Table 2 Purposefully anthrax spore-contaminated soil samples examined by the classic method at three dilution levels and by the GABRI method
Soil sample | Anthrax spores added to sample | CFU of B. anthracis isolated by classic method | CFU of contaminants isolated by classic method | CFU of B. anthracis and contaminants isolated by GABRI method | |||||
|---|---|---|---|---|---|---|---|---|---|
Total of 10 plates | Total of 10 plates | Total of 10 plates | |||||||
Undiluted | 1:10 | 1:100 | Undiluted | 1:10 | 1:100 | CFU of B. anthracis | CFU of contaminants | ||
N.1 | 520 | 0 | 0 | 0 | 725 | 341 | 124 | 2 | 8 |
N.2 | 480 | 0 | 0 | 0 | 714 | 337 | 8 | 2 | 9 |
N.3 | 500 | 0 | 0 | 0 | 1000 | 289 | 54 | 2 | 3 |
N.4 | 570 | 0 | 0 | 0 | 225 | 45 | 1 | 6 | 4 |
N.5 | 430 | 0 | 0 | 0 | 334 | 29 | 1 | 4 | 15 |
N.6 | 500 | 0 | 0 | 0 | 584 | 292 | 2 | 3 | 27 |
Average | 500 | 0 | 0 | 0 | 597 | 222.2 | 31.6 | 3.2 | 11.0 |