Table 1.
Performance of four commercial methods when compared with the reference BMD method
| MDR isolates (N = 43) | XDR isolates (N = 8) | PDR isolates (N = 3) | Non-MDR isolates (N = 33) | All isolates (N = 87) | |
|---|---|---|---|---|---|
| (CST R, n = 2) | (CST R, n = 1) | (CST R, n = 1) | (CST R, n = 8) | (CST R, n = 12) | |
| Essential agreement, n (%) | |||||
| RPPT | 43 (100) | 8 (100) | 3 (100) | 31 (93.9) | 85 (97.7) |
| MicroScan | 39 (90.7) | 8 (100) | 1 (33.3) | 8 (24.2) | 58 (66.7) |
| Etest | 23 (53.5) | 4 (50) | 1 (33.3) | 18 (54.5) | 55 (63.2) |
| MTS | 31 (72.1) | 4 (50) | 1 (33.3) | 17 (51.5) | 53 (60.9) |
| Categorical agreement, n (%) | |||||
| RPPT | 42 (97.7) | 8 (100) | 3 (100) | 33 (100) | 86 (98.9) |
| MicroScan | 39 (90.7) | 8 (100) | 1 (33.3) | 8 (24.2) | 56 (64.4) |
| Etest | 42 (97.7) | 7 (87.5) | 3 (100) | 23 (69.7) | 74 (85.1) |
| MTS | 39 (90.7) | 7 (87.5) | 3 (100) | 27 (81.8) | 76 (87.4) |
| Major errors, n (%) | |||||
| RPPT | 1 (2.4) | 0 (0) | 0 (0) | 0 (0) | 1 (1.3) |
| MicroScan | 4 (9.8) | 0 (0) | 2 (100) | 23 (92) | 29 (38.7) |
| Etest | 1 (2.4) | 1 (14.3) | 0 (0) | 3 (12) | 5 (6.7) |
| MTS | 3 (7.3) | 1 (14.3) | 0 (0) | 2 (8) | 6 (8) |
| Very major errors, n (%) | |||||
| RPPT | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| MicroScan | 0 (0) | 0 (0) | 0 (0) | 2 (25) | 2 (16.7) |
| Etest | 1 (50) | 0 (0) | 0 (0) | 7 (87.5) | 8 (66.7) |
| MTS | 1 (50) | 0 (0) | 0 (0) | 4 (50) | 5 (41.7) |
Total P. aeruginosa isolates (n = 87) are split by resistance categories according to the percentages of essential agreement and categorical agreement, and the number of major errors and very major errors.
CST R, colistin-resistant isolates.