TABLE 3.
Biochemical reactions of the five Enteric Group 137 strainsa
| Test | Cumulative % positive on day:
|
Reaction for strain 1b | ||
|---|---|---|---|---|
| 1 | 2 | 7 | ||
| Indole production | 100 | +2 | ||
| Methyl red | 100 | +2 | ||
| Voges-Proskauer (O'Meara) | 0 | − | ||
| Citrate utilization (Simmons)* | 0 | 0 | 70 | +5 |
| H2S on triple-sugar iron agar | 0 | 0 | 0 | − |
| H2S on peptone iron agar | 0 | 0 | 0 | − |
| Urea hydrolysis (Christensen)* | 0 | 70 | 80 | +2 |
| Phenylalanine deaminase | 0 | − | ||
| Lysine decarboxylase (Moeller) | 0 | 0 | 0 | − |
| Arginine dihydrolase (Moeller)* | 0 | 20 | 90 | +3 |
| Ornithine decarboxylase (Moeller) | 100 | 100 | 100 | + |
| Motility | 100 | 100 | 100 | + |
| Gelatin hydrolysis (20–22°C) | 0 | 0 | 0 | − |
| KCN test (% resistant to cyanide) | 100 | 100 | 100 | + |
| Malonate utilization* | 0 | 0 | 20 | − |
| d-Glucose: acid production | 100 | 100 | 100 | + |
| d-Glucose: gas production | 0 | 0 | 0 | − |
| Acid production from: | ||||
| Adonitol | 0 | 0 | 0 | − |
| l-Arabinose | 100 | 100 | 100 | + |
| d-Arabitol | 0 | 0 | 0 | − |
| Cellobiose | 100 | 100 | 100 | + |
| Dulcitol | 0 | 0 | 0 | − |
| Erythritol | 0 | 0 | 0 | − |
| d-Galactose | 100 | 100 | 100 | + |
| Glycerol | 100 | 100 | 100 | + |
| myo-Inositol | 0 | 0 | 0 | − |
| Lactose | 100 | 100 | 100 | + |
| Maltose | 100 | 100 | 100 | + |
| d-Mannitol | 100 | 100 | 100 | + |
| d-Mannose | 100 | 100 | 100 | + |
| Melibiose | 100 | 100 | 100 | + |
| α-Methyl-d-glucoside* | 10 | 80 | 100 | +2–3 |
| Raffinose | 100 | 100 | 100 | + |
| l-Rhamnose | 100 | 100 | 100 | + |
| Salicin | 100 | 100 | 100 | + |
| d-Sorbitol | 100 | 100 | 100 | + |
| Sucrose | 100 | 100 | 100 | + |
| Trehalose | 100 | 100 | 100 | + |
| d-Xylose | 100 | 100 | 100 | + |
| Esculin hydrolysis | 100 | 100 | 100 | + |
| Mucate fermentation | 100 | 100 | 100 | + |
| Tartrate fermentation (Jordan)* | 50 | 50 | 50 | +7 |
| Acetate utilization | 60 | 100 | 100 | + |
| Lipase (corn oil) | 0 | 0 | 0 | − |
| DNase (25°C) | 0 | 0 | 0 | − |
| Nitrate reduction to nitrite | 100 | + | ||
| Oxidase | 0 | − | ||
| ONPGc test | 80 | 100 | 100 | + |
| Yellow pigment production (25°C) | 0 | 0 | 0 | − |
| Citrate utilization (Christensen) | 30 | 90 | 100 | +2 |
| Tyrosine clearing | 0 | 0 | 0 | − |
Tests were done at the CDC with standard methods as previously described. Symbols: −, negative at end of the appropriate incubation time; + (no superscript), positive at 24 h. Superscripts give the day the reaction became positive if it was delayed (indole production, methyl red, and Voges-Proskauer tests are done only at 48 h). For most tests the percentages were based on one observation per strain, but for six tests (∗) final percentages were based on composite results after the strains were retested.
Strain 1 (ATCC BAA-68) is designated as the reference strain of Enteric Group 137 and will become the designated type strain if Enteric Group 137 is given a scientific name in the future.
ONPG, o-nitrophenyl-β-d-galactopyranoside.