TABLE 1.
Identification performance of Gram-positive bacteria, Gram-negative bacteria, and yeasts after reevaluation of DNA probe data with the 2017 Accelerate Pheno system software updatea
| Probe (category and species) | No. of samples with the following resultb: |
Sensitivity(%) (95% CI)c | Specificity (%) (95% CI)c | |||
|---|---|---|---|---|---|---|
| TP | FN | TN | FP | |||
| Gram-positive bacteria | ||||||
| Staphylococcus aureus | 242 | 5 | 1,643 | 19 | 98.0 (95.4–99.1) | 98.9 (98.2–99.3) |
| CoNSd | 264 | 15 | 1,589 | 28 | 94.6 (91.3–96.7) | 98.3 (97.5–98.8) |
| Staphylococcus lugdunensis | 77 | 2 | 1,857 | 1 | 97.5 (91.2–99.3) | 100.0 (99.7–100) |
| Enterococcus faecium | 109 | 4 | 1,809 | 9 | 96.5 (91.3–98.6) | 99.5 (99.1–99.7) |
| Enterococcus faecalis | 102 | 2 | 1,814 | 3 | 98.1 (93.3–99.5) | 99.8 (99.5–99.9) |
| Streptococcus spp. | 180 | 5 | 1,678 | 46 | 97.3 (93.8–98.8) | 97.3 (96.5–98) |
| Total | 974 | 33 | 10,390 | 106 | 96.7 (95.4–97.7) | 99.0 (98.8–99.2) |
| Gram-negative bacteria | ||||||
| Escherichia coli | 148 | 2 | 1,771 | 2 | 98.7 (95.3–99.6) | 99.9 (99.6–100) |
| Klebsiella spp. | 126 | 3 | 1,790 | 6 | 97.7 (93.4–99.2) | 99.7 (99.3–99.9) |
| Enterobacter spp. | 108 | 2 | 1,822 | 4 | 98.2 (93.6–99.5) | 99.8 (99.4–99.9) |
| Proteus spp. | 88 | 1 | 1,838 | 6 | 98.9 (93.9–99.9) | 99.7 (99.3–99.9) |
| Citrobacter spp. | 95 | 1 | 1,768 | 8 | 99.0 (94.3–100) | 99.6 (99.1–99.8) |
| Serratia marcescens | 50 | 0 | 1,885 | 1 | 100.0 (92.9–100) | 100.0 (99.7–100) |
| Pseudomonas aeruginosa | 57 | 1 | 1,865 | 3 | 98.3 (90.9–99.9) | 99.8 (99.5–100) |
| Acinetobacter baumannii | 69 | 1 | 1,854 | 3 | 98.6 (92.3–99.9) | 99.8 (99.5–100) |
| Total | 741 | 11 | 14,593 | 33 | 98.5 (97.4–99.2) | 99.8 (99.7–99.8) |
| Yeasts | ||||||
| Candida albicans | 44 | 1 | 1,827 | 7 | 97.8 (88.4–99.9) | 99.6 (99.2–99.8) |
| Candida glabrata | 49 | 1 | 1,818 | 8 | 98.0 (89.5–99.9) | 99.6 (99.1–99.8) |
| Total | 93 | 2 | 3,645 | 15 | 97.9 (92.7–99.4) | 99.6 (99.3–99.8) |
| Overall | 1,808 | 46 | 28,628 | 154 | 97.5 (96.7–98.1) | 99.5 (99.4–99.5) |
a
The overall data for all organisms tested are shown in boldface type in the table.
b
The test results are shown as follows: TP, true positive; FN, false negative; TN, true negative; FP, false positive. See the definitions for test results in the supplemental Materials section.
c
Sensitivity and specificity are shown as percentages. The values in parentheses are the 95% confidence intervals.
d
CoNS, coagulase-negative Staphylococcus spp.