TABLE 1.
Antimicrobials tested in the European Union and United States and criteria used to interpret microbiological and clinical resistance
| Breakpoints (μg/ml) | |||
|---|---|---|---|
| European Uniona | U.S.a | ||
| Antimicrobial | Microbiological | Clinical | Clinical |
| Tetracycline (TET) | >8 | >4b | >8 |
| Sulfonamide (SUL) | >256 | >256b | >256 |
| Ampicillin (AMP) | >8 | >8 | >16 |
| Chloramphenicol (CHL) | >16 | >8 | >16 |
| Nalidixic acid (NAL) | >16 | >16b | >16 |
| Third-generation cephalosporin (CEP)c | >0.5 | >1 | >2 |
| Gentamicin (GEN) | >2 | >2 | >8 |
| Trimethoprim-sulfa (COT)d | >2 | >2 | >2 |
| Ciprofloxacin (CIP) | >0.064 | >0.064 | >0.5 |
| Azithromycin (AZI) | >16e | >16e | >16f |
| Colistin (COL) | >2 | N/A | |
a
European Union breakpoints are from EUCAST, and U.S. breakpoints are from CLSI unless otherwise noted.
b
Derived from CLSI.
c
In the European Union, isolates are tested against ceftazidime and cefotaxime.
d
In the European Union, non-human isolates are tested against trimethoprim and sulfonamide separately. In the United States, isolates are tested against trimethoprim-sulfamethoxazole and sulfamethoxazole.
f
Reference 149.