Performance of the real-time PCR in predicting antimicrobial resistance to four antibiotic classes directly from Neisseria gonorrhoeae-positive clinical specimens with paired N. gonorrhoeae isolatesa

ReactionAssociated antibioticNo. of isolates with the following result:Sensitivity (95% CI)bSpecificity (95% CI)b
penA Asp345del ± penA Gly545SerESCs1c17d076941.00 (0.03, 1.00)0.82 (0.72, 0.89)
23S rRNA C2611T and/or 23S rRNA A2059GAZM11092941.00 (0.03, 1.00)0.99 (0.94, 1.00)
gyrA Ser91PheCIP411052941.00 (0.91, 1.00)0.98 (0.90, 1.00)
16S rRNA C1192TSPC0209294NA0.98 (0.93, 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 This isolate harbored a penA mosaic X allele and was correctly identified as ESC resistant by the penA Ala345del reaction.

  • d Three isolates were correctly predicted to harbor a mosaic penA allele on the basis of the molecular characterization but were susceptible to ESCs.