Table 4

Genetic characteristics and diagnostic performance of second-line drug resistance

DrugcGene and mutation/amino changeNo. of isolatesAccuracy value
ResistantSusceptibleSensitivityaSpecificityb
With mutationWithout mutationWith mutationWithout mutation
FQgyrA4114032574.5100
gyrA90, Val(GTG)847032514.5100
gyrA94, Gly(GGC)1639032529.1100
gyrA94, Asn(AAC)1045032518.2100
gyrA91, Pro(CCG)649032510.9100
gyrA74, Ser(TCC)35203255.5100
KMrrs4116132271.999.7
rrs1401, G4116132271.999.7
eis1443332024.699.1
eis, G(−10)A849232114.099.4
eis, C(−14)T651132210.599.7
rrs and/or eis534431993.098.8
AMKrrs386433286.498.8
rrs1401, G386433286.498.8
CAPrrs29121532470.795.6
rrs1401, G27141532465.995.6
rrs1402, T23903394.9100
tlyA43743359.898.8
tlyA, C14T14033362.499.1
tlyA, T708G33813387.399.7
rrs and/or tlyA30111732273.295.0
Pre-XDR-TBgyrA763433353.890.7
rrs583733038.589.9
gyrA and/or rrs941635169.295.6
  • a Sensitivity = no. of drug-resistant isolates with mutations/(no. of drug-resistant isolates with mutations + no. of drug-resistant isolates without mutations).

  • b Specificity = no. of drug-susceptible isolates without mutations/(no. of drug-susceptible isolates with mutations + no. of drug-susceptible isolates without mutations).

  • c FQ, fluoroquinolones; KM, kanamycin; CAP, capreomycin; AMK, amikacin; Pre-XDR-TB, preextensively drug-resistant tuberculosis.