Table. Antibiotic resistance pattern in a ceftriaxone-resistant Salmonella enterica serotype Typhi detected in Denmark, 2019.
| Antibiotic | Phenotype | Genotype | ||
|---|---|---|---|---|
| Zone diameter (mm) | MIC (mg/L) |
Interpretation S-I-Ra |
Resistance gene or point mutation detected (location on the chromosome (c) and/or the plasmid (p)) | |
| Mecillinam | 26 | NT | S | None |
| Ampicillin | 6 | NT | R | blaTEM-1B (c + p) |
| Amoxicillin/clavulanic acid | 19 | NT | S | None |
| Piperacillin/tazobactam | 22 | NT | S | None |
| Cefpodoxime | 6 | NT | R | blaCTX-M-15 (p) |
| Ceftriaxone | NT | > 32 | R | blaCTX-M-15 (p) |
| Ceftolozane/tazobactam | NT | 1.0 | S | None |
| Ceftazidime/avibactam | NT | 0.25 | S | None |
| Meropenem | 32 | NT | S | None |
| Gentamicin | 24 | NT | S | None |
| Aminoglycosides other than gentamicin | NT | NT | NT | aph[3]-1bb (c + p) aph[6]-1dc (c + p) aac[6]-1aa (c) |
| Ciprofloxacin | 20 | NT | R | gyrA S83F (c) qnrS1 (p) |
| Azithromycin | NT | 2 | S | None |
| Trimetoprim/sulfamethoxazole | 6 | NT | R | sul1 (c) sul2 (c + p) dfrA7 (c) |
| Aztreonam | NT | > 256 | R | blaCTX-M-15 (p) |
| Tigecycline | NT | 0.25 | S | None |
| Colistin | NT | 0.125 | S | None |
| Chloramphenicol | NT | NT | NT | catA1 (c) |
c: chromosome; I: intermediate sensitivity; MIC: minimum inhibitory concentration; NT: not tested; p: plasmid; R: resistant; S: sensitive.
a According to European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints (version 9.0) [3].
b Also called strA.
c Also called strB.