Evaluation of SpeeDx ResistancePlus® GC assay for ciprofloxacin resistance/susceptibility prediction, examining Ng isolates from 20 European countries,9 clinical AC2 samples and non-gonococcal Neisseria and closely related isolates
| . | . | ResistancePlus® GC . | In-house gyrA PCR . | ||||
|---|---|---|---|---|---|---|---|
| Samples (n) . | Ng (opa + porA) . | GyrA S91 WT . | GyrA S91F . | Indeterminate . | GyrA S91 WT . | GyrA S91F . | Indeterminate . |
| European isolates (967)9 | 967 | 447 (46.2%) | 520 (53.8%) | — | NA | NA | NA |
| Ng-positive AC2 samples (143) | 141a | 80 (55.9%) | 57 (39.9%) | 4 (2.8%) | 79 (55.2%) | 57 (39.9%) | 7 (4.9%)b |
| Samples without confirmed culture (106) | 104c | 64 (60.4%) | 37 (34.9%) | 3 (2.8%) | 63 (59.4%) | 37 (34.9%) | 6 (5.7%) |
| Samples with paired culture (37) | 37 | 16 (43.2%) | 20 (54.1%) | 1 (2.7%) | 16 (43.2%) | 20 (54.1%) | 1 (2.7%) |
| Ng-negative AC2 samples (167) | — | —d | — | 2 (1.2%)d | — | — | — |
| N. meningitidis (6) | — | — | — | — | — | — | — |
| – | |||||||
| Non-Ng commensals (137) | 2e | —f | —f | — | — | — | — |
| Neisseria flavescens (52) | — | — | — | — | — | — | — |
| Neisseria perflava (27) | — | — | — | — | — | — | — |
| N. macacae (9) | — | — | — | — | — | — | — |
| N. mucosa (6) | 1e | — | — | — | — | — | — |
| N. sicca (4) | — | — | — | — | — | — | — |
| Neisseria cinerea (2) | — | — | — | — | — | — | — |
| N. animalis (1) | 1e | — | — | — | — | — | — |
| Neisseria species (34) | — | — | — | — | — | — | — |
| M. osloensis (1) | — | — | — | — | — | — | — |
| M. catarrhalis (1) | — | — | — | — | — | — | — |
| . | . | ResistancePlus® GC . | In-house gyrA PCR . | ||||
|---|---|---|---|---|---|---|---|
| Samples (n) . | Ng (opa + porA) . | GyrA S91 WT . | GyrA S91F . | Indeterminate . | GyrA S91 WT . | GyrA S91F . | Indeterminate . |
| European isolates (967)9 | 967 | 447 (46.2%) | 520 (53.8%) | — | NA | NA | NA |
| Ng-positive AC2 samples (143) | 141a | 80 (55.9%) | 57 (39.9%) | 4 (2.8%) | 79 (55.2%) | 57 (39.9%) | 7 (4.9%)b |
| Samples without confirmed culture (106) | 104c | 64 (60.4%) | 37 (34.9%) | 3 (2.8%) | 63 (59.4%) | 37 (34.9%) | 6 (5.7%) |
| Samples with paired culture (37) | 37 | 16 (43.2%) | 20 (54.1%) | 1 (2.7%) | 16 (43.2%) | 20 (54.1%) | 1 (2.7%) |
| Ng-negative AC2 samples (167) | — | —d | — | 2 (1.2%)d | — | — | — |
| N. meningitidis (6) | — | — | — | — | — | — | — |
| – | |||||||
| Non-Ng commensals (137) | 2e | —f | —f | — | — | — | — |
| Neisseria flavescens (52) | — | — | — | — | — | — | — |
| Neisseria perflava (27) | — | — | — | — | — | — | — |
| N. macacae (9) | — | — | — | — | — | — | — |
| N. mucosa (6) | 1e | — | — | — | — | — | — |
| N. sicca (4) | — | — | — | — | — | — | — |
| Neisseria cinerea (2) | — | — | — | — | — | — | — |
| N. animalis (1) | 1e | — | — | — | — | — | — |
| Neisseria species (34) | — | — | — | — | — | — | — |
| M. osloensis (1) | — | — | — | — | — | — | — |
| M. catarrhalis (1) | — | — | — | — | — | — | — |
NA, not applicable.
Two AC2 samples (one urine sample and one rectal swab) were false-negative Ng compared with previous AC2 diagnostics.
One sample had equally amplified GyrA S91 WT and GyrA S91F target.
Two samples were only positive for the opa target, but reported as Ng positive by the analysis software.
Eight samples amplified GyrA S91 WT and two samples (vaginal and rectal swabs) were excluded due to invalid internal control (probable inhibition).
Positive for only the opa target, but reported as Ng positive by the analysis software. An additional eight non-gonococcal Neisseria isolates were positive for the opa target (N. cinerea, N. macacae, N. perflava, N. flavescens, N. mucosa and Neisseria species) and one isolate for porA (N. flavescens), but these were not reported as Ng using the analysis software.
Amplification of GyrA S91 WT target was seen in N. macacae (n = 2), N. mucosa (n = 1), N. sicca (n = 1) and Neisseria species (n = 1). Dual amplification of both gyrA targets was seen in N. macacae (n = 3), N. sicca (n = 1) and Neisseria species (n = 1). However, these were not reported as Ng using the analysis software.
Evaluation of SpeeDx ResistancePlus® GC assay for ciprofloxacin resistance/susceptibility prediction, examining Ng isolates from 20 European countries,9 clinical AC2 samples and non-gonococcal Neisseria and closely related isolates
| . | . | ResistancePlus® GC . | In-house gyrA PCR . | ||||
|---|---|---|---|---|---|---|---|
| Samples (n) . | Ng (opa + porA) . | GyrA S91 WT . | GyrA S91F . | Indeterminate . | GyrA S91 WT . | GyrA S91F . | Indeterminate . |
| European isolates (967)9 | 967 | 447 (46.2%) | 520 (53.8%) | — | NA | NA | NA |
| Ng-positive AC2 samples (143) | 141a | 80 (55.9%) | 57 (39.9%) | 4 (2.8%) | 79 (55.2%) | 57 (39.9%) | 7 (4.9%)b |
| Samples without confirmed culture (106) | 104c | 64 (60.4%) | 37 (34.9%) | 3 (2.8%) | 63 (59.4%) | 37 (34.9%) | 6 (5.7%) |
| Samples with paired culture (37) | 37 | 16 (43.2%) | 20 (54.1%) | 1 (2.7%) | 16 (43.2%) | 20 (54.1%) | 1 (2.7%) |
| Ng-negative AC2 samples (167) | — | —d | — | 2 (1.2%)d | — | — | — |
| N. meningitidis (6) | — | — | — | — | — | — | — |
| – | |||||||
| Non-Ng commensals (137) | 2e | —f | —f | — | — | — | — |
| Neisseria flavescens (52) | — | — | — | — | — | — | — |
| Neisseria perflava (27) | — | — | — | — | — | — | — |
| N. macacae (9) | — | — | — | — | — | — | — |
| N. mucosa (6) | 1e | — | — | — | — | — | — |
| N. sicca (4) | — | — | — | — | — | — | — |
| Neisseria cinerea (2) | — | — | — | — | — | — | — |
| N. animalis (1) | 1e | — | — | — | — | — | — |
| Neisseria species (34) | — | — | — | — | — | — | — |
| M. osloensis (1) | — | — | — | — | — | — | — |
| M. catarrhalis (1) | — | — | — | — | — | — | — |
| . | . | ResistancePlus® GC . | In-house gyrA PCR . | ||||
|---|---|---|---|---|---|---|---|
| Samples (n) . | Ng (opa + porA) . | GyrA S91 WT . | GyrA S91F . | Indeterminate . | GyrA S91 WT . | GyrA S91F . | Indeterminate . |
| European isolates (967)9 | 967 | 447 (46.2%) | 520 (53.8%) | — | NA | NA | NA |
| Ng-positive AC2 samples (143) | 141a | 80 (55.9%) | 57 (39.9%) | 4 (2.8%) | 79 (55.2%) | 57 (39.9%) | 7 (4.9%)b |
| Samples without confirmed culture (106) | 104c | 64 (60.4%) | 37 (34.9%) | 3 (2.8%) | 63 (59.4%) | 37 (34.9%) | 6 (5.7%) |
| Samples with paired culture (37) | 37 | 16 (43.2%) | 20 (54.1%) | 1 (2.7%) | 16 (43.2%) | 20 (54.1%) | 1 (2.7%) |
| Ng-negative AC2 samples (167) | — | —d | — | 2 (1.2%)d | — | — | — |
| N. meningitidis (6) | — | — | — | — | — | — | — |
| – | |||||||
| Non-Ng commensals (137) | 2e | —f | —f | — | — | — | — |
| Neisseria flavescens (52) | — | — | — | — | — | — | — |
| Neisseria perflava (27) | — | — | — | — | — | — | — |
| N. macacae (9) | — | — | — | — | — | — | — |
| N. mucosa (6) | 1e | — | — | — | — | — | — |
| N. sicca (4) | — | — | — | — | — | — | — |
| Neisseria cinerea (2) | — | — | — | — | — | — | — |
| N. animalis (1) | 1e | — | — | — | — | — | — |
| Neisseria species (34) | — | — | — | — | — | — | — |
| M. osloensis (1) | — | — | — | — | — | — | — |
| M. catarrhalis (1) | — | — | — | — | — | — | — |
NA, not applicable.
Two AC2 samples (one urine sample and one rectal swab) were false-negative Ng compared with previous AC2 diagnostics.
One sample had equally amplified GyrA S91 WT and GyrA S91F target.
Two samples were only positive for the opa target, but reported as Ng positive by the analysis software.
Eight samples amplified GyrA S91 WT and two samples (vaginal and rectal swabs) were excluded due to invalid internal control (probable inhibition).
Positive for only the opa target, but reported as Ng positive by the analysis software. An additional eight non-gonococcal Neisseria isolates were positive for the opa target (N. cinerea, N. macacae, N. perflava, N. flavescens, N. mucosa and Neisseria species) and one isolate for porA (N. flavescens), but these were not reported as Ng using the analysis software.
Amplification of GyrA S91 WT target was seen in N. macacae (n = 2), N. mucosa (n = 1), N. sicca (n = 1) and Neisseria species (n = 1). Dual amplification of both gyrA targets was seen in N. macacae (n = 3), N. sicca (n = 1) and Neisseria species (n = 1). However, these were not reported as Ng using the analysis software.
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