Table 1. MICs and zone diameters for A. urinae isolates when tested by EUCAST standardized disk diffusion method, Etest, and broth microdilution (Sensititre).
| A. urinae | Disk diffusion (wildtype) | Etest | Broth microdilution * | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of isolates with MIC (mg/L) | MIC (mg/L) | MIC (mg/L) | ||||||||||||||||
| Antibiotic | mm | <0.002 | 0.004 | 0.008 | 0.016 | 0.032 | 0.064 | 0.125 | 0.25 | 0.5 | 1 | 2 | MIC50 | MIC90 | Range | MIC50 | MIC90 | Range |
| Benzylpenicillin | 29-40 | 8 | 31 | 28 | 10 | 1 | 0.032 | 0.064 | 0.008-0.125 | ≤0.03 | 0.06 | ≤0.03-0.06 | ||||||
| Cefotaxime | 24-38 | 1 | 5 | 20 | 22 | 18 | 8 | 3 | 1 | 0.125 | 0.5 | 0.016-2 | 0.25 | 1 | ≤0.125-2 | |||
| Meropenem | 35-47 | 5 | 19 | 29 | 21 | 2 | 3 | 0.032 | 0.064 | 0.008-0.25 | ≤0.25 | ≤0.25 | ≤0.25 | |||||
| Vancomycin | 19-25 | 1 | 1 | 36 | 40 | 2 | 1 | 1 | 0.125-2 | ≤0.5 | ≤0.5 | ≤0.5 | ||||||
| Linezolid | 27-35 | 5 | 10 | 35 | 28 | 1 | 2 | 0.25-2 | 1 | 1 | ≤0.25-2 | |||||||
| Rifampicin | 34-46 | 5 | 11 | 27 | 26 | 5 | 1 | 1 | 0.008 | 0.016 | <0.002-0.125 | NR | NR | NR | ||||
* Susceptibility recommendation method: Medium: Mueller-Hinton (MH) plates with 5% defibrinated horse blood and 20 mg/L β-NAD (MH-F). Inoculum: McFarland 0.5. Incubation: 5% CO2, 35±1 °C, 18±2h. Isolates with insufficient growth after 16-20 h incubation were re-incubated immediately and inhibition zones and MICs read after a total of 40-44 h incubation. Reading: Read zone edges as the point showing no growth viewed from the front of the plate with the lid removed and with reflected light.