Table 2.
Number of Enterobacteriaceae and E. coli isolated by cultivation method and total DAPI cell counts and relative percentages of hybridized cells with specific probes
| Sampling site (n)a | Number of Enterobacteriaceae (CFU × 103)b (mean ± SD) | Number of E. coli (CFU × 103)b (mean ± SD) | Absolute DAPI counts (cells/ml × 108) (mean ± SD) | Fraction (%) of total cells (mean ± SD) detected with probec | ||||
|---|---|---|---|---|---|---|---|---|
| EUB338 | GAM42a | ENT183 | ECO1167 | KPN | ||||
| Hospital 1 (7)a | 170 ± 100 | 3 ± 2 | 1.2 ± 0.9 | 74.8 ± 13 | 9.1 ± 5 | 7.3 ± 4 | 2.2 ± 1 | 1.7 ± 1 |
| Hospital 2 (7) | 100 ± 90 | 4 ± 3 | 1.3 ± 1.2 | 71.2 ± 12 | 7.2 ± 3 | 4.2 ± 7 | 1.4 ± 2 | 1.5 ± 2 |
| Hospital 3 (7) | 2730 ± 180 | 16 ± 15 | 1.4 ± 0.8 | 66.7 ± 5 | 4.7 ± 2 | 1.1 ± 1 | 0.2 ± 0.1 | 0.3 ± 0.1 |
| Inflow sewage (7) | 1910 ± 680 | 55 ± 42 | 3.5 ± 1.8 | 76.5 ± 9 | 8.3 ± 3 | 0.5 ± 0.1 | 0.2 ± 0.1 | 0.1 ± 0.1 |
| Sewage in aeration tank (7) | 690 ± 460 | 15 ± 14 | 73.7 ± 27 | 59.3 ± 13 | 12.1 ± 4.7 | 0.8 ± 0.5 | 0.5 ± 0.3 | 0.4 ± 0.5 |
| Outflow (7) | 21 ± 10 | 3 ± 2 | 0.5 ± 0.3 | 29.5 ± 13 | 17.1 ± 16 | 1.1 ± 1 | 0.3 ± 0.1 | 0.2 ± 0.1 |
| River water (14) | 6 ± 2 | 0.2 ± 0.1 | 0.05 ± 0.01 | 38.5 ± 17 | 19.1 ± 15 | 1.9 ± 1.1 | 0.4 ± 0.1 | 0.3 ± 0.1 |
| Air near grit chamber (7) | 0.29 ± 0.3 | 0.02 ± 0.01 | 0.03 ± 0.01 | 62.3 ± 19 | 48.2 ± 33 | 8.7 ± 9 | 8.0 ± 7 | 5.1 ± 4 |
| Air near aeration tank (7) | 0.04 ± 0.03 | 0.01 ± 0.01 | 0.02 ± 0.01 | 81.1 ± 15 | 33.8 ± 18 | 11.2 ± 11 | 7.0 ± 8 | 5.0 ± 9 |
n number of samples, CFU colony forming units, SD standard deviation
aIn cultivation methods, the number of samples were performed in triplicate
bCFU on CCA medium by cultured method: in sewage and water—in colony forming units per milliliter, in air—in colony forming units per cubic meter
cPercent detection compared to DAPI; numbers have been corrected by subtracting NON338 counts