TABLE 5.
Phenotypic characteristics for six S. halichoeri human clinical isolates, S. halichoeri type strain (gray seal isolate), and related Streptococcus species based on comparative 16S rRNA sequence identity or possession of the group B Lancefield antigen
| Characteristic | Result for species and strainb: |
|||||||
|---|---|---|---|---|---|---|---|---|
| S. halichoeri (human isolates, n = 6) | S. halichoeri CCUG 48324T | S. canis ATCC 43496T | S. ictaluri ATCC BAA-1300T | S. agalactiae ATCC 13813T | S. porcinus (n = 19) | S. pseudoporcinus (n = 72) | S. phocae ATCC 51973T | |
| 16S rRNA gene identity (%)a | 100 | 98.6 | 97.9 | 97.8 | 95.5 | 95.7 | 95.7 | 93.7 |
| Conventional tests | ||||||||
| Hemolysis | γ | γ | β | γ | β | β | β | β |
| Lancefield group | B | B | G | None | B | B (79%) | B (83%) | F |
| PYRasec | + | + | + | − | V | V | − | |
| LAPased | + | + | + | + | + | + | + | + |
| Bile-esculin | + | − | − | − | − | − | V | − |
| 6.5% NaCl | + | + | W+e | − | + | + | + | + |
| Esculin | + | − | + | − | − | + | + | − |
| Arginine | + | + | − | − | + | + | + | − |
| Hippurate | − | − | − | − | + | − | + | − |
| Acid from | ||||||||
| Lactose | − | − | + | − | + | V | − | − |
| Maltose | + | + | + | + | + | + | + | + |
| Mannitol | + | + | − | − | − | + | + | − |
| Sorbitol | − | − | − | − | − | + | + | − |
| Sucrose | + | − | + | − | + | + | + | − |
| Trehalose | − | − | − | − | + | + | + | − |
| Methyl-α-d-glucopyranoside | − | V | + | − | − | V | + | − |
| Pullulan | + | + | + | − | + | V | V | + |
| Tagatose | V | W+ | + | − | + | + | + | − |
| Rapid ID 32 | ||||||||
| Arginine dihydrolase | + | + | + | − | + | + | + | − |
| β-Glucosidase | + | − | − | − | − | + | + | − |
| β-Galactosidase | − | − | + | − | − | − | − | − |
| β-Glucuronidase | + | − | − | − | + | + | + | − |
| α-Galactosidase | − | − | + | − | − | V | V | − |
| Mannitol | + | + | − | − | − | + | + | − |
| Sorbitol | − | − | − | − | − | + | + | − |
| Lactose | − | − (V) | + | − | + | V | − | − |
| Trehalose | − | − | − | − | + | + | + | − |
| Saccharose/sucrose | + | − | + | − | + | + | + | − |
| Cyclodextrin | + | + | − | − | − | − | − | − |
| β-Galactosidase | − | − | + | − | − | − | − | − |
| Pyroglutamic acid arylamidase | + | + | − | + | − | V | − | − |
| Glycyl-tryptophan arylamidase | V | − | + | − | − | − | − | V |
| Hydrolysis of hippurate | − | − | − | − | + | V | + | − |
| Pullulan | + | + | + | − | + | V | + | − |
| Maltose | + | + | + | − | + | + | + | + |
| Methyl-β-d-glucopyranoside | + | − | + | − | − | V | − | − |
a
16S rRNA gene sequence percent identity of S. halichoeri human clinical isolates to S. halichoeri gray seal and related species.
b
+, 100% of strains positive; −, 100% of strains negative; V, variable reaction within species or repeated testing; (V), variable reaction in species description.
c
PYRase, pyrrolidonyl arylamidase.
d
LAPase, leucine aminopeptidase.
e
W+, weakly positive result.