TABLE 3.
Invasion assays and plaque formation by S. flexneri degP, skp, and surA mutants
| Strain | Invasion (%)a
|
Plaque formationb
|
||||
|---|---|---|---|---|---|---|
| +DOC | −DOC | pBluescript vector | pGP25.7 (DegP+) | pGP56.4 (Skp+) | pGP60.1 (SurA+) | |
| 2457T | 100 | 63 ± 1.1 | + | ND | ND | ND |
| 2457T degP | 81 | 23 ± 1.6 | − | + | + | − |
| 2457T skp | 100 | 53 ± 4.8 | − | − | + | − |
| 2457T surA | NDc | 67 ± 2.7 | − | − | − | + |
a
Percent of the Henle cells that contained 3 or more intracellular bacteria. Bacteria were grown in Luria broth alone or with 2.5 mM DOC. Values are means of three or more independent experiments with 1 standard deviation (−DOC) or two experiments (+DOC).
b
Plaque formation in Henle cell monolayers by mutant strains carrying the indicated plasmid. +, wild-type size and number of plaques; −, no plaques; ND, not determined.
c
ND, not determined. Growth of 2457T surA was inhibited by DOC.