Table 2.
Predictive accuracy of discordant MICs derived from AST in CAMHB vs. DMEM in Gram-positive and Gram-negative murine sepsis models1
| MIC values (μg/mL) |
Mouse Survivors | CAMHB vs. DMEM Predicted/Actual | ||
|---|---|---|---|---|
| Pathogen/Antibiotic | CAMHB | DMEM | ||
| Gram-positive | ||||
| MRSA USA300 | ||||
| Ceftriaxone | 256 R | 8 S | 10/10 | R to S |
| Ertapenem | 8 R | 2 S | 9/10 | R to S |
| Piperacillin/Tazobactam | 64/4 R | 4/4 S | 8/10 | R to S |
| MRSA MT3302 | ||||
| Ceftriaxone | 64 R | 8 S | 8/10 | R to S |
| Cephalexin | 128 R | 8 S | 6/10 | R to S |
| Piperacillin/Tazobactam | 64/4 R | 4/4 S | 8/10 | R to S |
| MSSA Newman | ||||
| Cephalexin | 32 R | 4 S | 8/10 | R to S |
| Gram-negative | ||||
| A. baumannii 19606 | ||||
| Colistin | 0.5 S | 4 R | 5/10 | S to I/R |
| E. cloacae 13047 | ||||
| Ceftriaxone | 4 R | 0.25 S | 7/10 | R to S |
| K. pneumoniae 13883 | ||||
| Colistin | 0.25 S | 16 R | 3/10 | S to R |
| K. pneumoniae MT3325 | ||||
| Tetracycline | 4 S | 16 R | 5/10 | S to I/R |
| P. aeruginosa 10145 | ||||
| Colistin | 0.5 S | 8 R | 2/10 | S to R |
| S. Typhimurium 14028 | ||||
| Streptomycin | 16 I | 4 S | 9/10 | I to S |
MICs and susceptibility designations were determined by broth microdilution in CAMHB and DMEM.16,17,18Virulence assays: discordant MICs derived from AST in CAMHB and DMEM were tested for diagnostic accuracy in murine sepsis models (n = 10).10,19CAMHB vs. DMEM Predicted/Actual: the susceptibility designations denote the CAMHB predicted susceptibility vs. the DMEM predicted and actual clinical outcomes. S, susceptible; I, intermediate; R, resistant.