TABLE 1.
AST resultb | Vitek 2 result |
|||
---|---|---|---|---|
S (n = 17) |
R (n = 78) |
|||
n | % | n | % | |
Mueller-Hinton agar 1 (MHBD)c | ||||
Susceptible (standard dosing regime) | 17 | 100 | 66 | 84.6 |
Susceptible (with increased exposure) | 0 | 0 | 9 | 11.5 |
Resistant | 0 | 0 | 3 | 3.9 |
Mueller-Hinton agar 2 (MHBM)d | ||||
Susceptible (standard dosing regime) | 17 | 100 | 76 | 97.4 |
Susceptible (with increased exposure) | 0 | 0 | 0 | 0 |
Resistant | 0 | 0 | 2 | 2.6 |
Mueller-Hinton agar with 5% horse blood (MHF)c | ||||
Susceptible (standard dosing regime) | 17 | 100 | 71 | 91.0 |
Susceptible (with increased exposure) | 0 | 0 | 5 | 6.4 |
Resistant | 0 | 0 | 2 | 2.6 |
Broth microdilution | ||||
Susceptible (standard dosing regime) | 17 | 100 | 44 | 56.4 |
Susceptible (with increased exposure) | 0 | 0 | 32 | 52.6 |
Resistant | 0 | 0 | 2 | 2.6 |
Trimethoprim susceptibility (DD)e | ||||
Susceptible | 13 | 76.5 | 1 | 1.3 |
Resistant | 4 | 23.5 | 77 | 98.7 |
S, susceptible; R, resistant; AST, antibiotic susceptibility testing; DD, disk diffusion.
AST was interpreted according to EUCAST clinical breakpoints (v11.0) using the following categories: susceptible (standard dosing regime), susceptible (increased exposure), and resistant.
MHBD purchased from Becton, Dickinson, Germany.
MHBM purchased from bioMérieux, Germany.
Trimethoprim susceptibility was determined by disk diffusion on MHBD, MHBM, and MHF (all results were concordant). Phenotypic trimethoprim resistance is associated with Vitex 2 SXT resistance (P < 0.001 using chi-square test).