Comparative sensitivity of various faecal culture methods and ELISA in dairy cattle herds with endemic Johne's disease

Eamens, G. J.; Whittington, Richard J.; Marsh, Ian; Turner, Mark J.; Saunders, Vanessa F.; Kemsley, PD; Rayward, D

doi:10.1016/s0378-1135(00)00321-7

Cited by 73 publications

(56 citation statements)

References 7 publications

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“…Priors describing ELISA sensitivity in different parity groups were represented by only slightly informative beta distributions after considering previous studies. 14,15,18,36 Priors for FC sensitivity were assigned similarly but reflected the assumption that it is more sensitive than the ELISA, based on a study occurring under dairying conditions similar to those used in New Zealand. 14 The prior for the effect on sensitivity of lactation stage reflected the belief that sensitivity would be slightly higher in early lactation, due to the heightened stress associated with parturition and the onset of lactation.…”

Section: Methods For Evaluating the Performance Of Diagnostic Testsmentioning

confidence: 99%

Evaluation of Diagnostic Tests for Johne's Disease (Mycobacterium Avium Subspecies Paratuberculosis) in New Zealand Dairy Cows

et al. 2010

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Abstract. To quantify the sensitivity and specificity of a serum enzyme-linked immunosorbent assay (ELISA) and fecal culture (FC) tests and to estimate the prevalence of Johne's disease (JD) in New Zealand dairy herds using Bayesian methods, 4 New Zealand dairy herds were tested simultaneously by ELISA and FC 5 times over 3 lactations. Test results were dichotomized. A Bayesian regression model was developed that considered test sensitivity as a function of the covariates parity, lactation stage, and prevalence of JD, which is expected to vary between herds. It was applied to a cross-sectional subset of the data and the full, repeated measures data set. Results were compared with frequentist pseudo gold standard results of the full data. Using the regression model, sensitivity of the ELISA was higher in older animals, but the sensitivity of the FC test showed no trend across age groups. Both FC and ELISA sensitivity were lower in late lactation. Estimated prevalence was lower and FC sensitivity higher when analyzing the complete data. The regression model enabled a more accurate diagnosis of JD to be made because it incorporated cow-specific information in the diagnosis, such as age and lactation stage. The model also enabled the incorporation of previous test results for an individual when diagnosing disease. The trends in results from the regression model support the current understanding of the disease process. The advantage of repeated testing of individuals in the assessment of test performance is discussed in the current study.

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Section: Methods For Evaluating the Performance Of Diagnostic Testsmentioning

confidence: 99%

Evaluation of Diagnostic Tests for Johne's Disease (Mycobacterium Avium Subspecies Paratuberculosis) in New Zealand Dairy Cows

et al. 2010

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“…Different protocols recommended for culturing of M. avium subsp. paratuberculosis have different analytical sensitivities (9,16,34). However, there have been few studies to determine the optimum technique, particularly with the distinctive strains of M. avium subsp.…”

mentioning

confidence: 99%

Factors Affecting Isolation and Identification of Mycobacterium avium subsp. paratuberculosis from Fecal and Tissue Samples in a Liquid Culture System

Whittington

2009

J Clin Microbiol

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Culture of Mycobacterium avium subsp. paratuberculosis is the definitive diagnostic test for Johne's disease, a chronic granulomatous enteropathy of animals. Compared to solid media, the identification of all strains of the organism in liquid media can be more difficult because the appearance of colonies and mycobactin dependence are not observable, and the growth of other organisms needs to be distinguished, commonly by PCR. Factors affecting the isolation rate of S strains and the contamination rate in modified Middlebrook 7H9 broth (Bactec 12B) and 7H10 agar were studied using 11,598 fecal samples and 2,577 tissue samples from sheep from 1,421 farms over 10 years. Minimization of contamination in Bactec cultures required the avoidance of the carryover of fecal particles from the first sedimentation step in the double-incubation centrifugation method, and contamination was reduced significantly by incubating the sample in a solution containing vancomycin, amphotericin B, and nalidixic acid for 3 days compared to 2 days. The growth of irrelevant microorganisms confounded the identification of M. avium subsp. paratuberculosis in liquid culture by inhibiting IS900 PCR and in solid medium culture by inhibiting the growth of M. avium subsp. paratuberculosis or obscuring colonies. The contamination of samples was clustered in certain laboratory submissions and was reduced by including ampicillin in Bactec medium without affecting the odds of isolation of M. avium subsp. paratuberculosis. The long-term contamination rate for fecal cultures was about 7%, and that for tissue cultures was <0.2%. Liquid medium was more sensitive than solid medium culture for M. avium subsp. paratuberculosis.

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“…In chronic infection like pTB, local strains are key to the development of efficient diagnostic tests and vaccines; therefore, the use of commercial diagnostic kits globally has led to underreporting of the infection whenever used. When animals are tested positive, their breeding programmes get disturbed due to restrictions on (Eamens et al 2000). In smears or sections of tissues (ileo-ceccal valve/intestinal lymph nodes with gross lesions), visualization of groups of brightly pink coloured bacilli within the resident macrophages in the lesions is highly suggestive of pTB.…”

Section: Diagnosismentioning

confidence: 99%

Trends and advances in the diagnosis and control of paratuberculosis in domestic livestock

Chaubey

Gupta

et al. 2016

Veterinary Quarterly

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Paratuberculosis (pTB) is a chronic granulomatous enteritis caused by Mycobacterium avium subsp. paratuberculosis (MAP) in a wide variety of domestic and wild animals. Control of pTB is difficult due to the lack of sensitive, efficacious and cost-effective diagnostics and marker vaccines. Microscopy, culture, and PCR have been used for the screening of MAP infection in animals for quite a long time. Besides, giving variable sensitivity and specificity, these tests have not been considered ideal for large-scale screening of domestic livestock. Serological tests like ELISA easily detects anti-MAP antibodies. However, it cannot differentiate between the vaccinated and infected animals. Nanotechnology-based diagnostic tests are underway to improve the sensitivity and specificity. Newer generation diagnostic tests based on recombinant MAP secretory proteins would open new paradigm for the differentiation between infected and vaccinated animals and for early detection of the infection. Due to higher seroreactivity of secretory proteins vis-a-vis cellular proteins, the secretory proteins may be used as marker vaccine, which may aid in the control of pTB infection in animals. Secretory proteins can be potentially used to develop future diagnostics, surveillance and monitoring of the disease progression in animals and the marker vaccine for the control and eradication of pTB.

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Comparative sensitivity of various faecal culture methods and ELISA in dairy cattle herds with endemic Johne's disease

Cited by 73 publications

References 7 publications

Evaluation of Diagnostic Tests for Johne's Disease (Mycobacterium Avium Subspecies Paratuberculosis) in New Zealand Dairy Cows

Evaluation of Diagnostic Tests for Johne's Disease (Mycobacterium Avium Subspecies Paratuberculosis) in New Zealand Dairy Cows

Factors Affecting Isolation and Identification of Mycobacterium avium subsp. paratuberculosis from Fecal and Tissue Samples in a Liquid Culture System

Trends and advances in the diagnosis and control of paratuberculosis in domestic livestock

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