PCR to compare the expression of thirteen cytokine and cytokine-related genes in ileal tissue from sheep with the three forms of the disease. Results Three pathological forms of sheep paratuberculosis were defined on the basis of histopathology, cytochemistry (Zeihl-Neelsen and IS900 PCR. Paucibacillary lesions have largely T cell and eosinophil infiltration and are ZN negative; multibacillary lesions have macrophage infiltration and large numbers of acid-fast bacteria. The pauci- and multibacillary forms are linked to the differential expression of IFNγ and IL-10 respectively. In addition the increased levels of the proinflammatory cytokines (IL-1β and TNFα, IL-8, IL-18 and TRAF-1 in both diseased forms is indicative of persistent inflammatory lesions. No changes were seen in IL-1α in any sheep ileum tissues. Asymptomatic animals are IS900+ with normal histology but have significantly decreased levels of IL-18 and increased levels TNFα. Conclusion We have quantified the expression levels of thirteen cytokine and cytokine related genes in three forms of ovine paratuberculosis using real-time PCR analyses and confirm that sheep pauci- and
Rugbjerg, Helene; Nielsen, Eva Møller; Andersen, Jens Strodl
A risk-factor study was performed in eight dairy herds found to excrete verocytotoxin-producing Escherichia coli (VTEC) O157 in a former prevalence study. Associations between excretion of VTEC O157 and management factors such as housing and feeding were analysed in a generalised linear mixed mod...... days with the mother after calving. Calves aged 5-24 months that had been moved within the last 2 weeks had a higher risk, but risk was reduced if fed barley silage. Cows fed grain or molasses had a higher risk of excreting VTEC O157....
Prkno, Almut; Hoffmann, Donata; Goerigk, Daniela; Kaiser, Matthias; van Maanen, Anne Catherine Franscisca; Jeske, Kathrin; Jenckel, Maria; Pfaff, Florian; Vahlenkamp, Thomas W.; Beer, Martin; Ulrich, Rainer G.; Starke, Alexander; Pfeffer, Martin
Four cowpox virus (CPXV) outbreaks occurred in unrelated alpaca herds in Eastern Germany during 2012–2017. All incidents were initially noticed due to severe, generalized, and finally lethal CPXV infections, which were confirmed by testing of tissue and serum samples. As CPXV-infection has been described in South American camelids (SACs) only three times, all four herds were investigated to gain a deeper understanding of CPXV epidemiology in alpacas. The different herds were investigated twic...
Ramon A. Juste
Full Text Available Control of major mycobacterial diseases affecting livestock is a challenging issue that requires different approaches. The use of genetic markers for improving resistance to Mycobacterium avium subsp. paratuberculosis infection in cattle has been explored as a promising population strategy We performed paratuberculosis epidemiopathogenic phenotypic and genotypic characterization involving 24 SNPs in six candidate genes (NOD2, CD209, SLC11A1, SP110, TLR2 and TLR4 on 502 slaughtered Friesian cows. In the current study, we investigate whether recently proposed paratuberculosis (PTB epidemiopathogenic (EP forms (apparently free-AF, latent-LAT and patent-PAT could be associated with some combination of these 24 SNPs. Best EP form grouping was obtained using a combination of 5 SNPs in four genes (CD209: rs210748127; SLC11A1: rs110090506; SP110: rs136859213 and rs110480812; and TLR2: rs41830058. These groups were defined according to the level of infection progression risk to patent epidemiopathogenic forms and showed the following distributions: LOWIN (low with 39 (8% cases (94.9% AF/5.1% LAT/0% PAT; LATIN (low with 17 (3% cases (5.9% AF/94.1% LAT/0% PAT; AVERIN (average with 413 (82% cases (52.1% AF/38.5% LAT/9.4% PAT and PATIN (patent with 33 (7% cases (36.4% AF/24.2% LAT/39.4% PAT. Age of slaughter was significantly higher for LATIN (88.3 months compared to AVERIN (65.3 months; p = 0.0007 and PATIN (59.1 months; p = 0.0004, and for LOWIN (73.9 months compared to PATIN (p = 0.0233, and nearly significant compared to AVERIN (p = 0.0572 These results suggest that some selected genetic polymorphisms have a potential use as markers of PTB EP forms and thus add a new tool for the control of this widespread infection.
Full Text Available Mycobacterium avium subspecies paratuberculosis is a bacterial parasite and the causative agent of paratuberculosis, a disease predominately found in cattle and sheep. Infection with this microorganism results in substantial farming economic losses and animal morbidity. The link between infection with this pathogen and human disease has been theorised for many years with Crohn’s disease being one of many suspected resultant conditions. Mycobacterium avium may be spread from animal to human hosts by water and foodborne transmission routes, where the foodborne route of exposure represents a significant risk for susceptible populations, namely children and the immune-compromised. Following colonisation of the host, the parasitic organism evades the host immune system by use of molecular mimicry, displaying peptide sequences similar to that of the host cells causing a disruption of self-verses non self-recognition. Theoretically, this failure to recognise the invading organism as distinct from host cells may result in numerous autoimmune conditions. Here, the author presents current information assessing the link between numerous diseases states in humans such inflammatory bowel disease, Type 1 diabetes, rheumatoid arthritis, Hashimoto\\'s thyroiditis, multiple sclerosis and autism following infection with Mycobacterium avium paratuberculosis. The possibility of zoonotic transmission of the organism and its significant risk to public health safety as a consequence is also discussed.
Langley, David J.; Tan, Chee-Wee; Worm, Daniël
The online environment offers a fertile breeding ground for anti-brand herds of disgruntled consumers. Firms are often caught off guard by the unpredictability of such herds and, as a consequence, are forced into a reactive, defensive stance. We conduct a social media analysis that aims to shed...... light on the formation, growth, and dissolution of online anti-brand herds. First we expand on the concept of environmental turbulence to advance core properties unique to online herd behavior. Next, based on evidence gathered from 40 online anti-brand herd episodes targeting two prominent firms from...... the Netherlands, we develop an analytical model to investigate drivers of herd formation, growth, and dissolution. Finally, combining environmental turbulence literature with our empirical findings, we derive a novel typology of online anti-brand herd behaviors, and put forward six propositions to guide theory...
Full Text Available Samples from intestines, liver, and lymph nodes were collected from a dairy steer with clinical suspicion of paratuberculosis. The samples were processed for histologic examination with hematoxylin-eosin and Zihel-Neelsen (ZN staining for the detection of acid-fast bacilli (AFB, and submitted to immunohistochemistry (IHC. Macroscopic changes were observed in the small intestines, with thickening and corrugation of the mucosa. The main microscopic changes were found in small intestines, lymph vessels in the mesentery, and mesenteric lymph nodes characterized by enteritis, lymphangiectasia, and lymphadenitis. Liver presented with granulomatous hepatitis, an uncommon histopathological feature for paratuberculosis. The clinical features associated with positive culture of Mycobacterium avium subsp. paratuberculosis and detection of AFB by ZN and IHC in the cytoplasm of macrophages (epithelioid in the intestinal mucosa and submucosa, lymph nodes, and liver were important to confirm the diagnosis of paratuberculosis.
Fablet, C; Rose, N; Grasland, B; Robert, N; Lewandowski, E; Gosselin, M
Growing and finishing performances of pigs strongly influence farm efficiency and profitability. The performances of the pigs rely on the herd health status and also on several non-infectious factors. Many recommendations for the improvement of the technical performances of a herd are based on the results of studies assessing the effect of one or a limited number of infections or environmental factors. Few studies investigated jointly the influence of both type of factors on swine herd performances. This work aimed at identifying infectious and non-infectious factors associated with the growing and finishing performances of 41 French swine herds. Two groups of herds were identified using a clustering analysis: a cluster of 24 herds with the highest technical performance values (mean average daily gain = 781.1 g/day +/- 26.3; mean feed conversion ratio = 2.5 kg/kg +/- 0.1; mean mortality rate = 4.1% +/- 0.9; and mean carcass slaughter weight = 121.2 kg +/- 5.2) and a cluster of 17 herds with the lowest performance values (mean average daily gain =715.8 g/day +/- 26.5; mean feed conversion ratio = 2.6 kg/kg +/- 0.1; mean mortality rate = 6.8% +/- 2.0; and mean carcass slaughter weight = 117.7 kg +/- 3.6). Multiple correspondence analysis was used to identify factors associated with the level of technical performance. Infection with the porcine reproductive and respiratory syndrome virus and the porcine circovirus type 2 were infectious factors associated with the cluster having the lowest performance values. This cluster also featured farrow-to-finish type herds, a short interval between successive batches of pigs (≤3 weeks) and mixing of pigs from different batches in the growing or/and finishing steps. Inconsistency between nursery and fattening building management was another factor associated with the low-performance cluster. The odds of a herd showing low growing-finishing performance was significantly
de Kruijf, Marcel; Lesniak, Olga N; Yearsley, Dermot; Ramovic, Elvira; Coffey, Aidan; O'Mahony, Jim
Mycobacterial interspersed repetitive unit and variable number tandem repeat (MIRU-VNTR) has been developed as a simple, rapid and cost efficient molecular typing method to differentiate Mycobacterium avium subspecies paratuberculosis (MAP) isolates. The aim of this study was to determine the genomic diversity of MAP across the Republic of Ireland by utilising the MIRU-VNTR typing method on a large collection of MAP isolates. A total of 114 MAP isolates originated from 53 herds across 19 counties in the Republic of Ireland were genotyped based on eight established MIRU-VNTR loci. Four INMV groups were observed during this study. INMV 1 was found in 67 MAP isolates (58.8%) and INMV 2 was observed in 45 isolates (39.4%). INMV 3 and INMV 116 recorded only one isolate each (0.9%). The unique INMV 116 group has never been reported among herds thus far and the molecular pattern of the MAP isolate classified in INMV 116 showed a difference at the MIRU-VNTR X3 locus compared to the other three INMV groups observed. INMV 1, INMV 2 and INMV 3 are observed frequently in Europe and comprised 99.1% of the total MAP isolates characterised in this study, indicating that MAP exhibited low level of genetic diversity across the Republic of Ireland using the MIRU-VNTR method. By the implementation of SNP analysis or MLSSR as an additional typing method, MAP genetic diversity would increase. INMV 3 is unique to Ireland and whereas INMV 116 has never been previously reported among herds by MIRU-VNTR typing. Copyright © 2017 Elsevier B.V. All rights reserved.
Vlkova, H; Babak, V; Vrtkova, I; Cervinkova, D; Marosevic, D; Moravkova, M; Jaglic, Z
The aim of the present work was to examine a dairy herd with an anamnesis of recurrent clinical mastitis and decreased milk production. A total of 239 individual cow milk samples originating from asymptomatic cows were collected at four-month intervals and examined mainly for the presence of Staphylococcus aureus and mastitis streptococci using standard cultivation methods. In total, 29.7% and 9.2% samples were positive for S. aureus and mastitis streptococci, respectively. Unlike for mastitis streptococci, the prevalence of animals positive for S. aureus had an increasing trend (pmastitis, reproductive and periparturient disorders and administration of antibiotics. In contrast to S. aureus, the occurrence of mastitis streptococci in milk was linked with previous cases of clinical mastitis and intramammary administration of antibiotics.
Gavin, William G; Porter, Catherine A; Hawkins, Nathan; Schofield, Michael J; Pollock, John M
This retrospective analysis and report describes the successful eradication and posteradication surveillance programme for Johne's disease ( Mycobacterium avium subspecies paratuberculosis (MAP)) in a closed herd of dairy goats. In 1994, MAP's presence in the goat herd was first suspected through individual annual serological screening and then subsequently confirmed through faecal culture and histopathology in 1997 when implementation of a more aggressive programme of testing and eradication of the diseased animals began. This programme included frequent serological screening of all adult goats using ELISA and agar gel immunodiffusion assays. Faecal cultures for bacteria were performed on suspect or positive animals and for all goats found dead or euthanased, and tissues were submitted for histopathology and acid-fast staining. Additional disease eradication measures included maintaining a closed herd and minimising faecal-oral transmission of MAP. Following a more aggressive testing regimen and euthanasia of goats with positive faecal culture, the herd was first considered free of MAP in 2003 and has remained free to the present day. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Calvo Artavia, Francisco Fernando; Nielsen, Liza Rosenbaum; Dahl, J.
than in countries with few lightly infected cases per year. The aim of the present case-control study was to quantify associations between potential herd-level risk factors and BC in Danish cattle herds. Risk factors can be used in the design of a risk-based meat inspection system targeted towards...... a questionnaire and register data from the Danish Cattle Database were grouped into meaningful variables and used to investigate the risk factors for BC using a multivariable logistic regression model. Case herds were almost three times more likely than control herds to let all or most animals out grazing. Case...... the animals with the highest risk of BC. Cases (n = 77) included herds that hosted at least one animal diagnosed with BC at meat inspection, from 2006 to 2010. Control herds (n = 231) consisted of randomly selected herds that had not hosted any animals diagnosed with BC between 2004 and 2010. The answers from...
Full Text Available Mycobacterium avium subspecies paratuberculosis (M. ap, the causative agent of Johne’s disease (JD, infects many farmed ruminants, wildlife animals and humans. To better understand the molecular pathogenesis of these infections, we analyzed the whole genome sequences of several M. ap and M. avium subspecies avium (M. avium strains isolated from various hosts and environments. Using Next-generation sequencing technology, all 6 M. ap isolates showed a high percentage of homology (98% to the reference genome sequence of M. ap K-10 isolated from cattle. However, 2 M. avium isolates (DT 78 and Env 77 showed significant sequence diversity from the reference strain M. avium 104. The genomes of M. avium isolates DT 78 and Env 77 exhibited only 87% and 40% homology, respectively, to the M. avium 104 reference genome. Within the M. ap isolates, genomic rearrangements (insertions/deletions, Indels were not detected, and only unique single nucleotide polymorphisms (SNPs were observed among the 6 M. ap strains. While most of the SNPs (~100 in M. ap genomes were non-synonymous, a total of ~ 6000 SNPs were detected among M. avium genomes, most of them were synonymous suggesting a differential selective pressure between M. ap and M. avium isolates. In addition, SNPs-based phylo-genomic analysis showed that isolates from goat and Oryx are closely related to the cattle (K-10 strain while the human isolate (M. ap 4B is closely related to the environmental strains, indicating environmental source to human infections. Overall, SNPs were the most common variations among M. ap isolates while SNPs in addition to Indels were prevalent among M. avium isolates. Genomic variations will be useful in designing host-specific markers for the analysis of mycobacterial evolution and for developing novel diagnostics directed against Johne’s disease in animals.
Toft, Nils; Nielsen, Søren Saxmose; Jørgensen, Erik
We devised a general method for interpretation of multistage diseases using continuous-data diagnostic tests. As an example, we used paratuberculosis as a multistage infection with 2 stages of infection as well as a noninfected state. Using data from a Danish research project, a fecal culture...... testing scheme was linked to an indirect ELISA and adjusted for covariates (parity, age at first calving, and days in milk). We used the log-transformed optical densities in a Bayesian network to obtain the probabilities for each of the 3 infection stages for a given optical density (adjusted...... for covariates). The strength of this approach was that the uncertainty associated with a test was imposed directly on the individual test result rather than aggregated into the population-based measures of test properties (i.e., sensitivity and specificity)...
Yamasaki, Elise M.; Brito, Marilene F.; Mota, Rinaldo A.; McIntosh, Douglas; Tokarnia, Carlos H.
A paratuberculose ou doença de Johne é uma enterite granulomatosa causada por Mycobacterium avium subsp. paratuberculosis (Map) e comumente afeta ruminantes domésticos, no entanto, pode infectar várias espécies de mamíferos. Está presente nos cinco continentes e é considerada endêmica em algumas regiões pela Organização Internacional de Epizootias (OIE). Pertence à lista de enfermidades notificáveis, que compreende as doenças transmissíveis de importância sócio-econômica e/ou em saúde-pública...
Ruf, Sebastian F.
The problem of controlling complex networks is of interest to disciplines ranging from biology to swarm robotics. However, controllability can be too strict a condition, failing to capture a range of desirable behaviors. Herdability, which describes the ability to drive a system to a specific set in the state space, was recently introduced as an alternative network control notion. This paper considers the application of herdability to the study of complex networks. The herdability of a class of networked systems is investigated and two problems related to ensuring system herdability are explored. The first is the input addition problem, which investigates which nodes in a network should receive inputs to ensure that the system is herdable. The second is a related problem of selecting the best single node from which to herd the network, in the case that a single node is guaranteed to make the system is herdable. In order to select the best herding node, a novel control energy based herdability centrality measure is introduced.
Rowe Michael T
Full Text Available Abstract Background Interactions between Mycobacterium avium subsp. paratuberculosis (Map and free-living protozoa in water are likely to occur in nature. The potential impact of ingestion of Map by two naturally occurring Acanthamoeba spp. on this pathogen's survival and chlorine resistance was investigated. Results Between 4.6 and 9.1% of spiked populations of three Map strains (NCTC 8578, B2 and ATCC 19698, which had been added at a multiplicity of infection of 10:1, were ingested by Acanthamoeba castellanii CCAP 1501/1B and A. polyphaga CCAP 1501/3B during co-culture for 3 h at 25°C. Map cells were observed to be present within the vacuoles of the amoebae by acid-fast staining. During extended co-culture of Map NCTC 8578 at 25°C for 24 d with both A. castellanii and A. polyphaga Map numbers did not change significantly during the first 7 days of incubation, however a 1–1.5 log10 increase in Map numbers was observed between days 7 and 24 within both Acanthamoeba spp. Ingested Map cells were shown to be more resistant to chlorine inactivation than free Map. Exposure to 2 μg/ml chlorine for 30 min resulted in a log10 reduction of 0.94 in ingested Map but a log10 reduction of 1.73 in free Map (p Conclusion This study demonstrated that ingestion of Map by and survival and multiplication of Map within Acanthamoeba spp. is possible, and that Map cells ingested by amoebae are more resistant to inactivation by chlorine than free Map cells. These findings have implications with respect to the efficacy of chlorination applied to Map infected surface waters.
Slana, I.; Pribylova, R.; Kralova, A.; Pavlik, I.
In this study, products from all steps of anaerobic digestion at a farm-scale biogas plant supplied with manure from paratuberculosis-affected dairy cattle were examined and quantified for the presence of the causal agent of paratuberculosis, Mycobacterium avium subsp. paratuberculosis, using culture and quantitative real-time PCR (qPCR). Viable M. avium subsp. paratuberculosis cells were detected using culture in fermentors for up to 2 months; the presence of M. avium subsp. paratuberculosis DNA (101 cells/g) was demonstrated in all anaerobic fermentors and digestate 16 months after initiation of work at a biogas plant, using IS900 qPCR. F57 qPCR was able to detect M. avium subsp. paratuberculosis DNA (102 cells/g) at up to 12 months. According to these results, a fermentation process that extended beyond 2 months removed all viable M. avium subsp. paratuberculosis cells and therefore rendered its product M. avium subsp. paratuberculosis free. However, M. avium subsp. paratuberculosis DNA was found during all the examined periods (more than 1 year), which could be explained by either residual DNA being released from dead cells or by the presence of viable cells whose amount was under the limit of cultivability. As the latter hypothesis cannot be excluded, the safety of the final products of digestion used for fertilization or animal bedding cannot be defined, and further investigation is necessary to confirm or refute this risk. PMID:21398476
Marchandeau, Stéphane; Pontier, Dominique; Guitton, Jean-Sébastien; Letty, Jérôme; Fouchet, David; Aubineau, Jacky; Berger, Francis; Léonard, Yves; Roobrouck, Alain; Gelfi, Jacqueline; Peralta, Brigitte; Bertagnoli, Stéphane
The role of maternal antibodies is to protect newborns against acute early infection by pathogens. This can be achieved either by preventing any infection or by allowing attenuated infections associated with activation of the immune system, the two strategies being based on different cost/benefit ratios. We carried out an epidemiological survey of myxomatosis, which is a highly lethal infectious disease, in two distant wild populations of rabbits to describe the epidemiological pattern of the disease. Detection of specific IgM and IgG enabled us to describe the pattern of immunity. We show that maternal immunity attenuates early infection of juveniles and enables activation of their immune system. This mechanism associated with steady circulation of the myxoma virus in both populations, which induces frequent reinfections of immune rabbits, leads to the maintenance of high immunity levels within populations. Thus, myxomatosis has a low impact, with most infections being asymptomatic. This work shows that infection of young rabbits protected by maternal antibodies induces attenuated disease and activates their immune system. This may play a major role in reducing the impact of a highly lethal disease when ecological conditions enable permanent circulation of the pathogen.
Nickell, Jason S; White, Brad J; Larson, Robert L; Renter, David G; Sanderson, Mike W
Although numerous diagnostic tests are available to identify cattle persistently infected (PI) with Bovine viral diarrhea virus (BVDV) in cow-calf herds, data are sparse when evaluating the economic viability of individual tests or diagnostic strategies. Multiple factors influence BVDV testing in determining if testing should be performed and which strategy to use. A stochastic model was constructed to estimate the value of implementing various whole-herd BVDV cow-calf testing protocols. Three common BVDV tests (immunohistochemistry, antigen-capture enzyme-linked immunosorbent assay, and polymerase chain reaction) performed on skin tissue were evaluated as single- or two-test strategies. The estimated testing value was calculated for each strategy at 3 herd sizes that reflect typical farm sizes in the United States (50, 100, and 500 cows) and 3 probabilities of BVDV-positive herd status (0.077, 0.19, 0.47) based upon the literature. The economic value of testing was the difference in estimated gross revenue between simulated cow-calf herds that either did or did not apply the specific testing strategy. Beneficial economic outcomes were more frequently observed when the probability of a herd being BVDV positive was 0.47. Although the relative value ranking of many testing strategies varied by each scenario, the two-test strategy composed of immunohistochemistry had the highest estimated value in all but one herd size-herd prevalence permutation. These data indicate that the estimated value of applying BVDV whole-herd testing strategies is influenced by the selected strategy, herd size, and the probability of herd BVDV-positive status; therefore, these factors should be considered when designing optimum testing strategies for cow-calf herds.
paratuberculosis provide only partial protection and interfere with diagnostic tests for JD and surveillance for bovine TB. In contrast, recombinant subunit vaccines can be designed to be used without compromising control of bTB and Map. Taking advantage of data from mouse TB studies, and early Map vaccination...... in macrophages. The disease progression is very slow with neonatal animals being the most susceptible to infection, but without development of detectable IFN-γ responses for months after infection and rarely with clinical disease before the second or third year of life. Available whole cell vaccines against......- and field-studies we developed a vaccine with a single recombinant fusion protein comprising four acute-stage antigens (Ags) and one latent-stage Ag formulated in adjuvant (FET-vaccine). In post-exposure vaccination of calves and goats with necropsy 8-12 months post inoculation, we determined...
Full Text Available To establish infection, pathogens secrete virulence factors, such as protein kinases and phosphatases, to modulate the signal transduction pathways used by host cells to initiate immune response. The protein MAP3893c is annotated in the genome sequence of Mycobacterium avium subspecies paratuberculosis (MAP, the causative agent of Johne’s disease, as the serine/threonine protein kinase G (PknG. In this work, we report that PknG is a functional kinase that is secreted within macrophages at early stages of infection. The antigen is able to induce an immune response from cattle exposed to MAP in the form of interferon gamma production after stimulation of whole blood with PknG. These findings suggest that PknG may contribute to the pathogenesis of MAP by phosphorylating macrophage signalling and/or adaptor molecules as observed with other pathogenic mycobacterial species.
Jolly, Ana; Colavecchia, Silvia Beatriz; Fernández, Bárbara; Fernández, Eloy; Mundo, Silvia Leonor
Lipoarabinomannan (LAM) is a major glycolipidic antigen on the mycobacterial envelope. The aim of this study was to characterize the humoral immune response induced by immunization with a LAM extract in bovines and to evaluate the role of the generated antibodies in the in vitro infection of macrophages with Mycobacterium avium subsp. paratuberculosis (MAP). Sera from fourteen calves immunized with LAM extract or PBS emulsified in Freund's Incomplete Adjuvant and from five paratuberculosis-infected bovines were studied. LAM-immunized calves developed specific antibodies with IgG1 as the predominant isotype. Serum immunoglobulins were isolated and their effect was examined in MAP ingestion and viability assays using a bovine macrophage cell line. Our results show that the antibodies generated by LAM immunization significantly increase MAP ingestion and reduce its intracellular viability, suggesting an active role in this model.
Donat, K; Erhardt, G; Soschinka, A; Brandt, H R
Using well established metabolic parameters, this study aimed to substantiate differences in protein and energy metabolism between Mycobacterium avium subspecies paratuberculosis (MAP) positive and negative dairy cows tested by faecal culture. A total of 227 MAP-positive and 239 MAP-negative German Holstein cows kept in 13 MAP-positive dairy herds were selected for metabolic testing. The serum concentrations of total protein (TP), bilirubin, cholesterol and betahydroxybutyrate were measured as well as the activities of Glutamate-Dehydrogenase (GLDH) and Aspartate-Aminotransferase. MAP-positive cows were characterised by a decreased mean TP (66.5 g/l) compared to the MAP-negative controls (73.2 g/l). Mean log10 GLDH activities tended to be higher in MAP-positive than MAP-negative cows. Concerning TP, there was a significant interaction between MAP status and farm. Within four farms, the difference between MAP-positive and MAP-negative animals differed significantly, while in the other farms this difference was not significant. It is concluded that a decreased TP and an increased GLDH indicate alterations in protein metabolism. These findings suggest an enhanced liver cell turnover in MAP-positive cows. The results contribute to an understanding of the metabolic alterations in MAP-positive dairy cows.
Stege, H.; Christensen, J.; Nielsen, J.P.
seroprevalence. This resulted in a hybrid case-"control" design of the study and therefore, five different methods of categorising the data were used to ensure that variables were not wrongfully excluded as a result of using an improper design. Our questionnaire focused on management, infection...
de Castro Alessandra MMG
Full Text Available Abstract Background Porcine circovirus type 2 (PCV2 has been associated with several disease complexes, including reproductive failure. The aim of this study was to identify the subtypes of PCV2 that are associated with reproductive failure in pigs from the State of São Paulo, Brazil and to investigate co-infections with other infectious organisms. Findings Samples of 168 aborted foetuses or mummified foetuses from five farrow-to-finish swine farms known to be infected with PCV2 and located in the State of São Paulo were tested for PCV2 by polymerase chain reaction (PCR. Positive samples were additionally tested for porcine parvovirus (PPV, Leptospira spp. and Brucella spp. by PCR. PCV2 was detected in 18 of the samples (10.7%. PPV, Brucella spp. and Leptospira spp were found in 2, 10 and 0 cases, respectively. Eleven PCV2 strains were sequenced and determined to be either genotype 2a (n = 1 or 2b (n = 10. Conclusions The findings indicate that the frequency of PCV2 infections in aborted porcine foetuses from the State of São Paulo is rather low (10.7% and that co-infection with other pathogens is common and may be involved in PCV2 associated reproductive failure. No repeatable, characteristic amino acid motifs for regions of the PCV2 capsid protein seemed to be associated with abortion in sows.
Klausen, Joan; Andresen, Lars Ole; Barfod, Kristen
An indirect enzyme-linked immunoassay for serological surveillance of infection of pigs with Actinobacillus pleuropneumoniae (Ap) serotype 5 was developed. The antigen used was prepared from Ap serotype 5b strain L20. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis...
Full Text Available Four cowpox virus (CPXV outbreaks occurred in unrelated alpaca herds in Eastern Germany during 2012–2017. All incidents were initially noticed due to severe, generalized, and finally lethal CPXV infections, which were confirmed by testing of tissue and serum samples. As CPXV-infection has been described in South American camelids (SACs only three times, all four herds were investigated to gain a deeper understanding of CPXV epidemiology in alpacas. The different herds were investigated twice, and various samples (serum, swab samples, and crusts of suspicious pox lesions, feces were taken to identify additionally infected animals. Serum was used to detect CPXV-specific antibodies by performing an indirect immunofluorescence assay (iIFA; swab samples, crusts, and feces were used for detection of CPXV-specific DNA in a real-time PCR. In total, 28 out of 107 animals could be identified as affected by CPXV, by iIFA and/or PCR. Herd seroprevalence ranged from 16.1% to 81.2%. To investigate the potential source of infection, wild small mammals were trapped around all alpaca herds. In two herds, CPXV-specific antibodies were found in the local rodent population. In the third herd, CPXV could be isolated from a common vole (Microtus arvalis found drowned in a water bucket used to water the alpacas. Full genome sequencing and comparison with the genome of a CPXV from an alpaca from the same herd reveal 99.997% identity, providing further evidence that the common vole is a reservoir host and infection source of CPXV. Only in the remaining fourth herd, none of the trapped rodents were found to be CPXV-infected. Rodents, as ubiquitous reservoir hosts, in combination with increasingly popular alpacas, as susceptible species, suggest an enhanced risk of future zoonotic infections.
Prkno, Almut; Hoffmann, Donata; Goerigk, Daniela; Kaiser, Matthias; van Maanen, Anne Catherine Franscisca; Jeske, Kathrin; Jenckel, Maria; Pfaff, Florian; Vahlenkamp, Thomas W; Beer, Martin; Ulrich, Rainer G; Starke, Alexander; Pfeffer, Martin
Four cowpox virus (CPXV) outbreaks occurred in unrelated alpaca herds in Eastern Germany during 2012-2017. All incidents were initially noticed due to severe, generalized, and finally lethal CPXV infections, which were confirmed by testing of tissue and serum samples. As CPXV-infection has been described in South American camelids (SACs) only three times, all four herds were investigated to gain a deeper understanding of CPXV epidemiology in alpacas. The different herds were investigated twice, and various samples (serum, swab samples, and crusts of suspicious pox lesions, feces) were taken to identify additionally infected animals. Serum was used to detect CPXV-specific antibodies by performing an indirect immunofluorescence assay (iIFA); swab samples, crusts, and feces were used for detection of CPXV-specific DNA in a real-time PCR. In total, 28 out of 107 animals could be identified as affected by CPXV, by iIFA and/or PCR. Herd seroprevalence ranged from 16.1% to 81.2%. To investigate the potential source of infection, wild small mammals were trapped around all alpaca herds. In two herds, CPXV-specific antibodies were found in the local rodent population. In the third herd, CPXV could be isolated from a common vole ( Microtus arvalis ) found drowned in a water bucket used to water the alpacas. Full genome sequencing and comparison with the genome of a CPXV from an alpaca from the same herd reveal 99.997% identity, providing further evidence that the common vole is a reservoir host and infection source of CPXV. Only in the remaining fourth herd, none of the trapped rodents were found to be CPXV-infected. Rodents, as ubiquitous reservoir hosts, in combination with increasingly popular alpacas, as susceptible species, suggest an enhanced risk of future zoonotic infections.
Giese, Steen Bjørck; Ahrens, Peter
Milk and faecal samples from cows with clinical symptoms of paratuberculosis were examined for the presence of Mycobacterium avium subsp.paratuberculosis (M. a. paratuberculosis) by culture and PCR. M. a. paratuberculosis was isolated in varied numbers from faeces or intestinal mucosa in 8 of 11...... animals. In milk from 5 cows (all faecal culture-positive) we cultivated a few colonies of M. a. paratuberculosis (less than 100 CFU per mi). Milk samples from 2 cows were PCR-positive (both animals were faecal culture-positive, and 1 cow was milk culture positive). One cow was culture......-negative on intestinal mucosa, but culture-positive in milk, and both faeces and milk were negative in culture and PCR from 2 cows. In conclusion the presence of M. a. paratuberculosis could be detected in raw milk by PCR but cultivation of milk was more sensitive in detecting the organism....
Giese, Steen Bjørck; Ahrens, Peter
Milk and faeces samples from cows with clinical symptoms of paratuberculosis were examined for the presence of Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) by culture and PCR. M. paratuberculosis was cultivated in variable numbers from faeces or intestinal mucosa in eight of 11...... animals. In milk from five cows (all faeces culture positive), we cultivated a few colonies of M. paratuberculosis (culture positive, and one cow was milk culture positive). One cow was culture negative on intestinal...... mucosa, but culture positive in milk, and two cows were negative in culture and PCR from both faeces and milk. In conclusion, the presence of M. paratuberculosis could be detected in raw milk by PCR, but cultivation of milk was more sensitive. (C) 2000 Elsevier Science B.V. All rights reserved....
Full Text Available Control of paratuberculosis in livestock is hampered by the low sensitivity of established direct and indirect diagnostic methods. Like other bacteria, Mycobacterium avium subsp. paratuberculosis (MAP emits volatile organic compounds (VOCs. Differences of VOC patterns in breath and feces of infected and not infected animals were described in first pilot experiments but detailed information on potential marker substances is missing. This study was intended to look for characteristic volatile substances in the headspace of cultures of different MAP strains and to find out how the emission of VOCs was affected by density of bacterial growth. One laboratory adapted and four field strains, three of MAP C-type and one MAP S-type were cultivated on Herrold's egg yolk medium in dilutions of 10(-0, 10(-2, 10(-4 and 10(-6. Volatile substances were pre-concentrated from the headspace over the MAP cultures by means of Solid Phase Micro Extraction (SPME, thermally desorbed from the SPME fibers and separated and identified by means of GC-MS. Out of the large number of compounds found in the headspace over MAP cultures, 34 volatile marker substances could be identified as potential biomarkers for growth and metabolic activity. All five MAP strains could clearly be distinguished from blank culture media by means of emission patterns based on these 34 substances. In addition, patterns of volatiles emitted by the reference strain were significantly different from the field strains. Headspace concentrations of 2-ethylfuran, 2-methylfuran, 3-methylfuran, 2-pentylfuran, ethyl acetate, 1-methyl-1-H-pyrrole and dimethyldisulfide varied with density of bacterial growth. Analysis of VOCs emitted from mycobacterial cultures can be used to identify bacterial growth and, in addition, to differentiate between different bacterial strains. VOC emission patterns may be used to approximate bacterial growth density. In a perspective volatile marker substances could be used to
Trefz, Phillip; Koehler, Heike; Klepik, Klaus; Moebius, Petra; Reinhold, Petra; Schubert, Jochen K; Miekisch, Wolfram
Control of paratuberculosis in livestock is hampered by the low sensitivity of established direct and indirect diagnostic methods. Like other bacteria, Mycobacterium avium subsp. paratuberculosis (MAP) emits volatile organic compounds (VOCs). Differences of VOC patterns in breath and feces of infected and not infected animals were described in first pilot experiments but detailed information on potential marker substances is missing. This study was intended to look for characteristic volatile substances in the headspace of cultures of different MAP strains and to find out how the emission of VOCs was affected by density of bacterial growth. One laboratory adapted and four field strains, three of MAP C-type and one MAP S-type were cultivated on Herrold's egg yolk medium in dilutions of 10(-0), 10(-2), 10(-4) and 10(-6). Volatile substances were pre-concentrated from the headspace over the MAP cultures by means of Solid Phase Micro Extraction (SPME), thermally desorbed from the SPME fibers and separated and identified by means of GC-MS. Out of the large number of compounds found in the headspace over MAP cultures, 34 volatile marker substances could be identified as potential biomarkers for growth and metabolic activity. All five MAP strains could clearly be distinguished from blank culture media by means of emission patterns based on these 34 substances. In addition, patterns of volatiles emitted by the reference strain were significantly different from the field strains. Headspace concentrations of 2-ethylfuran, 2-methylfuran, 3-methylfuran, 2-pentylfuran, ethyl acetate, 1-methyl-1-H-pyrrole and dimethyldisulfide varied with density of bacterial growth. Analysis of VOCs emitted from mycobacterial cultures can be used to identify bacterial growth and, in addition, to differentiate between different bacterial strains. VOC emission patterns may be used to approximate bacterial growth density. In a perspective volatile marker substances could be used to diagnose MAP
Robinson, A L; Timms, L L; Stalder, K J; Tyler, H D
The objective of this study was to compare the effect of 4 antiseptic compounds on the healing rate and incidence of infection of umbilical cords in newborn calves (n=60). Late gestation Jersey cows were monitored at a commercial farm (Sioux Jersey, Salix, IA) and newborn purebred (n=30) and crossbred (n=30) calves were obtained within 30min after birth. Calves were alternately assigned by birth order to 4 treatment groups: 7% tincture of iodine, 0.1% chlorine created using a novel chlorine disinfectant technology, chlorohexidine gluconate 4.0% wt/vol, and 10% trisodium citrate. Prior to dipping (within 30min of birth), diameter of the umbilical cords (as an indicator of cord drying and healing) were determined using digital calipers. In addition, as an indicator of umbilical infections, surface temperature of the umbilical stump (along with a reference point at the midpoint of the sternum) was determined using a dual-laser infrared thermometer. These measurements were all repeated at 24±1 h of age. All data were analyzed using mixed model methods. All models included fixed effects of breed (Jersey or Jersey cross), sex (bull or heifer), and treatment. Fixed effect interactions were not included in the statistical model due to the relatively small sample size. No treatment differences were noted for healing rate of umbilical cords. Initially, mean umbilical cord diameter was 22.84±3.89mm and cords healed to a mean diameter of 7.64±4.12mm at 24 h of age. No umbilical infections were noted for calves on any treatment during the course of this study. Mean surface temperature of the umbilical stump was 33.1±2.2°C at birth (1.5±1.6°C higher than the sternal reference temperature), and at 24±1 h of age the mean temperature of the umbilical stump was 33.0±4.3°C (0.5±1.8°C lower than the sternal reference temperature). These data suggest that these antiseptic compounds are equally effective for preventing infections and permitting healing of the umbilical cord
Nielsen, Lennarth Ravn; Warnick, L. D.; Greiner, M.
test positive to negative, whereas the breed and neighbor factors were not found to be important for small herds. Organic production was associated with remaining test positive, but not with becoming test positive. The results emphasize the importance of external and internal biosecurity measures....... The objective of this study was to evaluate risk factors for changing from test negative to positive, which was indicative of herds becoming infected from one quarter of the year to the next, and risk factors for changing from test positive to negative, which was indicative of herds recovering from infection...
Okura, Hisako; Toft, Nils; Pozzato, Nicola
Presence of Mycobacterium avium subsp. paratuberculosis (MAP) in beef has been reported as a public health concern because asymptomatically infected cattle may contain MAP in tissues that are used for human consumption. Associations between MAP carcasses contamination and animal characteristics...... of two dairy cows were positive by culture whereas 4% of the animals were estimated with =10¿CFU/gram muscle based on realtime PCR. Age was found to be associated with carcass contamination with MAP. The observed viable MAP prevalence in beef carcasses was low. However, detection of MAP and MAP DNA...... such as age, breed, production type, and carcass classification were assessed. Cheek muscles from 501 carcasses were sampled cross-sectionally at a Danish abattoir and tested for presence of viable MAP and MAP DNA by bacterial culture and IS900 realtime PCR, respectively. Cheek muscle tissues from carcasses...
Full Text Available Swine dysentery (SD is a mucohaemorrhagic colitis of grower/finisher pigs classically resulting from infection by the anaerobic intestinal spirochaete Brachyspira hyodysenteriae. This study aimed to determine whether B. hyodysenteriae isolates from pigs in three healthy German multiplier herds supplying gilts to other farms differed from isolates from nine German production herds with SD. Isolates were subjected to whole genomic sequencing, and in silico multilocus sequence typing showed that those from the three multiplier herds were of previously undescribed sequence types (ST132, ST133 and ST134, with all isolates from the same herd having the same ST. All isolates were examined for the presence of 332 genes encoding predicted virulence or virulence lifestyle associated factors, and these were well conserved. Isolates from one multiplier herd were atypical in being weakly haemolytic: they had 10 amino acid substitutions in the haemolysin III protein and five in the haemolysin activation protein compared to reference strain WA1, and had a disruption in the promoter site of the hlyA gene. These changes likely contribute to the weakly haemolytic phenotype and putative lack of virulence. These same isolates also had nine base pair insertions in the iron metabolism genes bitB and bitC and lacked five of six plasmid genes that previously have been associated with colonisation. Other overall differences between isolates from the different herds were in genes from three of five outer membrane proteins, which were not found in all the isolates, and in members of a block of six plasmid genes. Isolates from three herds with SD had all six plasmid genes, while isolates lacking some of these genes were found in the three healthy herds-but also in isolates from six herds with SD. Other differences in genes of unknown function or in gene expression may contribute to variation in virulence; alternatively, superior husbandry and better general health may have
Nielsen, T D; Green, L E; Kudahl, A B; Østergaard, S; Nielsen, L R
The effect of Salmonella on milk production is not well established in cattle. The objective of this study was to investigate whether introduction of Salmonella into dairy cattle herds was associated with reduced milk yield and determine the duration of any such effect. Longitudinal data from 2005 through 2009 were used, with data from 12 mo before until 18 mo after the estimated date of infection. Twenty-eight case herds were selected based on an increase in the level of Salmonella-specific antibodies in bulk-tank milk from levels consistently energy-corrected milk (ECM)/cow were used to investigate daily milk yield before and after the estimated herd infection date for cows in parities 1, 2, and 3+. Control herds were used to evaluate whether the effects in the case herds could be reproduced in herds without Salmonella infection. Herd size, days in milk, somatic cell count, season, and year were included in the models. Yield in first-parity cows was reduced by a mean of 1.4 kg (95% confidence interval: 0.5 to 2.3) of ECM/cow per day from 7 to 15 mo after the estimated herd infection date, compared with that of first-parity cows in the same herds in the 12 mo before the estimated herd infection date. Yield for parity 3+ cows was reduced by a mean of 3.0 kg (95% confidence interval: 1.3 to 4.8) of ECM/cow per day from 7 to 15 mo after herd infection compared with that of parity 3+ cows in the 12 mo before the estimated herd infection. We observed minor differences in yield in second-parity cows before and after herd infection and observed no difference between cows in control herds before and after the simulated infection date. Milk yield decreased significantly in affected herds and the reduction was detectable several months after the increase in bulk tank milk Salmonella antibodies. It took more than 1 yr for milk yield to return to preinfection levels. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Evaluación de la reacción en cadena de la polimerasa para el diagnóstico de la brucelosis en un rebaño lechero infectado con Brucellaspp Assessment of polymerase chain reaction (PCR to diagnose brucellosis in a Brucella infected herd
Full Text Available Para el diagnóstico de la brucelosis bovina en muestras de sangre y/o leche, se comparó la reacción en cadena de la polimerasa (PCR con el aislamiento in vitro de Brucella abortus, las pruebas serológicas defijación del complemento (FC e inmunoenzimáticas de competición (ELISA-C en suero e indirecto (ELISA-I en leche. Se analizaron muestras de vacas lecheras de un rebaño infectado “A”, vacunadas con B. abortus cepa 19 antes de los 8 meses de edad y revacunadas con B. abortus cepa RB51 como adultas (n= 99 y de otro “B”, libre de brucelosis (n=100, como control. En A, la PCR identificó 14 vacas infectadas con B. abortus: nueve con cepa silvestre y cinco con cepa silvestre y RB51. No se identificó B. abortus cepa 19. El biotipo 1 se aisló en un caso. Las 14 vacas infectadas con la cepa silvestre resultaron positivas en las tres pruebas serológicas. En B, por PCR no se identificó Brucella. Las pruebas serológicas mostraron una sensibilidad del 100% respecto de PCR. La especificidad para FC, ELISA-C y ELISA-I fue del 100%, 99% y 95%, respectivamente. Se concluye que la PCR sería útil como complemento de las pruebas serológicas o cuando no hay un resultado concluyente.The diagnosis of bovine brucellosis using PCR in blood and milk samples from two dairy herds were compared to in vitro isolation, complement fixation test (CF, competitive ELISA (C-ELISA in serum, and indirect ELISA (I-ELISA in milk. Samples were obtained from 99 cows vaccinated with Brucella abortus strain 19, from a naturally infected herd (A, whose cows were also vaccinated with B. abortus strain RB51 as adults, and 100 from brucellosis free herd (B. In herd A, PCR identified 14 B. abortus infected cows: nine infected with wild type, and five with wild type and RB51, B. abortus S 19 was not identified. B. abortus biotype 1 was isolated from one cow. All cows infected with a wild strain of B. abortus were positive in serologic tests. Brucella was not found in
de la Fe, Christian; Sánchez, Antonio; Gutierrez, Aldo; Contreras, Antonio; Carlos Corrales, Juan; Assunçao, Patricia; Poveda, Carlos; Poveda, José B
This study was designed to assess the possible effects of mycoplasmas on the quality of milk produced by goat herds in a contagious agalactia (CA) endemic area with absence of classical symptoms. Several factors related to milk quality (percentages of fat, total protein, lactose and total solids, standard plate counts (SPC) and presence of Staphylococcus aureus) were compared in mycoplasma-infected and non-infected herds. To define the CA status of 26 herds on the island of Lanzarote (Spain), where CA is endemic, 570 individual milk samples and 266 bulk tank milk (BTM) samples were microbiologically analysed for the presence of Mycoplasma spp. A herd was considered infected by mycoplasmas when at least a sample (individual or BTM) was positive. BTM samples were also used to determine milk quality parameters. Mycoplasma infection was confirmed in 13 herds. A total of 31, 10 and 11 strains of Mycoplasma mycoides subsp. mycoides LC (MmmLC), Mp. agalactiae and Mp. capricolum subsp. capricolum were isolated. No significant differences were observed between the least square means of the variables fat, total protein, lactose and total solids or SPC recorded for the infected v. non-infected herds. The Staph. aureus status of a herd was also found to be independent of the presence of Mycoplasma spp. Our findings indicate that neither the presence of mycoplasmas in a goat herd with absence of classical symptoms seem to compromise the quality of the BTM.
Puput Tri Komalasari
Full Text Available Conceptually, the stock market is strong form efficient in the long term. However, in practice, there are various forms of market anomalies that undermine the accuracy of the efficient market hypothesis. One factor suspected as the cause of market inefficiency is herding behavior. Investors herd when they imitate the actions of other investors. This behavior occurs when there is a continuous interaction among rational investors that prevents them from seeking information about market fundamentals. This study provides new insights by including information asymmetry as a moderating variable. This research examines the phenomenon of herding behavior in the Indonesia Stock Exchange as well as examines directly the effect of information asymmetry on herding behavior. The period of study is 2008 using time series of daily stocks data that actively traded in the capital market. Results of this study find that investor tends to follow market consensus when price changes at the low level, but when there is large price swing market participant acts independently from other investors. Interestingly, this study finds that information asymmetry is a necessary condition for the existence of herding behavior.
Berchtold, B; Bodmer, M; van den Borne, B H P; Reist, M; Graber, H U; Steiner, A; Boss, R; Wohlfender, F
Bovine mastitis is a frequent problem in Swiss dairy herds. One of the main pathogens causing significant economic loss is Staphylococcus aureus. Various Staph. aureus genotypes with different biological properties have been described. Genotype B (GTB) of Staph. aureus was identified as the most contagious and one of the most prevalent strains in Switzerland. The aim of this study was to identify risk factors associated with the herd-level presence of Staph. aureus GTB and Staph. aureus non-GTB in Swiss dairy herds with an elevated yield-corrected herd somatic cell count (YCHSCC). One hundred dairy herds with a mean YCHSCC between 200,000 and 300,000cells/mL in 2010 were recruited and each farm was visited once during milking. A standardized protocol investigating demography, mastitis management, cow husbandry, milking system, and milking routine was completed during the visit. A bulk tank milk (BTM) sample was analyzed by real-time PCR for the presence of Staph. aureus GTB to classify the herds into 2 groups: Staph. aureus GTB-positive and Staph. aureus GTB-negative. Moreover, quarter milk samples were aseptically collected for bacteriological culture from cows with a somatic cell count ≥150,000cells/mL on the last test-day before the visit. The culture results allowed us to allocate the Staph. aureus GTB-negative farms to Staph. aureus non-GTB and Staph. aureus-free groups. Multivariable multinomial logistic regression models were built to identify risk factors associated with the herd-level presence of Staph. aureus GTB and Staph. aureus non-GTB. The prevalence of Staph. aureus GTB herds was 16% (n=16), whereas that of Staph. aureus non-GTB herds was 38% (n=38). Herds that sent lactating cows to seasonal communal pastures had significantly higher odds of being infected with Staph. aureus GTB (odds ratio: 10.2, 95% CI: 1.9-56.6), compared with herds without communal pasturing. Herds that purchased heifers had significantly higher odds of being infected with
Gavriilidis, Konstantinos; Kallinterakis, Vasileios; Tsalavoutas, Ioannis
In view of evidence linking herding and social mood, we examine whether the positive mood documented during Ramadan translates into higher herding compared to non-Ramadan days. Drawing on a sample of seven majority Muslim countries, we report significant herding during Ramadan in most of our sample markets. Additionally, we show that herding appears significantly stronger within rather than outside Ramadan for most tests whereby its significance is manifested on both Ramadan- and non-Ramadan-...
Kenneth R. Whitten
Researchers have described general patterns of population regulation that fit most caribou (Rangifer tarandus) herds. Nevertheless, specific factors operating on particular populations vary greatly, and efforts to categorize herds according to the general patterns often lead to confusion. It is difficult for biologists to attempt to describe population dynamics in terms of density relationships for wide-ranging arctic caribou such as the Porcupine Herd. In these herds density varies as a func...
Ćaǧlayan, Alper; Yüca, Songül
Herd management requires multidisciplinary practices including animal feeding, gynecology, artificial insemination, immunology, and similar topics. Animal feeding is the most delicate subject as the fodder expense is 70% of the farm cost and as nearly all of the metabolic diseases arising out as health problem are because of misfeeding. However, a business organization's being able to maintain making profit will be possible by taking a healthy calf from breeding herd every year. For this reason, precision registrations of birth and artificial insemination, following-up pregnant state of animals, and making the other animals pregnant as soon as possible should be primary aim. It should not be forgotten that diarrhea and pneumonia in calves are among the most frequently witnessed infection related health problems. Mastitis, metritis and foot diseases take an important place in mature cows. These diseases can be minimized by vaccinations that are done properly and in suitable time, in-service training of staffs, making shelters suitable for animals welfare, and improving the hygienic conditions.
Mycobacterium avium subsp. paratuberculosis is responsible for paratuberculosis in animals. This disease, leading to an inflammation of the gastrointestinal tract, has a high impact on animal health and an important economic burden. The environmental life cycle of Mycobacterium avium subsp. paratube...
Full Text Available BACKGROUND: Mycobacterium avium subsp. paratuberculosis (MAP causes chronic enteritis in a wide range of animal species. In cattle, MAP causes a chronic disease called Johne's disease, or paratuberculosis, that is not treatable and the efficacy of vaccine control is controversial. The clinical phase of the disease is characterised by diarrhoea, weight loss, drop in milk production and eventually death. Susceptibility to MAP infection is heritable with heritability estimates ranging from 0.06 to 0.10. There have been several studies over the last few years that have identified genetic loci putatively associated with MAP susceptibility, however, with the availability of genome-wide high density SNP maker panels it is now possible to carry out association studies that have higher precision. METHODOLOGY/PRINCIPAL FINDINGS: The objective of the current study was to localize genes having an impact on Johne's disease susceptibility using the latest bovine genome information and a high density SNP panel (Illumina BovineSNP50 BeadChip to perform a case/control, genome-wide association analysis. Samples from MAP case and negative controls were selected from field samples collected in 2007 and 2008 in the province of Lombardy, Italy. Cases were defined as animals serologically positive for MAP by ELISA. In total 966 samples were genotyped: 483 MAP ELISA positive and 483 ELISA negative. Samples were selected randomly among those collected from 119 farms which had at least one positive animal. CONCLUSION/SIGNIFICANCE: THE ANALYSIS OF THE GENOTYPE DATA IDENTIFIED SEVERAL CHROMOSOMAL REGIONS ASSOCIATED WITH DISEASE STATUS: a region on chromosome 12 with high significance (P<5x10(-6, while regions on chromosome 9, 11, and 12 had moderate significance (P<5x10(-5. These results provide evidence for genetic loci involved in the humoral response to MAP. Knowledge of genetic variations related to susceptibility will facilitate the incorporation of this information
Loeffen, W.L.A.; Hunneman, W.A.; Quak, J.; Verheijden, J.H.M.; Stegeman, J.A.
Influenza virus infections with subtypes H1N1, H3N2 and H1N2 are very common in domestic pigs in Europe. Data on possible differences of population dynamics in finishing pigs in farrow-to-finish herds and in specialised finishing herds are, however, scarce. The presence of sows and weaned piglets on
Morrison, Norman E.
Morrison, Norman E. (Johns Hopkins University-Leonard Wood Memorial Leprosy Research Laboratory, Baltimore, Md.). Circumvention of the mycobactin requirement of Mycobacterium paratuberculosis. J. Bacteriol. 89:762–767. 1965.—The mycobactin growth requirement of Mycobacterium paratuberculosis was circumvented on glucose-containing synthetic medium with an initial pH of 5.5. Mycobactin was required during the first transfer on the synthetic medium. Subsequent transfers have grown in the absence of mycobactin. The growth of mycobactin-“independent” strains of M. paratuberculosis on the synthetic medium was found to be stimulated by low concentrations of mycobactin. The circumvention of the mycobactin requirement appears to depend upon the properties of the medium and not upon having created conditions which promote endogenous mycobactin synthesis. Investigation of the glucose-containing synthetic medium showed that: (i) growth stimulatory compounds were formed during autoclaving, and (ii) compared with neutrality a pH of 5.5 gave markedly increased pellicle yields. It was suggested that the growth-stimulatory compounds formed during autoclaving may in part be responsible for the circumvention of the mycobactin requirement. PMID:14273658
Leonardo A Sechi
Full Text Available The factitive role of Mycobacterium avium ss. paratuberculosis (MAP in Crohn’s disease has been debated for more than a century. The controversy is due to the fact that Crohn’s disease is so similar to a disease of MAP-infected ruminant animals, Johne’s disease; and, though MAP can be readily detected in the infected ruminants, it is much more difficult to detect in humans. Molecular techniques that can detect MAP in pathologic Crohn’s specimens as well as dedicated specialty labs successful in culturing MAP from Crohn’s patients have provided strong argument for MAP’s role in Crohn’s disease. Perhaps more incriminating for MAP as a zoonotic agent is the increasing number of diseases with which MAP has been related: Blau syndrome, type 1 diabetes, Hashimoto thyroiditis and multiple sclerosis. In this article we debate about genetic susceptibility to mycobacterial infection and human exposure to MAP; moreover, it suggests that molecular mimicry between protein epitopes of MAP and human proteins is a likely bridge between infection and these autoimmune disorders.
Full Text Available Mycobacterium avium subsp. paratuberculosis (MAP is the causative bacterium of Johne's disease (JD in ruminants. The control of JD in the dairy industry is challenging, but can be improved with a better understanding of the diversity and distribution of MAP subtypes. Previously established molecular typing techniques used to differentiate MAP have not been sufficiently discriminatory and/or reliable to accurately assess the population structure. In this study, the genetic diversity of 182 MAP isolates representing all Canadian provinces was compared to the known global diversity, using single nucleotide polymorphisms identified through whole genome sequencing. MAP isolates from Canada represented a subset of the known global diversity, as there were global isolates intermingled with Canadian isolates, as well as multiple global subtypes that were not found in Canada. One Type III and six "Bison type" isolates were found in Canada as well as one Type II subtype that represented 86% of all Canadian isolates. Rarefaction estimated larger subtype richness in Québec than in other Canadian provinces using a strict definition of MAP subtypes and lower subtype richness in the Atlantic region using a relaxed definition. Significant phylogeographic clustering was observed at the inter-provincial but not at the intra-provincial level, although most major clades were found in all provinces. The large number of shared subtypes among provinces suggests that cattle movement is a major driver of MAP transmission at the herd level, which is further supported by the lack of spatial clustering on an intra-provincial scale.
Klem, T B; Tollersrud, T; Osterås, O; Stokstad, M
Antibody levels in bulk tank milk (BTM) against bovine respiratory syncytial virus (BRSV) are used to classify BRSV status of herds. The aim of this study was to investigate how these levels correspond with the time at which the herds were infected. Bulk tank milk, individual milk and serum samples from cows and young stock were investigated using an indirect ELISA. Screenings of BTM from 89 dairy herds during two winter seasons revealed a prevalence of positive herds from 82 per cent to 85 per cent. Eleven herds showed a marked increase in antibody levels between two screenings, indicating new infection. However, two of these herds had been free from BRSV for the last five to seven years. Two newly infected herds were monitored for four years and did not appear to get reinfected. Surprisingly, the BTM antibody levels in these herds remained high throughout the study period, but fluctuated significantly. This shows that the levels of antibodies in BTM can remain high for several years, even in herds where reinfection does not occur. BTM serology is a useful tool in the monitoring of infectious diseases in dairy herds, but has limitations as a diagnostic tool for BRSV infections. British Veterinary Association.
Bennedsgaard, Torben Werner; Klaas, Ilka Christine; Vaarst, Mette
, the project herds were smaller with lower production and had half the incidence rate of mastitis treatment than the organic herds from other dairies before the start of the project. The incidence rate of mastitis treatments was reduced considerably from 20 treatments per 100 cow years to 10 treatments per 100...... cow years after the project period. Somatic cell count (SCC) and scores for acute and chronic intramammary infections did not change significantly during the study period, and milk production increased at the same rate as in the other herd groups. The incidence rate of mastitis treatments...
Rinaldo A. Mota
subsp. paratuberculosis (MAP. No record on the occurrence of paratuberculosis in buffaloes in Brazil could be found. Five of 100 buffaloes in a herd in Pernambuco-Brazil showed clinical signs characteristic of PTB. At necropsy, of two animals the lesions were restricted to the small intestine with thickening and corrugation of the mucosa, increase of mesenteric lymph nodes and prominent lymph vessels. Histopathology revealed granulomatous inflammation infiltrated with numerous epithelioid macrophages, Langhans type giant cells, and clusters of Ziehl-Neelsen (ZN positive organisms within the intestinal mucosa. In the mesenteric lymph nodes there was thickening of the capsule and marked granulomatous inflammation. Smears of feces and scrapping smears were prepared from intestinal mucosa and cut surface of mesenteric lymph nodes and, stained by the Ziehl-Neelsen method for research of acid fast bacilli, with positive results. Lymph nodes and intestinal mucosa revealed at IS900 specific polymerase chain reaction amplification of a fragment of about 110pb, confirmed by the comparison with other sequences of M. avium subsp. paratuberculosis available in GenBank.
Larsen, Lars Erik; Tjørnehøj, Kirsten; Viuff, B.
and veal calf production units) in different years and from all confirmed outbreaks in Denmark within a short period. The results showed that identical viruses were isolated within a herd during outbreaks and that viruses from recurrent infections varied by up to 11% in sequence even in closed herds......The nucleotides coding for the extracellular part of the G glycoprotein and the full SH protein of bovine respiratory syncytial virus (BRSV) were sequenced from viruses isolated from numerous outbreaks of BRSV infection. The isolates included viruses isolated from the same herd (closed dairy farms....... It is possible that a quasispecies variant swarm of BRSV persisted in some of the calves in each herd and that a new and different highly fit virus type (master and consensus sequence) became dominant and spread from a single animal in connection with each new outbreak. Based on the high level of diversity...
Nielsen, T D; Green, L E; Kudahl, Anne Margrethe Braad
The effect of Salmonella on milk production is not well established in cattle. The objective of this study was to investigate whether introduction of Salmonella into dairy cattle herds was associated with reduced milk yield and determine the duration of any such effect. Longitudinal data from 2005...... through 2009 were used, with data from 12 mo before until 18 mo after the estimated date of infection. Twenty-eight case herds were selected based on an increase in the level of Salmonella-specific antibodies in bulk-tank milk from ... was randomly allocated to the control herds. Hierarchical mixed effect models with the outcome test-day yield of energy-corrected milk (ECM)/cow were used to investigate daily milk yield before and after the estimated herd infection date for cows in parities 1, 2, and 3+. Control herds were used to evaluate...
Jaravata, Carmela V; Smith, Wayne L; Rensen, Gabriel J; Ruzante, Juliana M; Cullor, James S
A modified forensic DNA extraction and real-time fluorescent polymerase chain reaction assay has been evaluated for the detection of Mycobacterium avium subsp. paratuberculosis (MAP) in bovine fecal samples using primers and fluorescent resonance energy transfer (FRET) probes targeting the IS900 gene sequence of MAP. DNA was successfully extracted from manure samples by utilizing the Whatman FTA card technology, which allows for simple processing and storage of samples at room temperature. The FTA cards were washed and subjected to a Chelex-100 incubation to remove any remaining polymerase chain reaction (PCR) inhibitors and to elute the DNA from the FTA card. This isolated DNA was then subjected to direct real time fluorescent PCR analysis. Detection of MAP DNA from bovine fecal samples spiked with known concentrations of viable MAP cells was obtained. The detection limits of the assay was consistently found to be between 10(2) and 10(4) colony forming units [CFU]/g, with some samples containing as low as 10 CFU/g, yielding positive assay results. This cost-efficient assay allows reporting of results as early as 4 h after fecal collection, which can be particularly useful in highthroughput herd screening.
Guyot, Hugues; Ramery, Eve; O'Grady, Luke; Sandersen, Charlotte; Rollin, Frédéric
Bovine ehrlichiosis is a tick-borne rickettsial disease caused by Anaplasma phagocytophilum. The disease can also be transmitted to humans. Outbreaks in cattle have been described in many European countries. In Belgium, infections caused by A. phagocytophilum have been reported in humans and dogs; however, this paper details the first report of ehrlichiosis in cattle herds in Belgium. The first case described was in a dairy herd located in eastern Belgium. Clinical signs included hyperthermia, polypnea, and swelling of the limbs. The other case was diagnosed in a second, mixed purpose herd in western Belgium. Within the second herd, all of the affected animals came from the same pasture. All animals in that pasture showed recurrent hyperthermia, and some also showed signs of mastitis and late-term abortions. Blood smears and serology revealed the presence of A. phagocytophilum in the majority of animals with pyrexia. Furthermore, the presence of leptospirosis, Neospora caninum, and Q fever antibodies was tested by serological analysis, but all results were negative. Paired serology for Adenovirus, BHV-4, BHV-1, BVD, PI3, and RSV-B did not show any significant seroconversion. Milk samples from cows affected by mastitis revealed minor pathogens. Fecal testing for the presence of Dictyocaulus viviparus in the first herd was negative. Recurrent pyrexia in pastured cattle is a non-specific sign, and can be related to several different pathogens. Bovine ehrlichiosis is transmitted by the tick species Ixodes ricinus which is known to be present throughout Belgium. Belgian practitioners should include ehrlichiosis in their differential diagnosis when confronted with pastured cattle suffering from recurrent pyrexia. Copyright © 2011 Elsevier GmbH. All rights reserved.
Nielsen, Liza Rosenbaum; Nielsen, Søren Saxmose
routes of infection; 4) interpretation of repeated testing of individual animals to detect high-risk animals for special hygienic management or culling; and 5) diagnostic testing of different age groups and bulk tank milk to evaluate progress of control over time. Serology, true prevalence estimates...... stock and adult cattle in 10 case herds that were followed for more than three years. The five steps in the structured approach were: 1) risk scoring to determine transmission routes within the herd and into the herd; 2) determining a plan of action; 3) performing management changes to close important...... and changes in herd classification in the Danish surveillance programme for Salmonella Dublin were used to assess the progress in the herds during and after the control period. Effective control of Salmonella Dublin was achieved in all participating herds through management that focused on closing infection...
Mahmmod, Y S; Klaas, I C; Katholm, J; Lutton, M; Zadoks, R N
Host-adaptation of Streptococcus agalactiae subpopulations has been described whereby strains that are commonly associated with asymptomatic carriage or disease in people differ phenotypically and genotypically from those causing mastitis in dairy cattle. Based on multilocus sequence typing (MLST), the most common strains in dairy herds in Denmark belong to sequence types (ST) that are also frequently found in people. The aim of this study was to describe epidemiological and diagnostic characteristics of such strains in relation to bovine mastitis. Among 1,199 cattle from 6 herds, cow-level prevalence of S. agalactiae was estimated to be 27.4% based on PCR and 7.8% based on bacteriological culture. Quarter-level prevalence was estimated at 2.8% based on bacteriological culture. Per herd, between 2 and 26 isolates were characterized by pulsed-field gel electrophoresis (PFGE) and MLST. Within each herd, a single PFGE type and ST predominated, consistent with a contagious mode of transmission or point source infection within herds. Evidence of within-herd evolution of S. agalactiae was detected with both typing methods, although ST belonged to a single clonal complex (CC) per herd. Detection of CC23 (3 herds) was associated with significantly lower approximate count (colony-forming units) at the quarter level and significantly lower cycle threshold value at the cow level than detection of CC1 (2 herds) or CC19 (1 herd), indicating a lower bacterial load in CC23 infections. Median values for the number of infected quarters and somatic cell count (SCC) were numerically but not significantly lower for cows infected with CC23 than for cows with CC1 or CC19. For all CC, an SCC threshold of 200,000 cells/mL was an unreliable indicator of infection status, and prescreening of animals based on SCC as part of S. agalactiae detection and eradication campaigns should be discouraged. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights
Graham, D A; Clegg, T A; Thulke, H-H; O'Sullivan, P; McGrath, G; More, S J
The control of bovine viral diarrhoea virus (BVDV) mainly focuses on the identification and restriction of persistently infected (PI) animals. However, other transmission pathways can also result in new breakdowns, including the movement of animals pregnant with PI calves (Trojan animals) and the spread of infection between contiguous farms. Contiguous spread is likely an important problem in the BVD eradication programme in Ireland, given the spatial distribution of residual infection, and the highly fragmented nature of land holdings on many Irish farms. In this study, we seek to quantify the risk of BVD spread between contiguous herds in Ireland. Multivariable logistic models were used to estimate the risk of a herd having BVD positive calves in January to June 2014 (the study period) when contiguous to a herd that had at least one BVD positive calf born in 2013. The models included risk factors relating to the study herd and to neighbouring herds. Separate multivariable models were built for each of four "PI-neighbour" factors relating to the presence of BVD+ animals and/or the presence of offspring of PI breeding animals. In total, 58,483 study herds were enrolled. The final model contained the province, the log of the number of calf births born during the study period, the number of cattle purchased between January 2013 and January 2014, and with a two-way interaction between the number of animals of unknown BVD status in the study herd and the PI-neighbour risk factor. When the number of PI-neighbour herds was used as the PI-neighbour risk factor, the odds ratio (OR) associated with the number of PI-neighbour herds ranged from 1.07 to 3.02, depending on the number of unknown animals present. To further explore the risk associated with PI-neighbour factors, the models were repeated using a subset of the study herds (n=7440) that contained no animals of unknown status. The best fitting model including "any PI-neighbour" as the PI-neighbour factor and also
Barlow, John W; Zadoks, Ruth N; Schukken, Ynte H
Treatment of subclinical mastitis during lactation can have both direct (individual animal level) and indirect (population level) effects. With a few exceptions, prior research has focused on evaluating the direct effects of mastitis treatment, and to date no controlled field trials have been conducted to test whether beneficial indirect effects of lactation treatment strategies targeting subclinical mastitis can be demonstrated on commercial dairy farms. Furthermore, there is limited knowledge on the impact of such interventions on the population dynamics of specific bacterial strains. The purpose of this study was to test the hypothesis that lactation therapy targeting S. aureus subclinical intramammary infection reduces transmission of S. aureus strains within dairy herds. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to determine strain specific infection dynamics in treated and control groups in a split herd trial conducted on 2 commercial dairy farms. The direct effect of 8 days intramammary lactation therapy with pirlimycin hydrochloride was demonstrated by an increased proportion of cure and a reduction in duration of infection in quarters receiving treatment compared to untreated controls. The indirect effect of lactation therapy was demonstrated by reduction of new S. aureus intramammary infections (IMI) caused by the dominant strain type in both herds. Strain typing of representative isolates taken over the duration of all IMI, including pre- and post-treatment isolates, provided more precise estimates of new infection, cure, and re-infection rates. New S. aureus infections in recovered susceptible quarters and the emergence of a new strain type in one herd influenced incidence measures. In addition to demonstrating positive direct effects of lactation therapy, this study provides evidence that treatment of subclinical S. aureus mastitis during lactation can have indirect effects including preventing new IMI and
Barlow John W
Full Text Available Abstract Background Treatment of subclinical mastitis during lactation can have both direct (individual animal level and indirect (population level effects. With a few exceptions, prior research has focused on evaluating the direct effects of mastitis treatment, and to date no controlled field trials have been conducted to test whether beneficial indirect effects of lactation treatment strategies targeting subclinical mastitis can be demonstrated on commercial dairy farms. Furthermore, there is limited knowledge on the impact of such interventions on the population dynamics of specific bacterial strains. The purpose of this study was to test the hypothesis that lactation therapy targeting S. aureus subclinical intramammary infection reduces transmission of S. aureus strains within dairy herds. Pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST were used to determine strain specific infection dynamics in treated and control groups in a split herd trial conducted on 2 commercial dairy farms. Results The direct effect of 8 days intramammary lactation therapy with pirlimycin hydrochloride was demonstrated by an increased proportion of cure and a reduction in duration of infection in quarters receiving treatment compared to untreated controls. The indirect effect of lactation therapy was demonstrated by reduction of new S. aureus intramammary infections (IMI caused by the dominant strain type in both herds. Strain typing of representative isolates taken over the duration of all IMI, including pre- and post-treatment isolates, provided more precise estimates of new infection, cure, and re-infection rates. New S. aureus infections in recovered susceptible quarters and the emergence of a new strain type in one herd influenced incidence measures. Conclusion In addition to demonstrating positive direct effects of lactation therapy, this study provides evidence that treatment of subclinical S. aureus mastitis during lactation can
dairy herds (e.g. after import of infected cattle) could be more difficult to detect compared to the past, due to the lower prevalence of antibody positive milking cows and the (expected) higher dilution of antibodies in bigger milk containers. Therefore, an evaluation and an eventual optimization...... ELISA (Rønsholt et al., 1997; Bitsch et al., 1997) and the SVANOVIR ELISA (Juntti at al., 1987; Niskanen, 1993) were compared on milk and serum samples. The prevalence of antibody positive milking cows, which can be detected by each of those tests, was estimated by diluting positive individual milk...... ELISA could detect a lower prevalence of antibody positive cows compared to the Danish blocking ELISA (0.78% vs. 50%). Hence, the former could detect newly infected herds shortly after infection when only few milking cows have seroconverted in the herd. In blood, the two tests performed similarly. Thus...
Mycobacterium avium subsp. paratuberculosis (MAP) is an intracellular pathogen that persists inside host macrophages despite severe oxidative stress and nutrient deprivation. Intrabacterial pH homeostasis is vital to pathogenic mycobacteria to preserve cellular biological processes and stability of ...
Mycobacterium avium subsp. paratuberculosis (MAP) purified protein derivatives (PPDs) are immunologic reagents prepared from cultured filtrates of the type strain ATCC 19698. Traditional production consists of floating culture incubation at 37oC, organism inactivation by autoclaving, coarse filtrat...
Full Text Available Peter Andrew WindsorFaculty of Veterinary Science, University of Sydney, Camden, NSW, AustraliaAbstract: Ovine caseous lymphadenitis (CLA and ovine Johne's disease (OJD or paratuberculosis have been serious diseases in the Australian sheep industry, mainly causing losses from abattoir condemnations from CLA or mortalities on the farm from OJD. CLA is now a disease of minimal concern, with clinical cases reported rarely. Although OJD continues to spread through parts of the sheep population, the catastrophic losses in flocks occurring prior to the introduction of vaccination are now uncommon. Change-management factors relevant to the improvements in both prevalence and producer concerns for CLA and OJD were examined, including drivers and motivation for change, resistance to change, knowledge management, farming system dimensions and leadership. Although extension programs addressing disease risk factors are likely to be of relevance to improved knowledge and attitudes towards disease risk management of producers, improvements in disease-control practices were considered largely attributable to the introduction of vaccination programs for CLA in 1983 and OJD in 2002. Inclusion of the CLA antigen within clostridial vaccines (“6 in 1” vaccine enabled routine annual CLA vaccination to occur in an increasing proportion of the national flock, with estimates of CLA prevalence suggesting a decline from 26% in 1995 to 5.2% in 2009. Encouraging the routine vaccination of lambs for OJD (Gudair vaccine in infected flocks to reduce or avoid losses significantly reduced the within-flock prevaccination–postvaccination median prevalence from 2.72% to 0.72%, based on estimated shedding rates of Mycobacterium avium subsp. paratuberculosis determined by pooled fecal culture in 37 infected flocks vaccinating for at least 5 years. Although persistent use of CLA vaccine is a convenient intervention for producers, promoting the persistent use of OJD vaccination
Jungersen, Gregers; Thakur, Aneesh; Aagaard, C.
, PPDj-specific IFN-γ responses or positive PPDa or PPDb skin tests developed in vaccinees. Antibodies and cell-mediated immune responses were developed against FET11 antigens, however. At necropsy 8 or 12 months of age, relative Map burden was determined in a number of gut tissues by quantitative IS900...... PCR and revealed significantly reduced levels of Map and reduced histopathology. Diagnostic tests for antibody responses and cell-mediated immune responses, used as surrogates of infection, corroborated the observed vaccine efficacy: Five of seven non‐vaccinated calves seroconverted in ID Screen......-γ assay responses from 40 to 52 weeks compared to non-vaccinated calves. These results indicate the FET11 vaccine can be used to accelerate eradication of paratuberculosis while surveillance or test-and-manage control programs for tuberculosis and Johne’s disease remain in place. Funded by EMIDA ERA...
Pierdzioch, C.; Rulke, J. C.; Stadtmann, G.
We analyze more than 20,000 forecasts of nine metal prices at four different forecast horizons. We document that forecasts are heterogeneous and report that anti-herding appears to be a source of this heterogeneity. Forecaster anti-herding reflects strategic interactions among forecasters...
Boklund, Anette; Mortensen, Sten; Houe, H.
Herds are under constant risk of introducing new pathogens from different sources. In this article we describe biosecurity practices in Danish sow herds. Between December 1, 1999 and February 29, 2000, 121 sow units were interviewed regarding biosecurity on the site. The questionnaire contained 6...
Pérez de Val Bernat
Full Text Available Abstract Background Most countries carrying out campaigns of bovine tuberculosis (TB eradication impose a ban on the use of mycobacterial vaccines in cattle. However, vaccination against paratuberculosis (PTB in goats is often allowed even when its effect on TB diagnosis has not been fully evaluated. To address this issue, goat kids previously vaccinated against PTB were experimentally infected with TB. Results Evaluation of interferon-γ (IFN-γ secretion induced by avian and bovine tuberculins (PPD showed a predominant avian PPD-biased response in the vaccinated group from week 4 post-vaccination onward. Although 60% of the animals were bovine reactors at week 14, avian PPD-biased responses returned at week 16. After challenge with M. caprae, the IFN-γ responses radically changed to show predominant bovine PPD-biased responses from week 18 onward. In addition, cross-reactions with bovine PPD that had been observed in the vaccinated group at week 14 were reduced when using the M. tuberculosis complex-specific antigens ESAT-6/CFP-10 and Rv3615c as new DIVA (differentiation of infected and vaccinated animals reagents, which further maintained sensitivity post-challenge. Ninety percent of the animals reacted positively to the tuberculin cervical comparative intradermal test performed at 12 weeks post-infection. Furthermore, post-mortem analysis showed reductions in tuberculous lesions and bacterial burden in some vaccinated animals, particularly expressed in terms of the degree of extrapulmonary dissemination of TB infection. Conclusions Our results suggest a degree of interference of PTB vaccination with current TB diagnostics that can be fully mitigated when using new DIVA reagents. A partial protective effect associated with vaccination was also observed in some vaccinated animals.
Relationship between presence of cows with milk positive for Mycobacterium avium subsp. paratuberculosis-specific antibody by enzyme-linked immunosorbent assay and viable M. avium subsp. paratuberculosis in dust in cattle barns.
Eisenberg, Susanne W F; Chuchaisangrat, Ruj; Nielen, Mirjam; Koets, Ad P
Paratuberculosis, or Johne's disease, in cattle is caused by Mycobacterium avium subsp. paratuberculosis, which has recently been suspected to be transmitted through dust. This longitudinal study on eight commercial M. avium subsp. paratuberculosis-positive dairy farms studied the relationship between the number of cows with M. avium subsp. paratuberculosis antibody-positive milk and the presence of viable M. avium subsp. paratuberculosis in settled-dust samples, including their temporal relationship. Milk and dust samples were collected in parallel monthly for 2 years. M. avium subsp. paratuberculosis antibodies in milk were measured by enzyme-linked immunosorbent assay (ELISA) and used as a proxy for M. avium subsp. paratuberculosis shedding. Settled-dust samples were collected by using electrostatic dust collectors (EDCs) at six locations in housing for dairy cattle and young stock. The presence of viable M. avium subsp. paratuberculosis was identified by liquid culture and PCR. The results showed a positive relationship (odds ratio [OR], 1.2) between the number of cows with ELISA-positive milk and the odds of having positive EDCs in the same airspace as the adult dairy cattle. Moreover, the total number of lactating cows also showed an OR slightly above 1. This relationship remained the same for settled-dust samples collected up to 2 months before or after the time of milk sampling. The results suggest that removal of adult cows with milk positive for M. avium subsp. paratuberculosis-specific antibody by ELISA might result in a decrease in the presence of viable M. avium subsp. paratuberculosis in dust and therefore in the environment. However, this decrease is likely delayed by several weeks at least. In addition, the data support the notion that M. avium subsp. paratuberculosis exposure of young stock is reduced by separate housing.
Widagdo S. Nugroho
Full Text Available Crohn’s disease (CD that becomes a public health concern in developed countries shows similarities in clinical signs and pathological features with Johne’s disease (JD in ruminants infected by Mycobacterium avium subspecies paratuberculosis (MAP. Few researches conducted in Europe, the USA, and Australia showed relationships between MAP, CD, JD and dairy products. Indonesians consume milk and diary products from domestic and imported source. Adji in 2004 found some domestic dairy cows that were seropositive for MAP, and this could be a serious problem in dairy farm animals and human health in the future. The aim of this study was to detect MAP in the growing up formula milk. Fifty samples from five established factories were taken from supermarkets in Bogor. Polymerase chain reaction method (PCR with insertion sequence (IS 900 as primer and culture in Herrold’s egg yolk media with mycobactin J (HEYM J as a gold standard were used in this study. Neither MAP grew up in HEYM J medium after 20 weeks of culture period nor positive samples by PCR IS 900 were found. Although there were no positive samples found in this study, further extensive and comprehensive studies on MAP should be done with more and varied samples, as well as in human to provide data on MAP in Indonesia. (Med J Indones 2008; 17: 183-7Keywords: Crohn’s disease, dairy cow, growing up formula milk
Jones, W G
Investigation of a high incidence of hip arthritis in a herd of Ayrshires resulted in the discovery of abnormal levels of fluorine in samples of bone. Suspicion of fluorosis was not aroused earlier as the area is not contaminated by industrial fall-out. In addition, many affected animals had no lesions in their teeth; this was because their dentition was complete before ingesting fluorine from a mineral supplement. Only cows receiving toxic levels of fluorine during their first lactation showed lesions, and these were confined to the fourth pair of incisors. Two metabolic profile tests were caried out to establish that the input-output balance in the main metabolites was normal. Analysis of various constituents of the diet revealed significant levels of fluorine in the mineral supplement only. Arthritis was the most prominent feature. This led to debility, with loss of milk and carcase value. Confirmation of fluorosis was obtained by analysis of bone and urine.
Kenneth R. Whitten
Full Text Available Researchers have described general patterns of population regulation that fit most caribou (Rangifer tarandus herds. Nevertheless, specific factors operating on particular populations vary greatly, and efforts to categorize herds according to the general patterns often lead to confusion. It is difficult for biologists to attempt to describe population dynamics in terms of density relationships for wide-ranging arctic caribou such as the Porcupine Herd. In these herds density varies as a function of dispersal and erratic movement patterns and is not simply the number of caribou divided by a fixed range area. Density is also a poor surrogate for resource availability per individual caribou because climatic factors affect forage and/or access to forage independendy of caribou numbers. Thus classic signs of nutritional stress such as delayed puberty, reduced productivity, and winter starvation can occur when a population is small as well as large and do not necessarily denote food competition brought on by high density, per se. Nutritional stress and exacerbated predation due to adverse weather conditions occasionally cause the Porcupine Herd to decline, and limiting factors such as poor nutrition, predation, harvest, accidents, and disease act in combination to keep herd growth rates low during periods of good weather. Adverse weather setbacks occur frequently, and the herd remains within a fairly restricted range of densities over long time periods. There is no true density dependent regulation and no equilibrium in this system.
Full Text Available Mycobacterium avium ssp. paratubercolosis (MAP is the causative agent of Johne’s disease (or paratubercolosis,a chronic infectious enteritis in cattle, sheep and goats. Infected animals shed viable MAP in their milk, faeces and semen. MAP may have a role in development of Crohn’s disease,a chronic inflammatory bowel disease in humans, via the consumption of contamined milk and milk products, meat and contamined water supplies. For some authors pasteurization is not sufficient to kill all MAP cells present in milk and it has been cultured from raw or pasteurizated milk and isolated from cheese. MAP has not isolated from retail beef to date, although limited testing has been carried out. Probably MAP may be involved in other chronic diseases like Type-1 Diabetes. Which is the possible public health consequence of periodically use by susceptible individuals is uncertain.
Full Text Available Swine dysentery (SD is a mucohemorrhagic colitis, classically seen in grower/finisher pigs and caused by infection with the anaerobic intestinal spirochete Brachyspira hyodysenteriae. More recently, however, the newly described species Brachyspira hampsonii and Brachyspira suanatina have been identified as causing SD in North America and/or Europe. Furthermore, there have been occasions where strains of B. hyodysenteriae have been recovered from healthy pigs, including in multiplier herds with high health status. This study investigated whether cases of SD in Australia may be caused by the newly described species; how isolates of B. hyodysenteriae recovered from healthy herds compared to isolates from herds with disease; and how contemporary isolates compare to those recovered in previous decades, including in their plasmid gene content and antimicrobial resistance profiles. In total 1103 fecal and colon samples from pigs in 97 Australian herds were collected and tested. Of the agents of SD only B. hyodysenteriae was found, being present in 34 (35.1% of the herds, including in 14 of 24 (58% herds that had been considered to be free of SD. Multilocus sequence typing applied to 96 isolates from 30 herds and to 53 Australian isolates dating from the 1980s through the early 2000s showed that they were diverse, distinct from those reported in other countries, and that the 2014/16 isolates generally were different from those from earlier decades. These findings provided evidence for ongoing evolution of B. hyodysenteriae strains in Australia. In seven of the 20 herds where multiple isolates were available, two to four different sequence types (STs were identified. Isolates with the same STs also were found in some herds with epidemiological links. Analysis of a block of six plasmid virulence-associated genes showed a lack of consistency between their presence or absence and their origin from herds currently with or without disease; however
Whittington, Richard J.; Marsh, Ian B.; Saunders, Vanessa; Grant, Irene R.; Juste, Ramon; Sevilla, Iker A.; Manning, Elizabeth J. B.; Whitlock, Robert H.
Mycobacterium avium subsp. paratuberculosis causes paratuberculosis (Johne's disease) in ruminants in most countries. Historical data suggest substantial differences in culturability of M. avium subsp. paratuberculosis isolates from small ruminants and cattle; however, a systematic comparison of culture media and isolates from different countries and hosts has not been undertaken. Here, 35 field isolates from the United States, Spain, Northern Ireland, and Australia were propagated in Bactec 12B medium and Middlebrook 7H10 agar, genomically characterized, and subcultured to Lowenstein-Jensen (LJ), Herrold's egg yolk (HEY), modified Middlebrook 7H10, Middlebrook 7H11, and Watson-Reid (WR) agars, all with and without mycobactin J and some with sodium pyruvate. Fourteen genotypes of M. avium subsp. paratuberculosis were represented as determined by BstEII IS900 and IS1311 restriction fragment length polymorphism analysis. There was no correlation between genotype and overall culturability, although most S strains tended to grow poorly on HEY agar. Pyruvate was inhibitory to some isolates. All strains grew on modified Middlebrook 7H10 agar but more slowly and less prolifically on LJ agar. Mycobactin J was required for growth on all media except 7H11 agar, but growth was improved by the addition of mycobactin J to 7H11 agar. WR agar supported the growth of few isolates. The differences in growth of M. avium subsp. paratuberculosis that have historically been reported in diverse settings have been strongly influenced by the type of culture medium used. When an optimal culture medium, such as modified Middlebrook 7H10 agar, is used, very little difference between the growth phenotypes of diverse strains of M. avium subsp. paratuberculosis was observed. This optimal medium is recommended to remove bias in the isolation and cultivation of M. avium subsp. paratuberculosis. PMID:21430104
Holm, Signe A.; Sørensen, Camilla; Thamsborg, Stig M.
The prevalence of gastrointestinal parasites in Danish goats and the presence of anthelmintic resistance (AR) in 10 selected herds were investigated during April-September 2012. All Danish herds (n = 137) with 10 or more adult goats were invited to participate, and of these 27 herds met......, resistance to the most commonly used anthelmintics is widespread in larger goat herds throughout Denmark....
Ramirez-Villaescusa Ana M
Full Text Available Abstract Background Bovine herpesvirus type-1 (BHV-1 is an important pathogen of cattle that presents with a variety of clinical signs, including the upper respiratory tract infection infectious bovine rhinotracheitis (IBR. A seroepidemiological study of BHV-1 antibodies was conducted in England from 2002 – 2004: 29,782 blood samples were taken from 15,736 cattle from 114 herds which were visited on up to three occasions. Antibody concentration was measured using a commercial ELISA. Farm management information was collected using an interview questionnaire, and herd size and cattle movements were obtained from the cattle tuberculosis testing database and the British Cattle Movement Service. Hierarchical statistical models were used to investigate associations between cattle and herd variables and the continuous outcome percentage positive (PP values from the ELISA test in unvaccinated herds. Results There were 7 vaccinated herds, all with at least one seropositive bovine. In unvaccinated herds 83.2% had at least one BHV-1 seropositive bovine, and the mean cattle and herd BHV-1 seroprevalence were 42.5% and 43.1% respectively. There were positive associations between PP value, age, herd size, presence of dairy cattle. Adult cattle in herds with grower cattle had lower PP values than those in herds without grower cattle. Purchased cattle had significantly lower PP values than homebred cattle, whereas cattle in herds that were totally restocked after the foot-and-mouth epidemic in 2001 had significantly higher PP values than those in continuously stocked herds. Samples taken in spring and summer had significantly lower PP values than those taken in winter, whereas those taken in autumn had significantly higher PP values than those taken in winter. The risks estimated from a logistic regression model with a binary outcome (seropositive yes/no were similar. Conclusion The prevalence of BHV-1 seropositivity in cattle and herds has increased since
Kirkeby, Carsten Thure; Græsbøll, Kaare; Nielsen, Søren Saxmose
consequences of continuously adapting the sampling interval in response to the estimated true prevalence in the herd. The key results were that the true prevalence was greatly affected by the hygiene level and to some extent by the test-frequency. Furthermore, the choice of prevalence that will be tolerated...... through a variety of test-strategies, but are challenged by the lack of perfect tests. Frequent testing increases the sensitivity but the costs of testing are a cause of concern for farmers. Here, we used a herd simulation model using milk ELISA tests to evaluate the epidemiological and economic...... in a control scenario had a major impact on the true prevalence in the normal hygiene setting, but less so when the hygiene was poor. The net revenue is not greatly affected by the test-strategy, because of the general variation in net revenues between farms. An exception to this is the low hygiene herd, where...
Bontje, D M; Backer, J A; Hogerwerf, L; Roest, H I J; van Roermund, H J W
Between 2006 and 2009 the largest human Q fever epidemic ever described occurred in the Netherlands. The source of infection was traced back to dairy goat herds with abortion problems due to Q fever. The first aim of control measures taken in these herds was the reduction of human exposure. To analyze Q fever dynamics in goat herds and to study the effect of control measures, a within-herd model of Coxiella burnetii transmission in dairy goat herds was developed. With this individual-based stochastic model we evaluated six control strategies and three herd management styles and studied which strategy leads to a lower Q fever prevalence and/or to disease extinction in a goat herd. Parameter values were based on literature and on experimental work. The model could not be validated with independent data. The results of the epidemiological model were: (1) Vaccination is effective in quickly reducing the prevalence in a dairy goat herd. (2) When taking into account the average time to extinction of the infection and the infection pressure in a goat herd, the most effective control strategy is preventive yearly vaccination, followed by the reactive strategies to vaccinate after an abortion storm or after testing BTM (bulk tank milk) positive. (3) As C. burnetii in dried dust may affect public health, an alternative ranking method is based on the cumulative amount of C. burnetii emitted into the environment (from disease introduction until extinction). Using this criterion, the same control strategies are effective as when based on time to extinction and infection pressure (see 2). (4) As the bulk of pathogen excretion occurs during partus and abortion, culling of pregnant animals during an abortion storm leads to a fast reduction of the amount of C. burnetii emitted into the environment. However, emission is not entirely prevented and Q fever will not be eradicated in the herd by this measure. (5) A search & destroy (i.e. test and cull) method by PCR of individual milk
Full Text Available Given the international financial situation of the last 50 years, and considering the complexity and severity of the financial crises, it is important to study the episodes of financial instability, and especially to understand both operating mechanisms and propagation mechanisms. One endogenous mechanism of financial instability is the herd behavior, which may increase the volatility and the amplitude of any sub-part of the financial system. This paper aims to analyze this phenomenon, considering the behavior of the financial market participants, the role of information in the making decisions process, banking responsibility regarding the herd behavior. The paper also illustrates two examples of herd behavior (run bank and the "too many to fail" problem, and presents three herding measures, in an attempt to achieve a quantitative analysis of the phenomenon, besides the qualitative analysis exposed above.
Obtención y evaluación de un derivado proteico purificado de una cepa argentina de Mycobacterium avium subsp. paratuberculosis Production and evaluation of a purified protein derivative from an Argentine strain of Mycobacterium avium subsp. paratuberculosis (MAP
Full Text Available Los derivados proteicos purificados (PPD son mezclas antigénicas no definidas obtenidas de distintas micobacterias. Los PPD bovino (PPDb y PPD aviar (PPDa son los antígenos que se emplean para evaluar la respuesta inmunitaria celular en infecciones como tuberculosis y paratuberculosis en el bovino. El PPDa comercial se produce a partir de Mycobacterium avium subsp. avium, y no a partir de la subespecie paratuberculosis. En este trabajo se seleccionó una cepa local de Mycobacterium avium subsp. paratuberculosis cuyo patrón molecular por RFLP es el más frecuente entre los aislamientos de nuestro país que han sido estudiados, y a partir de esta, se obtuvo un derivado proteico purificado: PPDj-IB. Se emplearon tanto el PPDa comercial como el PPDj-IB como antígenos en la prueba de liberación de gamma-interferón en animales de un tambo con paratuberculosis y en animales control. Aun cuando ambos PPD fueron capaces de estimular diferencialmente la liberación de la citoquina en el tambo infectado (respecto de los tambos control, no hubo diferencias significativas en los niveles de estimulación producidos y solo dos animales fueron positivos mediante el empleo de PPDj-IB. A partir del análisis por Western blot se demostró que el contenido de lipoarabinomano y del antígeno Apa/ModD era distinto en los PDD evaluados. Estas diferencias podrían explicar, en parte, las diferencias en los niveles de estimulación en términos individuales. Si bien el empleo de PPDj-IB no mejoró significativamente los resultados de la prueba de liberación de ?IFN, es importante destacar que se logró producir en el laboratorio un PPD apto para su empleo en ensayos in vitro.Purified Protein Derivatives (PPDs are non-defined antigens prepared from mycobacteria cultures. They are usually employed to evaluate the specific cellular immune response both in animals and humans. Bovine and avian PPDs are usually employed as antigens in mycobacterial infections such as
Fatores de risco associados à infecção pelo herpesvírus bovino 1 em rebanhos bovinos da região Oeste do Estado do Paraná Risk factors for bovine herpesvirus 1 infection in cattle herds in the West region of Parana State
Juliana A. Dias
Full Text Available O objetivo deste estudo foi determinar a prevalência de rebanhos positivos (focos e identificar os fatores de risco que possam estar associados com a infecção pelo herpesvírus bovino 1 (BoHV-1 em rebanhos bovinos com atividade reprodutiva, na região Oeste do Estado do Paraná. O delineamento estatístico, amostras de soro e informações referentes às propriedades foram as empregadas para o estudo da brucelose bovina no Estado do Paraná dentro do contexto do Programa Nacional de Controle e Erradicação da Brucelose e Tuberculose. Foram avaliadas 1930 fêmeas com idade igual ou superior a 24 meses, provenientes de 295 rebanhos não vacinados contra o BoHV-1. Para o diagnóstico sorológico da infecção pelo BoHV-1, foi utilizado um ensaio imunoenzimático (ELISA indireto. Em cada propriedade foi aplicado um questionário epidemiológico, afim de obter informações epidemiológicas e práticas de manejo empregadas. Dos 295 rebanhos analisados, 190 foram considerados positivos para o BoHV-1, com a prevalência de rebanhos de 64,41% (I.C.95% = 58,65-69,87%. As variáveis consideradas fatores de risco para a infecção pelo BoHV-1 na análise de regressão logística multivariada foram: i número (>23 fêmeas com idade >24 meses (OR=2,22; IC: 1,09-4,51; ii compra de reprodutores (OR=2,68; IC: 1,48-4,82; iii uso de pastagens comuns (OR=5,93; IC: 1,31-26,82; iv histórico de abortamento nos últimos 12 meses (OR=2,37; IC: 1,09-5,16; v presença de animais silvestres (OR=8,86; IC: 1,11-70,73. Estes resultados indicam que a infecção pelo BoHV-1 está amplamente distribuída na região estudada e que fatores relacionados às características das propriedades e ao manejo estão associados à infecção.The aim of this study was to determine the prevalence of positive herds and to identify the risk factors for BoHV-1 infection in breeding cattle herds in the Western region of Parana State. The statistic delineation, the serum samples and
Knobloch, Henri; Köhler, Heike; Nicola, Commander; Reinhold, Petra; Turner, Claire; Chambers, Mark
A proof of concept investigation was performed to demonstrate that two independent infectious diseases of cattle result in different patterns of volatile organic compounds (VOC) in the headspace of serum samples detectable using an electronic nose (e-nose). A total of 117 sera from cattle naturally infected with Mycobacterium avium subsp. paratuberculosis (paraTB, n = 43) or Brucella sp. (n = 26) and sera from corresponding control animals (n = 48) were randomly and analysed blind to infection status using a ST214 e-nose (Scensive Ltd, Leeds, UK). Samples were collected under non-standardised conditions on different farms from the UK (brucellosis) and Germany (paraTB). The e-nose could differentiate the sera from brucellosis infected, paraTB infected and healthy animals at the population level, but the technology used was not suitable for determination of the disease status of individual animals. Nevertheless, the data indicate that there are differences in the sensor responses depending on the disease status, and therefore, it shows the potential of VOC analysis from serum headspace samples for disease detection.
Nagy, Abdou; Fahnøe, Ulrik; Rasmussen, Thomas Bruun
Scandinavian countries have successfully pursued bovine viral diarrhea virus (BVDV) eradication without the use of vaccines. In Denmark, control and eradication of BVDV were achieved during the last two decades, but occasionally new BVDV infections are detected in some Danish cattle herds. The aim...
Laurin, Emilie L; Sanchez, Javier; Chaffer, Marcelo; McKenna, Shawn L B; Keefe, Greg P
Milk ELISA are commonly used for detection of Mycobacterium avium ssp. paratuberculosis (MAP) antibodies in dairy cows, due to low cost and quick processing for large numbers of samples. However, low sensitivity and variations from host and environmental factors can impede detection of MAP antibodies at early disease stages. The objectives of our study were to assess the sensitivity of milk ELISA in comparison with fecal tests and to evaluate how detectable antibody concentrations in milk vary with changes in fecal shedding of MAP, cow age, cow parity, days in milk, and time of year. To compare the sensitivity of a commercial milk ELISA with solid and broth fecal culture and with fecal real-time PCR, a longitudinal study was performed for the identification of MAP-infectious animals as determined by prior fecal testing for MAP shedding. In addition, associations between variation in milk MAP ELISA score and changes in fecal MAP shedding, host age, days in milk, and season were evaluated. Monthly milk and fecal samples were collected over 1 yr from 46 cows that were previously shedding MAP in their feces. Sensitivity of milk ELISA was 29.9% (95% CI: 24.8 to 35.1%), compared with 46.7% (40.7 to 52.7%) for fecal solid culture, 55.0% (49.3 to 60.7%) for fecal broth culture, and 78.4% (73.3 to 83.1%) for fecal direct real-time PCR. The effect of stage of lactation could not be separated from the effect of season, with increased milk ELISA scores at greater days in milk in winter. However, unpredictable monthly variations in results were observed among the 3 assays for individual cow testing, which highlights the importance of identifying patterns in pathogen and antibody detection over time in MAP-positive herds. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Naser, Saleh A; Sagramsingh, Sudesh R; Naser, Abed S; Thanigachalam, Saisathya
Crohn's disease (CD) is a chronic inflammatory condition that plagues millions all over the world. This debilitating bowel disease can start in early childhood and continue into late adulthood. Signs and symptoms are usually many and multiple tests are often required for the diagnosis and confirmation of this disease. However, little is still understood about the cause(s) of CD. As a result, several theories have been proposed over the years. One theory in particular is that Mycobacterium avium subspecies paratuberculosis (MAP) is intimately linked to the etiology of CD. This fastidious bacterium also known to cause Johne's disease in cattle has infected the intestines of animals for years. It is believed that due to the thick, waxy cell wall of MAP it is able to survive the process of pasteurization as well as chemical processes seen in irrigation purification systems. Subsequently meat, dairy products and water serve as key vehicles in the transmission of MAP infection to humans (from farm to fork) who have a genetic predisposition, thus leading to the development of CD. The challenges faced in culturing this bacterium from CD are many. Examples include its extreme slow growth, lack of cell wall, low abundance, and its mycobactin dependency. In this review article, data from 60 studies showing the detection and isolation of MAP by PCR and culture techniques have been reviewed. Although this review may not be 100% comprehensive of all studies, clearly the majority of the studies overwhelmingly and definitively support the role of MAP in at least 30%-50% of CD patients. It is very possible that lack of detection of MAP from some CD patients may be due to the absence of MAP role in these patients. The latter statement is conditional on utilization of methodology appropriate for detection of human MAP strains. Ultimately, stratification of CD and inflammatory bowel disease patients for the presence or absence of MAP is necessary for appropriate and effective
Full Text Available AbstractThe ability to maintain intra-cellular pH is crucial for bacteria and other microbes to survive in diverse environments, particularly those that undergo fluctuations in pH. Mechanisms of acid resistance remain poorly understood in mycobacteria. Although studies investigating acid stress in M. tuberculosis are gaining traction, few center on Mycobacterium avium subsp. paratuberculosis (MAP, the etiological agent of chronic enteritis in ruminants. We identified a MAP acid stress response network involved in macrophage infection. The central node of this network was MAP0403, a predicted serine protease that shared an 86% amino acid identity with MarP in M. tuberculosis. Previous studies confirmed MarP as a serine protease integral to maintaining intra-bacterial pH and survival in acid in vitro and in vivo. We show that MAP0403 is upregulated in infected macrophage and MAC-T cells and coincided with phagosome acidification. Treatment of mammalian cells with bafilomcyin A1, a potent inhibitor of phagosomal vATPases, diminished MAP0403 transcription. MAP0403 expression was also noted in acidic medium. A surrogate host, M. smegmatis mc2 155, was designed to express MAP0403 and when exposed to either macrophages or in vitro acid stress had increase bacterial cell viability, which corresponds to maintenance of intra-bacterial pH in acidic (pH = 5 conditions. These data suggest that MAP0403 may be the equivalent of MarP in MAP. Future studies confirming MAP0403 as a serine protease and exploring its structure and possible substrates are warranted.
Hussain, Muhammad Hammad; Saqib, Muhammad; Al-Maawali, Mahir Gharib; Al-Makhladi, Salim; Al-Zadjali, Mohammed Somar; Al-Sidairi, Talal; Asubaihi, Saud; Al-Rawahi, Abdulmajeed; Mansoor, Muhammad Khalid
Johne's disease (JD) is a World Animal Health Organization (OIE)-listed disease of ruminants including camels with serious economic impacts worldwide. A cross-sectional serological survey involving multistage simple random sampling was conducted to investigate the prevalence of JD in camels of Oman. In total, 2255 camels (254 males and 2001 females) and different ages from 553 geographically marked holdings were bled for serum. The samples were analyzed by a commercial indirect enzyme-linked immunosorbent assay (ELISA) with protein 'G' as conjugate (LSI VET Ruminant Serum Paratuberculosis Advanced, France). Results indicated a widespread herd and individual level seroprevalence, respectively of 9.2 % (95 % CI = 0.7-50) and 2.6 % (95 % CI = 2.0-3.4) in Oman. Differences (p 0.05) seroprevalence was observed in females (2.8 %), and their odds for testing positive were 3.69 (95 % confidence interval (CI) = 0.90-15.23) times higher as compared to males (0.8 %). Seropositivity increased with the age of camels, and the highest prevalence (4.4 %) was observed in camels of more than 10 years of age (p = 0.03). Large and medium size herds (odds ratio (OR) = 1.77, 95 % CI = 0.96-3.24) where camels were kept as single species (OR = 1.54, 95 % CI = 0.84-2.84) and confined (OR = 1.93, 95 % CI = 1.05-3.54) were found more likely to test positive. This is the first record of seroprevalence of JD among the camels in the country which highlights their potential as an important host of the disease. The results advocate that a comprehensive control program based upon further risk analysis and molecular study should be devised in Oman.
Nielsen, Liza Rosenbaum; Dohoo, Ian
, proportional hazard model allowing for recurrence within herds. During October to December the hazard of failures was higher (hazard ratio HR=3.4, P=0.0005) than the rest of the year. Accounting for the delay in bulk-tank milk antibody responses to S. Dublin infection, this indicates that introduction......-quarters (YQs), either at the start of the study period or after recovery from infection. Survival analysis was performed on a dataset including 6931 dairy herds with 118969 YQs at risk, in which 1523 failures (new infection events) occurred. Predictors obtained from register data were tested in a multivariable...
Oliveira, Victor Henrique Silva de; Sørensen, Jan Tind; Thomsen, Peter T.
as negative or positive for DD at the hind legs during milking in the milking parlor. Information about biosecurity was obtained through questionnaires addressed to farmers, on-farm observations, and information from the Danish Cattle Database (www.seges.dk). These assessment tools covered potential infection...... among cows and herds were 24 and 97%, respectively; the within-herd DD prevalence ranged from 0 to 56%. Poor external biosecurity measures associated with higher prevalence of DD were recent animal purchase, access to pasture, lack of boots available for visitors, farm staff working at other dairy farms...
Full Text Available Abstract Q fever is a worldwide zoonosis caused by the bacterium Coxiella burnetii. The control of this infection in cattle is crucial: infected ruminants can indeed encounter reproductive disorders and represent the most important source of human infection. In the field, vaccination is currently advised in infected herds but the comparative effectiveness of different vaccination protocols has never been explored: the duration of the vaccination programme and the category of animals to be vaccinated have to be determined. Our objective was to compare, by simulation, the effectiveness over 10 years of three different vaccination strategies in a recently infected dairy cattle herd. A stochastic individual-based epidemic model coupled with a model of herd demography was developed to simulate three temporal outputs (shedder prevalence, environmental bacterial load and number of abortions and to calculate the extinction rate of the infection. For all strategies, the temporal outputs were predicted to strongly decrease with time at least in the first years of vaccination. However, vaccinating only three years was predicted inadequate to stabilize these dynamic outputs at a low level. Vaccination of both cows and heifers was predicted as being slightly more effective than vaccinating heifers only. Although the simulated extinction rate of the infection was high for both scenarios, the outputs decreased slower when only heifers were vaccinated. Our findings shed new light on vaccination effectiveness related to Q fever. Moreover, the model can be further modified for simulating and assessing various Q fever control strategies such as environmental and hygienic measures.
Allore, H G; Schruben, L W; Erb, H N; Oltenacu, P A
A dynamic stochastic simulation model for discrete events, SIMMAST, was developed to simulate the effect of mastitis on the composition of the bulk tank milk of dairy herds. Intramammary infections caused by Streptococcus agalactiae, Streptococcus spp. other than Strep. agalactiae, Staphylococcus aureus, and coagulase-negative staphylococci were modeled as were the milk, fat, and protein test day solutions for individual cows, which accounted for the fixed effects of days in milk, age at calving, season of calving, somatic cell count (SCC), and random effects of test day, cow yield differences from herdmates, and autocorrelated errors. Probabilities for the transitions among various states of udder health (uninfected or subclinically or clinically infected) were calculated to account for exposure, heifer infection, spontaneous recovery, lactation cure, infection or cure during the dry period, month of lactation, parity, within-herd yields, and the number of quarters with clinical intramammary infection in the previous and current lactations. The stochastic simulation model was constructed using estimates from the literature and also using data from 164 herds enrolled with Quality Milk Promotion Services that each had bulk tank SCC between 500,000 and 750,000/ml. Model parameters and outputs were validated against a separate data file of 69 herds from the Northeast Dairy Herd Improvement Association, each with a bulk tank SCC that was > or = 500,000/ml. Sensitivity analysis was performed on all input parameters for control herds. Using the validated stochastic simulation model, the control herds had a stable time average bulk tank SCC between 500,000 and 750,000/ml.
Webb Ware, J K; Larsen, J W A; Kluver, P
To assess the financial effect of programs for controlling bovine Johne's disease (BJD) in beef herds. A spreadsheet simulation model of a self-replacing beef herd in south-eastern Australia selling 400-kg steers at 15 months old. The model calculated the monthly cash flow, and net present value (NPV) of cumulative cash flow, over 10 years. Four main control options were compared: (1) a base herd (no action to control the disease), (2) test and cull, and (3) partial and (4) total destocking. It was assumed that BJD was eradicated after 3 and 5 years with total and partial destocking, respectively, and not eradicated with a test and cull program. Scenarios were compared for both commercial and stud enterprises. If there was no discount on the sale price of cattle in commercial herds, deaths from BJD had to exceed 5% before the NPV of partial or total destocking was similar to taking no action to control the disease over a 10-year period. When cattle sales incurred a 10% discount, deaths had to exceed 1% before the destocking strategies would break even after 10 years. Control options for BJD should be carefully planned on an individual herd basis, as significant production and financial risks accompany destocking programs. Eradication will only be more profitable in the longer term, compared with living with the disease, when discounts on the sale of stock from infected herds are high. This can occur with the selling of store cattle or breeders. In stud herds, BJD will usually cause the total failure of the business. © 2012 The Authors. Australian Veterinary Journal © 2012 Australian Veterinary Association.
Moloney, B J; Heuer, C; Kirkland, P D
To determine the influence of farm-level and animal-level factors on the seroprevalence of antibodies to Neospora caninum and associations between seropositivity and reproductive outcomes. A questionnaire for a cross-sectional survey was posted to the 63 properties with a herd size ≥50 beef breeding cows that had participated in a previous seroprevalence study. Correspondence analysis, which does not appear to have been used previously in any Australian studies of livestock diseases, was used in conjunction with logistic regression to analyse the data. Geographic factors that increased the risk of seropositivity included higher rainfall North Coast location. Herd management factors that increased the risk of seropositivity included the use of Bos indicus genetics, cross-breeding and running several breeds in the one herd. Using fox control measures was found to be protective against infection with N. caninum. The risk of abortion was 12-fold greater in individual animals that were seropositive for N. caninum. Within a herd, the calving rate was 10.4% lower in herds with one or more N. caninum-positive animals (P = 0.03), but the difference in abortion rate was not significant between seropositive and seronegative herds (0.3% higher, P > 0.3). This study confirmed previous observations of increased risks for N. caninum seropositivity with being located in the coastal subtropics, some styles of herd management and canid exposure. In addition, it suggested that cross-breeding and proximity to an urban area may increase the risk, and that having pet dogs may reduce the risk of seropositivity. © 2017 State of New South Wales.
Jørgensen, H J; Nordstoga, A B; Sviland, S; Zadoks, R N; Sølverød, L; Kvitle, B; Mørk, T
Many free-stall bovine dairy herds in Norway fail to eradicate Streptococcus agalactiae despite long-term control measures. In a longitudinal study of 4 free-stall herds with automatic milking systems (AMS), milk and extramammary sites were sampled 4 times with 1-2 month intervals. Composite milk, rectal- and vaginal swabs were collected from dairy cows; rectal swabs from heifers and young stock; rectal- and tonsillar swabs from calves; and environmental swabs from the AMS, the floors, cow beds, watering and feeding equipment. A cross sectional study of 37 herds was also conducted, with 1 visit for environmental sampling. Fifteen of the herds were known to be infected with S. agalactiae while the remaining 22 had not had evidence of S. agalactiae mastitis in the preceding 2 years. All samples were cultured for S. agalactiae, and selected isolates (n=54) from positive herds were genotyped by Multi Locus Sequence Typing (MLST). Results show that the bovine gastrointestinal tract and the dairy cow environment are reservoirs of S. agalactiae, and point to the existence of 2 transmission cycles; a contagious transmission cycle via the milking machine and an oro-fecal transmission cycle, with drinking water as the most likely vehicle for transmission. Ten sequence types were identified, and results suggest that strains differ in their ability to survive in the environment and transmit within dairy herds. Measures to eradicate S. agalactiae from bovine dairy herds should take into account the extra-mammary reservoirs and the potential for environmental transmission of this supposedly exclusively contagious pathogen. Copyright © 2016. Published by Elsevier B.V.
Patrick Valkenburg et al.
Full Text Available After growing continuously for nearly 15 years, the Delta caribou herd began to decline in 1989. Most other Interior Alaskan herds also began declining. In the Delta herd, and in other herds, the declines were caused primarily by high summer mortality of calves and increased natural mortality of adult females. Other minor causes included increased winter mortality of calves, and reduced parturition rates of 3-year-old and older females. The decline in the Delta herd also coincided with increased wolf (Canis lupus numbers, winters with deeper than normal snow, and warm summers. Mean body weight of annual samples of 10-month-old female calves was consistently low during the decline. Except in some of the smallest Interior Alaskan herds, we conclude that evidence for population regulation in Alaskan caribou is weak, and that herds are likely to fluctuate within a wide range of densities due to complex interactions of predation and weather. Unless wolf numbers are influenced by man, the size of a caribou herd in a given year is likely to be largely a function of its size during the previous population low and the number of years of favorable weather in the interim.
Herd-level prevalence and associated risk factors for Toxoplasma gondii, Neospora caninum, Chlamydia abortus and bovine viral diarrhoea virus in commercial dairy and beef cattle in eastern, northern and northeastern China.
Sun, Wu-Wen; Meng, Qing-Feng; Cong, Wei; Shan, Xiao-Feng; Wang, Chun-Feng; Qian, Ai-Dong
Although the seroprevalence of Toxoplasma gondii, Neospora caninum, Chlamydia abortus and bovine viral diarrhea virus infection in cattle have been reported in some areas in China, most of them were conducted with small number of cattle samples and very limited districts and neglected the assessment of herd management factors associated with herd-level prevalence of these pathogen infections. Thus, from September 2013 to December 2014, a large-scale seroprevalence study was conducted to determine the animal-level and herd-level seroprevalence and identify herd-level risk factors associated with these pathogen infections in 4487 cattle from 134 herds in five provinces (Heilongjiang, Jilin, Liaoning, Shandong, Hebei) and Inner Mongolia Autonomous Region of China. At animal level, the true prevalence of antibodies against T. gondii, N. caninum, C. abortus and bovine viral diarrhoea virus (BVDV) was 10.48, 17.14, 11.92 and 50.10%, respectively. At herd level, the true prevalence of antibodies against T. gondii, N. caninum, C. abortus and BVDV was 27.16, 29.10, 37.31 and 40.30%, respectively. Multivariate analysis of these characteristics showed that source of water and presence of felids were significantly associated with T. gondii infection in the studied cattle herds. Source of water was significantly associated with N. caninum infection in the studied cattle herds. While herd size and management system were significantly associated with BVDV infection in the studied cattle herds, this is the first report of herd-level prevalence and associated risk factors of T. gondii, N. caninum, C. abortus and BVDV infection in cattle in China.
Afzal, Mamuna; Abidi, Soad; Mikkelsen, Heidi
We have sequenced a Danish isolate of Mycobacterium avium subspecies paratuberculosis, strain Ejlskov2007. The strain was isolated from faecal material of a 48 month old second parity Danish Holstein cow, with clinical symptoms of chronic diarrhoea and emaciation. The cultures were grown on Löwen......We have sequenced a Danish isolate of Mycobacterium avium subspecies paratuberculosis, strain Ejlskov2007. The strain was isolated from faecal material of a 48 month old second parity Danish Holstein cow, with clinical symptoms of chronic diarrhoea and emaciation. The cultures were grown......, consisting of 4317 unique gene families. Comparison with M. avium paratuberculosis strain K10 revealed only 3436 genes in common (~70%). We have used GenomeAtlases to show conserved (and unique) regions along the Ejlskov2007 chromosome, compared to 2 other Mycobacterium avium sequenced genomes. Pan......-genome analyses of the sequenced Mycobacterium genomes reveal a surprisingly open and diverse set of genes for this bacterial genera....
Nielsen, Elisabeth Okholm; Lauritsen, Klara Tølbøll; Friis, Niels Filskov
on porcine serum following experimental Mycoplasma infections as well as by analysis of samples from one Danish herd known to be free of M. hyosynoviae and samples from two Norwegian herds without clinical suspicion of M. hyosynoviae infections since their establishment. The epidemiology of M. hyosynoviae...... determined by culture of cross-sectional samples of whole-blood (n = 238) and tonsil scrapings (n = 322), respectively. Levels of serum antibodies (n = 396) were measured by the novel indirect ELISA test. There was no significant difference in the ELISA results between the MhA and the MhC herds. Pigs...
Parker Gaddis, K L; Cole, J B; Clay, J S; Maltecca, C
Genetic improvement of dairy cattle health through the use of producer-recorded data has been determined to be feasible. Low estimated heritabilities indicate that genetic progress will be slow. Variation observed in lowly heritable traits can largely be attributed to nongenetic factors, such as the environment. More rapid improvement of dairy cattle health may be attainable if herd health programs incorporate environmental and managerial aspects. More than 1,100 herd characteristics are regularly recorded on farm test-days. We combined these data with producer-recorded health event data, and parametric and nonparametric models were used to benchmark herd and cow health status. Health events were grouped into 3 categories for analyses: mastitis, reproductive, and metabolic. Both herd incidence and individual incidence were used as dependent variables. Models implemented included stepwise logistic regression, support vector machines, and random forests. At both the herd and individual levels, random forest models attained the highest accuracy for predicting health status in all health event categories when evaluated with 10-fold cross-validation. Accuracy (SD) ranged from 0.61 (0.04) to 0.63 (0.04) when using random forest models at the herd level. Accuracy of prediction (SD) at the individual cow level ranged from 0.87 (0.06) to 0.93 (0.001) with random forest models. Highly significant variables and key words from logistic regression and random forest models were also investigated. All models identified several of the same key factors for each health event category, including movement out of the herd, size of the herd, and weather-related variables. We concluded that benchmarking health status using routinely collected herd data is feasible. Nonparametric models were better suited to handle this complex data with numerous variables. These data mining techniques were able to perform prediction of health status and could add evidence to personal experience in herd
Ian G Handel
Full Text Available Bovine viral diarrhoea, caused by the bovine viral diarrhoea virus (BVDV in the Pestivirus genus of the Flaviviridae, is one of the most important diseases of cattle world wide causing poor reproductive performance in adult cattle and mucosal disease in calves. In addition it causes immunosuppression and increased susceptibility to other infections, the impact of which is uncertain, particularly in sub-Saharan Africa where animals are exposed to a much wider range and higher intensity of infections compared to Europe. There are no previous estimates of the seroprevalence of BVDV in cattle in Cameroon. This paper describes the serological screening for antibodies to BVDV and antigen of BVDV in a cattle population in the Adamawa Region of Cameroon in 2000. The estimates of herd-level and within herd seroprevalences adjusted for test imperfections were 92% and 30% respectively and 16.5% of herds were classed as having a persistently infected calf (PI in the herd within the last year based on the "spot" test approach. There was evidence of clustering of herds with PI calves across the north and west of the Region which corresponds with the higher cattle density areas and of self-clearance of infection from herds. A multivariable model was developed for the risk of having a PI calf in the herd; proximity to antelope, owning a goat, mixing with > 10 other herds at grazing and the catchment area of the veterinary centre the herd was registered at were all significant risk factors. Very little is known about BVDV in sub-Saharan Africa and these high seroprevalences suggest that there is a large problem which may be having both direct impacts on fertility and neonate mortality and morbidity and also indirect effects through immunosuppression and susceptibility to other infections. Understanding and accounting for BVDV should be an important component of epidemiological studies of other diseases in sub-Saharan Africa.
Tang, Sheila Tuyet; Lund, Ole; Jungersen, Gregers
Identification of bovine MHC class II reactive peptides that are specific/unique to paratuberculosis and conserved across pathogenic variations of the paratuberculosis proteome will be of high value for development of new vaccines and immune based diagnostics. Here, we present an in silico screen...... by statistical significance. BMC Bioinformatics, 2003. 4: p. 21. 2. Nielsen, M., et al., Quantitative predictions of peptide binding to any HLA-DR molecule of known sequence: NetMHCIIpan. PLoS Comput Biol, 2008. 4(7): p. e1000107....
Atreya, Raja; Bülte, Michael; Gerlach, Gerald-F; Goethe, Ralph; Hornef, Mathias W; Köhler, Heike; Meens, Jochen; Möbius, Petra; Roeb, Elke; Weiss, Siegfried
Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of paratuberculosis (Johne's disease [JD]), a chronic granulomatous enteritis in ruminants. JD is one of the most widespread bacterial diseases of domestic animals with significant economic impact. The histopathological picture of JD resembles that of Crohn's disease (CD), a human chronic inflammatory bowel disease of still unresolved aetiology. An aetiological relevance of MAP for CD has been proposed. This and the ambiguity of other published epidemiological findings raise the question whether MAP represents a zoonotic agent. In this review, we will discuss evidence that MAP has zoonotic capacity. Copyright © 2014 Elsevier GmbH. All rights reserved.
Stege, H.; Jensen, Tim Kåre; Møller, Kristian
Our aim was to determine the prevalence of the intestinal bacteria: Lawsonia intracellularis, Brachyspira hyodysenteriae, Serpulina intermedia, Brachyspira innocens, Brachyspira pilosicoli, pathogenic Escherichia coli (serogroups 0138, 0139, 0141 and 0149) and Salmonella enterica in Danish...... were collected and examined by polymerase chain reaction (PCR) or culture. L. intracellularis was found in 74 herds (93.7%), B. hyodysenteriae in two herds (2.5%), S. intermedia in 10 herds (12.7%), B. innocens in 27 herds (34.2%), B. pilosicoli in 15 herds (19.0%), pathogenic E. call in 19 herds (24...
Yu, Han; Miao, Chunyan; Leung, Cyril; Chen, Yiqiang; Fauvel, Simon; Lesser, Victor R; Yang, Qiang
Hierarchical crowdsourcing networks (HCNs) provide a useful mechanism for social mobilization. However, spontaneous evolution of the complex resource allocation dynamics can lead to undesirable herding behaviours in which a small group of reputable workers are overloaded while leaving other workers idle. Existing herding control mechanisms designed for typical crowdsourcing systems are not effective in HCNs. In order to bridge this gap, we investigate the herding dynamics in HCNs and propose a Lyapunov optimization based decision support approach - the Reputation-aware Task Sub-delegation approach with dynamic worker effort Pricing (RTS-P) - with objective functions aiming to achieve superlinear time-averaged collective productivity in an HCN. By considering the workers' current reputation, workload, eagerness to work, and trust relationships, RTS-P provides a systematic approach to mitigate herding by helping workers make joint decisions on task sub-delegation, task acceptance, and effort pricing in a distributed manner. It is an individual-level decision support approach which results in the emergence of productive and robust collective patterns in HCNs. High resolution simulations demonstrate that RTS-P mitigates herding more effectively than state-of-the-art approaches.
Pritchard, Tracey C; Coffey, Mike P; Bond, Karen S; Hutchings, Mike R; Wall, Eileen
The effect of subclinical paratuberculosis (or Johne's disease) risk status on performance, health, and fertility was studied in 58,096 UK Holstein-Friesian cows with 156,837 lactations across lactations 1 to 3. Low-, medium-, and high-risk group categories were allocated to cows determined by a minimum of 4 ELISA milk tests taken at any time during their lactating life. Lactation curves of daily milk, protein, and fat yields and protein and fat percentage, together with log e -transformed somatic cell count, were estimated using a random regression model to quantify differences between risk groups. The effect of subclinical paratuberculosis risk groups on fertility, lactation-average somatic cell count, and mastitis were analyzed using linear regression fitting risk group as a fixed effect. Milk yield losses associated with high-risk cows compared with low-risk cows in lactations 1, 2, and 3 for mean daily yield were 0.34, 1.05, and 1.61kg; likewise, accumulated 305-d yields were 103, 316, and 485kg, respectively. The total loss was 904kg over the first 3 lactations. Protein and fat yield losses associated with high-risk cows were significant, but primarily a feature of decreasing milk yield. Similar trends were observed for both test-day and lactation-average somatic cell count measures with higher somatic cell counts from medium- and high-risk cows compared with low-risk cows, and differences were in almost all cases significant. Likewise, mastitis incidence was significantly higher in high-risk cows compared with low-risk cows in lactations 2 and 3. Whereas the few significant differences between risk groups among fertility traits were inconsistent with no clear trend. These results are expected to be conservative, as some animals that were considered negative may become positive after the timeframe of this study, particularly if the animal was tested when relatively young. However, the magnitude of milk yield losses together with higher somatic cell counts and
Keshavarzi, Hamideh; Sadeghi-Sefidmazgi, Ali; Kristensen, Anders Ringgaard
Abortions, especially those occurring during late pregnancy, lead to considerable economic losses. To estimate the financial losses related to pregnancy loss, at first the influencing factors on abortion need to be identified. Thus, the objective of this study was to determine and quantify the risk...... factors and their interactions for abortion in Iranian dairy herds. Based on data from 6 commercial herds, logistic regression was used to identify the risk factors for abortion. The basic time unit used in the study was a 3-week period corresponding to an estrus cycle. Thus, stage of lactation...... factors were herd effect, pregnancy stage, previous abortion, calving month, cumulative fat corrected milk (FCM) yield level, mastitis in current 3-weeks in milk, accumulated number of mastitis and all 2-way interactions. Pregnancy tests were performed between 35 and 50 days after insemination. Abortion...
Thysen, Iver; Enevoldsen, Carsten
Two complementary approaches to produce visual information from reproduction records are described and exemplified. The Event Display shows all reproductive events, over a year, for all cows in a herd, by symbols placed in an array with columns representing calendar weeks and rows representing...... individual cows. The Reproduction Monitor consists of graphs of insemination and pregnancy rates evaluated weekly with a Bayesian technique. These visual monitoring tools are well suited to explore temporal variation in reproductive performance, they provide a quick overview of herd performance...
Mariana Noelia Viale
Full Text Available The binding and ingestion of Mycobacterium avium subsp. paratuberculosis (MAP by host cells are fibronectin (FN dependent. In several species of mycobacteria, a specific family of proteins allows the attachment and internalization of these bacteria by epithelial cells through interaction with FN. Thus, the identification of adhesion molecules is essential to understand the pathogenesis of MAP. The aim of this study was to identify and characterize FN binding cell wall proteins of MAP. We searched for conserved adhesins within a large panel of surface immunogenic proteins of MAP and investigated a possible interaction with FN. For this purpose, a cell wall protein fraction was obtained and resolved by 2D electrophoresis. The immunoreactive spots were identified by MALDI-TOF MS and a homology search was performed. We selected elongation factor Tu (EF-Tu as candidate for further studies. We demonstrated the FN-binding capability of EF-Tu using a ligand blot assay and also confirmed the interaction with FN in a dose-dependent manner by ELISA. The dissociation constant of EF-Tu was determined by surface plasmon resonance and displayed values within the μM range. These data support the hypothesis that this protein could be involved in the interaction of MAP with epithelial cells through FN binding.
Ayral, Florence C; Bicout, Dominique J; Pereira, Helena; Artois, Marc; Kodjo, Angeli
A retrospective study was conducted to identify and describe the distribution pattern of Leptospira serogroups in domestic animals in France. The population consisted of cattle herds and dogs with clinically suspected leptospirosis that were tested at the "Laboratoire des Leptospires" between 2008 and 2011. The laboratory database was queried for records of cattle and dogs in which seroreactivity in Leptospira microagglutination tests was consistent with a recent or current infection, excluding vaccine serogroups in dogs. A total of 394 cattle herds and 232 dogs were diagnosed with clinical leptospirosis, and the results suggested infection by the Leptospira serogroup Australis in 43% and 63%, respectively; by the Leptospira serogroup Grippotyphosa in 17% and 9%, respectively; and by the Leptospira serogroup Sejroe in 33% and 6%, respectively. This inventory of infecting Leptospira serogroups revealed that current vaccines in France are not fully capable of preventing the clinical form of the disease. © The American Society of Tropical Medicine and Hygiene.
Zhao, Zheng; Zhang, YongJie; Feng, Xu; Zhang, Wei
In this paper, we build undirected weighted networks to study herding behavior among analysts and to analyze the characteristics and the structure of these networks. We then construct a new indicator based on the average degree of nodes and the average weighted clustering coefficient to research the various types of herding behavior. Our findings suggest that every industry has, to a certain degree, herding behavior among analysts. While there is obvious uninformed herding behavior in real estate and certain other industries, industries such as mining and nonferrous metals have informed herding behavior caused by analysts’ similar reactions to public information. Furthermore, we relate the two types of herding behavior to stock price and find that uninformed herding behavior has a positive effect on market prices, whereas informed herding behavior has a negative effect.
Wong, Kachun; Peng, Chengbin; Li, Yue; Chan, Takming
, this principle is used to develop a new clustering algorithm. Inspired by herd behavior, the clustering method is a synergistic approach using collective intelligence called Herd Clustering (HC). The novel part is laid in its first stage where data instances
Wallgren, Per; Nörregård, Erik; Molander, Benedicta; Persson, Maria; Ehlorsson, Carl-Johan
Respiratory illness is traditionally regarded as the disease of the growing pig, and has historically mainly been associated to bacterial infections with focus on Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae. These bacteria still are of great importance, but continuously increasing herd sizes have complicated the scenario and the influence of secondary invaders may have been increased. The aim of this study was to evaluate the presence of A. pleuropneumoniae and M. hyopneumoniae, as well as that of the secondary invaders Pasteurella multocida and Streptococcus suis by serology in four pig herds (A-D) using age segregated rearing systems with high incidences of pleuritic lesions at slaughter. Pleuritic lesions registered at slaughter ranged from 20.5 to 33.1 % in the four herds. In herd A, the levels of serum antibodies to A. pleuropneumoniae exceeded A 450 > 1.5, but not to any other microbe searched for. The seroconversion took place early during the fattening period. Similar levels of serum antibodies to A. pleuropneumoniae were also recorded in herd B, with a subsequent increase in levels of antibodies to P. multocida. Pigs seroconverted to both agents during the early phase of the fattening period. In herd C, pigs seroconverted to P. multocida during the early phase of the fattening period and thereafter to A. pleuropneumoniae. In herd D, the levels of antibodies to P. multocida exceeded A 450 > 1.0 in absence (A 450 hyopneumoniae and to S. suis remained below A 450 hyopneumoniae late during the rearing period (herd B-D), or not at all (herd A). Different serological patterns were found in the four herds with high levels of serum antibodies to A. pleuropneumoniae and P. multocida, either alone or in combination with each other. Seroconversion to M. hyopneumoniae late during the rearing period or not at all, confirmed the positive effect of age segregated rearing in preventing or delaying infections with M
Zervens, Lisa Marie-Louise; Nielsen, Søren Saxmose; Jungersen, Gregers
Although colostrum has been used to detect specific immunoglobulin (Ig) G to Mycobacterium avium subsp. paratuberculosis (MAP) in cattle, confounding, non-specific reactions can be a problem. The objectives of this study were to determine the proportion of non-specific ELISA reactions in samples...
Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne’s disease in domestic animals and has been implicated in Crohn’s disease in humans. This bacterium is a slow growing, gram-positive, acid-fast organism which can be difficult to culture from the environment. For ...
Herthnek, D.; Englund, S.; Willemsen, P.T.J.; Bolske, G.
Aims: To develop a fast and sensitive protocol for detection of Mycobacterium avium subsp. paratuberculosis (MAP) in bovine semen and to make a critical evaluation of the analytical sensitivity. Methods and Results: Processed semen was spiked with known amounts of MAP. Semen from different bulls as
Langley, D.J.; Hoeve, M.; Ortt, J.R.; Pals, N.
Herding is convergent social behavior driven by inter-personal interaction, without centralized coordination. Herding in the online setting, which we call e-herding, is important for marketing scholars and practitioners because of its potential impact on product adoption and brand image and because
Stadtmann, Georg; Pierdzioch; Rülke
Price trends in housing markets may reflect herding of market participants. A natural question is whether such herding, to the extent that it occurred, reflects herding in forecasts of professional forecasters. Using more than 6,000 forecasts of housing approvals for Australia, we did not find...
... date of movement. If a group of captive cervids from a qualified herd is being moved interstate... unclassified herd. (4) Captive cervids being moved interstate for the purpose of exhibition only may be moved... being moved directly from a classified herd, the captive cervid must be isolated from all other animals...
Reardon, Fiona; Graham, David A; Clegg, Tracy A; Tratalos, Jamie A; O'Sullivan, Padraig; More, Simon J
A compulsory national programme to eradicate bovine viral diarrhoea virus (BVDv) began in Ireland on 1 January, 2013. The objective of the current study was to quantify the role of Trojan dams (animal(s) not persistently infected (PI) with BVDv but carrying PI foetus(es) and introduced to the herd while pregnant with the PI foetus(es)) in the farm-to-farm spread of BVDv in Ireland, and to identify herd-level risk factors for producing or introducing a Trojan dam. The study population included all BVD+ calves born in Ireland between 1 January, 2013 and 31 December, 2015, along with their dams. BVD+ calves included all calves on the national programme database with an initial positive or inconclusive virus test, without a confirmatory re-test (status BVDPOS) and those with an initial positive or inconclusive test and a positive confirmatory test (status BVDPI). The Trojan status of dams was determined after considering their history of movement and of potential BVDV exposure, relative to a defined window of susceptibility (WOS; days 30-120 of gestation). During 2013-15, there were 29,422 BVD+ birth events to dams that were not themselves BVD+, including 2526 (8.6%) most-likely attributable to Trojan dams. The percentage of these birth events attributable to Trojan dams was significantly different (P Trojan dam. In 2014 and 2015, the percentages were 11.8% and 13.3%, respectively. In 2013, in 7.8% of herds with one or more BVD+ birth to non-BVD+ dams, all of these births were attributable to Trojan dams. In 2014 and 2015, the percentages were 9.2% and 10.7%, respectively. A logistic GEE regression identified dam parity, herd size and an interaction between herd type and season as significant predictors for the birth of a BVD+ calf to a Trojan dam. Significant predictors for the sale of a Trojan dam from BVD+ herds included those selling more than one pregnant female and those with more than 2 BVD+ animals in the herd. Introduction of pregnant adult females is a
Knage-Rasmussen, Kristian Møllegaard; Houe, Hans; Rousing, Tine
included in the study were clinical parameters and factors related to the production system. Sows were examined visually by one of four trained observers. The organic sows were assigned scores for lameness, body condition, hoof length, bursitis, abscesses and leg wounds, while the conventional sows were...... assigned scores for lameness, body condition and bursitis. A multivariable analysis was carried out by logistic regression with the herd and observer as random effects. The average herd lameness prevalence in gestation and lactation sows in organic herds was 11% in summer/autumn and 4.6% in winter....../spring. ‘Wounds, bursitis and abscess’ on legs (OR=4.7, P3 (OR=1.79, P=0.008) were associated with increased risk of lameness in Danish organic sow herds. Season (winter/spring v. summer/autumn) lowered the risk of lameness (OR=0.37, P
Robert A. Dieterich
Full Text Available Approximately 20000 reindeer (Rangifer tarandus in Alaska are gathered once or twice yearly to facilitate identification, serologic sampling, treatment and antler removal. Various air and land craft are used to bring the animals into a corral system from which they can be herded into a padded, pneumatically operated, squeeze apparatus. Ear tags are applied or read if already in place and ears are notched. A portable, computerized rapid data retrieval system is used to record reproductive success, vaccination and treatment status and other miscellaneous information. Ivermectin is being administered in the early winter months to treat reindeer in many herds for warbles, nasal bots and internal parasites. A killed, homologous Brucella suis type 4 vaccine is being used in two large (3500 herds. Efforts are being made to incorporate other innovative methods to improve herding and corralling methods.
Griffin, J.F.T.; Hughes, A.D.; Liggett, S.; Farquhar, P.A.; Mackintosh, C.G.; Bakker, D.
Mycobacterium avium subsp. paratuberculosis [MAP], the Causative agent of enteric Johne's disease, incurs significant economic losses to the livestock industry. Prophylactic vaccination can be employed as a control means, however mineral oil-based vaccines Currently in practice have limited
Rodolakis, A; Berri, M; Héchard, C; Caudron, C; Souriau, A; Bodier, C C; Blanchard, B; Camuset, P; Devillechaise, P; Natorp, J C; Vadet, J P; Arricau-Bouvery, N
The shedding of Coxiella burnetii in bovine, caprine, and ovine milk was measured using PCR, in 3 herds for each species, the bulk tank milk samples of which were positive at the time of their selection. Milk samples of 95 cows, 120 goats, and 90 ewes were sampled over 16 wk, as was the bulk tank milk. The shedding of C. burnetii in vaginal mucus and feces was checked at the beginning of the experiment and 2 mo later. The clinical signs in the selected herds as well as the duration and the shedding routes differed among the 3 species. The cows were asymptomatic and shed C. burnetii almost exclusively in milk. In one of the caprine herds, abortions due to C. burnetii were reported. The goats excreted the bacteria mainly in milk. In contrast, the ewes, which came from flocks with abortions due to Q fever (C. burnetii infection), shed the bacteria mostly in feces and in vaginal mucus. This could explain why human outbreaks of Q fever are more often related to ovine flocks than to bovine herds. These excretions did not seem more frequent when the samples were taken close to parturition. The samples were taken from 0 to 421 d after parturition in bovine herds and from 5 to 119 d and 11 to 238 d after parturition in the caprine and ovine herds, respectively. The shedding in milk was sometimes intermittent, and several animals shed the bacteria but were negative by ELISA: 80% of the ewes were seronegative, underscoring the lack of sensitivity of the ELISA tests available for veterinary diagnosis. The detection of antibodies in milk seems more sensitive than it is in serum.
Full Text Available In order to survey the behaviour of choosing the alley area instead of a cubicle as a lying place (cubicle refusal, a questionnaire was sent to the 273 dairy farms in Norway known to keep cows in cubicle housing systems. Sixty-six percent of the farmers contacted were included in the study. The median herd size was 18 cows (range 7–118. More than 85% of the herds had sheds providing one or more cubicles per cow. The mean herd occurrence of cubicle refusal was 6%, but showed great variation (range 0–55%. Regression analysis showed a significant association between rearing heifers in slatted floor pens and an increased cubicle refusal occurrence (p = 0.02, R2 = 0.05, while herd size, use of litter, or cubicle-to-animal ratio were not found to be associated with cubicle refusal. The practice of rearing heifers in slatted floor pens accounted for about one half of the observed cubicle refusal (etiologic fraction = 0.51.
Hogerwerf, Lenny; Courcoul, Aurélie; Klinkenberg, Don; Beaudeau, François; Vergu, Elisabeta; Nielen, Mirjam
Between 2007 and 2009, the largest human Q fever epidemic ever described occurred in the Netherlands. The source was traced back to dairy goat farms, where abortion storms had been observed since 2005. Since one putative cause of these abortion storms is the intensive husbandry systems in which the goats are kept, the objective of this study was to assess whether these could be explained by herd size, reproductive pattern and other demographic aspects of Dutch dairy goat herds alone. We adapted an existing, fully parameterized simulation model for Q fever transmission in French dairy cattle herds to represent the demographics typical for Dutch dairy goat herds. The original model represents the infection dynamics in a herd of 50 dairy cows after introduction of a single infected animal; the adapted model has 770 dairy goats. For a full comparison, herds of 770 cows and 50 goats were also modeled. The effects of herd size and goat versus cattle demographics on the probability of and time to extinction of the infection, environmental bacterial load and abortion rate were studied by simulation. The abortion storms could not be fully explained by demographics alone. Adequate data were lacking at the moment to attribute the difference to characteristics of the pathogen, host, within-herd environment, or a combination thereof. The probability of extinction was higher in goat herds than in cattle herds of the same size. The environmental contamination was highest within cattle herds, which may be taken into account when enlarging cattle farming systems.
Nylin, Britta; Strøger, Ulla; Rønsholt, Leif
Bulk-tank milk samples analysed in a Bovine Herpesvirus-1 (BHV-1) blocking ELISA are still in use in the Danish BHV-1 programme as a tool to classify dairy herds as BHV-1 infected or BHV-1 free herds. in this retrospective study, we used data from the Danish BHV-1 eradication campaign to evaluate...
Byrne, Andrew W; McBride, Stewart; Lahuerta-Marin, Angela; Guelbenzu, Maria; McNair, Jim; Skuce, Robin A; McDowell, Stanley W J
Liver fluke (Fasciola hepatica) is a widespread parasite of ruminants which can have significant economic impact on cattle production. Fluke infection status at the animal-level is captured during meat inspection of all animals processed for human consumption within Northern Ireland. These national datasets have not been analysed to assess their utility in uncovering patterns in fluke infection at animal- and herd-levels in Northern Ireland. We utilised a dataset of 1.2 million animal records from ~18,000 herds across 3 years (2011-2013) to assess animal- and herd-level apparent prevalence and risk-factors associated with fluke infection. Animal-level apparent prevalence was measured as the proportion of animals exhibiting evidence of fluke infection at slaughter; between herd-level infection prevalence was measured by binary categorisation of herds (infected or not). "Within herd" infection prevalence was measured using the proportion of animals within a herd that showed evidence of fluke infection per year (ranging from 0-100%). "Within herd" infection prevalence at the herd level was investigated using multivariable modelling. At the animal level, the proportion of animals slaughtered that exhibited evidence of infection was 21-25% amongst years. Across herds, the proportion of herds with at least one infected animal, varied between 61 and 65%. However, there was a significant sampling effect at the herd-level; all herds where at least 105 animals slaughtered over the study period exhibited evidence of fluke infection (100%). There was significant variation in terms of within-herd infection prevalence. Risk factors included herd type, long-term weather variation, geographic location (region) and the abattoir. Liver fluke apparent prevalence was high at the herd-level across years. However, there was lower prevalence at the animal level, which may indicate significant variation in the exposure to fluke infection within herds. The proportion infected within-herds
Full Text Available We used the Wall Street Journal survey data for the period 2006–2012 to analyze whether forecasts of house prices and housing starts provide evidence of (anti-herding of forecasters. Forecasts are consistent with herding (anti-herding of forecasters if forecasts are biased towards (away from the consensus forecast. We found that anti-herding is prevalent among forecasters of house prices. We also report that, following the recent crisis, the prevalence of forecaster anti-herding seems to have changed over time.
Stadtmann, Georg; Pierdzioch; Ruelke
We used the Wall Street Journal survey data for the period 2006–2012 to analyze whether forecasts of house prices and housing starts provide evidence of (anti-)herding of forecasters. Forecasts are consistent with herding (anti-herding) of forecasters if forecasts are biased towards (away from) t......) the consensus forecast. We found that anti-herding is prevalent among forecasters of house prices. We also report that, following the recent crisis, the prevalence of forecaster anti-herding seems to have changed over time....
Bennedsgaard, Torben W.; Thamsborg, Stig M.; Aarestrup, Frank Møller
Background: Quarter milk samples from cows with high risk of intramammary infection were examined to determine the prevalence of Staphylococcus aureus (SA) and penicillin resistant SA (SAr) in conventional and organic dairy herds and herds converting to organic farming in a combined longitudinal......: 2%-5%) respectively. The prevalence of penicillin resistance among SA infected cows was 12% (95% confidence interval: 6%-19%) when calculated from the first herd visits. No statistically significant differences were observed in the prevalence of SAr or the proportion of isolates resistant...... to penicillin between herd groups. Conclusion: The proportion of isolates resistant to penicillin was low compared to studies in other countries except Norway and Sweden. Based on the low prevalence of penicillin resistance of SA, penicillin should still be the first choice of antimicrobial agent for treatment...
Tegtmeier, C.; Stryhn, H.; Uttenthal, Åse
A study was conducted in 1994-96 with the aim of assessing the serological prevalence of Border Disease (BD) among sheep and goats in Denmark and to investigate possible relations to herd factors. From each of 1000 herds, 2 blood samples were obtained from animals older than 1 year. The examination.......50. There was no difference between the prevalence in sheep and goat herds. Records for well over half of the herds could be combined with data from the Danish Central Husbandry Register. No association between occurrence of ED and herd size was found. Cattle were registered as contemporarily present on 135 out of 521 herds...... which was shown to be strongly associated to ED. The estimated herd prevalences of ED among farms with and without contemporary cattle were 0.24 and 0.042, respectively....
Foddai, Alessandro; Stockmarr, Anders; Boklund, Anette
The temporal sensitivity of the surveillance system (TemSSe) for Bovine Viral Diarrhea (BVD) in Danish dairy herds was evaluated. Currently, the Danish antibody blocking ELISA is used to test quarterly bulk tank milk (BTM). To optimize the surveillance system as an early warning system, we considered the possibility of using the SVANOVIR ELISA, as this test has been shown to detect BVD-positive herds earlier than the blocking ELISA in BTM tests. Information from data (2010) and outputs from two published stochastic models were fed into a stochastic scenario tree to estimate the TemSSe. For that purpose we considered: the risk of BVD introduction into the dairy population, the ELISA used and the high risk period (HRP) from BVD introduction to testing (at 90 or 365 days). The effect of introducing one persistently infected (PI) calf or one transiently infected (TI) milking cow into 1 (or 8) dairy herd(s) was investigated. Additionally we estimated the confidence in low (PLow) herd prevalence (tree methodology, could be applied to optimize early warning surveillance systems of different animal diseases.
Elise A Lamont
Full Text Available Mycobacteria are able to enter into a state of non-replication or dormancy, which may result in their chronic persistence in soil, aquatic environments, and permissive hosts. Stresses such as nutrient deprivation and hypoxia provide environmental cues to enter a persistent state; however, a clear definition of the mechanism that mycobacteria employ to achieve this remains elusive. While the concept of sporulation in mycobacteria is not novel, it continues to spark controversy and challenges our perceptions of a non-replication. We investigated the potential role of sporulation in one-year old broth cultures of Mycobacterium subsp. paratuberculosis (MAP. We show that dormant cultures of MAP contain a mix of vegetative cells and a previously unknown morphotype resembling a spore. These spore-like structures can be enriched for using sporulating media. Furthermore, purified MAP spore forms survive exposure to heat, lysozyme and proteinase K. Heat-treated spores are positive for MAP 16SrRNA and IS900. MAP spores display enhanced infectivity as well as maintain acid-fast characteristics upon germination in a well-established bovine macrophage model. This is the first study to demonstrate a new MAP morphotype possessing spore-like qualities. Data suggest that sporulation may be a viable mechanism by which MAP accomplishes persistence in the host and/or environment. Thus, our current understanding of mycobacterial persistence, pathogenesis, epidemiology and rational drug and vaccine design may need to be reevaluated.
Gillespie, B E; Headrick, S I; Boonyayatra, S; Oliver, S P
Coagulase-negative Staphylococcus species (CNS) were isolated from 11.3% (1407 of 12,412) of mammary quarter milk samples obtained from cows in three dairy research herds in 2005. Approximately 27% (383/1407) of CNS was identified to the species level. The species distribution among those CNS identified from all herds was Staphylococcus chromogenes (48%), Staphylococcus hyicus (26%), Staphylococcus epidermidis (10%), Staphylococcus simulans (7%), Staphylococcus warneri (2%), Staphylococcus hominis (2%), Staphylococcus saprophyticus (1%), Staphylococcus xylosus (1%), Staphylococcus haemolyticus (Staphylococcus sciuri (Staphylococcus intermedius (<1%). Staphylococcuschromogenes was the predominant CNS isolated from all three herds; however, differences were seen in the prevalence of other CNS species. A total of 158 CNS (S. chromogenesn=66, S. hyicusn=38, S. epidermidisn=37, S. simulans n=10, and S. warneri n=7) were analyzed by pulsed-field gel electrophoresis (PFGE). The majority (33/41) of CNS isolated from the same mammary quarter on more than one occasion had the same PFGE pattern indicating persistence of the same infection over time. When all PFGE patterns for each CNS were analyzed, no common pulsotype was seen among the three herds indicating that CNS are quite diverse. Composite milk somatic cell count (SCC) data were obtained +/-14d of when CNS were isolated. Average milk SCC (5.32 log(10)/ml) for cows in which CNS was the only bacteria isolated was significantly higher than the average milk SCC (4.90 log(10)/ml) from cows with quarter milk samples that were bacteriologically negative.
Alfaro, M.; Salazar, F.; Troncoso, E.; Mitchell, R. M.; Ramirez, L.; Naguil, A.; Zamorano, P.; Collins, M. T.
The study assessed the effect of soil slope on Mycobacterium avium subsp. paratuberculosis transport into rainwater runoff from agricultural soil after application of M. avium subsp. paratuberculosis-contaminated slurry. Under field conditions, 24 plots of undisturbed loamy soil 1 by 2 m2 were placed on platforms. Twelve plots were used for water runoff: 6 plots at a 3% slope and 6 plots at a 15% slope. Half of the plots of each slope were treated with M. avium subsp. paratuberculosis-contaminated slurry, and half were not treated. Using the same experimental design, 12 plots were established for soil sampling on a monthly basis using the same spiked slurry application and soil slopes. Runoff following natural rainfall was collected and analyzed for M. avium subsp. paratuberculosis, coliforms, and turbidity. M. avium subsp. paratuberculosis was detected in runoff from all plots treated with contaminated slurry and one control plot. A higher slope (15%) increased the likelihood of M. avium subsp. paratuberculosis detection but did not affect the likelihood of finding coliforms. Daily rainfall increased the likelihood that runoff would have coliforms and the coliform concentration, but it decreased the M. avium subsp. paratuberculosis concentration in the runoff. When there was no runoff, rain was associated with increased M. avium subsp. paratuberculosis concentrations. Coliform counts in runoff were related to runoff turbidity. M. avium subsp. paratuberculosis presence/absence, however, was related to turbidity. Study duration decreased bacterial detection and concentration. These findings demonstrate the high likelihood that M. avium subsp. paratuberculosis in slurry spread on pastures will contaminate water runoff, particularly during seasons with high rainfall. M. avium subsp. paratuberculosis contamination of water has potential consequences for both animal and human health. PMID:23542616
Full Text Available Saami society in Lapland (now often called Saapmi, particularly the seasonally-nomadic reindeer-breeding sector, is predicated upon mobility and autonomy of its actors. Runne-Beana, a talented reindeer-herding dog, exhibited both mobility and autonomy when allocating to himself a peripatetic ethnographer, on the first day of five years of doctoral dissertation fieldwork in arctic Norway in 1972. That family’s and the wider community’s reactions to Runne-Beana’s behavior, and mine, highlight the tensions when mobility and autonomy compound with ideologies of ownership and control. At the same time, his companionship profoundly shaped all field relationships, engendering an understanding of dog culture as it is manifest in the herder/herding dog/reindeer triad and in the interpenetration of assumptions concerning child/dog enculturation.
Bono, Claudia; Cornou, Cecile; Lundbye-Christensen, Søren
an expectation-maximization (EM) algorithm applied on a dataset containing data from 15 herds, each of them including insemination and farrowing observations over a period ranging from 150 to 800 weeks. The model included a set of parameters describing the parity-specific farrowing rate and the re......-insemination effect. It also provided reliable forecasting on weekly basis. Statistical control tools were used to give warnings in case of impaired farrowing rate. For each herd, farrowing rate profile, analysis of model components over time and detection of alarms were computed. The model provided a good overview...... of the development of the parity specific farrowing rate over time and the control charts were able to detect impaired results. Suggestions for future improvements include addition of parity-specific control charts, calibration of the charts for use in practice and inclusion of a sow effect in the farrowing model....
Mweu, Marshal M.; Nielsen, Søren S.; Hisham Beshara Halasa, Tariq
-level incidence rates and apparent prevalences of Streptococcus agalactiae (S. agalactiae) in the population of Danish dairy cattle herds over a 10-year period from 2000 to 2009 inclusive and (2) to estimate the herd-level entry and exit rates (demographic parameters), the transmission parameter, β, and recovery...... rate for S. agalactiae infection. Data covering the specified period, on bacteriological culture of all bulk tank milk samples collected annually as part of the mandatory Danish S. agalactiae surveillance scheme, were extracted from the Danish Cattle Database and subsequently analysed....... There was an increasing trend in both the incidence and prevalence of S. agalactiae over the study period. Per 100 herd-years the value of β was 54.1 (95% confidence interval [CI] 46.0–63.7); entry rate 0.3 (95% CI 0.2–0.4); infection-related exit rate 7.1 (95% CI 5.6–8.9); non-infection related exit rate 9.2 (95% CI 7...
Dieste-Pérez, L.; Frankena, K.; Blasco, J.M.; Muñoz, P.M.; Jong, de M.C.M.
Swine brucellosis caused by Brucella suis biovar 2 is an emerging disease in continental Europe. Without effective vaccines being available, the European Food Safety Authority (EFSA) recommends the full depopulation of infected herds as the only strategy to eradicate B. suis outbreaks. Using data
Dieste-Pérez, L.; Frankena, K.; Blasco, J. M.; Muñoz, P. M.; De Jong, M. C M
Swine brucellosis caused by Brucella suis biovar 2 is an emerging disease in continental Europe. Without effective vaccines being available, the European Food Safety Authority (EFSA) recommends the full depopulation of infected herds as the only strategy to eradicate B. suis outbreaks. Using data
Full Text Available The five naturally occurring and one transplanted caribou (Rangifer tarandus granti herd in southwestern Alaska composed about 20% of Alaska's caribou population in 2001. All five of the naturally occurring herds fluctuated considerably in size between the late 1800s and 2001 and for some herds the data provide an indication of long-term periodic (40-50 year fluctuations. At the present time, the Unimak (UCH and Southern Alaska Peninsula (SAP are recovering from population declines, the Northern Alaska Peninsula Herd (NAP appears to be nearing the end of a protracted decline, and the Mulchatna Herd (MCH appears to now be declining after 20 years of rapid growth. The remaining naturally occurring herd (Kilbuck has virtually disappeared. Nutrition had a significant effect on the size of 4-month-old and 10-month-old calves in the NAP and the Nushagak Peninsula Herd (NPCH and probably also on population growth in at least 4 (SAP, NAP, NPCH, and MCH of the six caribou herds in southwestern Alaska. Predation does not appear to be sufficient to keep caribou herds in southwestern Alaska from expanding, probably because rabies is endemic in red foxes (Vulpes vulpes and is periodically transferred to wolves (Canis lupus and other canids. However, we found evidence that pneumonia and hoof rot may result in significant mortality of caribou in southwestern Alaska, whereas there is no evidence that disease is important in the dynamics of Interior herds. Cooperative conservation programs, such as the Kilbuck Caribou Management Plan, can be successful in restraining traditional harvest and promoting growth in caribou herds. In southwestern Alaska we also found evidence that small caribou herds can be swamped and assimilated by large herds, and fidelity to traditional calving areas can be lost.
Gao, A; Mutharia, L; Chen, S; Rahn, K; Odumeru, J
Mycobacterium paratuberculosis (Mptb) is the causative agent of Johne's disease of ruminant animals including cattle, goats, and sheep. It has been suggested that this organism is associated with Crohn's disease in humans, and milk is a potential source of human exposure to this organism. A total of 18, including 7 regular batch and 11 high temperature short time (HTST) pasteurization experiments, were conducted in this study. Raw milk or ultra-high temperature pasteurized milk samples were spiked at levels of 10(3), 10(5), and 10(7) cfu of Mptb/ml. Escherichia coli and Mycobacterium bovis BCG strains at 10(7) cfu/ml were used as controls. Pasteurization experiments were conducted using time and temperature standards specified in the Canadian National Dairy Code: regular batch pasteurization method: 63 degrees C for 30 min, and HTST method: 72 degrees C for 15 s. The death curve of this organism was assessed at 63 degrees C. No survivors were detected after 15 min. Each spiked sample was cultured in Middlebrook 7H9 culture broth and Middlebrook 7H11 agar slants. Samples selected from 15 experiments were also subjected to BACTEC culture procedure. Survival of Mptb was confirmed by IS900-based PCR of colonies recovered on slants. No survivors were detected from any of the slants or broths corresponding to the seven regular batch pasteurization trials. Mptb survivors were detected in two of the 11 HTST experiments. One was by both slant and broth culture for the sample spiked to 10(7) cfu/ml of Mptb, while the other was detected by BACTEC for the sample spiked to 10(5) cfu/ml. These results indicate that Mptb may survive HTST pasteurization when present at > or = 10(5) cfu/ml in milk. A total of 710 retail milk samples collected from retail store and dairy plants in southwest Ontario were tested by nested IS900 PCR for the presence of Mptb. Fifteen percent of these samples (n = 110) were positive. However, no survivors were isolated from the broth and agar cultures of
Whittington, Richard J; Waldron, Anna; Warne, Darian
Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease in livestock and there is a debate about its role in humans in chronic inflammatory bowel disorders such as Crohn's disease, but the relationship remains unproven. Nevertheless livestock health authorities in many countries aim to lower the prevalence of this infection to reduce potential contamination of the human food supply. MAP may occur in bovine milk and data on thermal inactivation suggest pasteurisation is an effective process. Recently MAP has been identified in skeletal muscle of cattle and sheep but there are no data on its thermal inactivation in these substrates. In this study the inactivation of MAP was studied in a fluid homogenate of lamb skeletal muscle at temperatures previously identified as being relevant to cooking processes applied by domestic consumers. A PCR thermocycler was used to ensure accurate temperatures and rapid heat exchange, while radiometric culture was used to ensure sensitive detection of viable MAP for determination of D and z values. Among the two predominant strains of MAP, S and C, D(55) ranged from 56 to 89 min, D(60) was 8 to 11 min, D(65) was 26 to 35s while D(70) was 1.5 to 1.8s. Values for z were 4.21C degrees for the S strain and 4.51C degrees for the C strain. At temperatures of 65-70 degrees C, MAP appeared to be less heat tolerant in skeletal muscle fluid than in previous reports using milk as the medium. The total thermal exposure of MAP during baking of a sample of 16 leg-of-lamb roasts in domestic ovens was determined to result in more than 20 log reductions in most cases, that is the product was microbiologically safe. Based on the models used in this study, there is a low probability of survival of MAP provided that red meat is cooked to recommended standards. Crown Copyright 2009. Published by Elsevier B.V. All rights reserved.
Saini, V; McClure, J T; Scholl, D T; DeVries, T J; Barkema, H W
Surveillance of antimicrobial use and resistance is needed to manage antimicrobial resistance in bacteria. In this study, data were collected on antimicrobial use and resistance in Staphylococcus aureus (n=562), isolated from intramammary infections and (sub)clinical mastitis cases on 89 dairy farms in 4 regions of Canada [Alberta, Ontario, Québec, and the Maritime Provinces (Prince Edward Island, Nova Scotia, and New Brunswick)]. Dairy producers were asked to deposit empty drug containers into specially provided receptacles, and antimicrobial drug use rate was calculated to quantify antimicrobial use. Minimum inhibitory concentrations were determined using the Sensititer bovine mastitis plate system (TREK Diagnostic Systems Inc., Cleveland, OH), containing antimicrobials commonly used for mastitis treatment and control. Multivariable logistic regression models were built to determine herd-level risk factors of penicillin, ampicillin, pirlimycin, penicillin-novobiocin combination, tetracycline and sulfadimethoxine resistance in Staph. aureus isolates. Intramammary administration of the penicillin-novobiocin combination for dry cow therapy was associated with penicillin and ampicillin resistance [odds ratio (OR): 2.17 and 3.10, respectively]. Systemic administration of penicillin was associated with penicillin resistance (OR: 1.63). Intramammary administration of pirlimycin for lactating cow mastitis treatment was associated with pirlimycin resistance as well (OR: 2.07). Average herd parity was associated with ampicillin and tetracycline resistance (OR: 3.88 and 0.02, respectively). Average herd size was also associated with tetracycline resistance (OR: 1.02). Dairy herds in the Maritime region had higher odds of penicillin and lower odds of ampicillin resistance than dairy herds in Québec (OR: 2.18 and 0.19, respectively). Alberta dairy herds had lower odds of ampicillin and sulfadimethoxine resistance than dairy herds in Québec (OR: 0.04 and 0.08, respectively
Full Text Available Following the emergence of the Bluetongue virus serotype 8 (BTV-8 in France in 2006, a surveillance system (both passive and active was implemented to detect and follow precociously the progression of the epizootic wave. This system did not allow a precise estimation of the extent of the epizootic. Infection by BTV-8 is associated with a decrease of fertility. The objective of this study was to evaluate whether a decrease in fertility can be used to evidence the under-reporting of cases during an epizootic and to quantify to what extent non-reported cases contribute to the total burden of the epizootic. The cow fertility in herds in the outbreak area (reported or not was monitored around the date of clinical signs. A geostatistical interpolation method was used to estimate a date of clinical signs for non-reported herds. This interpolation was based on the spatiotemporal dynamic of confirmed case herds reported in 2007. Decreases in fertility were evidenced for both types of herds around the date of clinical signs. In non-reported herds, the decrease fertility was large (60% of the effect in reported herds, suggesting that some of these herds have been infected by the virus during 2007. Production losses in non-reported infected herds could thus contribute to an important part of the total burden of the epizootic. Overall, results indicate that performance data can be used to evidence the under-reporting during an epizootic. This approach could be generalized to pathogens that affect cattle's performance, including zoonotic agents such as Coxiella burnetii or Rift Valley fever virus.
Full Text Available Objective: To use PCR for the detection of Coxiella burnetii (C. burnetii in bulk tank milk samples collected from dairy caprine herds in southeast Iran. Methods: In the present study, 31 goat bulk milk from 31 dairy goat herds were tested for C. burnetii using trans-PCR assay. The animals which their milk samples collected for this study were clinically healthy. Results: In total, 5 of 31 (16.12% goat milk samples were positive. Conclusions: The results of this study indicate clinically healthy dairy goats are important sources of C. burnetii infection in this area.
Eisler Mark C
Full Text Available Abstract Background Human brucellosis has been found to be prevalent in the urban areas of Kampala, the capital city of Uganda. A cross-sectional study was designed to generate precise information on the prevalence of brucellosis in cattle and risk factors for the disease in its urban and peri-urban dairy farming systems. Results The adjusted herd prevalence of brucellosis was 6.5% (11/177, 95% CI: 3.6%-10.0% and the adjusted individual animal prevalence was 5.0% (21/423, 95% CI: 2.7% - 9.3% based on diagnosis using commercial kits of the competitive enzyme-linked immunosorbent assay (CELISA for Brucella abortus antibodies. Mean within-herd prevalence was found to be 25.9% (95% CI: 9.7% - 53.1% and brucellosis prevalence in an infected herd ranged from 9.1% to 50%. A risk factor could not be identified at the animal level but two risk factors were identified at the herd level: large herd size and history of abortion. The mean number of milking cows in a free-grazing herd (5.0 was significantly larger than a herd with a movement restricted (1.7, p Conclusions Vaccination should be targeted at commercial large-scale farms with free-grazing farming to control brucellosis in cattle in and around Kampala city.
Haine, Denis; Delgado, Hector; Cue, Roger; Sewalem, Asheber; Wade, Kevin; Lacroix, René; Lefebvre, Daniel; Arsenault, Julie; Bouchard, Émile; Dubuc, Jocelyn
Several health disorders, such as milk fever, displaced abomasum, and mastitis, as well as impaired reproductive performance, are known risk factors for the removal of affected cows from a dairy herd. While cow-level risk factors are well documented in the literature, herd-level associations have been less frequently investigated. The objective of this study was to investigate the effect of cow- and herd-level determinants on variations in culling risk in Québec dairy herds: whether herd influences a cow's culling risk. For this, we assessed the influence of herd membership on cow culling risk according to displaced abomasum, milk fever, and retained placenta. A retrospective longitudinal study was conducted on data from dairy herds in the Province of Québec, Canada, by extracting health information events from the dairy herd health management software used by most Québec dairy producers and their veterinarians. Data were extracted for all lactations starting between January 1st and December 31st, 2010. Using multilevel logistic regression, we analysed a total of 10,529 cows from 201 herds that met the inclusion criteria. Milk fever and displaced abomasum were demonstrated to increase the cow culling risk. A minor general herd effect was found for the culling risk (i.e. an intra-class correlation of 1.0% and median odds ratio [MOR] of 1.20). The proportion of first lactation cows was responsible for this significant, but weak herd effect on individual cow culling risk, after taking into account the cow-level factors. On the other hand, the herd's average milk production was a protective factor. The planning and management of forthcoming replacement animals has to be taken into consideration when assessing cow culling risks and herd culling rates. Copyright © 2017 Elsevier B.V. All rights reserved.
Johnston, C; Coffey, A; Sleator, RD
Mycobacterium avium subsp. paratuberculosis (MAP) is the etiological agent of Johne disease, a granulomatous enteritis of cattle and other domesticated and wild ruminant species. Johne disease is prevalent worldwide and has a significant impact on the global agricultural economy. Current vaccines against Johne are insufficient in stemming its spread, and associated side-effects prevent their widespread use in control programs. Effective and safe vaccine strategies are needed. The main purpose of this paper is to propose and evaluate the development of a novel oral subunit-vaccine using a patho-biotechnological approach. This novel strategy, which harnesses patho-genetic elements from the intracellular pathogen Listeria monocytogenes, may provide a realistic route towards developing an effective next generation subunit vaccine against Johne disease and paratuberculosis. PMID:21326921
Gardner, Ian A.; Nielsen, Søren Saxmose; Whittington, Richard
The Standards for Reporting of Diagnostic Accuracy (STARD) statement (www.stard-statement.org) was developed to encourage complete and transparent reporting of key elements of test accuracy studies in human medicine. The statement was motivated by widespread evidence of bias in test accuracy...... studies and the finding that incomplete or absent reporting of items in the STARD checklist was associated with overly optimistic estimates of test performance characteristics. Although STARD principles apply broadly, specific guidelines do not exist to account for unique considerations in livestock...... for Reporting of Animal Diagnostic Accuracy Studies for paratuberculosis), should facilitate improved quality of reporting of the design, conduct and results of paratuberculosis test accuracy studies which were identified as “poor” in a review published in 2008 in Veterinary Microbiology...
Hudson, Christopher D; Bradley, Andrew J; Breen, James E; Green, Martin J
Probabilistic sensitivity analysis (PSA) is a simulation-based technique for evaluating the relative importance of different inputs to a complex process model. It is commonly employed in decision analysis and for evaluation of the potential impact of uncertainty in research findings on clinical practice, but has a wide variety of other possible applications. In this example, it was used to evaluate the association between herd-level udder health and reproductive performance in dairy herds. Although several recent studies have found relatively large associations between mastitis and fertility at the level of individual inseminations or lactations, the current study demonstrated that herd-level intramammary infection status is highly unlikely to have a clinically significant impact on the overall reproductive performance of a dairy herd under typical conditions. For example, a large increase in incidence rate of clinical mastitis (from 92 to 131 cases per 100 cows per year) would be expected to increase a herd's modified FERTEX score (a cost-based measure of overall reproductive performance) by just £4.50(1) per cow per year. The herd's background level of submission rate (proportion of eligible cows served every 21 days) and pregnancy risk (proportion of inseminations leading to a pregnancy) correlated strongly with overall reproductive performance and explained a large proportion of the between-herd variation in performance. PSA proved to be a highly useful technique to aid understanding of results from a complex statistical model, and has great potential for a wide variety of applications within the field of veterinary science. Copyright © 2015 Elsevier Ltd. All rights reserved.
Pieper, L; Godkin, A; Roesler, U; Polleichtner, A; Slavic, D; Leslie, K E; Kelton, D F
Prototheca spp. are algae that cause incurable acute or chronic mastitis in dairy cows. The aim of this case-control study was the identification of cow- and herd-level risk factors for this unusual mastitis pathogen. Aseptically collected composite milk samples from 2,428 milking cows in 23 case and 23 control herds were collected between January and May 2011. A questionnaire was administered to the producers, and cow-level production and demographic data were gathered. In 58 of 64 isolates, Prototheca spp. and Prototheca zopfii genotypes were differentiated using PCR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. All isolates were identified as Prototheca zopfii genotype 2. The mean within-herd prevalence for Prototheca spp. was 5.1% (range 0.0-12.5%). Case herds had a significantly lower herd-level prevalence of Staphylococcus aureus and a higher prevalence of yeasts than did control herds. The final logistic regression model for herd-level risk factors included use of intramammary injections of a non-intramammary drug [odds ratio (OR) = 136.8], the number of different injectable antibiotic products being used (OR = 2.82), the use of any dry cow teat sealant (external OR = 80.0; internal OR = 34.2), and having treated 3 or more displaced abomasums in the last 12 mo OR = 44.7). The final logistic regression model for cow-level risk factors included second or greater lactation (OR = 4.40) and the logarithm of the lactation-average somatic cell count (OR = 2.99). Unsanitary or repeated intramammary infusions, antibiotic treatment, and off-label use of injectable drugs in the udder might promote Prototheca udder infection. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Cajueiro, Daniel O.; Tabak, Benjamin M.
In this paper we present evidence of multifractality and herding behavior for a large set of Japanese stocks traded in the Tokyo Stock Exchange. We find evidence that herding behavior occurs in periods of extreme market movements. Therefore, based on the intuition behind the tests to detect herding phenomenon developed, for instance, in Christie and Huang [Christie W, Huang R. Following the pied pier: do individual returns herd around the market? Financ Analysts J 1995;51:31-7] and Chang et al. [Chang EC, Cheng JW, Khorana A. Examination of herd behavior in equity markets: an international perspective. J Bank Finance 2000;24:1651-99], we suggest that herding behavior may be one of the causes of multifractality.
Crohn\\'s disease (CD) is a multifactorial syndrome with genetic and environmental contributions. Mycobacterium avium subspecies paratuberculosis (MAP) has been frequently isolated from mucosal tissues of patients with CD but the cellular immune response to this bacterium has been poorly described. Our aim was to examine the influence of MAP on T-cell proliferation and cytokine responses in patients with inflammatory bowel disease (IBD).
Nielsen, E. Okholm; Enøe, Claes; Jorsal, Sven Erik Lind
were 36 g and 52 g less in the case herds than in the control herds. By examining three weaner pigs from each herd the PMWS diagnosis was confirmed by histopathology and immunohistochemistry in 78 per cent of the case herds, but at least one PMWS-positive weaner pig was found in 19 of the control herds...
Okholm Nielsen, Elisabeth; Enøe, Claes; Jorsal, Sven Erik Lind
were 36 g and 52 g less in the case herds than in the control herds. By examining three weaner pigs from each herd the PMWS diagnosis was confirmed by histopathology and immunohistochemistry in 78 per cent of the case herds, but at least one PMWS-positive weaner pig was found in 19 of the control herds...
Carvalho, I A; Pietralonga, P A G; Schwarz, D G G; Faria, A C S; Moreira, M A S
Mycobacterium avium ssp. paratuberculosis (MAP) is the etiological agent of paratuberculosis, a chronic granulomatous enteritis that affects all ruminants worldwide. Some researchers have indicated a possible role of MAP in Crohn's disease. Despite extensive research and large and important advances in the past few decades, the etiology of Crohn's disease remains indefinite. The most probable transmission route of MAP from animals to humans is milk and dairy products. Mycobacterium avium ssp. paratuberculosis has already been detected in milk samples worldwide, and some studies have reported that MAP is resistant to pasteurization. In Brazil, MAP has been reported in raw milk samples; however, Brazilian retail pasteurized milk has not yet been tested for viable MAP. The aim of this study was to investigate MAP in pasteurized milk in the region of Viçosa (Minas Gerais, Brazil). Thirty-seven samples were collected and processed for culture of MAP. One colony similar to MAP was observed and confirmed by IS900-nested PCR and sequencing. Analysis revealed 97 to 99% identity with the MAP K-10 strain. This study is the first report of the presence of MAP in retail pasteurized whole milk in Brazil. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
David Itzcoatl MartÃnez Herrera
Full Text Available Seroprevalence of goat paratuberculosis and risk factors were determined in flocks from five municipalities in the center of the state of Veracruz, Mexico, by a cross-sectional study using a stratified multistage approach. Sample size was calculated with the program Win Episcope Version 2.0 using the mode "estimate percentages" for 50 % seroprevalence, 5 % error and 95 % confidence, resulting in 182 animals and six animals per flock. According to the tables by Cannon and Roe, a sample size of 26 flocks was obtained, of which six flocks were sampled in the municipality of Tlacolulan and five flocks in each of the remaining four municipalities (Chiconquiaco, Yecuatla, Coacoatzintla and Coatepec. Identification of antibodies against Mycobacterium avium ssp. paratuberculosis was made by indirect ELISA. Seroprevalence was determined with the program VassarStatÂ® for calculating ratios, and the risk factors by odds ratio. Overall seroprevalence was 0.6 % (95 % CI: 0.03 - 3.5. Reactors were only observed in Coatepec. Seroprevalence by municipality was 20 % (95 % CI: 1.0 - 70.12 and by flock 3.85 % (95 % CI: 0.2 - 21.59. There were no risk or protective factors detected. In conclusion, goat paratuberculosis is scarcely distributed in flocks from central Veracruz.
Fuller, James A; Eisenberg, Joseph N S
Herd immunity arises when a communicable disease is less able to propagate because a substantial portion of the population is immune. Nonimmunizing interventions, such as insecticide-treated bednets and deworming drugs, have shown similar herd-protective effects. Less is known about the herd protection from drinking water, sanitation, and hand hygiene (WASH) interventions. We first constructed a transmission model to illustrate mechanisms through which different WASH interventions may provide herd protection. We then conducted an extensive review of the literature to assess the validity of the model results and identify current gaps in research. The model suggests that herd protection accounts for a substantial portion of the total protection provided by WASH interventions. However, both the literature and the model suggest that sanitation interventions in particular are the most likely to provide herd protection, since they reduce environmental contamination. Many studies fail to account for these indirect effects and thus underestimate the total impact an intervention may have. Although cluster-randomized trials of WASH interventions have reported the total or overall efficacy of WASH interventions, they have not quantified the role of herd protection. Just as it does in immunization policy, understanding the role of herd protection from WASH interventions can help inform coverage targets and strategies that indirectly protect those that are unable to be reached by WASH campaigns. Toward this end, studies are needed to confirm the differential role that herd protection plays across the WASH interventions suggested by our transmission model. © The American Society of Tropical Medicine and Hygiene.
Kamal R. Acharya
Full Text Available Johne’s disease is a chronic debilitating enteropathy of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP. Current abattoir surveillance programs detect disease via examination of gross lesions and confirmation by histopathological and/or tissue culture, which is time-consuming and has relatively low sensitivity. This study aimed to investigate whether a high-throughput quantitative PCR (qPCR test is a viable alternative for tissue testing. Intestine and mesenteric lymph nodes were sourced from sheep experimentally infected with MAP and the DNA extracted using a protocol developed for tissues, comprised enzymatic digestion of the tissue homogenate, chemical and mechanical lysis, and magnetic bead-based DNA purification. The extracted DNA was tested by adapting a previously validated qPCR for fecal samples, and the results were compared with culture and histopathology results of the corresponding tissues. The MAP tissue qPCR confirmed infection in the majority of sheep with gross lesions on postmortem (37/38. Likewise, almost all tissue culture (61/64 or histopathology (52/58 positives were detected with good to moderate agreement (Cohen’s kappa statistic and no significant difference to the reference tests (McNemar’s Chi-square test. Higher MAP DNA quantities corresponded to animals with more severe histopathology (odds ratio: 1.82; 95% confidence interval: 1.60, 2.07. Culture-independent strain typing on tissue DNA was successfully performed. This MAP tissue qPCR method had a sensitivity equivalent to the reference tests and is thus a viable replacement for gross- and histopathological examination of tissue samples in abattoirs. In addition, the test could be validated for testing tissue samples intended for human consumption.
Wray, Christopher M; Bishop, Steven R
Herd behaviour in financial markets is a recurring phenomenon that exacerbates asset price volatility, and is considered a possible contributor to market fragility. While numerous studies investigate herd behaviour in financial markets, it is often considered without reference to the pricing of financial instruments or other market dynamics. Here, a trader interaction model based upon informational cascades in the presence of information thresholds is used to construct a new model of asset price returns that allows for both quiescent and herd-like regimes. Agent interaction is modelled using a stochastic pulse-coupled network, parametrised by information thresholds and a network coupling probability. Agents may possess either one or two information thresholds that, in each case, determine the number of distinct states an agent may occupy before trading takes place. In the case where agents possess two thresholds (labelled as the finite state-space model, corresponding to agents' accumulating information over a bounded state-space), and where coupling strength is maximal, an asymptotic expression for the cascade-size probability is derived and shown to follow a power law when a critical value of network coupling probability is attained. For a range of model parameters, a mixture of negative binomial distributions is used to approximate the cascade-size distribution. This approximation is subsequently used to express the volatility of model price returns in terms of the model parameter which controls the network coupling probability. In the case where agents possess a single pulse-coupling threshold (labelled as the semi-infinite state-space model corresponding to agents' accumulating information over an unbounded state-space), numerical evidence is presented that demonstrates volatility clustering and long-memory patterns in the volatility of asset returns. Finally, output from the model is compared to both the distribution of historical stock returns and the market
Christopher M Wray
Full Text Available Herd behaviour in financial markets is a recurring phenomenon that exacerbates asset price volatility, and is considered a possible contributor to market fragility. While numerous studies investigate herd behaviour in financial markets, it is often considered without reference to the pricing of financial instruments or other market dynamics. Here, a trader interaction model based upon informational cascades in the presence of information thresholds is used to construct a new model of asset price returns that allows for both quiescent and herd-like regimes. Agent interaction is modelled using a stochastic pulse-coupled network, parametrised by information thresholds and a network coupling probability. Agents may possess either one or two information thresholds that, in each case, determine the number of distinct states an agent may occupy before trading takes place. In the case where agents possess two thresholds (labelled as the finite state-space model, corresponding to agents' accumulating information over a bounded state-space, and where coupling strength is maximal, an asymptotic expression for the cascade-size probability is derived and shown to follow a power law when a critical value of network coupling probability is attained. For a range of model parameters, a mixture of negative binomial distributions is used to approximate the cascade-size distribution. This approximation is subsequently used to express the volatility of model price returns in terms of the model parameter which controls the network coupling probability. In the case where agents possess a single pulse-coupling threshold (labelled as the semi-infinite state-space model corresponding to agents' accumulating information over an unbounded state-space, numerical evidence is presented that demonstrates volatility clustering and long-memory patterns in the volatility of asset returns. Finally, output from the model is compared to both the distribution of historical stock
Herd behaviour in financial markets is a recurring phenomenon that exacerbates asset price volatility, and is considered a possible contributor to market fragility. While numerous studies investigate herd behaviour in financial markets, it is often considered without reference to the pricing of financial instruments or other market dynamics. Here, a trader interaction model based upon informational cascades in the presence of information thresholds is used to construct a new model of asset price returns that allows for both quiescent and herd-like regimes. Agent interaction is modelled using a stochastic pulse-coupled network, parametrised by information thresholds and a network coupling probability. Agents may possess either one or two information thresholds that, in each case, determine the number of distinct states an agent may occupy before trading takes place. In the case where agents possess two thresholds (labelled as the finite state-space model, corresponding to agents’ accumulating information over a bounded state-space), and where coupling strength is maximal, an asymptotic expression for the cascade-size probability is derived and shown to follow a power law when a critical value of network coupling probability is attained. For a range of model parameters, a mixture of negative binomial distributions is used to approximate the cascade-size distribution. This approximation is subsequently used to express the volatility of model price returns in terms of the model parameter which controls the network coupling probability. In the case where agents possess a single pulse-coupling threshold (labelled as the semi-infinite state-space model corresponding to agents’ accumulating information over an unbounded state-space), numerical evidence is presented that demonstrates volatility clustering and long-memory patterns in the volatility of asset returns. Finally, output from the model is compared to both the distribution of historical stock returns and the
Dufour, S; Fréchette, A; Barkema, H W; Mussell, A; Scholl, D T
peripartum period. Studies on automatic milking systems have frequently reported elevation of the herd SCC following transition to the new system. These elevations seemed to be mediated both by the lack of monitoring of chronically infected cows and by an elevated incidence of intramammary infections. By assembling the results reported in many different studies, this review generates a more comprehensive understanding of the management practices influencing SCC and highlights areas of SCC control knowledge that lack evidence of effectiveness. Copyright Â© 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Ågren, Estelle C C; Frössling, Jenny; Wahlström, Helene; Emanuelson, Ulf; Sternberg Lewerin, Susanna
In this study associations between potential risk factors and salmonella status in Swedish dairy herds were investigated. A case-control study design was used, including existing as well as new cases. Herds were assigned a salmonella status on the basis of antibody analysis of bulk milk samples. Information on potential risk factors was collected from registry data and from farmers via a questionnaire. Univariable and multivariable logistic regression analyses were used to investigate associations between salmonella status and potential risk factors. In addition, multivariate analysis with Additive Bayesian Network (ABN) modelling was performed to improve understanding of the complex relationship between all the variables. Because of the difficulty in identifying associations between potential risk factors and infections with low prevalence and a large regional variation, exposure of potential risk factors in the high-prevalence region (Öland) were compared to exposure in other regions in Sweden. In total 483 of 996 (48%) farmers responded to the questionnaire, 69 herds had test-positive bulk milk samples. The strongest association with salmonella status was 'presence of salmonella test-positive herds pastures and providing protective clothing for visitors. The latter is probably a reflection of increased disease awareness in Öland. The ABN model showed associations between herd size and housing as well as several management procedures. This provides an explanation why herd size frequently has been identified as a risk factor for salmonella by other studies. The study confirms the importance of local transmission routes for salmonella, but does not identify specific components in this local spread. Therefore, it supports the use of a broad biosecurity approach in the prevention of salmonella. In Öland, some potential risk factors are more common than in other parts of Sweden. Theoretically these could contribute to the spread of salmonella, but this was not
Duinhof, T F; Dierikx, C M; Koene, M G J; van Bergen, M A P; Mevius, D J; Veldman, K T; van Beers-Schreurs, H M G; de Winne, R T J A
This case study describes the isolation ofa multiresistant strain ofBrachyspira hyodysenteriae in April 2007 in a Dutch sow herd with recurrent diarrhoea. Examination of faecal samples taken from 7-month-old breeding gilts with diarrhoea revealed the presence of resistance against tiamulin, lincomycin, tylosin, doxycycline, and tylvalosin (the active substance in Aivlosin) in four of five samples. Tiamulin resistance has not been reported in The Netherlands before. The repeated use of tiamulin on the affected farm was assumed to be the main cause of the development of resistance to the drug. The farmer was advised to adopt a medication strategy and to implement management practices that would prevent an ongoing cycle of infection on the farm. It is important that the Dutch swine industry appreciates that tiamulin-resistant strains of B. hyodysenteriae may be found on other farms as well. The appropriate and prudent use of antibiotics is essential in order to prevent the development of resistance against the last option left to cure B. hyodysenteriae infections: valnemulin.
Grant, I R; Ball, H J; Rowe, M T
The efficacy of high-temperature, short-time (HTST) pasteurization (72 degrees C/15 s) when low numbers (HTST pasteurization using laboratory pasteurizing units. Ten bovine strains of Myco. paratuberculosis were tested in triplicate. Culture in BACTEC Middlebrook 12B radiometric medium detected acid-fast survivors in 14.8% and 10% of HTST-pasteurized milk samples at the 10(3) and 10(2) cfu ml-1 inoculum levels, respectively, whereas conventional culture on Herrold's egg yolk medium containing mycobactin J detected acid-fast survivors in only 3.7% and 6.7% of the same milk samples. IS900-based PCR confirmed that these acid-fast survivors were Myco. paratuberculosis. No viable Myco. paratuberculosis were isolated from HTST-pasteurized milk initially containing either 10 cfu ml-1 or 10 cfu 50 ml-1.
Haine, Denis; Delgado, Hector; Cue, Roger; Sewalem, Asheber; Wade, Kevin; Lacroix, René; Lefebvre, Daniel; Arsenault, Julie; Bouchard, Émile; Dubuc, Jocelyn
The relationship between cows' health, reproductive performance or disorders and their longevity is well demonstrated in the literature. However these associations at the cow level might not hold true at the herd level, and herd-level variables can modify cow-level outcomes independently of the cows' characteristics. The interaction between cow-level and herd-level variables is a relevant issue for understanding the culling of dairy cows. However it requires the appropriate group-level variables to assess any contextual effect. Based on 10 years of health and production data, the objectives of this paper are:(a) to quantify the culling rates of dairy herds in Québec; (b) to determine the profiles of the herds based on herd-level factors, such as demographics, reproduction, production and health indicators, and whether these profiles can be related to herd culling rates for use as potential contextual variables in multilevel modelling of culling risk. A retrospective longitudinal study was conducted on data from dairy herds in Québec, Canada, by extracting health information events from the dairy herd health management software used by most Québec producers and their veterinarians. Data were extracted for all lactations taking place between January 1st, 2001 and December 31st, 2010. A total of 432,733 lactations from 156,409 cows out of 763 herds were available for analysis. Thirty cow-level variables were aggregated for each herd and years of follow-up, and their relationship was investigated by Multiple Factor Analysis (MFA). The overall annual culling rate was 32%, with a 95% confidence interval (CI) of [31.6%,32.5%]. The dairy sale rate by 60 days in milk (DIM) was 3.2% [2.8%,3.6%]. The annual culling rate within 60 DIM was 8.2% [7.9%,8.4%]. The explained variance for each axis from the MFA was very low: 14.8% for the first axis and 13.1% for the second. From the MFA results, we conclude there is no relationship between the groups of herd-level indicators
Zhang, Ji-Qiang; Huang, Zi-Gang; Wu, Zhi-Xi; Su, Riqi; Lai, Ying-Cheng
Resource allocation takes place in various types of real-world complex systems such as urban traffic, social services institutions, economical and ecosystems. Mathematically, the dynamical process of resource allocation can be modeled as minority games. Spontaneous evolution of the resource allocation dynamics, however, often leads to a harmful herding behavior accompanied by strong fluctuations in which a large majority of agents crowd temporarily for a few resources, leaving many others unused. Developing effective control methods to suppress and eliminate herding is an important but open problem. Here we develop a pinning control method, that the fluctuations of the system consist of intrinsic and systematic components allows us to design a control scheme with separated control variables. A striking finding is the universal existence of an optimal pinning fraction to minimize the variance of the system, regardless of the pinning patterns and the network topology. We carry out a generally applicable theory to explain the emergence of optimal pinning and to predict the dependence of the optimal pinning fraction on the network topology. Our work represents a general framework to deal with the broader problem of controlling collective dynamics in complex systems with potential applications in social, economical and political systems.
Buist, Ian; Belore, Randy [SL Ross Environmental Research (Canada)], email: firstname.lastname@example.org
Chemical herding agents can be applied to deal with an oil slick. This study investigates the key system components of application systems for herding agents and shows how application systems can also be developed for operational herder usage in drift ice. These two application systems are respectively required for small boat and a helicopter operations. The factors, including the selection of flow rates, pressures and atomizing nozzle types, which give the appropriate herder droplet size distributions for small boat and aerial application systems were investigated in the initial stage of the study. In a later stage, on commercializing herders for in situ burning, further research is expected to deal with the many problems not tackled in the initial stage, such as the mounting of the nozzles, pumps and reservoirs on various aerial platforms and the provision of heating and insulation for cold-weather use. The paper presented the experiments and simulations that have been conducted as well as the basic design parameters for field application systems.
The genetic relationship between conformation traits and functional herd life of the South African Jersey population was investigated. Data on conformation traits (n = 46 238) and functional herd life (n = 90 530) on registered South African Jersey cows calving between 1989 and 2008 were obtained from the Integrated ...
Profit rate for a meat production enterprise can be decomposedinto the unit price for meat and herd ... supply and demand, whereas breeding improvement is gen- ... Herd efficiency is total live mass for slaughter divided by costs .... tenance and above-maintenance components by Dickerson, and ..... Growth and productivity.
Ferris, T A; Troyer, B W
Differences in Estimated Breeding Values expressed in dollars were compared by simulation of two, 100-cow, closed herds. One herd practiced normal intensity of female selection. The other herd generated various herd replacements by embryo transfer by varying 1) selection rate of embryo transfer dams and 2) numbers of daughters per dam from which embryos were transferred, while varying the merit of mates of embryo transfer dams. Estimated Breeding Value dollars were compounded each generation and regressed to remove age adjustments and added feed and health costs. Beginning values in both herds included a standard deviation of 55 Cow Index dollars, herd average of -23 Cow Index dollars, and a 120 Predicted Difference dollars for mates of dams not embryo transferred. Average merit of all sires used increased $12 per year. Herd calving rate (.70), proportion females (.5), calf loss (.15), and heifer survival rate (.83) were used. Breakeven cost per embryo transfer cow entering the milking herd was computed by Net Present Value analysis using a 10% discount rate over 10 and 20 yr. Breakeven cost or the maximum expense that would allow a 10% return on the expenditure ranged from $135 to $510 per surviving cow, $24 to $125 per transfer, $47 to $178 per pregnancy, and $81 to $357 per female calf born. As the number of replacements resulting from embryo transfer increased, breakeven cost per embryo transfer cow decreased due to diminishing return.
... accredited herd. If a group of captive cervids from an accredited herd is being moved interstate together to... cervids is being moved together, the entire group must be isolated from all other livestock during the... from isolation; or (3) If the captive cervid to be added is not being moved directly from a classified...
Ifende, V.I.; Derks, M.; Hooijer, G.A.; Hogeveen, H.
Veterinary herd health management (VHHM) programmes are meant to support herd health and farmers’ income (Brand and Guard 1996). They were introduced in the Netherlands in the 1970s (Sol and Renkema 1984) and at present many veterinarians provide them to farmers. VHHM comprises a basic structure of
Langley, D.J.; Hoeve, M.C.; Ortt, J.R.; Pals, N.; Vecht, B. van der
When groups of consumers share information or express their opinions about products and services, their attitudes or behavior sometime align without centralized coordination, a phenomenon known as herding. Building on pattern-based explanations of herding from the cognitive science literature, we
Allaire, F R; Gibson, J P
Cow herd life adjusted for lactational milk production was investigated as a genetic trait in the breeding objective. Under a simple model, the relative economic weight of milk to adjusted herd life on a per genetic standard deviation basis was equal to CVY/dCVL where CVY and CVL are the genetic coefficients of variation of milk production and adjusted herd life, respectively, and d is the depreciation per year per cow divided by the total fixed costs per year per cow. The relative economic value of milk to adjusted herd life at the prices and parameters for North America was about 3.2. An increase of 100-kg milk was equivalent to 2.2 mo of adjusted herd life. Three to 7% lower economic gain is expected when only improved milk production is sought compared with a breeding objective that included both production and adjusted herd life for relative value changed +/- 20%. A favorable economic gain to cost ratio probably exists for herd life used as a genetic trait to supplement milk in the breeding objective. Cow survival records are inexpensive, and herd life evaluations from such records may not extend the generation interval when such an evaluation is used in bull sire selection.
Skjerve, Eystein; Lium, Bjørn; Nielsen, Bent
of slaughter pigs (OR = 0.44) also lowered the herd prevalence. The most expressed risk factor was using an own farm vehicle for transport of slaughter pigs to abattoirs (OR = 12.92). Separation between clean and unclean section in herds (OR = 2.67), daily observations of a cat with kittens on the farm (OR = 2...
Langley, David J.; Hoeve, Maarten C.; Ortt, J. Roland; Pals, Nico; van der Vecht, Bob
When groups of consumers share information or express their opinions about products and services, their attitudes or behavior sometime align without centralized coordination, a phenomenon known as herding. Building on pattern-based explanations of herding from the cognitive science literature, we
Van Vlaenderen, Ilse; Van Bellinghen, Laure-Anne; Meier, Genevieve; Nautrup, Barbara Poulsen
Indirect herd effect from vaccination of children offers potential for improving the effectiveness of influenza prevention in the remaining unvaccinated population. Static models used in cost-effectiveness analyses cannot dynamically capture herd effects. The objective of this study was to develop a methodology to allow herd effect associated with vaccinating children against seasonal influenza to be incorporated into static models evaluating the cost-effectiveness of influenza vaccination. Two previously published linear equations for approximation of herd effects in general were compared with the results of a structured literature review undertaken using PubMed searches to identify data on herd effects specific to influenza vaccination. A linear function was fitted to point estimates from the literature using the sum of squared residuals. The literature review identified 21 publications on 20 studies for inclusion. Six studies provided data on a mathematical relationship between effective vaccine coverage in subgroups and reduction of influenza infection in a larger unvaccinated population. These supported a linear relationship when effective vaccine coverage in a subgroup population was between 20% and 80%. Three studies evaluating herd effect at a community level, specifically induced by vaccinating children, provided point estimates for fitting linear equations. The fitted linear equation for herd protection in the target population for vaccination (children) was slightly less conservative than a previously published equation for herd effects in general. The fitted linear equation for herd protection in the non-target population was considerably less conservative than the previously published equation. This method of approximating herd effect requires simple adjustments to the annual baseline risk of influenza in static models: (1) for the age group targeted by the childhood vaccination strategy (i.e. children); and (2) for other age groups not targeted (e
Background Indirect herd effect from vaccination of children offers potential for improving the effectiveness of influenza prevention in the remaining unvaccinated population. Static models used in cost-effectiveness analyses cannot dynamically capture herd effects. The objective of this study was to develop a methodology to allow herd effect associated with vaccinating children against seasonal influenza to be incorporated into static models evaluating the cost-effectiveness of influenza vaccination. Methods Two previously published linear equations for approximation of herd effects in general were compared with the results of a structured literature review undertaken using PubMed searches to identify data on herd effects specific to influenza vaccination. A linear function was fitted to point estimates from the literature using the sum of squared residuals. Results The literature review identified 21 publications on 20 studies for inclusion. Six studies provided data on a mathematical relationship between effective vaccine coverage in subgroups and reduction of influenza infection in a larger unvaccinated population. These supported a linear relationship when effective vaccine coverage in a subgroup population was between 20% and 80%. Three studies evaluating herd effect at a community level, specifically induced by vaccinating children, provided point estimates for fitting linear equations. The fitted linear equation for herd protection in the target population for vaccination (children) was slightly less conservative than a previously published equation for herd effects in general. The fitted linear equation for herd protection in the non-target population was considerably less conservative than the previously published equation. Conclusions This method of approximating herd effect requires simple adjustments to the annual baseline risk of influenza in static models: (1) for the age group targeted by the childhood vaccination strategy (i.e. children); and (2
Van Vlaenderen Ilse
Full Text Available Abstract Background Indirect herd effect from vaccination of children offers potential for improving the effectiveness of influenza prevention in the remaining unvaccinated population. Static models used in cost-effectiveness analyses cannot dynamically capture herd effects. The objective of this study was to develop a methodology to allow herd effect associated with vaccinating children against seasonal influenza to be incorporated into static models evaluating the cost-effectiveness of influenza vaccination. Methods Two previously published linear equations for approximation of herd effects in general were compared with the results of a structured literature review undertaken using PubMed searches to identify data on herd effects specific to influenza vaccination. A linear function was fitted to point estimates from the literature using the sum of squared residuals. Results The literature review identified 21 publications on 20 studies for inclusion. Six studies provided data on a mathematical relationship between effective vaccine coverage in subgroups and reduction of influenza infection in a larger unvaccinated population. These supported a linear relationship when effective vaccine coverage in a subgroup population was between 20% and 80%. Three studies evaluating herd effect at a community level, specifically induced by vaccinating children, provided point estimates for fitting linear equations. The fitted linear equation for herd protection in the target population for vaccination (children was slightly less conservative than a previously published equation for herd effects in general. The fitted linear equation for herd protection in the non-target population was considerably less conservative than the previously published equation. Conclusions This method of approximating herd effect requires simple adjustments to the annual baseline risk of influenza in static models: (1 for the age group targeted by the childhood vaccination strategy
Losinger, W C; Heinrichs, A J
A national US survey collected data on herd milk production and management of Holstein herds. Step-wise selection identified management practices that were related to herd milk production using only operations that calculated herd milk production as well as using data from all operations. Results were similar. Milk production was highest in the West. Operations with 25% registered cattle had higher production than operations with no registered cattle. Dairy operations that reported a mean BW > 545 kg at first calving had higher mean milk production than operations with a mean BW or = 27 mo at first calving. In addition, use of the following management practices was associated with higher rolling herd average milk production: calves born in individual areas in buildings, calves hand-fed first colostrum, starter grain fed to preweaned calves, ionophores fed to heifers from birth to first calving, DHIA record-keeping system used, computerized records, and no new cattle introduced in the previous 12 mo.
Full Text Available Abstract Background Swine dysentery (SD, a mucohaemorrhagic diarrhoeal disease of pigs, results from infection of the large intestine with the spirochaete Brachyspira hyodysenteriae. ELISA systems using whole spirochaete cells (WC and the B. hyodysenteriae outer membrane lipoprotein Bhlp29.7 previously have been established as potential diagnostic tools for SD. However, their true value in identifying infected herds remains unclear. The present study aimed to compare the performance of whole-cell and Bhlp29.7 based ELISAs in detecting specific immunoglobulin class IgG and IgM to B. hyodysenteriae in growing pigs, and additionally evaluated whether meat juice could serve as a source of specific antibodies. Results Levels of circulating IgG and IgM reacting with WC spirochaete preparations and recombinant Bhlp29.7 peaked 4-6 weeks post-infection in the experimentally challenged pigs, and remained elevated in the present study. In a cohort of pigs on an infected farm levels of antibody directed against both antigens showed a progressive increase with time. However, other than for the level of IgG against WC antigen, a significant increase in antibody levels also was observed in a cohort of pigs on a non-infected farm. In addition, assays using meat juice had 100% specificity and equivalent sensitivity to those based on serum, and likewise the best performance was achieved using the WC IgG ELISA. Conclusions IgG ELISAs using either WC or Bhlp29.7 as plate-coating antigens were shown to be useful for monitoring the dynamics of B. hyodysenteriae infection in grower pigs. Of the two antigens, the WC preparation tended to give better discrimination between pigs from infected and non-infected farms. Testing of meat juice was shown to have potential for identifying infected herds.
van der Wolf, P J; van Schie, F W; Elbers, A R; Engel, B; van der Heijden, H M; Hunneman, W A; Tielen, M J
The aim of the study was to test whether acidified drinking water, with two millilitres of an acid mixture per litre, was able to reduce the number of Salmonella infections in finishing pig herds. In each compartment, half of the pens were supplied with acidified water and the other pens served as negative control. In three herds the required dose was not applied to the pigs as a result of various practical problems. In another herd, all pigs remained seronegative throughout the study. Analysis of the remaining three herds showed a large and significant treatment effect in one herd (Pdrinking nipples as a result of fungal growth in the pipelines.
was: high-risk litters are (1) large litters, (2) litters with previous diseases or deaths, (3) litters where the nursing sow had been treated, or (4) litters from high-parity sows. Litters from large conventional herds or from herds with a high stocking density were expected to have a high risk...
Mayer, Timothy J
Dissatisfaction with the industrial model of food production has caused many consumers to seek out food produced on local, family-scale farms that use U.S. Department of Agriculture certified organic or other sustainable practices to grow their food and raise their livestock. While almost all of the types of food that are available at the grocery store can also be found at the local farmers market, one food that is difficult to find in many states is raw milk—that is, milk that has not undergone pasteurization (heat treatment). This difficulty lies in the fact that most states prohibit the direct retail sale of raw milk to the final consumer because public health officials and state legislators fear that raw milk may contain bacteria harmful to human health such as E. coli, Campylobacter, and Listeria. However, some consumers reject these warnings and instead believe that raw milk possesses both nutritional and medicinal qualities. Indeed, an ever-increasing body of scientific research published in peer-reviewed journals supports the claim that raw milk consumption can mitigate or prevent some allergies and infections, especially in young children. In order for consumers to obtain raw milk in states where its sale is prohibited, some consumers have entered into arrangements with farmers known as “herd sharing,” through which the consumer effectively becomes an owner of the herd of cows or goats. For the price of the share and a monthly boarding fee, the shareholder can receive a weekly distribution of the herd’s primary dividend, namely the raw milk. Several states expressly permit this practice while most are silent and still a few prohibit it outright. The three courts in the United States that have ruled on herd share agreements have split, with two courts rejecting the agreements as a circumvention of the state’s prohibition on the sale of raw milk, and the other court assuming the agreement’s validity in light of the state’s failure to adequately
Li, Z; Kang, H; You, Q; Ossa, F; Mead, P; Quinton, M; Karrow, N A
The yeast Saccharomyces cerevisiae and its components are used for the prevention and treatment of enteric disease in different species; therefore, they may also be useful for preventing Johne's disease, a chronic inflammatory bowel disease of ruminants caused by Mycobacterium avium ssp. paratuberculosis (MAP). The objective of this study was to identify potential immunomodulatory S. cerevisiae components using a bovine macrophage cell line (BOMAC). The BOMAC phagocytic activity, reactive oxygen species production, and immune-related gene (IL6, IL10, IL12p40, IL13, IL23), transforming growth factor β, ARG1, CASP1, and inducible nitric oxide synthase expression were investigated when BOMAC were cocultured with cell wall components from 4 different strains (A, B, C, and D) and 2 forms of dead yeast from strain A. The BOMAC phagocytosis of mCherry-labeled MAP was concentration-dependently attenuated when BOMAC were cocultured with yeast components for 6 h. Each yeast derivative also induced a concentration-dependent increase in BOMAC reactive oxygen species production after a 6-h exposure. In addition, BOMAC mRNA expression of the immune-related genes was investigated after 6 and 24 h of exposure to yeast components. All yeast components were found to regulate the immunomodulatory genes of BOMAC; however, the response varied among components and over time. The in vitro bioassessment studies reported here suggest that dead yeast and its cell wall components may be useful for modulating macrophage function before or during MAP infection. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Full Text Available Mycobacterium avium subspecies paratuberculosis (MAP is a versatile pathogen with a broad host range. Its association with type-1 diabetes mellitus (T1DM has been recently proposed. Rapid identification of infectious agents such as MAP in diabetic patients at the level of clinics might be helpful in deciphering the role of chronic bacterial infection in the development of autoimmune diseases such as T1DM.We describe use of an ELISA method to identify live circulating MAP through the detection of a cell envelope protein, MptD by a specific M13 phage--fMptD. We also used another ELISA format to detect immune response to MptD peptide. Both the methods were tested with blood plasma obtained from T1DM, type-2 diabetes (T2DM patients and non-diabetic controls. Our results demonstrate MptD and fMptD ELISA assays to be accurate and sensitive to detect MAP bacilli in a large fraction (47.3% of T1DM patients as compared to non-diabetic controls (12.6% and those with confirmed T2DM (7.7%. Comparative analysis of ELISA assays performed here with 3 other MAP antigen preparations, namely HbHA, Gsd and whole cell MAP lysates confirmed comparable sensitivity of the MptD peptide and the fMptD based ELISA assays. Moreover, we were successful in demonstrating positive bacterial culture in two of the clinical specimen derived from T1DM patients.The MptD peptide/fMptD based ELISA or similar tests could be suggested as rapid and specific field level diagnostic tests for the identification of MAP in diabetic patients and for finding the explanations towards the occurrence of type-1 or type-2 diabetes in the light of an active infectious trigger.
Piñero, A; Barandika, J F; Hurtado, A; García-Pérez, A L
Bulk-tank milk (BTM) samples are frequently used to evaluate the health status of dairy livestock. A large-scale investigation carried out in BTM samples from dairy cattle herds from a Q fever-endemic region in Northern Spain revealed a high degree of exposure to Coxiella burnetii. This study was aimed at assessing the value of BTM samples analysis as an indicator of the C. burnetii status in dairy cattle herds. Three herds with BTM samples positive for C. burnetii by ELISA and PCR were selected, and blood, faeces and individual milk and BTM samples were analysed by serology and PCR. In spite of the high antibodies titres found in BTM samples, only one of the three farms presented an active infection by C. burnetii, as revealed by the presence of bacterial DNA in vaginal mucus and in environmental samples collected in the calving area, a seroprevalence around 40% in heifers and the seroconversion rate observed in cows. Results obtained indicated that the analysis of BTM samples is a good epidemiological tool at the population level that can be used to discriminate between seropositive and seronegative herds, but at the herd level, additional tests are necessary to evaluate whether Q fever is a potential problem in the farm. When Q fever is suspected in a cattle herd, sera from a small group of 1- to 3-year-old animals need to be analysed to investigate recent contact with C. burnetii. © 2012 Blackwell Verlag GmbH.
Maria do Carmo Pessôa Silva
Full Text Available Bovine tuberculosis is a zoonosis with worldwide distribution. Its control has a direct impact on public health and livestock production. This study estimated the prevalence of infected herds and adult bovines and evaluated risk factors associated with the presence of tuberculosis within herds in the state of Paraná. The state was divided in seven livestock regions and independent sampling was performed. A total of 1,419 farms were sampled and 16,045 animals were tested using the intradermal comparative cervical tuberculin diagnostic test. The apparent and estimated prevalence rates in farms and adult bovine animals were 2.15% (95% CI: 1.31-3.00 and 0.42% (95% CI: 0.04-0.81, respectively. It was not possible to state with 95% confidence that the disease prevalence in any region was significantly different from that in other regions. There were no positive animals in the western region, and the prevalence of positive herds and animals in the other regions ranged from 1.03% to 3.89% and 0.17% to 1.08%, respectively. The logistic regression model identified larger herd size (OR = 2.4 and mechanical cmilking (OR = 5.18 as risk factors associated with the presence of bovine tuberculosis. The combination of low prevalence with risk factors associated to larger herds and more intensive dairy farming, renders the state of Paraná a good candidate for the implementation of industry-based free-herd accreditation schemes and makes a case for planning risk-based surveillance targeted at major dairy basins.
Greg L. Finstad
Full Text Available The reindeer industry has existed in Alaska since 1892. This industry has largely been concentrated on the Seward Peninsula, Alaska because suitable habitat has been available and caribou have been absent here for over 100 years. Until recently, reindeer meat and velvet antler production consistently generated millions of dollars in revenue critical to the economies of rural Alaskan communities. From 1976 to 1996 the Western Arctic Caribou Herd (WACH increased from about 75 000 to 463 000 animals. Concurrently, seasonal range use of the WACH shifted westward onto traditional reindeer ranges of the Seward Peninsula. Reindeer herders lost 75-100% of their herds through commingling and out¬migration with wild caribou. This loss of over 12 000 reindeer represents a potential economic value of 13 million dollars. Sustainable meat and velvet antler production and the economies of western Alaskan are likely to be affected by these changes.
Ferguson, James D; Skidmore, Andrew
Sixteen herds were selected from a pool of 64 herds nominated by consultants for participation in a national survey to demonstrate excellence in reproductive performance. For inclusion in the survey, herds had to have comprehensive records in a farm computer database or participate in a Dairy Herd Improvement Association record system and have superior reproductive performance as judged by the herd advisor. Herd managers were asked to fill out a questionnaire to describe their reproductive management practices and provide herd records for data analysis. Reproductive analysis was based on individual cow records for active and cull dairy cows that calved during the calendar year 2010. Breeding records by cow were used to calculate indices for insemination rate (IR), conception rate (CR), pregnancy rate (PR), and culling. Herds ranged in size from 262 to 6,126 lactating and dry cows, with a mean of 1,654 [standard deviation (SD) 1,494] cows. Mean days to first insemination (DFS) was 71.2d (SD 4.7d), and IR for first insemination was 86.9%. Mean days between inseminations were 33.4d (SD 3.1d), and 15.4% of insemination intervals were greater than 48 d (range: 7.2 to 21.5%). First-service conception rate was 44.4% (SD 4.8%) across all herds and ranged from 37.5 to 51.8%. Mean PR was 32.0% (SD 3.9%) with a range of 26.5 to 39.4%. Lactation cull rate was 32.2% (SD 12.4%) with a range from 13.6 to 58.1%. Compared with mean data and SD for herds in the Raleigh Dairy Herd Improvement Association system, mean indices for these herds ranked them in the 99 th percentile for IR (using heat detection rate as comparison), 99 th percentile for PR, the bottom 18.6 percentile for DFS, and around the 50th percentile for CR. This suggests that excellent herd reproductive performance was associated with reproductive management that resulted in high insemination rates combined with average CR. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights
van den Borne, Bart H P; Graber, Hans U; Voelk, Verena; Sartori, Carlotta; Steiner, Adrian; Haerdi-Landerer, M Christina; Bodmer, Michèle
Staphylococcus aureus is a common mastitis causing pathogen of dairy cattle. Several S. aureus genotypes exist, of which genotype B (GTB) is highly prevalent in Swiss dairy herds. Dairy farming in mountainous regions of Switzerland is characterised by the movement of dairy cattle to communal pasture-based operations at higher altitudes. Cows from different herds of origin share pastures and milking equipment for a period of 2 to 3 months during summer. The aim of this longitudinal observational study was to quantify transmission of S. aureus GTB in communal dairy operations. Cows (n=551) belonging to 7 communal operations were sampled at the beginning and end of the communal period. Transmission parameter β was estimated using a Susceptible-Infectious-Susceptible (SIS) model. The basic reproduction ratio R 0 was subsequently derived using previously published information about the duration of infection. Mean transmission parameter β was estimated to be 0.0232 (95% CI: 0.0197-0.0274). R 0 was 2.6 (95% CI: 2.2-3.0), indicating that S. aureus GTB is capable of causing major outbreaks in Swiss communal dairy operations. This study emphasized the contagious behaviour of S. aureus GTB. Mastitis management in communal dairy operations should be optimized to reduce S. aureus GTB transmission between cows and back to their herds of origin. Copyright © 2016 Elsevier B.V. All rights reserved.
Full Text Available An outbreak of coliform mastitis is described in a dairy herd from the State of Rio de Janeiro, Brazil. During a four-month period 14 fatal cases of Klebsiella pneumoniae-related mastitis were observed in a herd of 104 lactating cows. The symptoms included peracute enterotoxemia in which the cows died 6 to 12 h after the detection of mastitis by CMT. Staphylococcus aureus and Streptococcus agalactiae Streptococcus agalactiae were also isolated although could not be associated with cases of acute fatal mastitis. Milking practices were also evaluated. The milking machine was being used correctly and adequate precautions for hygiene and pre-milking and post-milking teat dipping were used. The organism was sensitive to gentamicin. Therapy for acute toxic mastitis required early action for the treatment of infections, involving corticosteroids and fluid therapy. The use of a Klebsiella vaccine produced from the microorganisms isolated from the herd, associated with hygiene measures, resulted in the control of the outbreak.
Stuart G. Masterson
Full Text Available The recent West African Ebola virus pandemic, which affected >28,000 individuals increased interest in anti-Ebolavirus vaccination programs. Here, we systematically analyzed the requirements for a prophylactic vaccination program based on the basic reproductive number (R0, i.e., the number of secondary cases that result from an individual infection. Published R0 values were determined by systematic literature research and ranged from 0.37 to 20. R0s ≥ 4 realistically reflected the critical early outbreak phases and superspreading events. Based on the R0, the herd immunity threshold (Ic was calculated using the equation Ic = 1 − (1/R0. The critical vaccination coverage (Vc needed to provide herd immunity was determined by including the vaccine effectiveness (E using the equation Vc = Ic/E. At an R0 of 4, the Ic is 75% and at an E of 90%, more than 80% of a population need to be vaccinated to establish herd immunity. Such vaccination rates are currently unrealistic because of resistance against vaccinations, financial/logistical challenges, and a lack of vaccines that provide long-term protection against all human-pathogenic Ebolaviruses. Hence, outbreak management will for the foreseeable future depend on surveillance and case isolation. Clinical vaccine candidates are only available for Ebola viruses. Their use will need to be focused on health-care workers, potentially in combination with ring vaccination approaches.
Ibrahim F.M. Marai
Full Text Available Doe rabbit's replacement constitutes the annual renewal rate of new breeders that must be incorporated into the production stock. Criterion for culling non-productive animals differs significantly among fryer production colonies, foundation stocks and a colony with continuous enzootic disease or continuous malnourishment. In commercial rabbit production, good management improves the health and productivity of the entire herd, by reducing the all-time high replacement rates and improving economic viability. In the present article, a comprehensive review of numerous experiences in the rabbit production field of different countries, was presented. Basic recommendations for professional breeders were highlighted, covering critical issues such as the need for continuously upgrading the health status of the colony, the positive effect ofÂ Â genetic selection and the nutritional conditioning and special treatment of young does being groomed as future replacements.
Cláudio E. F. Cruz
Full Text Available Over the last decades, the emphasis on the health of dairy cows has changed from an individual to a herd level. In this scenario, the role played by the recording system and its interpretation by veterinarians has gained primordial importance. The records of productive and reproductive performance and of sanitary status from a southern Brazilian dairy cattle herd have been presented and discussed. The period of study was 2000-2009. Mean values per lactation period were 349D 8436M 290F 275P 201SCS (D: days in lactation, M: kg of milk yield, F: kg of fat, P: kg of protein and SCS: somatic cell score in 1000 cells/ml of milk. Major indexes of reproductive efficiency included age at first calving (31 months, services per conception (2.1, intercalving interval (428 days, calving to conception interval (146 days, mean annual rates of parturitions (76.2%, fetal losses (9.8-19.0%, and stillbirths (3.6%, apart of voluntary waiting period (94 days. Main information on sanitary status of the herd was associated with the mean prevalence of common disorders of dairy cattle such as anaplasmosis (29.8%, mastitis (27.8%, digital diseases (26.3%, ovarian cysts (21.3%, placental retention (19.7%, postpartum uterine infections (10.6%, and calf diarrhea (23.7% and pneumonia (16.8%, among others. In addition, culling reasons (low reproductive performance [56.3%] and udder/mastitis problems [33.6%], causes of cattle deaths (anaplasmosis [16.4%] and leukosis [11.4], and the impact of cattle diseases such as tuberculosis, leukosis, and neosporosis on the herd have also been presented and succinctly discussed. Numbers between brackets represent rates accumulated in the 10-year period.
Kenneth F. Abraham
Full Text Available In this paper, we describe the Pen Islands Herd of caribou, the largest aggregation of caribou in Ontario (it also occupies a portion of northeastern Manitoba. Photographic counts showed the herd had a minimum population of 2300 in 1979, 4660 in 1986, 7424 in 1987 and 10 798 in 1994. Throughout the 1980s, the Pen Islands caribou exhibited population behaviour similar to migratory barren-ground caribou herds, although morphology suggests they are woodland caribou or possibly a mixture of subspecies. The herd had well-defined traditional tundra calving grounds, formed nursery groups and large mobile post-calving aggregations, and migrated over 400 km between tundra summer habitats and boreal forest winter habitats. Its migration took it into three Canadian jurisdictions (Ontario, Manitoba, Northwest Territories and it was important to residents of both Manitoba and Ontario. It is clear that the herd should be managed as a migratory herd and the critical importance of both the coastal and variable large winter ranges should be noted in ensuring the herd's habitat needs are secure.
Schwarz, D G G; Lima, M C; Barros, M; Valente, F L; Scatamburlo, T M; Rosado, N; Oliveira, C T S A M; Oliveira, L L; Moreira, M A S
Goat farming is a low-cost alternative to dairy production in developing countries. In Brazil, goat production has increased in recent years due in part to the implementation of programs encouraging this activity. Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of paratuberculosis, a disease that causes chronic granulomatous enteritis in ruminants, but MAP transmission dynamics are still poorly understood in goats. In a previously published study of our research group, 10 dairy goat farms (467 animals) from Minas Gerais state were analyzed for MAP detection; 2 fecal cultures and 11 milk samples tested positive for MAP by conventional PCR and were confirmed by sequencing. Because no clinical signs were observed over 1 yr of monitoring, we hypothesized that these MAP-positive goats could be passive shedders. Thus, in the present study, 4 positive goats (4/13) from the previous study were purchased and feces and milk samples were collected for evaluation (twice, with an interval of 3 mo between tests) by culture of MAP, IS900 PCR, or both. All analyses were negative for MAP. At the last time point, blood samples were collected for ELISA, the animals were killed, and tissues collected for tissue culture and histopathology. At necropsy, no macroscopic lesions related to paratuberculosis were observed. Similarly, no histological changes were observed and MAP in samples stained by Ziehl-Neelsen was not detected. These animals were characterized as potential passive shedders with upward contamination of the teat canal by MAP. This is the first report of the passive shedding phenomenon in goats in Brazil and it highlights the importance of identifying these animals for control programs and to ensure the quality of dairy products. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Galiero, Alessia; Turchi, Barbara; Pedonese, Francesca; Nuvoloni, Roberta; Cantile, Carlo; Colombani, Giuseppe; Forzan, Mario; Cerri, Domenico; Bandecchi, Patrizia; Fratini, Filippo
Mycobacterium avium paratuberculosis (Map) is a pathogen which causes a chronic progressive granulomatous enteritis known as paratuberculosis or Johne's disease and it primarily affects wild and domestic ruminants. The aim of this research was to examine a flock which consisted of 294 goats and was located in Garfagnana district (Tuscany, Italy) performing ELISA tests, culture and IS900 PCR assay; direct diagnostic methods were carried out not only on bulk tank milk and cheese samples but also on individual milk and tissue specimens collected from nine subjects positive to ELISA tests. Out of 294 animals, 20 goats (6.8%) were positive to ELISA surveys. Bulk tank milk samples were negative to culture and to PCR assay carried out on the DNA extracted directly from them, while, with respect to cheese, Map was detected by culture in 2/12 (16.66%) cheeses ripened for 3-7 days, and by PCR in 2/12 (16.66%) cheeses ripened for 3-7 days and in 3/12 (25%) cheeses ripened for 45 days. Regarding individual milk samples, Map was detected by culture in 2/9 (22.22%) specimens and by PCR in 5/9 (55.55%) samples. Furthermore, Map was isolated from the intestine in 9/9 (100%) animals, from the mesenteric lymph nodes in 8/9 (88.88%) subjects, from the liver in 4/9 (44.44%) goats, from the spleen in 5/9 (55.55%) animals, while Map DNA was found in all the tissue samples analyzed.The results demonstrated the presence of paratuberculosis in a goat flock located in Garfagnana district (Tuscany, Italy).
Brotzman, R L; Döpfer, D; Foy, M R; Hess, J P; Nordlund, K V; Bennett, T B; Cook, N B
A survey of management practices was conducted to investigate potential associations with groupings of herds formed by cluster analysis (CA) of Dairy Herd Improvement (DHI) data of 557 Upper Midwest herds of 200 cows or greater. Differences in herd management practices were identified between the groups, despite underlying similarities; for example, freestall housing and milking in a parlor. Group 6 comprised larger herds with a high proportion of primiparous cows and most frequently utilized practices promoting increased production [e.g., 84.4% used recombinant bovine somatotropin (rbST)], decreased lameness (e.g., 96.9% used routine hoof trimming for cows), and improved efficiency in reproduction [e.g., 93.8% synchronized the first breeding in cows (SYNCH)] and labor (e.g., mean ± SD, 67 ± 19 cows per 50-h per week full-time equivalent worker). Group 1 had the best mean DHI performances and followed most closely group 6 for the rate of adoption of intensive management practices while tending to outperform group 6 despite a generally smaller mean herd size (e.g., 42.3 ± 3.6 kg vs. 39.9 ± 3.6 kg of energy-corrected milk production; 608 ± 352 cows vs. 1,716 ± 1,405 cows). Group 2 were smaller herds with relatively high levels of performance that used less intensive management (e.g., 100% milked twice daily) and less technology (33.3 vs. 73.0% of group 1 used rbST). Group 4 were smaller but poorer-performing herds with low turnover and least frequently used intensive management practices (e.g., 39.1% SYNCH; 30.4% allowed mature, high-producing cows access to pasture). Group 5 used modern technologies and practices associated with improved production, yet had the least desirable mean DHI performance of all 6 groups. This group had the lowest proportion of deep loose-bedded stalls (only 52.2% used sand bedding) and the highest proportion (34.8%) of herds not using routine hoof trimming. The survey of group 3 herds did not reveal strong trends in management. The
Increasing the ex vivo antigen-specific IFN-γ production in subpopulations of T cells and NKp46+ cells by anti-CD28, anti-CD49d and recombinant IL-12 costimulation in cattle vaccinated with recombinant proteins from Mycobacterium avium subspecies paratuberculosis
Thakur, Aneesh; Riber, Ulla; Davis, William C.
-γ secretion by CD4, CD8, γδ T cells and NK cells. Age matched male jersey calves, experimentally infected with Mycobacterium avium subsp. paratuberculosis (MAP), were vaccinated with a cocktail of recombinant MAP proteins or left unvaccinated. Vaccine induced ex vivo recall responses were measured through Ag......T cells, which encounter specific antigen (Ag), require additional signals to mount a functional immune response. Here, we demonstrate activation of signal 2, by anti-CD28 mAb (aCD28) and other costimulatory molecules (aCD49d, aCD5), and signal 3, by recombinant IL-12, enhance Ag-specific IFN...
Abebe, Rahmeto; Hatiya, Hagere; Abera, Mesele; Megersa, Bekele; Asmare, Kassahun
Mastitis is a disease of major economic importance in dairy industry worldwide. It is of particular concern in developing countries like Ethiopia, where milk and milk products are scarce. The objectives of the study were to estimate the prevalence of mastitis, identify the cow-and herd-level potential risk factors and isolate Staphylococcus aureus, one of etiological agents for contagious mastitis, from cows positive for mastitis. A total of 529 lactating cows selected randomly from 95 herds were screened by California mastitis test (CMT) for sub-clinical mastitis. Also 172 milk samples collected from CMT positive cows were cultured for isolation of S. aureus. Based on CMT result and clinical examination, the prevalence of mastitis at herd-level was 74.7% (95% CI: 64.5, 82.8). The corresponding cow-level prevalence was 62.6% (95% CI: 58.3, 66.7), of which 59.2 and 3.4% were sub-clinical and clinical mastitis cases, respectively. S. aureus was isolated from 51.2% of the milk samples cultured and 73.2% of the herds affected with mastitis. In the multivariable logistic regression model, the herd-level factors significantly associated (p mastitis were herd size, bedding material, and milking mastitic cows last, while at cow-level, breed, parity, stage of lactation, udder and leg hygiene, and teat end shape were noted to have a significant effect on mastitis occurrence. The very high prevalence of mastitis, more importantly the sub-clinical one, in the herds examined revealed the huge potential economic loss the sector suffers. Perhaps this was attributed to lack of implementation of the routine mastitis prevention and control practices by all of the herd owners. The findings of this study warrants the need for strategic approach including dairy extension that focus on enhancing dairy farmers' awareness and practice of hygienic milking, regular screening for sub-clinical mastitis, dry cow therapy and culling of chronically infected cows.
characteristic in severe gram-negative sepsis. Hypertriglyceridemia results from an increase in hepatic synthesis in combination with diminished activity of...induced stress, and tissue repair (1). The magnitude and type of nutritional losses caused by an infection reflect both the severity and duration of an... several functional forms of nutrient loss must be anticipated. Functional losses are defined as the within-body losses of nutrients due to infection
G. S. Abdellrazeq
Full Text Available Background: Johne's disease (JD caused by Mycobacterium avium subsp. paratuberculosis (MAP represents a real threat to the agriculture and dairy food industries and believed to be a potential public health problem. Signs of infection in ruminant include weight loss, diarrhea, decreased milk production, and eventually death. The definition of an infected animal based either on the presence of anti-MAP antibodies, or positive bacterial culture. No treatment for the disease exists and controlling the disease is difficult due to its long latent period. JD is a worldwide problem and multiple studies in many countries have been carried out to determine the prevalence of MAP infections. Although some primary non intensive studies confirm presence of JD in Egypt, the disease is currently neglected by the official Egyptian veterinary agencies. There is no official data, no national control program, and no used vaccine. Aim: This study aimed to evaluate three conventional diagnostic methods for MAP under the Egyptian circumstances with a general aim to determine the appropriate strategy to develop a JD control program. These methods were pooled fecal culture, humoral response and insertion sequence IS900 targets polymerase chain reaction (IS900 PCR. Materials and Methods: Fecal and serum samples (500 each were collected from Holstein-Friesian cattle and buffaloes housed in five Egyptian governorates. Fecal samples were examined for MAP on the basis of a strategic pooling procedure and performed on Herrold's Egg Yolk Agar Medium (HEYM. Smears were prepared from developed colonies and stained using a Ziehl-Neelsen (ZN technique. The identity of developed colonies was further confirmed by PCR analysis of IS900 sequence. Sera from both culture-positive and culture-negative animals were evaluated individually for humoral response. Results: Out of 50 pooled specimens, 34 (68% fecal cultures were positive for MAP. Serum positive samples of culture
Márcio Ferraz Cunha
Full Text Available Mycobacterium avium subesp. paratuberculosis é conhecida como o agente etiológico da doença de Johne, ou paratuberculose, que afeta principalmente animais ruminantes. É integrante da família Mycobacteriaceae, da qual também fazem parte a M. tuberculosis e a M. bovis, responsáveis pela tuberculose humana e bovina, respectivamente. Foi sugerido que a M. paratuberculosis poderia estar envolvida na patogênese da doença de Crohn, a qual possui sintomas similares à paratuberculose, mas afeta seres humanos. Como o microrganismo pode ser excretado no leite de animais infectados, o primeiro passo foi avaliar a sua termoresistência. Alguns estudos indicaram que a bactéria sobrevive ao tratamento térmico da pasteurização HTST (72ºC/15 s. Entretanto, os estudos existentes na literatura científica até o momento não permitem afirmar que M. paratuberculosis seja responsável pela doença de Crohn, bem como apresentam dúvidas sobre a termoresistência dessa bactéria. A realização de mais pesquisas sobre este microrganismo é de fundamental importância, com o objetivo de orientar a produção de produtos lácteos isentos de contaminação por M. paratuberculosis.
Several novel antigens of Mycobacterium avium subsp. paratuberculosis have been studied as vaccine components and their immunogenicity has been evaluated. Previously, we reported that 85 antigen complex (85A, 85B, and 85C), superoxide dismutase (SOD), and 35kDa protein could induce significant lymph...
Mycobacterium avium subsp. paratuberculosis (MAP) is the etiologic agent of Johne’s disease in ruminants and it has been implicated as a cause of Crohn’s disease in humans. The generation of comprehensive random mutant banks by transposon mutagenesis is a fundamental wide genomic technology utilized...
Mycobacterium avium subsp. paratuberculosis (MAP), the etiologic agent of Johne’s disease, is one of the most important bacterial pathogens in ruminants. The lack of efficacious control measures demands a thorough understanding of MAP pathogenesis to develop new vaccines and diagnostic tests. The ge...
The role of Mycobacterium avium subspecies paratuberculosis (MAP) in Crohn’s disease (CD) remains controversial. One issue that has been raised is the lack of data showing a cellular immune response to MAP. Earlier studies have mostly focused on responses in peripheral blood which have several limit...
Kampen Annette H
Full Text Available Abstract Background Infection with Coxiella burnetii, the cause of Q-fever, has never been detected in Norwegian animals. Recognising the increasing prevalence of the infection in neighbouring countries, the aim of the study was to perform a survey of Norwegian farmed ruminants for the prevalence of C. burnetii infection. Results Milk and blood samples from more than 3450 Norwegian dairy cattle herds, 55 beef cattle herds, 348 dairy goat herds and 118 sheep flocks were serologically examined for antibodies against C. burnetii. All samples were negative for antibodies against C. burnetii. The estimated prevalences of infected herds were 0 (95% confidence interval: 0% - 0.12%, 0 (0% - 12%, 0 (0% - 1.2% and 0 (0% - 10% for dairy cattle herds, beef cattle herds, goat herds and sheep flocks, respectively. Conclusions The study indicates that the prevalence of C. burnetii infection in farmed Norwegian ruminants is low, and it cannot be excluded that Norway is free of the infection. It would be beneficial if Norway was able to maintain the current situation. Therefore, preventive measures should be continued.
Full Text Available Q fever is a zoonotic disease caused by Coxiella burnetii. The main source of infection are ruminants (cattle, sheep, and goats. C. burnetii is excreted via birth products, vaginal mucus, milk, and faeces. Raw milk is considered useful for epidemiological examinations of animals and evaluation of infection dynamics at the herd level. This article summarises data on prevalence studies on C. burnetii in bulk-tank milk in different European countries with the means of serological tests and PCR. It also summarises the results of studies to evaluate the actual risk of disease transmission to humans through consumption of raw milk. Moreover, the available diagnostic tools for detection C. burnetii infection are presented.
Rehbein, Steffen; Kaulfuß, Karl-heinz; Visser, Martin; Sommer, Maria Franziska; Grimm, Felix; Silaghi, Cornelia
This paper reports on endoparasite infections diagnosed in 2012 by standard coproscopical techniques and coproantigen Giardia ELISA in 165 dogs used for sheep herding in 36 farms in central Germany. The overall prevalence of dogs with evidence of endoparasite infections was 27.3% (95% CI 20.6-34.7). The most frequently identified faecal forms were those of ascarids (Toxocara, 6.7%; Toxascaris 3.6%), hookworms (5.5%) and taeniid cestodes (4.2%), followed by those of Trichuris whipworms (3.0%), Capillaria aerophila (1.8%), Angiostrongylus and Crenosoma lungworms (1.2% each) and Cystoisospora canis coccidians (0.6%). Molecular identification demonstrated the seven dogs shedding taeniid eggs positive for Taenia (T.) species tapeworms (five, T. hydatigena; one, T. ovis; one Taenia sp.). Screening of the faeces with the coproantigen ELISA revealed Giardia specific antigen in 5.5% of the samples. The majority of the dogs had evidence of single endoparasite infections (22.4%) while evidence for infection with two or three parasites concurrently was found in six (3.6%) and two (1.2%) of the dogs, respectively. Dogs ≤ 1 year (n = 19) were parasitized more frequently (p < 0.05) with overall gastrointestinal parasites (63.2% vs. 20.5%), ascarids (36.8% vs. 6.8%) and Giardia spp. (21.1% vs. 3.4%) than older dogs (n = 146). Dogs which had been wormed within six months of examination tested less frequently positive for gastrointestinal helminths compared to dogs not wormed (11.1% vs. 25.0%; p = 0.0567). In addition, ear swabs taken from 43 sheep dogs in 2012 were examined, and Otodectes cynotis mites were extracted from one dog. Identification of ectoparasites collected by full body search and combing from 113 sheep dogs in the years 2011 to 2013 revealed infestation of fleas and ticks (each up to five specimens per dog) on 13 and 108 dogs, respectively, with nine dogs carrying both fleas and ticks. Archaeopsylla erinacei, Ctenocephalides (C) canis, C. felis and Pulex irritans
Douglas C. Heard
Full Text Available The Kaminuraik caribou herd apparently declined from about 120 000 animals in 1950 to 63 000 in 1968. Beginning in 1968 documentation of herd trend was based on the estimate of the number of breeding (pregnant and post-partum females on the calving ground during the birth peak. It appeared as if we understood the basic population processes responsible for the decline when we correctly predicted a drop from 14 800 breeding females in 1977 to 13 000 in 1980. However a three-fold increase, to 41 000 breeding females in 1982, and continued growth thereafter, was unanticipated. Most of that increase must have resulted from an immigration of cows to the herd's traditional calving ground around Kaminuriak Lake, although increased birth rates, and increased survival rates also contributed to herd growth. Immigrant cows probably came from the northeastern mainland of the NWT
O'Reilly, Ciara E; O'Connor, Lisa; Anderson, Wayne; Harvey, Peter; Grant, Irene R; Donaghy, John; Rowe, Michael; O'Mahony, Pat
Over the 13-month period from October 2000 to November 2001 (inclusive), the Food Safety Authority of Ireland (FSAI) carried out surveillance of Irish bulk raw (n = 389) and commercially pasteurized (n = 357) liquid-milk supplies to determine the incidence of Mycobacterium paratuberculosis. The pasteurization time-temperature conditions were recorded for all pasteurized samples. Overall, 56% of whole-milk pasteurized samples had been heat treated at or above a time-temperature combination of 75 degrees C for 25 s. All analyses were undertaken at the Department of Food Science (Food Microbiology) laboratory at Queen's University Belfast. Each milk sample was subjected to two tests for M. paratuberculosis: immunomagnetic separation-PCR (IMS-PCR; to detect the presence of M. paratuberculosis cells, live or dead) and chemical decontamination and culture (to confirm the presence of viable M. paratuberculosis). Overall, M. paratuberculosis DNA was detected by IMS-PCR in 50 (12.9%; 95% confidence interval, 9.9 to 16.5%) raw-milk samples and 35 (9.8%; 95% confidence interval, 7.1 to 13.3%) pasteurized-milk samples. Confirmed M. paratuberculosis was cultured from one raw-milk sample and no pasteurized-milk samples. It is concluded that M. paratuberculosis DNA is occasionally present at low levels in both raw and commercially pasteurized cows' milk. However, since no viable M. paratuberculosis was isolated from commercially pasteurized cows' milk on retail sale in the Republic of Ireland, current pasteurization procedures are considered to be effective.
It has been observed the breed herd of Texel sheep in the foothills area of Orlické mountains in the year 2005-2008. The base of herd was consisted of 374 ewes, 575 lambs and 6 rams in total. These parametres of reproduction - conception, fertility, rearing, empty ewes, abortions, lambing, stillborn, death after born, were monitored at ewes. For the parametres of reproduction at ewes were found significant effects of ewe´s age and ram´s line.
Improved Culture Medium (TiKa) for Mycobacterium avium Subspecies Paratuberculosis (MAP) Matches qPCR Sensitivity and Reveals Significant Proportions of Non-viable MAP in Lymphoid Tissue of Vaccinated MAP Challenged Animals
Bull, Tim J.; Munshil, Tulika; Melvang, Heidi Mikkelsen
The quantitative detection of viable pathogen load is an important tool in determining the degree of infection in animals and contamination of foodstuffs. Current conventional culture methods are limited in their ability to determine these levels in Mycobacterium avium subspecies paratuberculosis......Ka culture equates well with qPCR and provides important evidence that accuracy in estimating viable MAP load using DNA tests alone may vary significantly between samples of mucosal and lymphatic origin....... (MAP) due to slow growth, clumping and low recoverability issues. The principle goal of this study was to evaluate a novel culturing process (TiKa) with unique ability to stimulate MAP growth from low sample loads and dilutions. We demonstrate it was able to stimulate a mean 29-fold increase...
Trypanosoma vivax infection dynamics in a cattle herd maintained in a transition area between Pantanal lowlands and highlands of Mato Grosso do Sul, Brazil Dinâmica de infecção de Trypanosoma vivax em rebanho bovino mantido numa área de transição entre o Pantanal e o planalto de Mato Grosso do Sul
Charles F. Martins
Full Text Available Trypanosoma vivax outbreaks in beef cattle in the Pantanal region of Mato Grosso do Sul state, Brazil, causes relevant economical impact due to weight loss, abortion and mortality. Cattle moved from the Pantanal to adjacent areas of this ecosystem for breeding and fattening is a common feature. Therefore an epidemiological study on breeding cows in the transition area between Pantanal lowland and adjacent highlands of Mato Grosso do Sul was performed to determine the T. vivax infection dynamics and outbreak risk. Three experimental groups were formed: Group 1 consisted of cows parasitologically negative by the Woo test and in the enzyme-linked immunosorbent assay for T. vivax antibody detection (Tv-ELISA-Ab; Group 2 parasitologically negative and positive in the Tv-ELISA-Ab; and in Group 3 cows were parasitologically positive and with positive reactions in the Tv-ELISA-Ab. During 24 months, the cows' dislodgment between the above established groups was monitored by Woo test and Tv-ELISA-Ab exams. The tabanid population was also monitored and the highest number occurred during the rainy season. Although parasitemias were detected only in the first four samplings of the experimental period, the cows could be considered as trypanotolerant, because no clinical signs were observed. Despite the higher T. vivax incidence during the dry season, no disease symptoms were seen. Even though T. vivax epidemiological situation in the herd was characterized as endemic with seasonal variation, the probability of outbreaks was null within the conditions of the study.Surtos de Trypanosoma vivax em bovinos de corte do Pantanal foram responsáveis por relevante impacto econômico, devido a perda de peso, abortos e mortalidade. Um manejo comum é o deslocamento de bovinos do Pantanal baixo para áreas adjacentes desse ecosistema para reprodução e engorda. Por essa razão, foi efetuado um estudo epidemiológico em rebanho de vacas movidas para uma área de transi
Begg, Douglas J.; Dhand, Navneet K.; Watt, Bruce; Whittington, Richard J.
The duration of survival of both the S and C strains of Mycobacterium avium subsp. paratuberculosis in feces was quantified in contrasting climatic zones of New South Wales, Australia, and detailed environmental temperature data were collected. Known concentrations of S and C strains in feces placed on soil in polystyrene boxes were exposed to the environment with or without the provision of shade (70%) at Bathurst, Armidale, Condobolin, and Broken Hill, and subsamples taken every 2 weeks were cultured for the presence of M. avium subsp. paratuberculosis. The duration of survival ranged from a minimum of 1 week to a maximum of 16 weeks, and the provision of 70% shade was the most important factor in extending the survival time. The hazard of death for exposed compared to shaded samples was 20 and 9 times higher for the S and C strains, respectively. Site did not affect the survival of the C strain, but for the S strain, the hazard of death was 2.3 times higher at the two arid zone sites (Broken Hill and Condobolin) than at the two temperate zone sites (Bathurst and Armidale). Temperature measurements revealed maximum temperatures exceeding 60°C and large daily temperature ranges at the soil surface, particularly in exposed boxes. PMID:24463974
Ganareal, Thenor Aristotile Charles S; Balbin, Michelle M; Monserate, Juvy J; Salazar, Joel R; Mingala, Claro N
Gold nanoparticle (AuNP) is considered to be the most stable metal nanoparticle having the ability to be functionalized with biomolecules. Recently, AuNP-based DNA detection methods captured the interest of researchers worldwide. Paratuberculosis or Johne's disease, a chronic gastroenteritis in ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP), was found to have negative effect in the livestock industry. In this study, AuNP-based probes were evaluated for the specific and sensitive detection of MAP DNA. AuNP-based probe was produced by functionalization of AuNPs with thiol-modified oligonucleotide and was confirmed by Fourier-Transform Infrared (FTIR) spectroscopy. UV-Vis spectroscopy and Scanning Electron Microscopy (SEM) were used to characterize AuNPs. DNA detection was done by hybridization of 10 μL of DNA with 5 μL of probe at 63 °C for 10 min and addition of 3 μL salt solution. The method was specific to MAP with detection limit of 103 ng. UV-Vis and SEM showed dispersion and aggregation of the AuNPs for the positive and negative results, respectively, with no observed particle growth. This study therefore reports an AuNP-based probes which can be used for the specific and sensitive detection of MAP DNA. Copyright © 2018 Elsevier Inc. All rights reserved.
Stanitznig, A; Khol, J L; Lambacher, B; Franz, S; Wittek, T; Kralik, P; Slana, I; Vasickova, P
Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of paratuberculosis in domestic ruminants and New World Camelids (NWC). Hepatitis E virus (HEV) is an important public health concern worldwide. The virus has been identified in several species, some of them serving as a reservoir for zoonotic HEV strains. Husbandry and breeding of llamas and alpacas have increased in Austria in recent years. Therefore, the aim of the present study was to evaluate the prevalence of MAP and HEV in NWC in Austria. Altogether 445 animals, originating from 78 farms were enrolled in the study. Of the animals sampled, 184 (41.35%) were llamas and 261 (58.65%) were alpacas. 443 blood samples for MAP-ELISA and 399 faecal samples for quantitative PCR (qPCR) and culture for MAP as well as for HEV detection by RT-qPCR have been collected. All of the 399 animals tested for shedding of MAP were negative by faecal solid culture. Using qPCR, 15 (3.8%) of the animals were MAP positive and 384 (96.2%) negative. Out of the 443 serum samples examined for specific antibodies against MAP by ELISA, 6 (1.4%) were positive, 1 (0.2%) was questionable and 436 (98.4%) samples were negative. All faecal samples were tested negative for HEV.
This review covers some epidemiological aspects that allow Brucella to survive, spread, and maintain itself in the environment. Because the success of maintaining Brucella-free herds is determined by the efficiency of the serological tests to detect a single infected animal the limitations of the
Full Text Available Animal husbandry is a recent innovation in Greenland, specifically reindeer husbandry is less than 50 years old. Reindeer husbandry was first established in mid-west Greenland and later in southern Greenland. The Greenland hunter tradition and culture is, however, still dominant in many communities. During the 1980s and 1990s, the incompatibility of these two traditions resulted in the failure of reindeer husbandry in mid-west Greenland. There were neither herding nor seasonal herd movements. Animals remained year round on the winter range, which was destroyed as lichens were trampled every summer. Without seasonal herd movements both sustainable range use and control of the herd were lost. Today, there are just two semi-domestic reindeer herds left, and both are in southern Greenland. One herd is commercially successful, and the other is under development. In mid-west Greenland, semi-domestic reindeer husbandry officially ended in 1998, and a hunt was initiated to remove the remaining population. Possibly, by the year 2000 any animals left in this region will be considered wild caribou.
Carro, Adrián; Toral, Raúl; San Miguel, Maxi
We focus on the influence of external sources of information upon financial markets. In particular, we develop a stochastic agent-based market model characterized by a certain herding behavior as well as allowing traders to be influenced by an external dynamic signal of information. This signal can be interpreted as a time-varying advertising, public perception or rumor, in favor or against one of two possible trading behaviors, thus breaking the symmetry of the system and acting as a continuously varying exogenous shock. As an illustration, we use a well-known German Indicator of Economic Sentiment as information input and compare our results with Germany's leading stock market index, the DAX, in order to calibrate some of the model parameters. We study the conditions for the ensemble of agents to more accurately follow the information input signal. The response of the system to the external information is maximal for an intermediate range of values of a market parameter, suggesting the existence of three different market regimes: amplification, precise assimilation and undervaluation of incoming information.
Full Text Available We focus on the influence of external sources of information upon financial markets. In particular, we develop a stochastic agent-based market model characterized by a certain herding behavior as well as allowing traders to be influenced by an external dynamic signal of information. This signal can be interpreted as a time-varying advertising, public perception or rumor, in favor or against one of two possible trading behaviors, thus breaking the symmetry of the system and acting as a continuously varying exogenous shock. As an illustration, we use a well-known German Indicator of Economic Sentiment as information input and compare our results with Germany's leading stock market index, the DAX, in order to calibrate some of the model parameters. We study the conditions for the ensemble of agents to more accurately follow the information input signal. The response of the system to the external information is maximal for an intermediate range of values of a market parameter, suggesting the existence of three different market regimes: amplification, precise assimilation and undervaluation of incoming information.
Broens Els M
Full Text Available Abstract Background Since the detection of MRSA CC398 in pigs in 2004, it has emerged in livestock worldwide. MRSA CC398 has been found in people in contact with livestock and thus has become a public health issue. Data from a large-scale longitudinal study in two Danish and four Dutch pig herds were used to quantify MRSA CC398 transmission rates within pig herds and to identify factors affecting transmission between pigs. Results Sows and their offspring were sampled at varying intervals during a production cycle. Overall MRSA prevalence of sows increased from 33% before farrowing to 77% before weaning. Overall MRSA prevalence of piglets was > 60% during the entire study period. The recurrent finding of MRSA in the majority of individuals indicates true colonization or might be the result of contamination. Transmission rates were estimated using a Susceptible-Infectious-Susceptible (SIS-model, which resulted in values of the reproduction ratio (R0 varying from 0.24 to 8.08. Transmission rates were higher in pigs treated with tetracyclins and β-lactams compared to untreated pigs implying a selective advantage of MRSA CC398 when these antimicrobials are used. Furthermore, transmission rates were higher in pre-weaning pigs compared to post-weaning pigs which might be explained by an age-related susceptibility or the presence of the sow as a primary source of MRSA CC398. Finally, transmission rates increased with the relative increase of the infection pressure within the pen compared to the total infection pressure, implying that within-pen transmission is a more important route compared to between-pen transmission and transmission through environmental exposure. Conclusion Our results indicate that MRSA CC398 is able to spread and persist in pig herds, resulting in an endemic situation. Transmission rates are affected by the use of selective antimicrobials and by the age of pigs.
Mikkelsen, Heidi; Aagaard, Claus; Nielsen, Søren Saxmose
antigens, heat shock antigens and hypothetical antigens. Strategies for evaluation of novel antigen candidates are discussed critically. Relatively few of the described antigens were evaluated for their use in CMI based diagnostic assays and so far, no obvious candidate has been identified...... to development of antibodies and shedding of detectable amounts of MAP. At present, available diagnostic assays are limited by the lack of MAP specific antigens included in these assays resulting in poor specificity. The objective of this review is to provide a systematic overview of diagnostic MAP antigen...... faeces; however, these diagnostic tools are often not applicable until years after infection. Detection of MAP specific cell-mediated immune (CMI) responses can serve as an alternative and be implemented in a diagnostic tool. CMI responses can be measured at an early stage of infection, prior...
Shahid, M Q; Reneau, J K; Chester-Jones, H; Chebel, R C; Endres, M I
The objectives of this study were to describe on-farm mortality and to investigate cow- and herd-level risk factors associated with on-farm mortality in Midwest US dairy herds using lactation survival analysis. We analyzed a total of approximately 5.9 million DHIA lactation records from 10 Midwest US states from January 2006 to December 2010. The cow-level independent variables used in the models were first test-day milk yield, milk fat percent, milk protein percent, fat-to-protein ratio, milk urea nitrogen, somatic cell score, previous dry period, previous calving interval, stillbirth, calf sex, twinning, calving difficulty, season of calving, parity, and breed. The herd-level variables included herd size, calving interval, somatic cell score, 305-d mature-equivalent milk yield, and herd stillbirth percentage. Descriptive analysis showed that overall cow-level mortality rate was 6.4 per 100 cow-years and it increased from 5.9 in 2006 to 6.8 in 2010. Mortality was the primary reason of leaving the herd (19.4% of total culls) followed by reproduction (14.6%), injuries and other (14.0%), low production (12.3%), and mastitis (10.5%). Risk factor analysis showed that increased hazard for mortality was associated with higher fat-to-protein ratio (>1.6 vs. 1 to 1.6), higher milk fat percent, lower milk protein percent, cows with male calves, cows carrying multiple calves, higher milk urea nitrogen, increasing parity, longer previous calving interval, higher first test-day somatic cell score, increased calving difficulty score, and breed (Holstein vs. others). Decreased hazard for mortality was associated with higher first test-day milk yield, higher milk protein, and shorter dry period. For herd-level factors, increased hazard for mortality was associated with increased herd size, increased percentage of stillbirths, higher somatic cell score, and increased herd calving interval. Cows in herds with higher milk yield had lower mortality hazard. Results of the study
Waters, W. Ray; Stevens, Gary E.; Schoenbaum, Mark A.; Orloski, Kathy A.; Robbe-Austerman, Suelee; Harris, N. Beth; Hall, S. Mark; Thomsen, Bruce V.; Wilson, Arach J.; Brannian, Roger E.; Nelson, Jeffrey T.; Schafer, Shawn; Esfandiari, Javan; Dutton, Meghan; Greenwald, Rena
In 2009, Mycobacterium bovis infection was detected in a herd of 60 elk (Cervus elaphus) and 50 fallow deer (Dama dama) in Nebraska, USA. Upon depopulation of the herd, the prevalence of bovine tuberculosis (TB) was estimated at ∼71–75%, based upon histopathology and culture results. Particularly with elk, gross lesions were often severe and extensive. One year ago, the majority of the elk had been tested for TB by single cervical test (SCT), and all were negative. After initial detection of ...
Gurung, Ratna B.; Purdie, Auriol C.; Whittington, Richard J.; Begg, Douglas J.
Control of Johne's disease, caused by Mycobacterium avium subspecies paratuberculosis (MAP) in ruminants using commercially available vaccine reduces production losses, mortality, fecal shedding and histopathological lesions but does not provide complete protection from infection and interferes with serological diagnosis of Johne's disease and bovine tuberculosis. At this time no recombinant antigens have been found to provide superior protection compared to whole killed or live-attenuated MAP vaccines. Therefore, there is a need to evaluate more candidate MAP antigens. In this study recombinant MAP antigens MAP2698c and MAP3567 were formulated with four different MONTANIDE™ (ISA 50V2, 61VG, 71VG, and 201VG) adjuvants and evaluated for their ability to produce specific immune responses in vaccinated sheep. The cellular immune response was measured with an interferon-gamma (IFN-γ) release assay and the humoral immune response was measured by antibody detection enzyme linked immunosorbent assay. Recombinant vaccine formulation with the antigen MAP2698c and MONTANIDE™ ISA 201VG adjuvant produced strong whole-MAP as well as MAP2698c-specific IFN-γ responses in a high proportion of the vaccinated sheep. The formulation caused less severe injection site lesions in comparison to other formulations. The findings from this study suggest that the MAP2698c + 201VG should be evaluated in a challenge trial to determine the efficacy of this vaccine candidate. PMID:25077074
Sardaro, Ruggiero; Pieragostini, Elisa; Rubino, Giuseppe; Petazzi, Ferruccio
A recent study on paratubercolosis in semi-extensive dairy sheep and goat farms in Apulia revealed a flock positivity of 60.5% and a seroprevalence of 3.0% for sheep and 14.5% for goat, with peaks of 50%. In such a context, providing detailed economic information is crucial for the implementation of a suitable control plan. In this paper we investigated the impact of Mycobacterium avium subspecies paratuberculosis (MAP) on profit efficiency of the Apulian dairy sheep and goat farms. Empirical results through a stochastic frontier model showed that the uninfected farms had a mean level of profit efficiency of 84%, which dropped to 64% in the presence of paratubercolosis as it negatively affected the productivity of feeding, veterinary and labour factors. Structural, managerial and production aspects were involved in the greater inefficiency of the infected farms compared to the uninfected ones: lower experience and schooling of farmers, no access to credit, fewer family members (women in particular) participating in the farming activities, high density of animals per hectare, small flocks, high number of goats in mixed flocks, no confinement practices for young and purchased animals and no pasture rotation. Hence, targeted interventions on these factors by decision makers can ensure effectiveness and efficiency to veterinary and economic action plans. Copyright © 2016 Elsevier B.V. All rights reserved.
Durnez, Lies; Sadiki, Harrison; Katakweba, Abdul
A study was conducted to determine the prevalence of Mycobacterium bovis-infection and atypical mycobacterioses in different cattle herd management systems in and around Morogoro, Tanzania. Between April and June 2005, a total of 728 bovines from 49 herds were tested for M. bovis-infection and a...
Hogerwerf, L.; Koop, G.; Klinkenberg, D.; Roest, H.J.; Vellema, P.; Nielen, M.
A major human Q fever epidemic occurred in The Netherlands during 2007–2009. In response, all pregnant goats from infected herds were culled before the 2010 kidding season without individual testing. The aim of this study was to assess whether high risk animals from recently infected naive herds can
Hogerwerf, Lenny; Koop, Gerrit; Klinkenberg, Don; Roest, Hendrik I J; Vellema, Piet; Nielen, Mirjam
A major human Q fever epidemic occurred in The Netherlands during 2007-2009. In response, all pregnant goats from infected herds were culled before the 2010 kidding season without individual testing. The aim of this study was to assess whether high risk animals from recently infected naive herds can
Mina, Michael J
disease in the population, especially among the elderly and others most susceptible to pneumococcal disease. However, these effects may also be beneficial, for example the large reductions in all-cause mortality noted following measles vaccines. Here we discuss evidence for these novel vaccine effects and suggest that vaccine monitoring and evaluation programs should consider generalized herd effects to appreciate the full impacts of vaccines, beneficial or detrimental, across species and scales that are inevitably hiding in plain sight, affecting human health and disease. © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.
Pollard, Suzanne L; Malpica-Llanos, Tanya; Friberg, Ingrid K; Fischer-Walker, Christa; Ashraf, Sania; Walker, Neff
Diarrhea is one of the leading causes of death in children under 5, and an estimated 39% of these deaths are attributable to rotavirus. Currently two live, oral rotavirus vaccines have been introduced on the market; however, the herd immunity effect associated with rotavirus vaccine has not yet been quantified. The purpose of this meta-analysis was to estimate the herd immunity effects associated with rotavirus vaccines. We performed a systematic literature review of articles published between 2008 and 2014 that measured the impact of rotavirus vaccine on severe gastroenteritis (GE) morbidity or mortality. We assessed the quality of published studies using a standard protocol and conducted meta-analyses to estimate the herd immunity effect in children less than one year of age across all years presented in the studies. We conducted these analyses separately for studies reporting a rotavirus-specific GE outcome and those reporting an all-cause GE outcome. In studies reporting a rotavirus-specific GE outcome, four of five of which were conducted in the United States, the median herd effect across all study years was 22% [19-25%]. In studies reporting an all-cause GE outcome, all of which were conducted in Latin America, the median herd effect was 24.9% [11-30%]. There is evidence that rotavirus vaccination confers a herd immunity effect in children under one year of age in the United States and Latin American countries. Given the high variability in vaccine efficacy across regions, more studies are needed to better examine herd immunity effects in high mortality regions. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Bauman, Cathy A; Jones-Bitton, Andria; Jansen, Jocelyn; Kelton, David; Menzies, Paula
The study's objective was to evaluate the ability of fecal culture (FCUL) and fecal PCR (FPCR) to identify dairy goat and dairy sheep shedding Mycobacterium avium ssp. paratuberculosis. A cross-sectional study of the small ruminant populations was performed in Ontario, Canada between October 2010 and August 2011. Twenty-nine dairy goat herds and 21 dairy sheep flocks were visited, and 20 lactating females > two years of age were randomly selected from each farm resulting in 580 goats and 397 sheep participating in the study. Feces were collected per rectum and cultured using the BD BACTEC™ MGIT™ 960 system using a standard (49 days) and an extended (240 days) incubation time, and underwent RT-PCR based on the hsp-X gene (Tetracore®). Statistical analysis was performed using a 2-test latent class Bayesian hierarchical model for each species fitted in WinBUGS. Extending the fecal culture incubation time statistically improved FCUL sensitivity from 23.1 % (95 % PI: 15.9-34.1) to 42.7 % (95 % PI: 33.0-54.5) in dairy goats and from 5.8 % (95 % PI: 2.3-12.4) to 19.0 % (95 % PI: 11.9-28.9) in dairy sheep. FPCR demonstrated statistically higher sensitivity than FCUL (49 day incubation) with a sensitivity of 31.9 % (95 % PI: 22.4-43.1) in goats and 42.6 % (95 % PI: 28.8-63.3) in sheep. Fecal culture demonstrates such low sensitivity at the standard incubation time it cannot be recommended as a screening test to detect shedding of MAP in either goats or sheep. Extending the incubation time resulted in improved sensitivity; however, it is still disappointingly low for screening purposes. Fecal PCR should be the screening test of choice in both species; however, it is important to recognize that control programs should not be based on testing alone when they demonstrate such low sensitivity.
B. Bhutto, J. A. Gadahi, G. Shah1, P. Dewani2 and A.G. Arijo
Full Text Available Blood samples were collected from 240 camels (183 male and 57 female of four breeds from six districts of Sindh. An overall infection was determined as 11.25%. Species of Trypanosoma was identified as Trypanosoma evansi. District wise infection was found to be 2.5, 7.5, 12.5, 15.00, 22.5 and 7.5% in Hyderabad, Mirpur Khas, Umerkot, Badin, Thatta and Larkana, respectively. A higher infection was found in females (15.79% as compared to males (9.84%. Highest (14.96% infection was noted in age group >7 years, followed by 8.57 and 4.65% in 3 to 7 years and less than to 3 years old camels, respectively. Four breeds of camels were surveyed and the highest infection rate was found in Sakrai breed (21.82%, followed by 16.67, 6.15 and 5.95% in Kharai, Sindhi and Dhati breeds respectively. When herd size was considered, infection rate was 1.67, 6.67, 15.00 and 21.67% in herds possessing 1 to 5, 6 to 10, 11 to 20 and more than 20 animals, respectively.
Barkema, H.W.; Orsel, K.; Nielsen, S.; Koets, Ad; Rutten, V.P.M.G.; Bannantine, J.P.; Keefe, G.P.; Kelton, D.F.; Wells, S.J.; Whittington, R.J.; Mackintosh, C.G.; Manning, E.J.; Weber, M.F.; Heuer, C.; Forde, T.L.; Ritter, C.; Roche, S.; Corbett, C.S.; Wolf, R.; Griebel, P.J.; Kastelic, J.P.; Buck, De J.
In the last decades, many regional and country-wide control programmes for Johne's disease (JD) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were