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

ReactionAssociated antibioticNo. of isolates with the following result:Sensitivity (95% CI)bSpecificity (95% CI)b
penA Asp345del ± penA Gly545SerESCs1c2d037401.00 (0.03, 1.00)0.95 (0.83, 0.99)
23S rRNA C2611T and/or 23S rRNA A2059GAZM10039401.00 (0.03, 1.00)1.00 (0.91, 1.00)
gyrA Ser91PheCIP180022401.00 (0.81, 1.00)1.00 (0.85, 1.00)
16S rRNA C1192TSPC0004040NA1.00 (0.91, 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 Asp345del reaction.

  • d One isolate was correctly predicted to harbor a mosaic penA allele on the basis of the molecular characterization but was susceptible to ESCs.