TABLE 2.
Overall performance of disk diffusion compared to BMD for 109 S. maltophilia bloodstream isolatesa
| Antimicrobial, breakpoint source | No./total (%) |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Overall CA | VME |
ME |
MI |
||||||||
| Total | ≥R + 1 or ≥I + 2 | R + S or I ±1 | Total | ≤S − 1 or ≤I − 2 | S + R or I ±1 | Total | ≥R + 1 or ≥I + 2 | S + R or I ±1 | ≤S − 1 or ≤I − 2 | ||
| SXT, S. maltophilia M100 | 101/109 (93) | 0/10 (0) | 0/9 (0) | 0/23 (0) | 1/100 (1) | 0/77 (0) | 1/23 (4) | 8/109 (7) | 0/9 (0) | 7/23 (30) | 1/77 (1) |
| LEV, S.maltophilia M100 | 97/109 (89) | 0/22 (0) | 0/9 (0) | 0/40 (0) | 0/78 (0) | 0/60 (0) | 0/40 (0) | 12/109 (11) | 0/9 (0) | 12/40 (30) | 0/60 (0) |
| MIN, S. maltophilia M100 | 104/109 (95) | 0/0 (0) | 0/0 (0) | 0/4 (0) | 0/109 (0) | 0/105 (0) | 0/4 (0) | 5/109 (5) | 0/0 (0) | 1/4 (25) | 4/105 (4) |
| CAZ, * S. maltophilia M100 | 83/109 (76) | 4/44 (9) | 2/34 (6) | 2/35 (6) | 7/54 (13) | 5/40 (13) | 2/35 (6) | 15/109 (14) | 0/34 (0) | 14/35 (40) | 1/40 (3) |
| LEV, * P. aeruginosa M100 | 91/109 (83) | 3/31 (10) | 0/31 (0) | 3/78 (4) | 0/60 (0) | 0/31 (0) | 0/78 (0) | 15/109 (14) | 0/21 (0) | 15/78 (19) | 0/10 (0) |
| LEV,* EUCAST PK/PD | 96/109 (88) | 10/69 (14) | 3/40 (8) | ||||||||
| CIP,* EUCAST PK/PD | 86/109 (79) | 22/105 (21) | 1/4 (25) | ||||||||
| CIP, * P. aeruginosa M100 | 78/109 (72) | 15/69 (22) | 6/69 (9) | 9/40 (23) | 1/40 (3) | 0/69 (0) | 1/40 (3) | 15/109 (14) | 0/51 (0) | 14/40 (35) | 1/18 (6) |
| TGC, * EUCAST PK/PD | 79/109 (73) | 3/50 (6) | 27/59 (46) | ||||||||
SXT, MIN, and LEV evaluations are based on existing CLSI M100 breakpoints for S. maltophilia. CAZ, LEV, CIP, and TGC evaluations indicated by an asterisk (*) are based on disk-to-MIC correlates and zone diameter breakpoints generated by dBETS software using either M100 S. maltophilia MIC breakpoints, CLSI P. aeruginosa MIC breakpoints, or EUCAST PK/PD breakpoints as indicated. Categorical agreement (CA), very major errors (VMEs), major errors (MEs), and minor errors (MIs) 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.