TABLE 1.
Organism and antimicrobial drug combinations tested by the simulated adult blood culture model
| Species (strain) | Drug | MIC (μg/ml)a | Drug concentration (μg/ml)b
|
||
|---|---|---|---|---|---|
| Cmax | C/2 | C/4 | |||
| Gram-negative organism | |||||
| Bacteroides fragilis (ATCC 25285) | Meropenem | 0.12 | 50 | 25 | 12.5 |
| Metronidazole | 0.5 | 25 | 12.5 | 6.3 | |
| Piperacillin-tazobactam | 0.06 | 368/23 | 184/11.5 | 92/5.8 | |
| Escherichia coli (ATCC 25922) | Ceftaroline | 0.06 | 39 | 19.5 | 9.75 |
| Ciprofloxacin | 0.016 | 3.9 | 1.95 | 0.97 | |
| Gentamicin | 0.5 | 12 | 6 | 3 | |
| Levofloxacin | 0.06 | 9.5 | 4.75 | 2.38 | |
| Meropenem | 0.06 | 50 | 25 | 12.5 | |
| Piperacillin-tazobactam | 2 | 368/23 | 184/11.5 | 92/5.8 | |
| Tigecycline | 0.12 | 1.5 | 0.75 | 0.37 | |
| Klebsiella pneumoniae (ATCC 700603) | Ceftaroline | 0.5 | 39 | 19.5 | 9.75 |
| Ciprofloxacin | 0.25 | 3.9 | 1.95 | 0.97 | |
| Gentamicin | 2 | 12 | 6 | 3 | |
| Levofloxacin | 0.06 | 9.5 | 4.75 | 2.38 | |
| Meropenem | 0.12 | 50 | 25 | 12.5 | |
| Piperacillin-tazobactam | 8 | 368/23 | 184/11.5 | 92/5.8 | |
| Tigecycline | 0.5 | 1.5 | 0.75 | 0.37 | |
| Pseudomonas aeruginosa (ATCC 27853) | Ciprofloxacin | 0.5 | 3.9 | 1.95 | 0.97 |
| Gentamicin | 1 | 12 | 6 | 3 | |
| Meropenem | 0.25 | 50 | 25 | 12.5 | |
| Piperacillin-tazobactam | 4 | 368/23 | 184/11.5 | 92/5.75 | |
| Gram-positive organism | |||||
| Enterococcus faecalis (ATCC 29212) | Ampicillin | 0.5 | 47 | 23.5 | 11.75 |
| Linezolid | 2 | 20 | 10 | 5 | |
| Tigecycline | 0.12 | 1.5 | 0.75 | 0.37 | |
| Vancomycin | 2 | 50 | 25 | 12.5 | |
| Methicillin-susceptible Staphylococcus aureus (ATCC 29213) | Ceftaroline | 0.12 | 39 | 19.5 | 9.75 |
| Daptomycin | 0.25 | 57 | 28.5 | 14.25 | |
| Linezolid | 2 | 20 | 10 | 5 | |
| Tigecycline | 0.06 | 1.5 | 0.75 | 0.37 | |
| Vancomycin | 0.5 | 50 | 25 | 12.5 | |
| Methicillin-resistant Staphylococcus aureus (ATCC 43300) | Ceftaroline | 0.5 | 39 | 19.5 | 9.75 |
| Ciprofloxacin | 0.5 | 3.9 | 1.95 | 0.97 | |
| Gentamicin | 1 | 12 | 6 | 3 | |
| Linezolid | 2 | 20 | 10 | 5 | |
| Tigecycline | 0.25 | 1.5 | 0.75 | 0.37 | |
| Vancomycin | 1 | 50 | 25 | 12.5 | |
| Streptococcus pneumoniae (ATCC 49619) | Ciprofloxacin | 0.12 | 3.9 | 1.95 | 0.97 |
| Linezolid | 0.5 | 20 | 10 | 5 | |
| Penicillin G | 0.25 | 40 | 20 | 10 | |
| Vancomycin | 0.12 | 50 | 25 | 12.5 | |
a
MICs of the antimicrobial drugs for each organism tested were determined by the EUCAST broth microdilution method according to standard procedures (18).
b
For each antimicrobial drug tested, concentrations corresponding to the plasma peak (Cmax), half (C/2), and quarter (C/4) levels are indicated. The Cmax values were those reported in online documents by EUCAST (http://www.eucast.org/fileadmin/src/media/PDFs/EUCAST_files/Breakpoint_tables/v_9.0_Breakpoint_Tables.pdf).