TABLE 1.
Antibiotic resistance profiles of S. flexneri serotype X variant isolates
| Antimicrobial agenta | % of strainsb |
||
|---|---|---|---|
| R | I | S | |
| Ampicillin | 100 | 0 | 0 |
| Amoxicillin-clavulanic acid | 0 | 0 | 100 |
| Ampicillin-sulbactam | 2.6 | 68.1 | 24.1 |
| Ticarcillin-clavulanic acid | 0 | 0.9 | 99 |
| Piperacillin-tazobactam | 0 | 0 | 100 |
| Piperacillin | 12.9 | 5.2 | 73.3 |
| Aztreonam | 38.8 | 2.6 | 58.6 |
| Cefepime | 34.5 | 0.9 | 95.7 |
| Cefotaxime | 6.1 | 0.9 | 93.1 |
| Ceftazidime | 0 | 0.9 | 99 |
| Ceftriaxone | 5.2 | 0 | 94.8 |
| Ciprofloxacin | 13.8 | 0.9 | 85.3 |
| Gatifloxacin | 0 | 0.9 | 99 |
| Levofloxacin | 0.9 | 10.3 | 88.8 |
| Imipenem | 0 | 0 | 100 |
| Trimethoprim-sulfamethoxazole | 89.7 | 0 | 10.3 |
| Nalidixic acid | 100 | 0 | |
| Chloramphenicol | 96.20 | 0.8 | |
| Tetracycline | 99.06 | 0.94 | |
a
Results for the first 16 antibiotics were based on tests of 116 serotype X variant isolates using the Microscan Gram-negative panel Neg Combo 31 (Siemens Healthcare Diagnostics, United Kingdom). The remaining antibiotics were tested using the calibrated dichotomous sensitivity test (CDS) method, as the Microscan panel does not contain these antibiotics.
b
R, resistance; I, intermediate sensitivity; S, sensitivity. Resistance was determined according to the manufacturer's instructions for Microscan or by the annular radius using the CDS method.