TABLE 3.
Detection and isolation of EPEC and EAEC with LC-PCR and conventional PCR analysis and culture analysis of 22 stool samples and a water sample in a waterborne outbreak
| Sampling dates (yr/mo/day) | Patient no. or contaminated water | Results with detection methodd:
|
|||||||
|---|---|---|---|---|---|---|---|---|---|
| EPEC (eaeA gene positive)
|
astA gene-positive E. coli
|
||||||||
| Direct analysis
|
After enrichment
|
Direct analysis
|
After enrichment
|
||||||
| CFU/g by LC-PCRa | Isolation (CFU/g) | Conventional PCR | Serotype of isolates | CFU/g by LC-PCRa | Isolation | Conventional PCR | Serotype of isolates | ||
| 2002/10/10 | 1 | −*b | − | − | − | − | − | ||
| 2 | −* | − | − | − | − | − | |||
| 3 | −* | − | − | − | − | − | |||
| 4 | *2 × 107 | 2 × 107 | + | O125 | 2 × 108 | + | OUT | ||
| 5 | −* | − | − | − | − | − | |||
| 6 | −* | − | − | − | − | − | |||
| 7 | −* | − | − | − | − | − | |||
| 8 | − | − | − | − | − | − | |||
| 9 | − | − | − | − | − | + | O1 | ||
| 10 | − | − | − | − | − | − | |||
| 11 | − | − | − | − | − | − | |||
| Contaminated water | NTc | NT | + | O166, OUT | NT | NT | + | O27, OUT | |
| 2002/10/11 | 12 | − | NT | − | − | NT | − | ||
| 13 | 2 × 106 | NT | + | O166, OUT | 3 × 105 | NT | + | ||
| 14 | − | NT | + | OUT | − | NT | − | ||
| 15 | − | NT | − | − | NT | − | |||
| 16 | − | NT | − | − | NT | − | |||
| 17 | − | NT | − | 4 × 106 | NT | + | OUT | ||
| 18 | 2 × 106 | NT | + | OUT | − | NT | − | ||
| 19 | − | NT | − | − | NT | − | |||
| 20 | 3 × 105 | NT | + | OUT | − | NT | − | ||
| 21 | − | NT | − | − | NT | − | |||
| 22 | − | NT | − | − | NT | − | |||
a
The CFU/gram of feces was counted by LC-PCR quantitative analysis.
b
Seven stool samples were examined first by using duplex LC-PCR on 10 October 2002.
c
NT, not tested.
d
+, positive result; −, negative result. OUT, untypeable.