A longitudinal study of cattle found positive to the interferon g assay for Mycobacterium bovis infection: preliminary findings

Department of Agriculture, Food and the MarineTeagascDeposited by bulk impor

Tuberculosis in cattle and its control: limitations to the use of the interferon-gamma assay in attested herds

Department of Agriculture, Food and the MarineTeagascDeposited by bulk impor

Trophic enrichment factors for blood serum in the European badger (Meles meles).

Ecologists undertaking stable isotopic analyses of animal diets require trophic enrichment factors (TEFs) for the specific animal tissues that they are studying. Such basic data are available for a small number of species, so values from trophically or phylogenetically similar species are often substituted for missing values. By feeding a controlled diet to captive European badgers (Meles meles) we determined TEFs for carbon and nitrogen in blood serum. TEFs for nitrogen and carbon in blood serum were +3.0 ± 0.4‰ and +0.4 ± 0.1‰ respectively. The TEFs for serum in badgers are notably different from those published for the red fox (Vulpes vulpes). There is currently no data for TEFs in the serum of other mustelid species. Our data show that species sharing similar niches (red fox) do not provide adequate proxy values for TEFs of badgers. Our findings emphasise the importance of having species-specific data when undertaking trophic studies using stable isotope analysis

Stable isotopic values of serum from captive badgers fed a diet of biscuits and peanuts.

<p>These plots use trophic enrichment factors (TEFs) derived from three captive animals fed on a biscuit-only diet. The TEF for each dietary source is represented by a mean and standard deviation for both axes (δ¹⁵N and δ¹³C), plotted using SIAR <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053071#pone.0053071-Parnell1" target="_blank">[2]</a>. Additional data for earthworms are provided for comparison. a. May 2008 (16 badgers). b. June 2008 (10 badgers). c. July 2008 (10 badgers).</p

Mean isotopic changes for δ¹³C after lipid extraction (including P values and sample sizes from comparison T-tests) of dog biscuits, peanuts and badger blood serum and badger red blood cells (RBCs).

<p>Reported values are provided with only one decimal place, to reflect the accuracy and precision of the analytical machinery.</p

Mean isotopic values for δ¹⁵N and δ¹³C (lipid extracted) obtained from serum of three captive badgers fed on a controlled diet for one month, and the calculated trophic enrichment factors (TEF) for each animal.

<p>Isotopic values (with corrections for lipid extraction) are the mean of three samples for each badger and nine samples of biscuit. Reported values are provided with only one decimal place, to reflect the accuracy and precision of the analytical machinery. TEFs for serum were calculated by subtracting the mean stable isotopic values of the diet (biscuits) from that of serum.</p

Oral Vaccination of Free-Living Badgers (<i>Meles meles</i>) with Bacille Calmette Guérin (BCG) Vaccine Confers Protection against Tuberculosis

<div><p>A field trial was conducted to investigate the impact of oral vaccination of free-living badgers against natural-transmitted <i>Mycobacterium bovis</i> infection. For a period of three years badgers were captured over seven sweeps in three zones and assigned for oral vaccination with a lipid-encapsulated BCG vaccine (Liporale-BCG) or with placebo. Badgers enrolled in Zone A were administered placebo while all badgers enrolled in Zone C were vaccinated with BCG. Badgers enrolled in the middle area, Zone B, were randomly assigned 50:50 for treatment with vaccine or placebo. Treatment in each zone remained blinded until the end of the study period. The outcome of interest was incident cases of tuberculosis measured as time to seroconversion events using the BrockTB Stat-Pak lateral flow serology test, supplemented with post-mortem examination. Among the vaccinated badgers that seroconverted, the median time to seroconversion (413 days) was significantly longer (p = 0.04) when compared with non-vaccinated animals (230 days). Survival analysis (modelling time to seroconversion) revealed that there was a significant difference in the rate of seroconversion between vaccinated and non-vaccinated badgers in Zones A and C throughout the trial period (p = 0.015). For badgers enrolled during sweeps 1–2 the Vaccine Efficacy (VE) determined from hazard rate ratios was 36% (95% CI: -62%– 75%). For badgers enrolled in these zones during sweeps 3–6, the VE was 84% (95% CI: 29%– 97%). This indicated that VE increased with the level of vaccine coverage. Post-mortem examination of badgers at the end of the trial also revealed a significant difference in the proportion of animals presenting with <i>M</i>. <i>bovis</i> culture confirmed lesions in vaccinated Zone C (9%) compared with non-vaccinated Zone A (26%). These results demonstrate that oral BCG vaccination confers protection to badgers and could be used to reduce incident rates in tuberculosis-infected populations of badgers.</p></div

Kaplan-Meier survival curves (time to seroconversion) for non-vaccinated and vaccinated badgers enrolled in sweeps 1–2 (A) and in sweeps 3–6 (B).

<p>Kaplan-Meier survival curves (time to seroconversion) for non-vaccinated and vaccinated badgers enrolled in sweeps 1–2 (A) and in sweeps 3–6 (B).</p

Kaplan-Meier survival curves (time to seroconversion) for non-vaccinated and vaccinated badgers during the whole period of study.

<p>Kaplan-Meier survival curves (time to seroconversion) for non-vaccinated and vaccinated badgers during the whole period of study.</p

Time (days) to seroconversion for all badgers that seroconverted during the trial: non-vaccinated (N = 30), vaccinated (N = 21).

<p>Time (days) to seroconversion for all badgers that seroconverted during the trial: non-vaccinated (N = 30), vaccinated (N = 21).</p