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Table 1 Clinical and analytical detection of the updated Aptima Combo 2 assay (AC2; detecting CT and NG), which provides detection coverage of all diagnostic-escape new variants of CT [18–25, the present study]

From: Sensitivity, specificity, inclusivity and exclusivity of the updated Aptima Combo 2 assay, which provides detection coverage of the new diagnostic-escape Chlamydia trachomatis variants

Clinical specimen Number tested Positive AC2 Positive updated AC2
CT NG CT NG
CT wild type (C1515)-positive clinical AC2 specimensa,b 488 488 84 486 84
FI-nvCT (C1515T)-positive clinical AC2 specimensb 114 0 0 114 0
nvCT-G1523A-positive clinical AC2 specimensa,b 46 0 1 46 1
nvCT-C1522T-positive clinical AC2 specimensb 6 0 0 6 0
nvCT-C1514T-positive clinical AC2 specimensb 4 0 0 4 0
N. gonorrhoeae-positive, CT-negative AC2 specimens 129 0 129 0 129
T. vaginalis-positive AC2 specimens 5 0 0 0 0
Bacterial vaginosis-positive AC2 specimens 5 0 0 0 0
Candida spp.-positive AC2 specimens 5 0 0 0 0
C. trachomatis and N. gonorrhoeae-negative clinical AC2 specimens 202 0 0 0 0
Microbial species in spiked specimens
C. trachomatis Ba, D, E, F, G, H, J, K, L2b 9 9 0 9 0
C. trachomatis SE-nvCT [4,5,6] 1 1 0 1 0
FI-nvCT 23S rRNA in vitro transcript 20 0 0 20 0
C. suis (ATCC VR-1474)c 2 0 0 0 0
C. muridarum (ATCC VR-123)c 2 0 0 0 0
C. pneumoniae (ATCC VR-2282, MBC011) 4 0 0 0 0
C. psittaci (MBC013) 2 0 0 0 0
Neisseria gonorrhoeae 2016 WHO reference strains [28] 14 0 14 0 14
N. animalis 1 0 0 0 0
N. bergeri 1 0 0 0 0
N. cinerea 9 0 0 0 0
N. elongatac 3 0 0 0 0
N. flava 1 0 0 0 0
N. flavescens 32 0 0 0 0
N. lactamica 12 0 0 0 0
N. macacae 17 0 0 0 0
N. mucosa 17 0 0 0 0
N. oralis 1 0 0 0 0
N. perflava 22 0 0 0 0
N. sicca 9 0 0 0 0
N. subflava 6 0 0 0 0
N. meningitidisd 17 0 0 0 0
Moraxella catarrhalis 1 0 0 0 0
M. nonliquefaciens 1 0 0 0 0
M. osloensis 1 0 0 0 0
Trichomonas vaginalis (ATCC 30001, ATCC 50140) 10 0 0 0 0
T. aotus (ATCC 50649) 2 0 0 0 0
T. gallinae (ATCC 30002, 30,230) 4 0 0 0 0
T. stableri (ATCC PRA-412) 2 0 0 0 0
T. tenax (ATCC 30207) 2 0 0 0 0
  1. AC2, Aptima Combo 2; CT, Chlamydia trachomatis; NG, Neisseria gonorrhoeae; FI-nvCT, Finnish new variant of CT; SE-nvCT, Swedish new variant of CT; ATCC, American Type Culture Collection; WHO, World Health Organization; RLU, relative light unit
  2. a84 samples and one sample, respectively, were also confirmed positive for NG
  3. bConfirmed by sequencing of the 23S rRNA gene or the FI-nvCT TMA assay [23]
  4. cPositive in very high concentration, but negative in clinically more relevant concentrations
  5. dRepresenting major meningococcal clones spreading worldwide, including serogroups A, B, C, E, W, X, Y and Z