Table 1. Pathogen performance of the multiplexed prototype assay [including discrepant results resolution in brackets].
Sensitivity | Specificity | |||||||
Cultured organisms: | TPa | FNb | FPc | TNd | [%] | [%] | PPVe [%] | NPVf [%] |
Acinetobacter baumannii | 2 | 0 | 5 [1] | 531 | 100 | 99.1 | 28.6 | 100 |
Enterobacter spp. | 7 | 3 [2] | 55 [14] | 397 | 70 | 87.8 | 11.3 | 99.3 |
Escherichia coli | 19 | 8 [5] | 12 [7] | 509 | 70.4 | 97.7 | 61.3 | 98.5 |
Haemophilus influenzae | 4 | 0 | 43 [33] | 473 | 100 | 91.7 | 8.5 | 100 |
Klebsiella oxytoca | 0 | 1 [0] | 5 [1] | 335 | 0 | 98.5 | 0 | 99.7 |
Klebsiella pneumoniae | 10 | 8 [7] | 0 | 381 | 55.6 | 100 | 100 | 97.9 |
Moraxella catarrhalis | 0 | 1 [0] | 15 [12] | 498 | 0 | 97.1 | 0 | 99.8 |
Morganella morganii | 0 | 1 [0] | 6 [1] | 514 | 0 | 98.8 | 0 | 99.8 |
Proteus spp. | 4 | 4 [3] | 7 [0] | 465 | 50.0 | 98.5 | 36.4 | 99.1 |
Pseudomonas aeruginosa | 19 | 10 [6] | 6 [3] | 306 | 65.5 | 98.1 | 76 | 96.8 |
Serratia marcescens | 11 | 1 [1] | 6 [6] | 529 | 91.7 | 98.9 | 64.7 | 99.8 |
Staphylococcus aureus | 22 | 12 [11] | 13 [9] | 433 | 64.7 | 97.1 | 62.9 | 97.3 |
Stenotrophomonas maltophilia | 20 | 1 [1] | 46 [28] | 471 | 95.2 | 91.1 | 30.3 | 99.8 |
Streptococcus pneumoniae | 2 | 0 | 98 [69]* | 414 | 100 | 80.9 | 2 | 100 |
Total | 120 | 50 [36] | 317 [184] | 6256 | 70.6 | 95.2 | 27.5 | 99.2 |
true positive: positive in microbiological standard-of-care testing and positive in the multiplexed assay.
false negative: positive in microbiological standard-of-care testing and negative in the multiplexed assay.
false positive: negative in microbiological standard-of-care testing and positive in the multiplexed assay.
true negative: negative in microbiological standard-of-care testing and negative in the multiplexed assay.
positive predictive value.
negative predictive value [confirmed FN and FP in brackets].
* confirmation of Streptococcus: only as "Streptococcus spp."
Additional pathogens not covered by the multiplexed assay: 114 yeasts (including 85 Candida spp.), 7 other fungi, 9 Citrobacter spp., 49 coagulase neg. staphylococci, 34 enterococci, 35 streptococci (mostly viridans group), 8 other Gram-positive bacteria (Leuconostoc spp., Rothia spp., Corynebacterium spp.), 3 Pseudomonas spp., 10 Neisseria spp., 3 Haemophilus spp., 10 Citrobacter spp., 7 other Gram-negative bacteria (Ralstonia spp., Achromobacter spp., Burkholderia spp., Raoultella spp., Serratia spp.).