Genetic Association Analysis of Paratuberculosis Forms in Holstein-Friesian Cattle
Table 1
Characterization of paratuberculosis (PTB) status of the subgroup of 636 animals considered in genotypic association analysis, according to histopathological findings, seroprevalence estimates, and frequency of MAP detection in tissues.
PTB status
Total
Apparently free
Latent
Patent
Histopathology
No lesions
Focal type
Multifocal and diffuse types
ELISA
(i) Number of negative (% specificity)
330 (97.4)
223 (—)
16 (—)
569
(ii) Number of positive (% sensitivity)
9 (—)
12 (5.1)
46 (74.2)
67
(iii) Mean OD ± SD
0.2 ± 0.2
0.2 ± 0.3
1.7 ± 1.0
2.1 ± 1.5
(iv) Percentage of ELISA positive
2.7
5.1
74.2
(v) Histopathology complementary sensitivity (%)
—
1061.9
29.1
Tissue culture
(i) Number of negative (specificity)
310 (91.5)
192 (—)
9 (—)
511
(ii) Number of positive (sensitivity)
29 (—)
43 (18.3)
53 (85.5)
125
(iii) High bacterial load1 ()
2
4
31
37
(iv) Percentage of culture positive
8.6
18.3
85.5
(v) Histopathology complementary sensitivity (%)
—
266.7
11.0
Tissue rtPCR
(i) Number of negative (specificity)
254 (74.9)
164 (—)
4 (—)
422
(ii) Number of positive (sensitivity)
85 (—)
71 (30.2)
58 (93.5)
214
(iii) Mean Ct2 ± SD
36.2 ± 3.0
35.3 ± 3.5
25.4 ± 7.4
33.0 ± 7.4
(iv) Percentage of rtPCR positive
25.1
30.2
93.6
(v) Histopathology complementary sensitivity (%)
—
105.1
2.8
High bacterial load was considered if >50 CFU/tube was observed. Mean threshold cycle (Ct) values are referred to the rtPCR positive subgroup. OD: optical density readings. SD: standard deviation.
