Skip to main content

Table 7 Comparisons of identification of D. nodosus by the aprV2 rtPCR and culture/gelatinase gel test from subsets of presence/absence or both of foot lesions from the clinically affected flocks, consisting of 135 clinically affected sheep and 35 clinically healthy sheep

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

Flocks Sheep clinical status (foot lesions) No. sheep tested aprV2 PCR Run/Cut-off Culture Gelatinase Thermostable (Virulent) vs aprV2 PCR Percentage positive results
Concordant results Culture +ve PCR + ve p value Kappa Culture aprV2 PCR
+ve -ve PCR -ve Culture -ve
12 to 24 +ve 135 Run 1 / 40 31 17 0 87 < 0.0001 0.082 23.0% 87.4%
12 to 24 +ve 135 Run 1 / 35 31 20 0 84 < 0.0001 0.1 23.0% 85.2%
12 to 14 -ve 35 Run 1 / 40 3 16 0 16 0.0002 0.146 8.6% 54.3%
12 to 14 -ve 35 Run 2 / 40 3 12 0 20 < 0.0001 0.093 8.6% 65.7%
12 to 14 -ve 35 Run 1 / 35 3 20 0 12 0.0015 0.222 8.6% 42.9%
12 to 14 -ve 35 Run 2 / 35 3 19 0 13 0.0009 0.2 8.6% 45.7%
12 to 14 -ve & + ve 72 Run 1 / 40 9 20 0 43 < 0.0001 0.104 12.50% 72.20%
12 to 14 -ve & + ve 72 Run 2 / 40 9 16 0 47 < 0.0001 0.078 12.50% 77.80%
12 to 14 -ve & + ve 72 Run 1 / 35 9 27 0 36 < 0.0001 0.158 12.50% 62.50%
12 to 14 -ve & + ve 72 Run 2 / 35 9 27 0 36 < 0.0001 0.158 12.50% 62.50%
12 to 24 -ve & + ve 170 Run 1 / 40 34 33 0 103 < 0.0001 0.114 20.0% 80.6%
12 to 24 -ve & + ve 170 Run 1 / 35 34 40 0 96 < 0.0001 0.143 20.0% 76.5%
  1. The p-value for McNemar’s test for independence between culture gelatinase thermostable (Virulent) and aprV2 PCR result is shown. Detection rates of both culture and rtPCR are presented as percentage positive results