Factors Influencing the Isolation of <i>Mycobacterium Avium</i> Subsp. <i>Paratuberculosis</i> from Bovine Fecal Samples

Kalis, C.H.J.; Hesselink, Jan Willem; Russchen, E. W.; Barkema, Herman W.; Collins, Michael T.; Visser, I. J. R.

doi:10.1177/104063879901100409

Cited by 53 publications

(42 citation statements)

References 10 publications

(13 reference statements)

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“…Test schemes were based on herd examinations by serology (ELISA), individual faecal culture (IFC) [21] or pooled faecal culture (PFC) [22]. For each test scheme, the number of negative herd examinations required for a 'red' herd to move to the pool of 'green' herds was determined by the confidence that the concentration of Map in bulk milk was < 10 3 /L.…”

Section: Preventive Management Measuresmentioning

confidence: 99%

Milk quality assurance for paratuberculosis: simulation of within-herd infection dynamics and economics

Weber

Nielen²,

Velthuis³

et al. 2008

Vet. Res.

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-A 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 schemes in a simulated population of closed Dutch dairy herds over a 20-year period. Herds were certified as 'low-Map bulk milk' if, with a certain probability, the concentration of Map in bulk milk did not exceed a maximum acceptable concentration of 10 3 Map organisms per litre (based on pasteurisation studies). The programme started with an initial assessment; test-negative herds entered a surveillance procedure and test-positive herds a control procedure. The simulations showed that herd examinations by ELISA for the initial assessment, surveillance and control procedures effectively ensure the quality of 'lowMap bulk milk': > 75% of simulated herds were certified and > 96% of certified herds produced bulk milk with < 10 3 Map/L if the initial herd-level prevalence was 30%. Preventive management measures only had a minor effect on bulk milk quality of certified herds. Culling based on biennial faecal culture was more effective than culling based on annual ELISA. Average total discounted costs for 20-year participation in a programme consisting of initial assessment by ELISA, surveillance by biennial ELISA and control by biennial faecal culture were e16 × 10 3 per herd.In conclusion, this study shows that a bulk milk quality assurance programme for closed Dutch dairy herds is feasible and provides information on the cost-effectiveness of different programmes. The concepts of this study equally apply to other countries because mechanisms of paratuberculosis infection, disease, and testing are comparable in other dairy cattle populations. dairy cattle / milk / paratuberculosis / stochastic simulation model / quality assurance programme

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Section: Preventive Management Measuresmentioning

confidence: 99%

Milk quality assurance for paratuberculosis: simulation of within-herd infection dynamics and economics

Weber

Nielen²,

Velthuis³

et al. 2008

Vet. Res.

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“…3,21,25 Identification of Mptb shedders is most effectively achieved by culture of fecal samples, 25 but this technique is expensive and requires at least 16 weeks for completion. 3,9,12,13,25 Serologic tests are less expensive, faster, and easier to perform, but in general results are considered less reliable because of false-positive and false-negative re- …”

mentioning

confidence: 99%

Evaluation of Two Absorbed Enzyme-Linked Immunosorbent Assays and a Complement Fixation Test as Replacements for Fecal Culture in the Detection of Cows SheddingMycobacterium AviumSubspeciesParatuberculosis

et al. 2002

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Abstract. Control of paratuberculosis in dairy herds is based on preventing the transmission of Mycobacterium avium subsp. paratuberculosis (Mptb) from cows to calves by management measures, supported by removal of cows excreting these bacteria by the fecal route (Mptb shedders). Fecal culture is the most accurate test for identifying Mptb shedders, but this technique is expensive and takes up to 16 weeks for results to be available. Serologic tests are inexpensive, rapid, and easy to perform. Of serologic tests, the complement fixation test (CFT) and absorbed enzyme-linked immunosorbent assay (ELISA) are the serologic tests used most frequently; the CFT is considered less accurate than the ELISA with respect to sensitivity and specificity. The commonly accepted absorbed ELISA is from the Australian Central Serum Laboratory. However, a European supplier has marketed a second ELISA that is supposed to be more sensitive in detecting Mptb shedders. These 2 absorbed ELISAs, designated ELISA-A and ELISA-B, and an in-house CFT were compared with data from 2 serum panels. The Mptb shedding panel consisted of sera from 198 culture-positive cows from 53 infected herds. The method used for culture of fecal samples was a modified Jørgensen method on individual samples. The Mptb shedder detection rate by the 3 serologic tests ranged from 29.8% to 39.4%. Detection rate for ELISA-A was lower than that for ELISA-B and CFT. For all 3 tests, detection rate was dependent on the level of Mptb shedding and the age of the animals. Detection rates increased as cattle age increased to 4 years. The specificity panel was initially composed of sera from 811 cows randomly selected from 41 herds without clinical paratuberculosis that were negative for Mptb based on whole-herd fecal culture. The modified Jørgensen method for culture was used on pooled fecal samples. Serologic test specificity ranged from 93.4% to 99.8%. The specificity of ELISA-A was higher than that of ELISA-B and CFT. Specificity of ELISA-B between herds was 75-100%. Specificity of CFT between herds was 62-100%. The low specificity of ELISA-B and CFT could not be explained by a higher sensitivity for Mptb-infected cows before onset of shedding, because in the 19 herds with 8 more subsequent negative whole-herd fecal cultures in the 4 years after sampling, specificity was not improved. The insufficient specificity of ELISA-B was not corrected sufficiently by heightening the cutoff value because Mptb shedder detection rate was lowered to 28.9%, equal to that of ELISA-A, and specificity only rose to 97%, much lower than that of ELISA-A. Taking into account the different test characteristics, serologic tests are a cost-effective alternative to fecal culture in high-prevalence herds. For certification programs, only ELISA-A is recommended because in a large number of nonsuspect herds specificity remained almost 100%.Paratuberculosis, or Johne's disease, in cattle is a chronic, infectious enteric disease caused by Mycobacterium avium subsp. paratuberculosis (Mptb). Clinical sig...

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“…One hypothesis for this observation is that the interaction between the host immune system and this pathogen may contribute to the cyclic pattern of shedding observed early in infection. 4,8 The M. paratuberculosis is also notorious for its propensity to clump during growth, 26 so despite efforts to ensure homogeneity of a sample, bacilli may remain unevenly distributed throughout the feces and thus contribute to this phenomenon. Alternatively, the insensitivity of the culture method itself may prevent M. paratuberculosis from being detected reliably when present in low numbers.…”

Section: Discussionmentioning

confidence: 99%

“…2,7,18 Intermittent shedding of M. paratuberculosis in the feces also affects the detection of subclinically infected cattle. 4,8 Although this cyclic shedding is generally assumed to be a manifestation of the disease process in the animal, 4 others have suggested that shedding may appear to be sporadic due to the limits of sensitivity of the culture method itself. 8 Media used for culturing M. paratuberculosis from diagnostic specimens have traditionally included egg yolk emulsion as both a source of supplemental iron and to neutralize the toxic effects of the decontamination method used on fecal and intestinal specimens.…”

Section: Introductionmentioning

confidence: 99%

“…4,8 Although this cyclic shedding is generally assumed to be a manifestation of the disease process in the animal, 4 others have suggested that shedding may appear to be sporadic due to the limits of sensitivity of the culture method itself. 8 Media used for culturing M. paratuberculosis from diagnostic specimens have traditionally included egg yolk emulsion as both a source of supplemental iron and to neutralize the toxic effects of the decontamination method used on fecal and intestinal specimens. 12 However, little information is available regarding the optimization of egg yolk concentration in liquid media for M. paratuberculosis.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Egg Yolk on the Detection ofMycobacterium AviumSubsp.ParatuberculosisUsing the ESP II Liquid Culture System

2005

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Abstract. Rapid diagnosis of paratuberculosis in infected cattle is important for the successful control of Johne disease within herds. Thus, improving culture methods for Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) will aid in the identification of asymptomatic animals. Egg yolk is a component of the media used for growing M. paratuberculosis, but its requirement as a supplement has not been reported. Using the ESP II liquid culture system, 2 different sources and 5 concentrations (3.3%, 1.6%, 0.8%, 0.4%, and 0%) of egg yolk were analyzed. Egg yolk source did not affect either recovery rate or time to detection, but both parameters were significantly improved when the 3.3% egg yolk concentrations (final volume) were used over media containing no egg yolk. This study also assessed the recovery of M. paratuberculosis from fecal samples that were cultured multiple times using Herrold egg yolk agar (HEY). Specimens containing greater than 70 cfu/g feces could routinely be identified as positive for M. paratuberculosis after only 1 culture attempt, whereas specimens with fewer bacteria were only intermittently positive, even after 5 replicate cultures. Therefore, this study indicates that the sensitivity of the Trek Diagnostic ESP II liquid culture system for M. paratuberculosis is affected by egg yolk concentration and that single culture attempts using HEY solid media may not identify specimens containing low numbers of bacteria.

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Factors Influencing the Isolation of Mycobacterium Avium Subsp. Paratuberculosis from Bovine Fecal Samples

Cited by 53 publications

References 10 publications

Milk quality assurance for paratuberculosis: simulation of within-herd infection dynamics and economics

Milk quality assurance for paratuberculosis: simulation of within-herd infection dynamics and economics

Evaluation of Two Absorbed Enzyme-Linked Immunosorbent Assays and a Complement Fixation Test as Replacements for Fecal Culture in the Detection of Cows SheddingMycobacterium AviumSubspeciesParatuberculosis

Effect of Egg Yolk on the Detection ofMycobacterium AviumSubsp.ParatuberculosisUsing the ESP II Liquid Culture System

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