TABLE 2.
Plasmid profiles, plasmid-borne virulence genes, and corresponding phenotypes of Czech and German SF EHEC O157:H− strains
| Strain | Serotype | Country of origina | Plasmid size (kb)/sfpA hybridizationb | Presence of plasmid-borne virulence genec |
Phenotype |
|||||
|---|---|---|---|---|---|---|---|---|---|---|
| EHEC-hlyA | katP | espP | etpD | sfpA | EHEC hemolysind | Sfp fimbriaee | ||||
| 258/98 | O157:H− | CR | 79/+, 86/− | −/− | −/− | −/− | −/− | +/4.9 | − | + |
| 269/98 | O157:H− | CR | 79/+, 86/− | −/− | −/− | −/− | −/− | +/4.9 | − | + |
| 493/89 | O157:H− | G | 121/+ | +/15.0 | −/− | −/− | +/3.9; 1.9 | +/4.9 | − | + |
| 3072/96 | O157:H− | G | 121/+ | +/15.0 | −/− | −/− | +/3.9; 1.9 | +/4.9 | − | + |
| EDL933 | O157:H7 | USA | 92/− | +/12.0 | +/9.0 | +/7.5 | +/3.9; 1.9 | −/− | + | − |
| Sakai | O157:H7 | J | 92/− | +/12.0 | +/9.0 | +/7.5 | +/3.9; 1.9 | −/− | + | − |
CR, Czech Republic; G, Germany; USA, United States; J, Japan.
Hybridization of undigested plasmids with an sfpA probe. +, positive result; −, no signal obtained.
Detection of genes was performed by PCR/Southern blot hybridization with the respective probe. +, positive result; −, no signal obtained. Plasmid DNA was digested with BamHI before hybridization with the EHEC-hlyA, espP, and etpD probes and with SmaI before hybridization with the katP and sfpA probes. Sizes of hybridizing fragments (in kilobases) are shown.
Production of EHEC hemolysin was sought on enterohemolysin agar. +, hemolysis present; −, no hemolysis (SF EHEC O157:H− strains usually do not produce EHEC hemolysin even though they possess the hlyCABD operon).
Sfp fimbriae were detected by immunoblotting with an anti-SfpA antibody. +, signal present; −, signal absent.