Table 1.
Staphylococcal strains used in this study and their results in the ONPG assay
| Species | Source | β−Gal activity according to reference 2a | No. of ONPG-positive isolates/total no. of isolates (%)b |
|---|---|---|---|
| S. aureus | Human | − | 57/59 (96.6) |
| Animal surveillancec | − | 50/60 (83.3) | |
| Othersd | − | 4/4 (100) | |
| S. capitis | Human | − | 1/8 (12.5) |
| S. caprae | Human | − | 0/2 (0) |
| S. epidermidis | Human | − | 14/14 (100) |
| S. haemolyticus | Human | − | 2/3 (66.7) |
| S. hominis | Human | − | 1/4 (25) |
| S. lugdunensis | Human | − | 14/15 (93.3) |
| S. pseudintermedius | Canine | + | 12/12 (100) |
| S. schleiferi | Human | ND | 1/1 (100) |
a
−, 90% or more strains negative; +, 90% or more strains positive; ND, not determined or insufficient data.
b
Major discrepancies between previously described results and the assay results are in boldface.
c
Only one isolate from each animal is included. Isolates were sampled from 21 chickens, 14 cats, 10 dogs, 13 pigs, and 2 rats.
d
These include two atypical clinical strains as mentioned in the text, the reference stain ATCC 25923, and the laboratory strain RN4220.