TABLE 3.
Overall performance of Etest and MTS compared to BMD for 109 S. maltophilia bloodstream isolatesa
| Antimicrobial | Isolate group | n | No. (%) with indicated value |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Etest |
MTS |
|||||||||
| CA | VME | ME | MI | CA | VME | ME | MI | |||
| SXT | Overall | 109 | 107 (98) | 1 (9) | 0 (0) | 0 (0) | 107 (98) | 1 (9) | 0 (0) | 109 (0.9) |
| ≥R + 1 | 9 | 0 | NA | 0 | 0 | NA | 0 | |||
| R + S | 23 | 1 (4) | 0 | 0 | 1 (4) | 0 | 1 (4) | |||
| ≤S − 1 | 77 | NA | 0 | 0 | NA | 0 | 0 | |||
| LEV | Overall | 109 | 93 (85) | 4 (9) | 4 (7) | 17 (16) | 90 (83) | 1 (5) | 0 (0) | 16 (15) |
| ≥R + 2 | 9 | 0 | NA | 0 | 0 | NA | 0 | |||
| I ± 1 | 40 | 0 | 1 (3) | 15 (38) | 1 (3) | 0 | 14 (35) | |||
| ≤I − 2 | 60 | NA | 1 (2) | 2 (3) | NA | 0 | 2 (3) | |||
| MIN | Overall | 101 (93) | 0 (0) | 0 (0) | 0 (0) | 108 (99) | 0/0 (0) | 0 (0) | 0 (0) | |
| ≥R + 2 | 0 | 0 | NA | 0 | 0 | NA | 0 | |||
| I ± 1 | 4 | 0 | 0 | 0 | 0 | 0 | 0 | |||
| ≤I − 2 | 105 | NA | 0 | 8 (8) | NA | 0 | 1 (1) | |||
| CAZ | Overall | 109 | 77 (71) | 13 (30) | 3 (6) | 16 (15) | 90 (73) | 4 (9) | 7 (13) | 19 (17) |
| ≥R + 2 | 34 | 1 (3) | NA | 0 | 1 (3) | 0 | 2 (6) | |||
| I ± 1 | 35 | 3 (9) | 1 (3) | 14 (40) | 3 (9) | 1 (3) | 14 (40) | |||
| ≤I − 2 | 40 | NA | 3 (8) | 1 (3) | NA | 6 (15) | 3 (8) | |||
| CIP (PK/PD) | 109 | 90 (83) | 0 (0) | 2 (50) | 17 (15) | 86 (76) | 2 (2) | 0 (0) | 21 (19) | |
| TGC (PK/PD) | 109 | 60 (55) | 1 (2) | 48 (80) | 65 (60) | 5 (10) | 30 (65) | |||
CLSI breakpoints (M100) and EUCAST PK/PD breakpoints used to interpret MIC results as indicated. Categorical agreement (CA), very major errors (VMEs), major errors (MEs), and minor errors (MIs) were calculated. Errors rates for antimicrobials with no intermediate MIC category parsed as follows: ≥R + 1, MIC greater than or equal to 1 doubling dilution of the resistant breakpoint; R + S, MIC at susceptible or resistant breakpoint; and ≤S − 1, MIC less than or equal to 1 doubling dilution of the susceptible breakpoint. Errors rates for antimicrobials with intermediate MIC category parsed as follows: ≥I + 2, MIC greater than or equal to 2 doubling dilutions of the intermediate breakpoint; I ± 1, MIC plus or minus 1 doubling dilution of the intermediate breakpoint; and ≤I − 2, MIC less than or equal to 2 doubling dilutions of the intermediate breakpoint. NA, not applicable.