TABLE 4.
Detection of CFs in the Israeli ETEC strain collection by dot blot, PCR, and DNA probe hybridization
| CF | No. of strains positive by indicated method (no. of strains positive by both phenotypic and indicated genotypic methods):
|
||
|---|---|---|---|
| Dot blot | PCR | Probe hybridization | |
| CFA/Ia | 3 | 3 (3) | 3 (3) |
| CS2b | 10 | 11 (10) | 10 (10) |
| CS3b | 10 | 11 (10) | NTb |
| CS4a | 3 (0) | ||
| CS5 | 12 | 12 (12) | 12 (12) |
| CS6 | 26 | 26 (26) | 25 (25) |
| CS7 | 11 (0)c | ||
| CS8 | 4 | 4 (4) | 8 (3)d |
a
The DNA/DNA hybridization probe for CFA/I cross-hybridized with CS4.
b
One genotypically positive and phenotypically negative CS2/CS3 strain was detected by PCR. CS3 was not tested (NT) by DNA/DNA hybridization.
c
The assays for the closely related CFs CS5 and CS7 cross-reacted during DNA/DNA hybridization. PCR distinguished between CS5 and CS7 and detected only CS5 in this strain collection.
d
The CS8 DNA/DNA hybridization assay identified five strains as positive for CS8 that were not recognized by either dot blot or PCR for CS8 and missed one strain positive by dot blot and PCR.