Table 1 Frequency and patterns of mutations associated with phenotypic resistance to second-line anti-TB drugs among MDR- and XDR-TB isolates resistant to a second-line TB drug from eSwatini, Somalia and Uganda (2014–2016)
Drug | Locus | Mutation | Frequency (No. of isolates):- | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
MDR & LXF/MXF resistant (n = 18) | LXF/MXF susceptible / Pan-susceptible (n = 40) | |||||||||
With mutation | Relative Frequency (%) | Without mutation | Relative Frequency (%) | With mutation | Relative Frequency (%) | Without mutation | Relative Frequency (%) | |||
FLUOROQUINOLONES (LXF, MXF) | gyrA | Thr2Ala | 05 | 27.8 | 13 | 72.2 | 0 | 0 | 40 | 100 |
Thr2Arg | 05 | 27.8 | 13 | 72.2 | 0 | 0 | 40 | 100 | ||
Thr2Ala/Arg | 10 | 55.6 | 08 | 44.4 | 0 | 0 | 40 | 100 | ||
Asp3Glu | 04 | 22.2 | 14 | 77.8 | 02 | 5 | 38 | 95 | ||
Asp3Arg | 03 | 16.7 | 15 | 83.3 | 01 | 2.5 | 39 | 98 | ||
Asp3Val | 04 | 22.2 | 14 | 77.8 | 0 | 0 | 40 | 100 | ||
Asp3Glu/Asp3Ar/Asp3Val | 11 | 61.1 | 07 | 40 | 0 | 0 | 40 | 100 | ||
Asp3Arg | 03 | 16.7 | 15 | 83.3 | 0 | 0 | 40 | 100 | ||
Asp3Val | 01 | 5.6 | 17 | 94.4 | 0 | 0 | 40 | 100 | ||
Gly88Cys | 01 | 5.6 | 17 | 94.4 | 0 | 0 | 40 | 100 | ||
Gly88Ala | 01 | 5.6 | 17 | 94.4 | 0 | 0 | 40 | 100 | ||
Gly88Ala/Cys | 02 | 11.1 | 16 | 89 | 0 | 0 | 40 | 100 | ||
Ala90Val | 03 | 16.7 | 15 | 83.3 | 0 | 0 | 40 | 100 | ||
Ser91Pro | 01 | 5.6 | 17 | 94.4 | 0 | 0 | 40 | 100 | ||
Asp94Gly | 06 | 33.3 | 12 | 66.7 | 0 | 0 | 40 | 100 | ||
Asp94Asn | 01 | 5.6 | 17 | 94.4 | 0 | 0 | 40 | 100 | ||
Asp94Asn/Gly | 07 | 39 | 11 | 61.1 | 0 | 0 | 40 | 100 | ||
Gly88Ala/Gly88Cys/Gly88Ala/Ala90Val/Ser91Pro/Asp94Gly/Asp94Asn/Asp94Gly a | 13 | 72.2 | 05 | 27.8 | 0 | 0 | 40 | 100 | ||
Arg128Ser | 01 | 5.6 | 17 | 94.4 | 01 | 2.5 | 39 | 98 | ||
Tyr129Asn | 04 | 22.2 | 14 | 77.8 | 01 | 2.5 | 39 | 98 | ||
Ala132Glu | 02 | 11.1 | 16 | 89 | 0 | 0 | 40 | 100 | ||
gyrB | Gln608His | 01 | 5.6 | 17 | 94.4 | 0 | 0 | 40 | 100 | |
Arg609Gly | 02 | 11.1 | 16 | 89 | 0 | 0 | 40 | 100 | ||
Tyr610Thr | 01 | 5.6 | 17 | 94.4 | 0 | 0 | 40 | 100 | ||
Arg485His | 01 | 5.6 | 17 | 94.4 | 0 | 0 | 40 | 100 | ||
Lys611Gln | 03 | 16.7 | 15 | 83.3 | 01 | 2.5 | 39 | 98 | ||
Asp500His | 03 | 16.7 | 15 | 83.3 | 0 | 0 | 40 | 100 | ||
Asn538Asp | 01 | 5.6 | 17 | 94.4 | 0 | 0 | 40 | 100 | ||
Asp500His/ Asn538Asp | 04 | 22.2 | 14 | 77.8 | 0 | 0 | 40 | 100 | ||
KAN CAP AMK | rss | MDR & KAN/CAP/AMK resistant (n = 28) | KAN/CAP/AMK susceptible / Pan-susceptible (n = 40) | |||||||
a1401g | 17 | 60.7 | 11 | 39.3 | 0 | 0 | 40 | 100 | ||
g1484 t | 01 | 3.6 | 27 | 96.4 | 0 | 0 | 40 | 100 | ||
a1401g/g1484 t a | 18 | 64.3 | 10 | 35.7 | 0 | 0 | 40 | 100 | ||
g1158 t | 01 | 3.6 | 27 | 96.4 | 0 | 0 | 40 | 100 | ||