TABLE 1.
Biochemical testing of environmental E. coli isolates with the API 20E biochemical test strip
| Enzymatic testb | Test resulta for isolate: |
||||||
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | |
| β-Galactosidase (ONPG) | + | + | + | + | + | + | + |
| Arginine dihydrolase (ADH) | − | − | − | − | − | − | − |
| Lysine decarboxylase (LDC) | + | + | + | + | + | + | + |
| Ornithine decarboxylase (ODC) | − | − | + | + | + | − | − |
| Citrate utilization (CIT) | − | − | − | − | − | − | − |
| H2S production (H2S) | − | − | − | − | − | − | − |
| Urease (URE) | − | − | − | − | − | − | − |
| Tryptophan deaminase (TDA) | − | − | − | − | − | − | − |
| Indole production (IND) | + | + | + | + | + | + | + |
| Acetoin production (VP) | − | − | − | − | − | − | − |
| Gelatinase (GEL) | − | − | − | − | − | − | − |
| Fermentation/oxidation of: | |||||||
| Glucose (GLU) | + | + | + | + | + | + | + |
| Mannitol (MAN) | + | + | + | + | + | + | + |
| Inositol (INO) | − | − | − | − | − | − | − |
| Sorbitol (SOR) | + | + | + | + | − | + | + |
| Rhamnose (RHA) | + | + | + | + | + | + | + |
| Saccharose (SAC) | − | + | − | + | + | − | − |
| Melibiose (MEL) | + | + | + | + | + | + | + |
| Amygdalin (AMY) | − | + | − | − | − | − | − |
| Arabinose (ARA) | + | + | + | + | + | + | + |
| Cytochrome oxidase (OX) | − | − | − | − | − | − | − |
| Nitrate reduction (GLU) | + | + | + | NT | NT | NT | + |
a
+, positive result; −, negative result; NT, not tested. Results are given in boldface when they differ for different isolates.
b
Biochemical test, with letters in parentheses representing the respective reaction/enzyme.