TABLE 2.
Virulence phenotypes of wild-type strain and mxiM mutant derivativesa
| Strain (phenotype or genotype) | Crbb | Invasionc | Secretion ofd:
|
|
|---|---|---|---|---|
| IpaB | IpaC | |||
| 2457T (wild-type) | + | 85.0 ± 6.3 | 100 | 100 |
| BS547 (mxiM1) | − | 0 | 3.1 ± 1.4 | 5.8 ± 3.8 |
| BS575 (mxiM1/PLAC-mxiM+) | + | 81.5 ± 7.3 | 89.3 ± 4.3 | 95.0 ± 3.7 |
| BS588 (mxiM1/pBluescript) | − | 0 | 3.7 ± 1.6 | 1.1 ± 0.2 |
| BS548 (mxiM1/PBAD-mxiM+) | + | 78.5 ± 1.6 | NDe | ND |
| BS599 (2457T/PBAD-mxiM2) grown with: | ||||
| Glucose, 0.2% | + | 78.1 ± 7.7 | ||
| Arabinose, 0.2% | − | 20.0 ± 1.6 | ||
| Arabinose, 0.01% | − | 38.1 ± 4.9 | ||
| Arabinose, 0.005% | +/− | 56.4 ± 5.5 | ||
| Arabinose, 0.0005% | + | 75.9 ± 2.6 | ||
| BS603 (mxiM1/PBAD-mxiM2) | − | 8.5 ± 3.4 | ||
a
Each numerical value shown represents the average of at least three to five independent experiments ± standard deviation.
b
The Crb phenotype is based on a qualitative analysis of Congo red binding by bacterial colonies grown on nutrient agar. The +/− designation represents an intermediate phenotype.
c
Values are expressed as a percentage of 300 L2 cells in a semiconfluent monolayer which contained three or more internalized bacteria as determined by light microscopy.
d
Values were determined by SLIM and are expressed as a percentage of wild-type strain reactivity.
e
ND denotes that these values were not determined.