Table 1.
Occurrence and abundance (cfu/100 cm3) of sorbitol-fermenting Bifidobacteria (SFB), associated background and detection limits from respectively investigated environmental sources
| Log cfu per 1 cm3 faeces or per 100 cm3 water/wastewater | ||||||||
|---|---|---|---|---|---|---|---|---|
| Samples | SFB | Background bacteria | DL† | |||||
| Source | N* | Positive (%) | Median | Range | Median | Range | MDL‡ | RDL§ |
| Human faeces | 15 | 100 | 9.4 | 8.1–10.4 | 11.4 | 9.9–12.7 | – | – |
| Sewage | 12 | 100 | 6.8 | 3.4–7.9 | 8.8 | 4.4–10.2 | – | – |
| Polluted water | 15 | 100 | 3.5 | 2.8–5.6 | 5.5 | 4.4–8.8 | – | – |
| Pig faeces | 10 | 0 | nd¶ | nd | 5.5 | 5.2–5.7 | <3.5 | <3.2–3.7 |
| Cattle faeces | 10 | 0 | nd | nd | 4.8 | 4.3–5.2 | <2.8 | <2.3–2.9 |
| Hen faeces | 10 | 0 | nd | nd | 6.8 | 6.0–7.4 | <4.8 | <4.0–4.9 |
| Goat faeces | 10 | 0 | nd | nd | 5.6 | 5.4–6.7 | <3.6 | <3.4–4.7 |
| Dog faeces | 10 | 0 | nd | nd | 4.2 | 3.3–4.9 | <2.0 | <1.3–2.9 |
| Soil | 10 | 0 | nd | nd | 4.8 | 3.9–5.6 | <2.8 | <1.9–3.1 |
| Tap water | 10 | 0 | nd | nd | 1.0 | 0.8–1.4 | <0.1 | <0.6 |
*
Number of replicates (N).
†
Estimated detection limit (DL) of HBSA, assuming a detection threshold of ≥ 1 SFB colony within 100 colonies of background bacteria (c.f. materials and methods).
‡
Median detection limit (MDL).
§
Range of detection limit (RDL).
¶
SFB were not detectable above the given detection limits (nd).