TABLE 6.
Performance of the real-time PCR in predicting antimicrobial resistance to four antibiotic classes directly from Neisseria gonorrhoeae-positive extragenital specimens with paired N. gonorrhoeae isolatesa
| Reaction | Associated antibiotic | No. of isolates with the following result: |
Sensitivity (95% CI)b | Specificity (95% CI)b | ||||
|---|---|---|---|---|---|---|---|---|
| TP | FP | FN | TN | Total | ||||
| penA Asp345del ± penA Gly545Ser | ESCs | 0 | 15c | 0 | 39 | 54 | NA | 0.72 (0.58, 0.84) |
| 23S rRNA C2611T and/or 23S rRNA A2059G | AZM | 0 | 1 | 0 | 53 | 54 | NA | 0.98 (0.90, 1.00) |
| gyrA Ser91Phe | CIP | 23 | 1 | 0 | 30 | 54 | 1.00 (0.85, 1.00) | 0.97 (0.83, 1.00) |
| 16S rRNA C1192T | SPC | 0 | 2 | 0 | 52 | 54 | NA | 0.96 (0.87, 1.00) |
a
CI, confidence interval; TP, true positive; FP, false positive; FN, false negative; TN, true negative; ESCs, extended-spectrum cephalosporins; AZM, azithromycin; CIP, ciprofloxacin; SPC, spectinomycin; NA, not applicable.
b
Sensitivity and specificity were calculated on the basis of the susceptibility phenotype (MICs) of the paired culture isolates.
c
Two isolates were correctly predicted to harbor a mosaic penA allele on the basis of the molecular characterization but were susceptible to ESCs.