TABLE 2.

Formation of plaques on confluent monolayers of HeLa and Caco-2 cellsa

StrainDescriptionHeLa at 72 h (mm)Caco-2 at 48 h (mm)
M90TWild type1.22.5
HND115phoN20.41.35
HND115/pHN28phoN2/PBADphoN20.451.35
HND115/pHN28phoN2/PBADphoN2 + l-arabinose0.91.9
HND115/pFB1-4phoN2/pBluescript SKapyR192P0.952.15
HND201ospB1.32.35
HND205ospB-phoN20.451.35
HND205/pHN28ospB-phoN2/PBADphoN20.451.3
HND205/pHN28ospB-phoN2/PBADphoN2 + l-arabinose0.91.95
  • a Monolayers infected by the various strains were overlaid with gentamicin-containing soft agar supplemented with 0.2% l-arabinose or not, incubated for 48 h or 72 h at 37°C, fixed, and stained with Giemsa. The diameter of the plaques are indicated in millimeters and is the average of at least 10 plaques.