TABLE 2.
External validation of the identification potential of univariate FTIR, ANN, and API using 277 Listeria strains not included in the reference data set
| Species | No. of strains tested | Univariate FTIR analysis
|
ANN identification
|
API Listeria
|
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Correct identification % (no.) | Misidentificationa % (no.) | No identificationb % (no.) | Correct identification % (no.) | Misidentificationc % (no.) | No identificationd % (no.) | Correct identification % (no.) | Misidentificatione % (no.) | No identificationf % (no.) | ||
| L. innocua | 60 | 91.7 (55) | 8.3 (5) | 93.3 (56) | 6.7 (4) | 90.0 (54) | 8.3 (5) | 1.7 (1) | ||
| L. ivanovii | 28 | 71.4 (20) | 28.6 (8) | 96.4 (27) | 3.6 (1) | 89.3 (25) | 3.6 (1) | 7.1 (2) | ||
| L. monocytogenes | 130 | 93.0 (121) | 7.0 (9) | 99.2 (129) | 0.8 (1) | 93.1 (121) | 6.9 (7) | 1.5 (2) | ||
| L. seeligeri | 48 | 64.6 (31) | 35.4 (17) | 93.8 (45) | 6.2 (3) | 75.0 (36) | 2.1 (1) | 22.9 (11) | ||
| L. welshimeri | 11 | 81.8 (9) | 18.2 (2) | 81.8 (9) | 18.2 (2) | 72.7 (8) | 27.3 (3) | |||
| Total | 277 | 85.2 (236) | 14.8 (41) | 96.0 (266) | 4.0 (11) | 88.0 (244) | 5.1 (14) | 6.9 (19) | ||
a
Strains yielding an SD value below or equal to the threshold value of 0.5 used for correct identification of Listeria species, but their identification corresponded to an incorrect species.
b
Strains yielding an SD value higher than the threshold value of 0.5 used for correct identification of Listeria species.
c
Strains yielding identification results corresponding to an incorrect species.
d
Strains not yielding identification results.
e
Strains yielding identification results corresponding to an incorrect species.
f
Strains yielding no or multiple results.