Table 4.
Effect of resistance profile on FICI and SBPI values in the study population.
| Gradient Diffusion Method % a (No. of Isolates) b | Comparator Agreement % a (No. of Isolates) b | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Resistance Profile | No * | Index | Result | CB £ | Cross | DO £ | MIC:MIC | Cross | DO £ | MIC:MIC | |
| TM (R #) | TZ (R #) | 33 | FICI | Syn $ | 21.21 (7) | 33.33 (11) | 15.15 (5) | 18.18 (6) | 57.14 (4) | 57.14 (4) | 28.57 (2) |
| NI $ | 78.79 (26) | 66.67 (22) | 84.85 (28) | 81.82 (27) | 69.23 (18) | 96.15 (25) | 84.62 (22) | ||||
| SBPI | ≤2.0 | 63.64 (21) | 78.79 (26) | 96.97 (32) | 72.73 (24) | 95.24 (20) | 100 (21) | 90.48 (19) | |||
| 2.0–50.00 | 36.36 (12) | 21.21 (7) | 3.03 (1) | 24.24 (8) | 50.00 (6) | 8.33 (1) | 50.00 (6) | ||||
| TM (R #) | TZ (I #) | 18 | FICI | Syn $ | 27.78 (5) | 66.67 (12) | 5.56 (1) | 5.56 (1) | 100.00 (5) | 20.00 (1) | 20.00 (1) |
| NI $ | 72.22 (13) | 33.33 (6) | 94.44 (17) | 94.44 (17) | 46.15 (13) | 100.00 (13) | 100.00 (13) | ||||
| SBPI | ≤2.0 | 66.67 (12) | 55.56 (10) | 61.11 (11) | 83.33 (15) | 83.33 (10) | 75.00 (9) | 91.67 (11) | |||
| 2.0–50.00 | 33.33 (6) | 44.44 (8) | 38.89 (7) | 16.67 (3) | 100.00 (6) | 66.67 (4) | 33.33 (2) | ||||
| TM (S #) | TZ (R #) | 11 | FICI | Syn $ | 45.45 (5) | 36.36 (4) | 0(0) | 45.45 (5) | 20.00 (1) | 0(0) | 60.00 (3) |
| NI $ | 54.55 (6) | 63.64 (7) | 100.00 (11) | 54.55 (6) | 50.00 (3) | 100.00 (6) | 66.67 (4) | ||||
| SBPI | ≤2.0 | 9.09 (1) | 0(0) | 45.45 (5) | 0(0) | 0(0) | 100.00 (1) | 0(0) | |||
| 2.0–50.00 | 81.82 (9) | 100.00 (11) | 54.55 (6) | 100.00 (11) | 100.00 (9) | 55.56 (5) | 100.00 (9) | ||||
| TM (S #) | TZ (I #) | 8 | FICI | Syn $ | 37.50 (3) | 62.50 (5) | 0(0) | 0(0) | 66.67 (2) | 0(0) | 0(0) |
| NI $ | 62.50 (5) | 37.50 (3) | 100.00 (8) | 100.00 (8) | 40.00 (2) | 100.00 (5) | 100.00 (5) | ||||
| SBPI | ≤2.0 | 0(0) | 12.50 (1) | 25.00 (2) | 12.50 (1) | 0(0) | 0(0) | 0(0) | |||
| 2.0–50.00 | 100.00 (8) | 87.50 (7) | 75.00 (6) | 87.50 (7) | 87.50 (7) | 75.00 (6) | 87.50 (7) | ||||
# M, tobramycin; TZ, ceftazidime; R, resistant; I, susceptible after increased exposure; S, susceptible; * total number of isolates in the resistance profile; $ Syn, synergistic; NI, no interaction; £ CB, checkerboard; DO, direct overlay; a proportion of isolate; b number of isolates.