Table 1.
Molecular characteristics and drug susceptibility patterns of heteroresistant isolates
| Group | QRDR typea | MIRU-VNTR typeb | Combined resistance profile determined by DSTc | No. of isolates with drug susceptibility pattern |
|---|---|---|---|---|
| Group I isolates | ||||
| W; D94A | 1 | INH, RIF, STR | 1 | |
| W; D94A | M | INH, RIF, STR, PAS | 1 | |
| W; D94A | M | INH, RIF | 1 | |
| W; D94G | 1 | INH, RIF, STR, KAN, AMI, PAS | 1 | |
| W; D94G | 1 | INH, STR | 1 | |
| W; D94G | M | RIF | 1 | |
| W; D94G | 1 | 2 | ||
| W; D94G | 1 | RIF, AMI | 1 | |
| W; D94G | M | INH, RIF, STR, KAN, AMI, PAS | 2 | |
| W; D94G | 1 | STR | 1 | |
| W; D94G | 1 | INH, RIF, PAS | 1 | |
| W; D94G | M | INH, RIF, STR, KAN, AMI | 1 | |
| W; D94N | 1 | RIF, STR, KAN, AMI, PAS | 1 | |
| W; D94N | 1 | INH, RIF, STR, KAN, AMI, CAP, PAS | 1 | |
| W; D94N | 1 | INH, RIF, STR | 1 | |
| W; D94Y | 1 | 1 | ||
| W; D94Y | M | 1 | ||
| W; D94Y | 1 | STR, AMI | 1 | |
| W; D94Y | 1 | INH, RIF, KAN, CAP | 1 | |
| W; A90V; D94N | 1 | 1 | ||
| W; A90V; D94Y | 1 | 1 | ||
| W; D94G; D94Y | 1 | INH, STR | 1 | |
| W; D94G; D94Y | 1 | EMB | 1 | |
| W; D94N; D94G | 1 | INH, RIF, STR, KAN, AMI, PAS | 1 | |
| W; S91P; D94A | 1 | INH, RIF, EMB, STR | 1 | |
| W; A90V; S91P; D94G | 1 | INH, RIF, STR, KAN, AMI | 1 | |
| Group II isolates | ||||
| A90V; D94A | M | INH, RIF, STR, KAN, AMI | 1 | |
| A90V; D94G | 1 | 1 | ||
| A90V; D94G | 1 | PAS | 1 | |
| A90V; D94G | 1 | INH, RIF, STR | 1 | |
| A90V; D94H | 1 | INH, RIF, STR, KAN, AMI, PAS | 1 | |
| A90V; D94N | 1 | INH, STR, AMI | 1 | |
| A90V; D94N | 1 | INH, RIF, STR | 1 | |
| D94G; D94Y | 1 | INH, RIF, STR, KAN, AMI | 1 | |
| D94H; D94G | 1 | INH, RIF, STR | 1 | |
| D94N; D94A | 1 | INH, RIF, KAN, AMI | 1 | |
| D94N; D94G | 1 | INH, RIF, STR | 1 | |
| D94N; D94G | 1 | INH, RIF | 1 | |
| D94N; D94G | 1 | 1 | ||
| D94N; D94G | 1 | INH, RIF, STR, KAN, AMI, CAP | 1 | |
| D94N; D94Y | 1 | INH, RIF, STR, KAN, AMI, CAP | 1 | |
| S91P; D94N | 1 | INH, RIF, STR | 1 | |
| A90V; A90V+D94G | M | INH, STR, KAN, PAS | 1 | |
| A90V; D94N; D94Y | 1 | INH, RIF, STR | 1 | |
| A90V; S91P; D94G | 1 | RIF | 1 | |
| A90V; S91P; D94N | 1 | INH, RIF, STR, KAN | 1 | |
| D94A; A90V+D94A | 1 | INH, RIF, KAN, AMI, PAS | 1 | |
| D94A; A90V+D94A | M | INH, RIF, KAN, AMI, PAS | 1 | |
| D94A; A90V+D94A | 1 | INH, RIF, KAN, AMI | 1 | |
| D94N; D94G; D94Y | 1 | INH, RIF, STR, KAN, AMI, CAP | 1 | |
| D94N; D94G; D94Y | 1 | INH, RIF, STR, KAN, CAP, PAS | 1 | |
| D94N; D94G; S91P+D94N | 1 | INH, STR | 1 | |
| Total no. of isolates | 54 |
a
The QRDR type is shown. The wild type (W) and the mutation in codon 90, 91, or 94 of the gyrA gene is shown.
b
The mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) type is shown: 1 type or multiple (M) types.
c
The combined resistance profiles determined by drug susceptibility testing (DST) are shown. MDR-TB strains are shown in boldface type. Drug abbreviations: INH, isoniazid; RIF, rifampin; STR, streptomycin; PAS, p-aminosalicyclic acid; KAN, kanamycin; AMI, amikacin; CAP, capreomycin; EMB, ethambutol.