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Table 3 Clinical scores and results of D. nodosus culture, gelatinase test and rtPCR (aprB2/aprV2 positive, two cut offs, duplicate runs) in 318 sheep from flocks considered to be free of footrot (clinically healthy), 170 sheep from flocks considered having virulent footrot (clinically affected) and 27 sheep from a closed flock (#11) that apparently eradicated virulent footrot more than 10 years ago. Flocks were sampled from October 2014 to August 2015

From: Assessment of a rtPCR for the detection of virulent and benign Dichelobacter nodosus, the causative agent of ovine footrot, in Australia

  Flock ID No. sheep tested Results aprB2 rtPCRd aprV2 rtPCRd
Clinical Scoreb Culturec Gelatinase testd
Run 1 Run 2 Run 1 Run 2
0 1 2 3 4 5 Mean Benign Virulent Undetermined Cut-off Cut-off Cut-off Cut-off
40 35 40 35 40 35 40 35
Clinically healthy 1 18 18 0
2 18 18 0 1 1 2 2 2 2
3 19 17 1 1 0.1 1
4 18 11 1 6 0.6 4
5 19 19 0 2
6 18 11 3 1 1 2 0.8 5 4 6 4
7 18 16 2 0.1
8 55 55 0 5 1 1 1 3 2 4 2
9 81 81 0 2 2 5 3 4 3 2 5
10 54 51 3 0.1 8 2 1 2 1
Subtotal 318 297 9 8 1 1 2   3 2 0 1 18 4 # 4 14 9 19 9
  11a 27 11 16 0.6 16 10 20 13
Clinically affected 12 26 14 12 0.5 7 5 2 26 25 26 26
13 10 1 3 5 1 2.2 4 2 2 5 3 3 3 9 6 9 6
14 36 20 8 3 5 1.1 2 2 6 5 6 5 17 14 21 13
15 10 1 2 7 4.5 2 2 ND ND 10 9 ND ND
16 10 4 3 2 1 3 5 5 ND ND 10 10 ND ND
17 10 4 2 4 1 10 4 6 4 4 ND ND 6 6 ND ND
18 9 9 4.9 3 3 ND ND 9 9 ND ND
19 10 1 9 2.7 3 3 ND ND 9 9 ND ND
20 10 4 5 1 1.1 3 2 1 10 10 ND ND 10 10 ND ND
21 10 9 1 3.5 2 2 ND ND 2 1 ND ND
22 10 1 5 3 1 3.3 6 1 5 ND ND 10 10 10 10
23 10 10 4 ND ND 10 10 ND ND
24 9 5 2 2 2.6 ND ND 9 8 ND ND
Subtotal 170 35 41 23 22 26 23   45 9 34 2 27 24 9 8 137 127 66 55
  1. a Flock 11 has been excluded from specificity and sensitivity calculations because of its history
  2. b Results expressed as a number of sheep in which the highest rated foot was in the particular score
  3. c Results expressed as a number of sheep from which an organism morphologically consistent with D. nodosus was isolated
  4. d Results expressed as a number of sheep that tested positive