TABLE 2.
Selective media and organism-specific variations used for enumeration of bacterial zoonotic agents from livestock wastesa
| Parameter | Selective media and organism-specific variation(s) for:
|
|||
|---|---|---|---|---|
| E. coli O157 | Salmonella sp. | Listeria sp. | Campylobacter sp. | |
| Initial diluent | mTSB, 80 μg of novobiocin ml−1 | mTSB, 40 μg of novobiocin ml−1 | LSEB | PSW (boiled to remove O2) |
| Cellulose nitrate filter pore size (μm) | 0.45 | 0.45 | 0.45 | 0.1 |
| Resuscitation medium | mTSB, 40 μg of novobiocin ml−1 | mTSB, 20 μg of novobiocin ml−1; 1% (wt/vol) iodine | LSEB | BFEB (microaerophilic conditions) |
| Resuscitation time (h) | 6 | 16 | 24 | 24 |
| Counting medium | CHROMagar O157 (Becton Dickson 264105) | Rambach agar | BCM listeria agar (Biosynth C0608 and C0610) | CCDA microaerophilic conditions |
| Incubation conditions prior to counting | 16 h at 41°C | 28 h at 37°C | 28 h at 37°C | 28 h at 37°C |
| Color/morphology of pre- sumptive positive colonies | Purple | Pinkish red | Blue/convex | Gray/moist/flat |
| Confirmation method or apparatus | Latex agglutination (Oxoid DR120M) | API 20E (BioMérieux) | Listeria confirmation agar (Biosynth C0612) | API Campylobacter (BioMérieux) |
a
All media were from Oxoid (Basingstoke, United Kingdom) unless otherwise specified. mTSB, modified tryptone soy broth; LSEB, Listeria selective enrichment broth; PSW, peptone salt water; BFEB, blood-free enrichment broth; CCDA, Campylobacter agar with charcoal and deoxycholate.