scholarly journals Economic analysis of Mycobacterium avium subspecies paratuberculosis vaccines in dairy herds

2012 ◽  
Vol 95 (4) ◽  
pp. 1855-1872 ◽  
Author(s):  
J. Cho ◽  
L.W. Tauer ◽  
Y.H. Schukken ◽  
M.I. Gómez ◽  
R.L. Smith ◽  
...  
Keyword(s):  
Economic Analysis ◽  
Mycobacterium Avium ◽  
Mycobacterium Avium Subspecies Paratuberculosis ◽  
Dairy Herds

scholarly journals Within-herd prevalence thresholds for the detection of Mycobacterium avium subspecies paratuberculosis-positive dairy herds using boot swabs and liquid manure samples

2015 ◽  
Vol 144 (2) ◽  
pp. 413-424 ◽  
Author(s):  
K. DONAT ◽  
N. HAHN ◽  
T. EISENBERG ◽  
K. SCHLEZ ◽  
H. KÖHLER ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Avium Subspecies Paratuberculosis ◽  
Threshold Level ◽  
Johne's Disease ◽  
Probability Of Detection ◽  
Johne’S Disease ◽  
Dairy Herds ◽  
Liquid Manure ◽  
Herd Prevalence ◽  
Faecal Culture

SUMMARYThe control of Johne's disease requires the identification of Mycobacterium avium ssp. paratuberculosis (MAP)-positive herds. Boot swabs and liquid manure samples have been suggested as an easy-to-use alternative to sampling individual animals in order to diagnose subclinical Johne's disease at the herd level, but there is a need to evaluate performance of this approach in the field. Using a logistic regression model, this study aimed to calculate the threshold level of the apparent within-herd prevalence as determined by individual faecal culture, thus allowing the detection of whether a herd is MAP positive. A total of 77 boot swabs and 75 liquid manure samples were taken from 19 certified negative and 58 positive dairy herds. Faecal culture, three different polymerase chain reaction (PCR) methods and the combination of faecal culture with PCR were applied in order to detect MAP. For 50% probability of detection, a within-herd prevalence threshold of 1·5% was calculated for testing both matrices simultaneously by faecal culture and PCR, with the threshold increased to 4·0% for 90% probability of detection. The results encourage the use of boot swabs or liquid manure samples, or a combination both, for identifying MAP-positive herds and, to a certain extent, for monitoring certified Johne's disease-negative cattle herds.

scholarly journals Environmental sampling to assess the bioburden of Mycobacterium avium subspecies paratuberculosis in drylot pens on California dairies

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8081 ◽  
Author(s):  
Tapakorn Chamchoy ◽  
Deneice R. Williams ◽  
John M. Adaska ◽  
Randall J. Anderson ◽  
Sharif S. Aly
Keyword(s):  
Mycobacterium Avium ◽  
Environmental Samples ◽  
Mycobacterium Avium Subspecies Paratuberculosis ◽  
High Reliability ◽  
Intraclass Correlation ◽  
Economic Losses ◽  
Dairy Herds ◽  
Environmental Sampling ◽  
Sampling Protocol ◽  
Central California

Mycobacterium avium subspecies paratuberculosis (MAP) is a bacterium that can cause substantial economic losses in infected dairy herds due to reduced milk production and increased cow-replacement costs. In order to control MAP in dairies with drylot pens, a standardized environmental sampling protocol to quantify MAP in fecal slurry was developed based on an existing protocol for freestall pens. Specifically, following a 24 h hold of the flush, a grab sample of approximately 10 ml of fecal slurry was collected every 1 m along the flush lane of the drylot pens, avoiding individual cow fecal pats. To determine the reliability and repatability of the new environmental sampling protocol for estimation of MAP bioburden at the pen level, two collectors simultaneously collected fecal slurry samples every day for 3 days from six drylot cow pens on two Central California dairies. During the study period no cow movement between pens was allowed with the exception of sick cows. The study herds had MAP seroprevalence of 5.8% and 3.2%, respectively, based on whole pen serum ELISA results. Variance components models for quantitative real-time PCR (qPCR) results showed samples collected from different pens on different dairies accounted for greater variablitiy in MAP concentration (65%), while samples collected by different collectors had the least variability (0.1%). In contrast, variability in MAP concentration in environmental samples collected on different days had 25% variability. The intraclass correlation coefficient showed high reliability (93%) of environmental sampling simultaneously by different collectors. In contrast, the reliability of environmental sampling at different days was 65%, which was similar to the reliability for sampling by different collectors on different days. Investigators can expect high reliability when employing the new environmental sampling protocol along with qPCR testing of environmental samples from drylot pens.

scholarly journals Electrochemical Detection of Serum Antibodies Against Mycobacterium avium Subspecies paratuberculosis

2021 ◽  
Vol 8 ◽  
Author(s):  
Kaoru Hatate ◽  
J. Hunter Rice ◽  
Karsten Parker ◽  
J. Jayne Wu ◽  
Amy Turner ◽  
...  
Keyword(s):  
Electrochemical Detection ◽  
Mycobacterium Avium ◽  
Magnetic Beads ◽  
Mycobacterium Avium Subspecies Paratuberculosis ◽  
Diagnostic System ◽  
New Method ◽  
Economic Losses ◽  
Dairy Herds ◽  
Redox Active ◽  
Active Probe

Mycobacterium avium subsp. paratuberculosis (MAP) causes a chronic inflammatory intestinal disease, called Johne's disease (JD) in many ruminants. In the dairy industry, JD is responsible for significant economic losses due to decreased milk production and premature culling of infected animals. Test-and-cull strategy in conjunction with risk management is currently recommended for JD control in dairy herds. However, current diagnostic tests are labor-intensive, time-consuming, and/or too difficult to operate on site. In this study, we developed a new method for the detection of anti-M. paratuberculosis antibodies from sera of M. paratuberculosis-infected animals. M. paratuberculosis antigen-coated magnetic beads were sequentially reacted with bovine serum followed by a horseradish peroxidase (HRP)-labeled secondary antibody. The reaction of HRP with its substrate was then quantitatively measured electrochemically using a redox-active probe, ferrocyanide. After optimization of electrochemical conditions and concentration of the redox-active probe, we showed that the new electrochemical detection method could distinguish samples of M. paratuberculosis-infected cattle from those of uninfected cattle with greater separation between the two groups of samples when compared with a conventional colorimetric testing method. Since electrochemical detection can be conducted with an inexpensive, battery-operated portable device, this new method may form a basis for the development of an on-site diagnostic system for JD.

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