Fig. 1.
Methods used in the diagnosis of N. gonorrhoeae.
Table I
FDA-approved molecular diagnostic tests for the clinical diagnosis of gonorrhea, based on CDC Recommendations (2014)
| NAAT test detected pathogens | Producer | Method | Molecular targets N. gonorrhoeae |
|---|---|---|---|
| Aptima NG assay N. gonorrhoeae | (Hologic/Gen-Probe, SanDiego, California) | TMA | Specific region of 16S rRNA, different than in the Aptima Combo 2 assay |
| Aptima Combo 2 assay C. trachomatis, N. gonorrhoeae | (Hologic/Gen-Probe, SanDiego, California) | TMA | Specific region of 16S rRNA |
| Abbott Real Time 2000 CT/NG C. trachomatis, N. gonorrhoeae | Abbott Molecular Inc. Des Plaines, Illinois | qPCR | 48 bp sequence within the Opa gene |
| Cobas CT/NG C. trachomatis, N. gonorrhoeae | Roche Molecular Diagnostics, Branchburg, New Jersey | PCR | two sequences within the fragment DR 9A and DR 9B (DR – direct repeat) |
| BD ProbeTec ET CT/GC Ampliefied DNA assay C. trachomatis, N. gonorrhoeae | Becton Dickinson, Sparks, Maryland | SDA | Chromosomal pilin gene-inverting protein homolog |
| BD ProbeTec NG Q N. gonorrhoeae | Becton Dickinson, Sparks, Maryland | SDA | Chromosomal pilin gene-inverting protein homolog |
| Xpert CT/NG Assay C. trachomatis, N. gonorrhoeaes | Cepheid, Sunnyvale, California | qPCR | two specific chromosomal DNA sequence |
Table II.
MIC breakpoint range for N. gonorrhoeae according to EUCAST recommendations v 12.0 2023.01.01 and CLSI 2020
| Antibiotic (abbreviation) | MIC limit values (mg/l) | |||
|---|---|---|---|---|
| EUCAST v 12.0 2023 | CLSI 2020 | |||
| ≤ W | > O | ≤ W | > O | |
| Penicillin (P) | 0,06 | 1,0 | 0,06 | 2,0 |
| Cefixime (CFM) | 0,125 | 0,125 | 0,25 | - |
| Ceftriaxone (CRO) | 0,125 | 0,125 | 0,25 | - |
| Cefotaxime (CTX) | 0,125 | 0,125 | 0,5 | - |
| Azithromycin (AZM)* | 1,0 (ECOFF) | 1,0 | - | |
| Ciprofloxacin (CIP) | 0,03 | 0,06 | 0,06 | 1,0 |
| Tetracycline (T) | 0,5 | 0,5 | 0,25 | 2,0 |
| Spectinomycin (SPT) | 64,0 | 64,0 | 32,0 | 128,0 |
1 Azitromycin* - According to EUCAST v.12.0 recommendations for azithromycin, it is possible to provide MIC values (mg/l) without a sensitive/ resistant interpretation. The ECOFF value (epidemiological cut-off value) is 1.0 mg/l, in the case of MIC value < 1 mg/l, azithromycin can be used in combination with another active antibiotic. MIC value > 1 mg/l indicates the presence of acquired resistance mechanisms.