Beads with
S.
Typhimurium LPS (B) compared with a commercial BC1D1 ELISA
|
Relative sensitivity (%) | 90.6 | 92.2 | 93.8 | 95.3 | 96.9 | 98.4 | 100 |
Relative specificity (%) | 98.2 | 97.3 | 93.7 | 93.7 | 91.9 | 63.7 | 62.2 |
Cut-off (MFI) | 1713 | 1668 | 1453 | 1406 | 1311 | 636 | 617 |
E+ Bb- (FN) | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
E- Bb + (FP) | 2 | 3 | 7 | 7 | 9 | 40 | 42 |
Bb+ | 60 | 62 | 67 | 68 | 71 | 103 | 106 |
Beads with
S.
Enteritidis LPS (D1) compared with a commercial BC1D1 ELISA
|
Relative sensitivity (%) | 65.6 | | | | | | |
Relative specificity (%) | 100 | | | | | | |
Cut-off (MFI) | 1105 | | | | | | |
E+ Db- (FN) | 22 | | | | | | |
E- Db + (FP) | 0 | | | | | | |
Db+ | 42 | | | | | | |
E+ Bb- Db+ | 2 | | | | | | |
- Data of 175 sera from slaughter pigs were subjected to ROC analysis using the results of a BC1D1 LPS ELISA as criterion (111 ELISA negatives, 64 ELISA positives). For the bead set with B LPS (upper table), specificities and cut-offs are given for sensitivities ranging from 90 to 100%. In addition, the numbers of false negatives (E+ Bb-), false positives (E- Bb+) and the total of positives on the B beads (Bb+) are given. For the bead set with D1 LPS (lower table), for 100% specificity the corresponding sensitivity and cut-off are given, as well as the numbers of false negatives (E+ Db-), false positives (E- Db+), the total of positives on the D beads (Db+), and the number of ELISA positives that are negative on B beads but positive on D1 beads (E+ Bb- Db+). As the used ELISA is assumed to be the perfect test, sensitivity and specificity related to this ELISA are referred to as ‘relative sensitivity’ and ‘relative specificity’. Abbreviations: E+, ELISA positive; E-, ELISA negative; Bb+, positive on B beads; Bb-, negative on B beads; D+, positive on D1 beads; D-, negative on D1 beads, FN, false negative; FP, false positive
