TABLE 4.
Effect of age of protozoa during coculture on Campylobacter disinfection resistancea
| Protozoan age (days) | Location | Avg Campylobacter count (CFU/ml) ± SD
|
||
|---|---|---|---|---|
| C. coli NCTC 11366 | C. jejuni NCTC 11351 | C. jejuni (poultry isolate) | ||
| T. pyriformis | ||||
| 3 | Internal | (3.52 × 103) ± 285 | (4.28 × 103) ± 730 | (5.77 × 103) ± 999 |
| 3 | External | 0 ± 0 | 132 ± 18 | 313 ± 22 |
| 6 | Internal | (11.21 × 102) ± 134 | (3.25 × 103) ± 164 | (4.56 × 103) ± 644 |
| 6 | External | 5 ± 3 | 16 ± 10 | 33 ± 10 |
| 9 | Internal | 0 ± 0 | 0 ± 0 | 0 ± 0 |
| 9 | External | 0 ± 0 | 0 ± 0 | 0 ± 0 |
| A. castellanii | ||||
| 3 | Internal | 269 ± 33 | 326 ± 32 | 375 ± 16 |
| 3 | External | 1 ± 1 | 3 ± 1 | 5 ± 1 |
| 6 | Internal | 113 ± 12 | 154 ± 24 | 172 ± 20 |
| 6 | External | 0 ± 0 | 0 ± 0 | 0 ± 0 |
| 9 | Internal | 0 ± 0 | 0 ± 0 | 0 ± 0 |
| 9 | External | 0 ± 0 | 0 ± 0 | 0 ± 0 |
a
T. pyriformis (CCAP 1630/14A) and A. castellanii (CCAP 1501/10) were each grown for 3, 6, and 9 days before being cocultured for 3 h at 25°C (1:1 ratio) with Campylobacter spp. in PAS solution. A 1:1,000 dilution of Virudine (1-min contact time) was then used to kill planktonic C. jejuni, followed by neutralization using STS, gravity filtration (0.8-μm pore size), rinsing and resuspension in PAS, sonication (10 s at 40 W), and counts of viable Campylobacter. Results are presented as the average (performed in quadruplicate) numbers of viable Campylobacter recovered ml of PAS.