Table 2.

Virulence phenotypes of wild-type strain andmxiM mutant derivativesa

Strain (phenotype or genotype)CrbbInvasioncSecretion ofd:
IpaBIpaC
2457T (wild-type)+85.0 ± 6.3100100
BS547 (mxiM1)03.1 ± 1.45.8 ± 3.8
BS575 (mxiM1/PLAC-mxiM +)+81.5 ± 7.389.3 ± 4.395.0 ± 3.7
BS588 (mxiM1/pBluescript)03.7 ± 1.61.1 ± 0.2
BS548 (mxiM1/PBAD-mxiM +)+78.5 ± 1.6NDe 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.